Rainfall Sentence Examples
The average rainfall at Perth is 33 in.
The rainfall, which varies between 39 and 47 in.
The rainfall in the south-west portion of the island is considerably greater than in other districts.
The rainfall of New South Wales ranges from an annual average of 64 in.
The climate is mild but damp. The annual rainfall over the greater part varies from.
In inland localities, where the rainfall is much lower, steppes occur.
The temperature and rainfall are governed by conditions different from those in corresponding latitudes of the northern hemisphere..
The rainfall of Melbourne averages 25.58 in., the mean number of rainy days being 131.
The mean annual rainfall (1861 to 1899) is 26 06 in.
At Ghardaia, in south-eastern Algeria, the mean annual rainfall, from 1887 to I892, was about 43/4 in.
AdvertisementThe average rainfall is about 38 in.
The rainfall in the extreme north, especially in January and February, is very heavy, and the annual average along the coast is about 63 in.
This zone has an abundant rainfall, dense forests and a fertile soil.
In northern Asia there is a generally equal rainfall of 19 to 29 in.
It is found in greatest perfection in the forests of the west coasts of Burma and the Indian peninsula, where the rainfall is heaviest, growing to a height of too or 150 ft., mixed with other trees and bamboos.
AdvertisementThe rainfall in the wet season is heavy, but not excessive, and during the dry season the ground is refreshed with occasional showers and heavy dews.
The rainfall, though moderate, is still sufficient to maintain the supply of water in the great rivers that traverse the country to the Arctic Sea, and to support an abundant vegetation.
This belt, which embraces Asia Minor, northern Persia, Afghanistan, and the southern slopes of the Himalaya, from its elevation has a temperate climate, and throughout it the rainfall is sufficient to maintain a vigorous vegetation, while the summers, though hot, and the winters, though severe, are not extreme.
The truly tropical flora of the hotter and wetter regions of eastern India is continuous with that of the Malayan peninsula and islands, and extends along the lower ranges of the Himalaya, gradually becoming less marked and rising to lower elevations as we go westward, where the rainfall diminishes and the winter cold increases.
Among the more mountainous regions of the south-western part of Arabia, known as Arabia Felix, the summits of which rise to 6000 or 7000 ft., the rainfall is sufficient to develop a more luxuriant vegetation, and the valleys have a flora like that of similarly situated parts of southern Persia, and the less elevated parts of Afghanistan and Baluchistan, partaking of the characters of that of the hotter Mediterranean region.
AdvertisementThe mean annual rainfall is greater on the slopes of the ranges by which the moisturebearing clouds are intercepted.
The rainfall varies from about 30 in.
The district is subject to very heavy rainfall approaching r50 in.
The rainfall is abundant, and the climate hot, damp and malarial.
To the former belong the Black Sea littoral, where the rainfall averages 59 to 93 in.
AdvertisementIn Lenkoran also the rainfall averages 40 to 50 in.
The cultivation of the soil is, however, attended in many parts with great difficulties owing to the scanty rainfall and the very primitive implements still in use, and in the valley of the Kura heavy losses are frequently incurred from depredations by locusts.
The climate of Bellary is characterized by extreme dryness, due to the passing of the air over a great extent of heated plains, and it has a smaller rainfall than any other district in south India.
The winters in the uplands are generally severe, and the rainfall heavy.
The contrasts shown by the mean annual rainfall are similarly marked.
The hot drought of 1893 extended over the spring and summer months, but there was an abundant rainfall in the autumn; correspondingly there was an unprecedentedly bad yield of corn and hay crops, but a moderately fair yield of the main root crops (turnips and swedes).
The year 1903 was memorable for a very heavy rainfall, comparable though not equal in its disastrous effects to that of 1879.
It may mean what is ordinarily understood by the word - climate, rainfall, railway rates or anything else except " indestructible powers of the soil."
The soil is an oozy mud which can only be made capable of carrying buildings by the artificial means of pile-driving; there is no land fit for agriculture or the rearing of cattle; the sole food supply is fish from the lagoon, and there is no drinking-water save such as could be stored from the rainfall.
During June and the first fortnight in July plenty of sunshine is necessary, accompanied by sufficient rain to promote healthy, but not excessive, growth; the normal rainfall in the cotton belt for this period is about 42 in.
In either case an adequate but not excessive rainfall, increasing from the time of sowing to the period of active growth, and then decreasing as the bolls ripen, with a dry picking season, combined with sunny days and warm nights, provide the ideal conditions for successful cotton cultivation.
The total amount of water given is approximately equivalent to a rainfall of about 35 in.
The rainfall is uncertain and low, however, never exceeding 40 in., and on the supply of water by irrigation the future of the industry mainly depends.
Even the steppe exhibits great contrasts of temperature; there the rainfall is slight and the air exceedingly exhilarating and healthy.
Palestine, being less shut in and enjoying a comparatively large general rainfall, would be still a land " flowing with milk and honey " had its forests not been destroyed, and the terracing, which used to hold up soil on the highlands, been maintained.
Commagene, where not rocky, and the district lying along the southward drains from its divide (anc. Cyrrhestica), is in better case, enjoying perennial streams which can be utilized, and the fringe of the Tauric rainfall.
The average annual rainfall is about 30 in.
The rainfall averages 52.09 in.
The average annual rainfall is 33 in.
The water parting is about twice as far from the north coast as it is from the south coast, the rainfall is greater on the north slope, and the principal rivers - Rio Loiza, Rio de la Plata, Rio Manati and Rio Arecibo are on the north side.
The average annual rainfall on the north-east coast, at the foot of El Yunque Mountain, is 120 in.
At San Juan the average annual rainfall is about 55 in.; nearly two-thirds of this falls from J une to November inclusive.
It is well watered by numerous small streams and one larger river, the Aguascalientes or Rio Grande, and has a mild healthy climate with a moderate rainfall.
The eastern part of the Nagpur country and the Chhattisgarh plain, comprising the Mahanadi basin, form the great rice tract of the province, its heavy rainfall and hard yellowish soil rendering it excellently adapted for the growth of this crop.
The rainfall of the province is considerably heavier than in northern India, and the result of this is a cooler and more pleasant atmosphere during the monsoon season.
This mountainous district, having the sea to the west, records an unusually heavy rainfall.
Near Seathwaite, below Styhead Pass, the largest annual rainfall in the British Isles is recorded, the average (1870-1899) being 133.53 in., while 173.7 was measured in 1903 and 243.98 in.
The months of maximum rainfall at Seathwaite are November, December and January and September.
The higher lands form part of what is known as the "Rain Preserve," where, in order to attract and preserve the rainfall, the trees are never allowed to be felled.
The rainfall is from 4 to 8 in.
The average annual rainfall at Berbera is about 8 in., and more than half of this amount has fallen in one day.
North of this region the surface of the province is of most fertile soil, the ordinary rainfall sufficing for agriculture.
The average rainfall does ndt exceed 35 in.
West of the Pondaung ridge, however, under the Chin hills, the rainfall exceeds 50 inches.
Rainfall is usually heavy in the S.E., but it decreases toward the N.W.
Much more rain falls in summer than in any other season, but in some parts the heaviest rainfall is in the spring and in others in the winter.
Heavy rainfall, high temperature and fertile soil combine to cover the greater part of the state, and particularly the alluvial regions and the coast swamps, with a most luxuriant subtropical vegetation, both arborescent and herbaceous.
The mean rainfall at Havana is about 40 6 in.
The rainfall recorded in 1901 at Nassau amounted to 63.32 in.
The mountainous tract has probably an average altitude of between 6000 and 7000 ft., with a temperate climate and regular rainfall, and is fertile and populous.
The amount of rain decreases from east to west, the mean annual rainfall being 32.7 in.
The rainfall is abundant, especially on the mountain slopes of the south.
The nature of the soil appears, however, to be of secondary importance, provided that it is able to hold moisture and that climatic conditions of high and even temperature with considerable rainfall and absence of wind are satisfied.
The Manihot tree has been widely introduced into other countries, and appears to succeed wherever the rainfall is not excessive.
North of this zone the rainfall decreases towards the Arctic.
The rainfall is exceptionally large, and snow lies on some of the loftier elevations for a considerable portion of the year.
The annual rainfall rarely exceeds 5 in., and there is often no rain from June till October.
The rainfall is abundant, and especially so in summer (December to March) when the humidity is extreme.
The rainfall in 1905 was 91.65 in.
Its semi-arid character is due to the mountain ranges on its northern frontier, which extract the moisture from the north-east trades and leave the Brazilian plateau behind them with a very limited rainfall, except near the Atlantic coast.
This great chapadao is in many respects the best part of Brazil, having a temperate climate,- extensive areas of fertile soil, rich forests and a regular rainfall.
This region is more tropical in character, partially barren, and has an uncertain rainfall, a large part of the Sao Francisco basin and the upper Atlantic slope of its eastern rim being subject to long-continued droughts.
This region is well wooded along the river courses of Minas Geraes, the lower Atlantic slopes of Bahia, which are perhaps outside the plateau proper, and on the weather side of some of the elevated ridges where the rainfall is heavy and regular.
It resembles the Sao Francisco region in its uncertain rainfall and exposure to droughts, and in having large areas of campos suitable for grazing purposes.
The rainfall is good, but not heavy.
In both classes navigation is greatly impeded by sandbars at the mouths of these rivers, while in the districts of periodical rainfall it is greatly restricted in the dry season.
All the rivers in this division are influenced by the periodical character of the rainfall, their navigable channels being greatly shortened in the dry season (August-January).
The rainfall, also, is limited and uncertain.
The Sao Francisco, which belongs to the inland plateau region, is the largest river of the eastern coast of Brazil and exists by virtue of climatic conditions wholly different from those of the coast where it enters the Atlantic. The tributaries of the lower half of this great river, which belong to the Atlantic coast region, are small and often dry, but the upper river where the rainfall is heavier and more regular receives several large affluents.
There are a few small lakes in Maranhao and Piauhy, some in Goyaz in the great valley of the Araguaya, and a considerable number in Matto Grosso, especially in the Paraguay basin, where the sluggish current of that river is unable to carry away the rainfall in the rainy season.
The forest-covered, lowland valley of the Amazon is a region of high temperatures which vary little throughout the year, and of heavy rainfall.
There is no appreciable change of seasons, except that produced by increased rainfall in the rainy season.
The average rainfall throughout the whole Amazon valley is estimated by Reclus as " probably in excess of 2 ' metres " (78.7 in.), and the maximum rise of the great flood is about 45 ft.
The " dry " season, however, is a season of moderate rainfall, except on the north-east coast where arid conditions prevail.
Another exception is that of the Pernambuco coast, where the rainy season comes between March and August, with the heaviest rainfall from May to July, which is the time of the southern winter.
South of Bahia there is a gradual increase in the rainfall, that of Rio de Janeiro exceeding 43 in.
At Santos the rainfall is exceptionally heavy and the mean temperature high, but below that point the climatic conditions are considerably modified, the range in temperature being greater, the mean annual temperature lower, and the rainfall more evenly distributed throughout the year.
At Blumenau, on the Santa Catharina coast, the annual rainfall is 53 in.
Minas Geraes is forested along its water courses and along its southern border only; its sun temperature, therefore, is high and the rainfall in its northern districts is comparatively light.
The rainfall throughout this region is abundant, except in northern Minas Geraes, where the climatic conditions are influenced to some extent by the arid eastern plateau.
South of Sao Paulo the tablelands of Parana, Santa Catharina and Rio Grande do Sul enjoy a temperate climate, with an abundant rainfall.
The slopes of the plateau, which receive a better rainfall, are more heavily forested, some districts being covered with deciduous trees, forming catingas in local parlance.
This dry, thinly-wooded region extends south to the states of Parahyba, where a more regular rainfall favours forest growth nearer the coast.
It is a region of light rainfall, and cultivation depends chiefly on the Gash flood.
At Durban the annual rainfall is about 40 in., at Pietermaritzburg 38.
In 1893, the year of highest recorded rainfall, 70 in.
The rainfall in Hungary, except in the mountainous regions, is small in comparison with that of Austria.
In general the state is insufficiently watered, the rainfall being light and the rivers small.
Since the first advent of white colonists many springs and pans and small streams have dried up, this desiccation being attributed, not so much to decreased rainfall, as to the burning off of the grass every winter, so that the water, instead of soaking in, runs off the hard, baked'ground into the larger rivers.
The chief characteristic of the rainfall is its frequent intensity and short duration.
The heaviest rain is experienced between January and April and is usually accompanied by severe thunderstorms. On the eastern escarpment of the Drakensberg the rainfall is heavy, 50 or 60 in.
The rainfall in the low country is more erratic than on the plateau, and in some districts, a whole year will pass without rain.
Many regions suffer permanently from deficient rainfall; in others, owing to the absence of irrigation works, the water supply is lost, while the burning of the grass at the end of summer, a practice adopted by many farmers, tends to impoverish the soil and render it arid.
The hydrography of the region last mentioned, where the lowlands are flat and the rainfall heavy, is extremely complicated owing to the great number of small rivers and of lakes on or near the lower river courses.
At Caracas the annual rainfall ranged from 602 to 863 millimetres between 1894 and 1902.
Irrigation, which has not been used to any great extent, is needed in some parts of the country for the best results, but in others, as in the valleys and on the northern slopes of the Maritime Andes, the rainfall is sufficiently well distributed to meet most requirements.
The mean annual rainfall ranges in different parts of the metropolis from about 202 to 272 in.
Mines may become flooded by the inrush of surface waters in times of great rainfall or sudden floods, or by the undermining of surface waters.
Although liable to great extremes of temperature, and to a very scanty rainfall, the district is not unhealthy.
North of the apex of the delta and the boundary between the deltaic and inland tracts, the rainfall gradually lessens as far as Minbu, where what was formerly called the rainless zone commences and extends as far as Katha.
In the extreme north of Upper Burma the rainfall is rather less than in the country adjoining Rangoon, and in the dry zone the annual average falls as low as 20 and 30 in.
The temperature varies almost as much as the rainfall.
The rainfall in the hills varies very considerably, but seems to range from about 60 in.
The average rainfall is about 372 inches.
To secure this marvellous return, with an annual rainfall of 26 in., as much as 52,000,000 gallons of water are pumped per 24 hours from artesian wells on one estate alone.
Without a sufficient supply plants remain stunted and the crop yield is seriously reduced, as we see in dry seasons when the rainfall is much below the average.
If one condition is more necessary than another for good crops it is a suitable supply of water, for no amount of manuring or other treatment of the soil will make up for a deficient rainfall.
This may be more than the rainfall, in which case irrigation or special control of the water supply may be necessary.
In the semi-arid regions of the United States, Argentina and other countries where the average annual rainfall lies between ioa to 20 in., irrigation is necessary to obtain full crops every year.
In certain districts where the rainfall is low a crop can only be obtained once every alternate year, the intervening season being devoted to tillage with a view of getting the rain into the soil and retaining it there for the crop in the following year.
Above the level of the ground-water the soil is kept moist by capillary attraction and by evaporation of the water below, by rainfall, and by movements of the ground-water; on the other hand, the upper layers are constantly losing moisture by evaporation from the surface and through vegetation.
Cuban tobacco is grown as a " winter " crop, the summer months being those of high rainfall.
The average annual rainfall is about 60 in., September being the wettest month.
Its chief characteristic is the bareness and aridity of its surface; one-third of the whole desert, and of the remainder only a small proportion is suited to settled life, owing to its scanty water-supply and uncertain rainfall.
Akhdar in the east, which with a temperate climate, due to their great elevation and their proximity to the sea, deserve, if any part of Arabia does, the name of Arabia Felix - the population is settled and agricultural, and the soil, wherever the rainfall is sufficient, is productive.
The rainfall throughout northern and central Arabia is chiefly in the winter months between October and April, and is scanty and irregular.
This appears to be about the northern limit reached by the south-west monsoon, which from June to September brings a fairly abundant rainfall to the Yemen highlands, though the Tehama remains almost entirely rainless.
The rainfall is heaviest along the western fringe of the plateau, and penetrates inland in decreasing quantity over a zone which perhaps extends to loo m.
In the Tehama occasional showers fall during the winter months; at Aden the average rainfall for the year is 2.97 in., but during 1904 only 0.5 in.
Violent storms occur in spring and autumn, and the rainfall, including snow, amounts to 25 in.
Nevertheless, all this southern district of Tunisia bears evidence of once having been subject to a heavy rainfall, which scooped out deep valleys in the original table-land, and has justified the present existence of immense watercourses - watercourses which are still, near their origin, favoured with a little water.
The rainfall in the first geographical division is pretty constant, and may reach a yearly average of about 22 in.
Over the second and third divisions the rainfall is less constant, and its yearly average may not exceed 17 in.
Occasionally two or three years may pass without any rainfall; then may come floods after a heavy downfall of a few weeks.
The rainfall varies greatly, but the mean is about 90 in.
The annual rainfall is nearly 30 in.
Agriculture is the principal occupation of its inhabitants, though the soil is generally sterile and the rainfall uncertain and very light.
The mean annual rainfall is about 50 in., ranging from 47.4 in.
Sugar, cotton, Indian corn, beans and considerable quantities of wheat are grown, but agriculture is largely hampered by the uncertainty of the rainfall.
Japan is emphatically a wet country so far as quantity of rainfall is concerned, the average for the whole country being 1570 mm.
While there can be no doubt that the luxuriance of Japans flora is due to rich soil, to high temperature and to rainfall not only plentiful but well distributed over the whole year, the wealth and variety of her trees and shrubs must be largell the result of immigration.
The rains usually begin at the end of June and last till the middle of September; average annual rainfall, 55 in.
The rainfall, however, after the eastern monsoons, is very heavy, and the island is liable to violent hurricanes.
The climate is hot and dry, the rainfall being too small to influence climatic conditions.
There is an abundant rainfall, but owing to the porous nature of the soil the water percolates into deep caves which have communication with the sea, and becomes brackish.
The rainfall is light in the lower regions and irrigation is generally employed.
Dunbar is said to have the smallest rainfall in Scotland and is a favourite summer resort.
The Blue Clay forms, at the higher levels, a stratum impervious to water, and holds up the rainfall, which soaks through the spongy mass of the superimposed coralline formations.
The average rainfall is in.; it is, however, uncertain; periods of drought have extended over three years.
The outlet was further examined in 1876 by Mr (afterwards Sir Henry) Stanley, who found that a bar had formed across the outlet, and it has since been proved that the outflow is intermittent, ceasing almost entirely after a period of scanty rainfall, and becoming again established when the lake-level has been raised by a series of rainy years.
In any case, the alterations in level appear to be merely periodic, and due to fluctuations in rainfall, and do not point, as some have supposed, to a secular drying up of the lake.
At the same time, any excessive local rainfall is productive of difficulty and danger from the floods of liquid mud and loose boulders which sweep like an avalanche down the hill sides.
The rainfall is on an average greater than in any province except those of the extreme north-west.
The annual rainfall, greater on the coast than inland, ranges from 40 to 45 in.
The Agricultural Experiment Station, at Newark, publishes in its Annual Report a record of temperature and rainfall.
A similar range occurs on the Dutch coast in the North Sea, where the maximum level is reached in October, the month of highest rainfall, and there is a range of 8 in.
Their experiments show that in similar conditions the evaporation of sea-water amounts to from 70 to 91% of the evaporation of fresh water, a fact of some importance in geophysics on account of the vast expanses of ocean the evaporation from which determines the rainfall and to a large extent the heat-transference in the atmosphere.
The climate is temperate, and the rainfall moderate.
The average annual rainfall decreases quite regularly westward and south-westward from 47.6 in.
Along the coast the autumn months are the wettest and the spring months are the driest; for example, at Galveston the rainfall amounts to 5.7 in.
In the middle, eastern and north-eastern parts of Texas the spring months are the wettest and the winter months are the driest; for example, at Waco the rainfall amounts to 4.5 in.
In the western and southwestern parts the summer months are the wettest and the spring months are the driest; thus, at El Paso the rainfall amounts to 2.2 in.
The rainfall is one of the lowest in the kingdom.
The rainfall is also very unequal in distribution throughout the year, as also between the same periods of different years, and as between the different parts of the state.
The rainfall is very heavy and usually exceeds i 50 inches.
The average annual rainfall is 40 in.
The warm currents setting landwards from the Indian Ocean bring both moisture and heat, so that the Swahili coast has a higher temperature and heavier rainfall than the Atlantic seaboard under the same parallels of latitude.
Kilimanjaro has a climate of its own; the west and south sides of the mountain receive the greatest rainfall, while the east and north sides are dry nearly all the year.
The rainfall on Ruwenzori and the central Semliki valley is quite loo in.
Like the districts round Lake Rudolf, the average altitude (near the Nile) is not more than 2000 ft., but the rainfall is more abundant than in the terrible Rudolf region, being an average of 30 in.
The annual rainfall at the same two places is 13.4 and 17.4 in.
The rainfall, however, is light, about 20 to 25 in., but, with the assistance of irrigation, it serves to sustain a considerable degree of cultivation in the neighbourhood of the city.
The rainfall in 1905 was 230 49 in.
The winds are very variable; the average number of rainy and snowy days is 146 at Riga (rainfall 24.1 in.).
The average rainfall is between 40 and 45 in., but it is less than 30 in.
Though, thanks to the overlaying porous pumice, the Taupo plateau is not fertile, it has a good rainfall and is drained by unfailing rivers running through deep terraced ravines.
The rainfall in most of the settled districts ranges from 30 to 50 ins.
Meteorological statistics are collected at Auckland, Wellington, Christchurch, and Dunedin and eight other stations; and observations of rainfall, temperature, and wind-directions are received from eighteen stations of the second class.
The climate is in general very hot and unhealthy, the rainfall being very heavy.
The flora is typical of a region of scanty rainfall.
The rainfall is sufficient for good grazing, but except in the Flathead valley cultivation was long considered to be dependent on irrigation; and consequently farming was only incidental to stock raising and mining until after 1870, and as late as 1900 the ratio of improved farm land to the total land area was less than in any other state or territory except New Mexico, Wyoming, Arizona and Hawaii.
The streams flowing from the central area have cut deep gorges and canons, and among the ridges the granitic rocks have assumed many strange forms. Though rising from a semi-arid plateau, these mountains have sufficient rainfall to support an abundant plant growth, and have derived their name from the fact that their slopes are dark with heavy forests.
Owing to the northern latitude, comparatively high altitudes, and the great distance from the ocean, there are great annual variations of temperature and a very small amount of rainfall.
The average annual amount of rainfall for the state is about 20 in., ranging from 13.9 in.
The average amount of rainfall for the spring is 6 or 7 in.; for the summer, 8 or 9 in.; for the autumn, 3 or 4 in.; and for the winter, 1 or 2 in.
The climate, though somewhat relaxing, is healthy, but there is a scarcity of drinking water, the average annual rainfall being only 272 in.
The average annual rainfall is 78 inches.
Rainfall is light, the mean annual being 27'72 in.
The rainfall follows the valleys of the Mu and the Irrawaddy, and leaves the rest of the district comparatively dry.
While the rainfall is always below the normal amount for humid regions, by far the greater part of it occurs in the spring and summer, and growing crops receive the full benefit.
In seasons of high rainfall, the river can ascend 50 meters.
The full force of the monsoon is, however, broken by the western frontier hills; and while the rainfall at Mergui is over 180, and at Moulmein 240 in., that of Bangkok seldom exceeds 54, and Chiengmai records an average of about 42 in.
Puket and Chantabun, being both on a lee shore, in this season experience rough weather and a heavy rainfall; the latter, being farther from the equator, is the worse off in this respect.
Water-supply depends chiefly, therefore, on local rainfall.
In a few days, or at most a fortnight, after a rainfall numberless specimens of these sizes were found swimming about, " and as not a single one was to be found in the water-pools prior to the rain, these must have been developed from the egg."
The great warming and abundant rainfall of the island regions of the western Pacific, and the low temperature of the surface water in the east, cause a displacement of the southern tropical maximum of pressure to the east; hence we have a permanent " South Pacific anticyclone " close to the coast of South America.
The rainfall is abundant; in the western island groups there is no well-marked rainy season, but over the whole region the greater part of the rainfall takes place during the southern summer, even as far north as Hawaii.
In the trade-wind region we find the characteristic heavy rainfall on the weather sides of the islands, and a shorter rainy season at the season of highest sun on the lee side.
Buchan describes the island-studded portion of the western Pacific as the most extensive region of the globe characterized by an unusually heavy rainfall.
The normal rainfall is about 80 in., but as cloud-bursts are common, it may rise to 150 in.
The climate of Porthcawl is bracing, and the rainfall (averaging 25 in.) is about the lowest on the South Wales coast.
The climate, although healthy, is very changeable, with great extremes of temperature and heavy rainfall, especially in the summer.
Snow is unknown, and the average annual rainfall is 25.58 in.
Add to this the light rainfall on the plateau and a lack of forests, and we have conditions which make large rivers impossible.
This is due to the porosity of the soil in the former, and the very limited rainfall in the latter.
The relief of the land and varying degrees of rainfall and vegetation, however, serve to modify these conditions in many important particulars.
The rainfall is heavy in the south, except Yucatan, but diminishes gradually toward the north, until on the Pacific and Gulf of California coasts it almost disappears.
The heavy rainfall on the Gulf coast, however, which reaches a maximum of 90 to too in.
The rainfall is abundant in the rainy season, but in the long dry season it is extremely rare.
The coast is low and extremely arid, and would be uninhabitable were it not for the proximity of the Sierra Madre, where a light rainfall is experienced, and for the numerous rivers that cross the arid belt between the mountains and the sea.
The windward slopes of the Sierra Madre Oriental receive the greater part of the rainfall, and the winds, deprived of their moisture, pass over the northern plateau without further precipitation.
The southern terraces of the plateau have no high mountain barriers between them and the moist winds of the Caribbean, and they too receive an abundant rainfall in the wet season, especially during the prevalence of heavy " northers " on the Gulf coast.
A fertile soil, abundant rainfall and high temperatures have covered these mountain slopes and lowland plains with a wealth of vegetation.
In the sierra regions of western Chihuahua and Durango, Nuevo Leon, Coahuila, Aguascalientes, San Luis Potosi, and the plateau states farther south, the rainfall is more abundant and the conditions more favourable.
In the western regions the rainfall does not exceed 10 in.
The rainy season is the summer months, November to April, but the rains are irregular, and, from the causes already indicated, the rainfall is steadily declining.
The average rainfall is very heavy, especially on the Atlantic slope, where the prevailing winds are charged with moisture from the Gulf of Mexico or the Caribbean Sea; at Tual, a high station on the Atlantic slope, it reaches 195 in.; in central Guatemala it is only 27 in.
Along parts of their eastern border, where the rainfall is a little increased by the approach of the westerly winds to the Rocky Mountains, there is a belt of very deep, impalpably fine soil, supposed to be a dust deposit brought from the drier parts of the plains farther west; excellent crops of wheat are here raised.
With this goes a general increase of precipitation with altitude, so that a good rainfall map would have its darker shades very generally along the mountain ranges.
Thus the heaviest measured rainfall east of the Mississippi is on the southern Appalachians; while in the west, where observations are as yet few at high level stations, the occurrence of forests and pastures on the higher slopes of mountains which rise from desert plains clearly testifies to the same rule.
The rainfall from the stromy westerly winds is largely deposited on the western slopes of the mountains near the Pacific coast, and arid or desert interior plains are thus found close to the great ocean.
The ranges of the Rocky Mountains in their turn receive some rainfall from the passing winds, but it is only after the westerlies are reinforced by a moist indraft from the Gulf of Mexico and the Atlanticthe result of summer or of cyclonic inflowthat rainfall increases to a sufficient measure on the lower lands to support agriculture without irrigation.
The region east of the Mississippi is singularly favored in this way; for it receives a good amount of rainfall, well distribu ted through the year, and indeed is in this respect one of the largest regions in the temperate zones that are so well watered.
The Great Plains are under correspondingly unfavourable conditions, for their scanty rainfall is of very variable amount.
Along the transition belt between plains and prairies the climate is peculiarly trying as to rainfall; one series of five or ten years may have sufficient rainfall to enable the farmers to gather good crops; but the next series following may be so dry that the crops fail year after year.
The district is highly fertile and is well watered, owing in great measure to its abundant rainfall.
In Quebec and northern Ontario the rainfall is diminished, ranging from 20 to 40 in., while the snows of winter are deep and generally cover the ground from the beginning of December to the end of March.
The climate of the Cordilleran region presents even more variety than that of the other provinces because of the ranges of mountains which run parallel to the Pacific. Along the coast itself the climate is insular, with little frost in winter and mild heat in summer, and with a very heavy rainfall amounting to ioo in.
The Selkirk Mountains have a heavy rainfall and a tremendous snowfall on their western flanks, but very much less precipitation on their eastern side.
One is situated at Lethbridge, southern Alberta, where problems will be investigated concerning agriculture upon irrigated land and dry farming under conditions of a scanty rainfall.
Every year there are, normally, two distinct periods of high water; one an early freshet due mainly to the heavy winter rainfall on the lower river, when the upper river is still frozen hard; the other in the late spring, due to the setting in of rains along the upper courses also, and to the melting of the snow in the mountains.
The average rainfall for the state is 49.3 in.; the maximum is 71.7 in., at Rabun Gap in the extreme N.E.
The rainfall averages 34 in.
The Yeres, a tributary of the Seine, and the Grand Morin and Petit Morin, tributaries of the Marne, are the chief rivers, but the region is not abundantly watered and the rainfall is only between 20 and 24 in.
The annual rainfall is about 302 in.
The climate is temperate and the rainfall usually adequate, but one year in five is expected to be droughty.
The average annual rainfall is about 23.5 in.; but this varies greatly in different districts.
The rainfall is unusually heavy.
An abundant rainfall during the growing season is also a desideratum.
Among the natural causes may be classed all failures of crops due to excess or defect of rainfall and other meteorological phenomena, or to the ravages of insects and vermin.
It is less easy to provide against the evils of excessive rainfall and of frost, hail and the like.
It is impossible to regulate the rainfall of any district, or wholly to supply its failure by any system of water-storage.
Every year sufficient rain falls in India to secure an abundant harvest if it were evenly distributed over the whole country; but as a matter of fact the distribution is so uneven and so uncertain that every year some district suffers from insufficient rainfall.
But beyond the sphere of irrigation, where the land is dependent on the rainfall, there is much rough stony ground broken by great fissures cut by flood-water from the border hills.
Both sources of supply are precarious, and instances are not infrequent of the almost entire failure of either the winter or the summer rainfall.
The average rainfall is 30 in., but the period 1891-1901 was a decade of low rainfall, and distress was caused by famine.
The average rainfall is 28 in.
The rainfall averages 23 in.
The greatest recorded extremes of local rainfall for a year within the larger islands range from 12 to 300 in.
For Honolulu the mean annual rainfall (1884-1899) was 28.18 in.; the maximum 49.82; and the minimum 13.46.
In regions of heavy rainfall the ohia-lehua (Metrosideros polymorpha), a tree growing from 30 to 100 ft.
As they lie near or under the equator, the monsoons blowing over them are less regular, and the rainfall, of large volume throughout the year, is dependent on the height and direction of the chains.
Fraser (Short Cut to India, p. 1 34) insists that in the undulating plains the direct rainfall is quite sufficient for agricultural purposes.
The average annual rainfall is 44 in.
The amount of rainfall during the summer is about 3 in.
The climate is mild and the rainfall more abundant than at the northern part of the valley, and the effects of this are to be seen in the better pasturage.
Snow falls early and lies late in the mountains, and there is a heavy rainfall in the north-west.
The rainfall rarely exceeds io in.
The total rainfall in 1905 was 34.76 in., taken at Sagaing.
At Kupang, on the south coast, the number of rainy days per month in the six months May to October dwindles from 4 to o, while the monthly rainfall gradually sinks from a little less than 2 in.
Its waters are mainly collected from the rainfall upon the plateaux, and from the hot springs and geysers, most of which are within its drainage area.
Here the rainfall for the year increases from the southern and northern extremities towards the middle.
Here, too, the prevailing rainfall is brought by the north-west monsoon, but in this belt its prevalence is not so pronounced, Padang getting 94 in.
The mountain chain immediately overhanging it, the high temperature of the sea washing it,,the frequent thunderstorms to which it is subject, the moist atmosphere of its equatorial situation, and the shorter regime of the dry south-east wind are the principal causes of the heavier rainfall on the west coast.
The higher stations of middle Sumatra, on the lee side of the western mountain chain, have a yearly rainfall of only 78.7 in.
The mean annual barometric height is 29.93 in.; the mean annual moisture, 81%; the mean annual rainfall, 27.99 in.
The prevalence of south-west winds during nine months of the year and of north-west during three (April - June) has a strong influence on the temperature and rainfall, tides, river mouths and outlets, and also, geologically, on dunes and sand drifts, and on fens and the accumulation of clay on the coast.
The rainfall in 1905 was 80.30 in.
Its situation is very beautiful, the moist climate (mean annual rainfall, 74 in.) fostering on the steep surrounding hills a vegetation unusually luxuriant for the latitude.
As there is no highland area draining into Kordofan, the underground reservoirs are dependent on the local rainfall, and a large number of the wells are dry during many months.
The annual rainfall is about 46 in., fairly well distributed throughout the year, though the heaviest precipitation occurs in August, September and October.
The climate resembles that of Great Britain, but the winters are generally more severe; the mean annual temperature is 48 F., and the annual rainfall is about 28 in.
In "cold deserts" the want of vegetation is wholly due to the prevailing low temperature, while in "hot deserts" the surface is unproductive because, on account of high temperature and deficient rainfall, evaporation is largely in excess of precipitation.
The rainfall chiefly occurs in violent cloudbursts, and the soluble matter in the soil is carried down by intermittent streams to salt lakes around which deposits are formed as evaporation takes place.
Streams are few and the rainfall is scanty, averaging only 16 in.
In any case results deduced from the annual wave must be expected to vary in different years according to the distribution of the rainfall, as the values represent averages depending chiefly on the diffusion of heat by percolating water.
But it often happens that, although there is sufficient rainfall to raise an inferior crop, there is not enough to raise a more valuable one.
Elsewhere the rainfall may be sufficient for ordinary crops, but not for the more valuable kinds.
Elsewhere in India the rainfall is usually sufficient for all the cultivation of the district, but about every eleven years comes a season of drought, during which canal water is so precious as to make it worth while to construct costly canals merely to serve as a protection against famine.
The Godaveri, Kistna and Kaveri all take their rise on the Western Ghats, a region where the rainfall is never known to fail in the monsoon season.
The engineer must not decide upon the plan till he has gauged at different seasons the stream which has to supply the water, and has ascertained the rain-collecting area available, and the rainfall of the district, as well as the proportion of storable to percolating and evaporating water.
Character- As every one knows, the valley of the Nile outside of Istics of the tropics is practically devoid of rainfall.
This increase was not due to famine in Sind, for that rainless province depends always on the Indus, as Egypt does on the Nile, and where there is no rainfall there can be no drought.
The water is there in abundance, the land is well adapted for irrigation, but as there is a considerable rainfall, it is doubtful whether the scheme would prove remunerative, and a large section of the landowners have hitherto opposed it, as likely to waterlog the country.
The canal system of Orissa was never expected to be remunerative, since in five years out of six the local rainfall is sufficient for the rice crop. In1878-1879the area irrigated was 111,250 acres, and the outlay up to date was Rx.1,750,000.
The rainfall on the west very much exceeds that on the east, and the Periyar used to find its way by a short torrent course to the sea, rendering no service to mankind.
In addition to all these great engineering systems, southern India is covered with minor works of irrigation, some drawn from springs in the sandy beds of rivers, some from the rainfall of 2 sq.
The rainfall was very deficient in 18 9518 97, causing famine in 1897; and in 1899-1900 there was drought in some sections.
The rainfall is about 70 in.
Although there are very considerable differences in the range of temperature and the amount of rainfall throughout Germany, these are not so great as they would be were it not that the elevated plateaus and mountain chains are in the south, while the north is occupied by low-lying plains.
As regards rainfall, Germany belongs to those regions where precipitation takes place at all seasons, but chiefly in the form of summer rains.
The rainfall is greatest in the Bavarian tableland and the hilly regions of western Germany.
Mecklenburg, Brandenburg and Lusatia, Saxony and the plateau of Thuringia, West Prussia, Posen and lower Silesia are also to be classed among the more arid regions of Germany, the annual rainfall being 16 to 20 in.
The annual rainfall except on the higher mountains does not reach 30 in., and, as in other parts of the extreme south of Europe, it occurs chiefly in the winter months, while the three months (June, July and August) are almost quite dry.
During these months the whole rainfall does not exceed 2 in., except on the slopes of the mountains in the north-east.
Owing to the slight rainfall, and the rapid weathering of the rocks by the great range of teniperature, these hills rise steeply from the valleys at their feet as almost bare rock, supporting hardly any vegetation.
Records at Cairo show that the rainfall is very irregular, and is furnished by occasional storms rather than by any regular rainy season; still, most falls in the winter months, especially December and January, while, on the other hand, none has been recorded in June and July.
The average annual rainfall does not exceed I 50 in.
The desert was full of wild life, the balance of nature being preserved by the carnivorous animals preying on the herbivorous; trees watered by soakage from the Nile protected the undergrowth and encouraged occasional rainfall.
More than half the rainfall occurs from July to November, the wettest month being September, with an average of 2.95 in.; the driest month is April, with an average of 1 14 in.
The climate of Transylvania is healthy; hot summers alternate with very cold winters, but the rainfall is not great.
A few algae approach the ordinary terrestrial plants in their capacity to live in a sub-aerial habitat subject only to such occasional supplies of water as is afforded by the rainfall.
The rainfall averages 223 in.
Perhaps the cause is to be sought mainly in differences of rainfall.
No doubt, too, the preponderance of rainfall in the west has persisted for an enormous period.
How powerfully the configuration affects the climate is shown in the remarkable difference between the rainfall of the mountainous west and of the lowland east.
The south-west prevails from July to October, and again from December to February; accordingly in these months the rainfall is heaviest.
On the other hand, the climates of the east are dry, because the surface is lower and more level; and the breezes borne thither from the west, being robbed of most of their superabundant moisture in crossing the western hills, are drier and precipitate a greatly diminished rainfall.
In these districts the annual rainfall averages 26 in., whereas over extensive breadths in the west it exceeds too in., in Glencroe being nearly 130 in., and on the top of Ben Nevis it may reach 150 in.
The rainfall of Singapore for 1906 was 129.64 in.; the heaviest rainfall for any one month being 15.23 in.
The water-supply is rarely abundant, and agriculture is more or less dependent on an uncertain rainfall.
The rainfall (1904) is 75.3 in.
Travancore has an abundant rainfall, with every variety of temperature.
Farther north the rainfall becomes heavier, the plateau is covered with vegetation, and a considerable number of small rivers flow westward through the Cordillera to the Pacific. The Eastern Cordillera, or Andes, forms the water-parting between the two systems. The largest of the eastward-flowing rivers is the Napo, which rises in the eastern defiles of Cotopaxi and Sincholagua - the principal source being the Rio del Valle, which traverses the Valle Vicioso.
In addition to the climatic changes due to altitude, there are others caused by local arid conditions, by volcanic influences and by the influence of mountain ranges on the temperature and rainfall of certain districts.
There is no great display of arboreal vegetation anywhere except in the valleys and lower passes where the rainfall is abundant, but in general terms it may be said that the rainfall and vegetation which characterize the Quito basin soon disappear as one proceeds southward, and are substituted by arid conditions.
On the eastern slopes of the Andes, where the rainfall is continuous throughout the year and the atmosphere is surcharged with moisture, the forest growth is phenomenal.
In the north and west the rainfall is greater than on the south and east coasts.
As is to be expected, the rainfall on the peninsula is somewhat greater than on the Arab coast.
The rainfall amounts to 56 in.
The rainfall is rather lower than among the mountains.
The rainfall is about 28 in., sometimes less, and in exceptional years as much as 10 in.
It is distinguished by its low rainfall and arid soil.
The average rainfall is 85.54 in.
Indeed, the special feature of the Himalayas is that they send down the rainfall from their northern as well as from their southern slopes to the Indian plains.
In this way the rainfall, alike from the northern and southern slopes of the Himalayas, pours down into the river plains of Bengal.
Through these openings the rainfall of the southern half of the inner plateau reaches the sea.
The Nerbudda and Tapti carry the rainfall of the southern slopes of the Vindhyas and of the Satpura hills, in almost parallel lines, into the Gulf of Cambay.
As far south as Sirsa and Multan the average rainfall does not much exceed 7 in.
The climate of these plains is damp and equable, and the rainfall is prolonged and generally heavy, especially on the southern slopes of the hills.
Together with the two parallel valleys of the Nerbudda and Tapti, which drain the flanks of its western half, it gives, at opposite seasons of the year, a decided easterly and westerly direction to the winds of this part of India, and condenses a tolerably copious rainfall during the south-west monsoon.
This range exerts an important influence on the direction of the wind, and also on the rainfall.
This plateau is swept by the south-west monsoon, but not until it has surmounted the western barrier of the Ghats; and hence the rainfall is, as a rule, light at Poona and places similarly situated under the lee of the range, and but moderate over the more easterly parts of the plateau.
The country to the east of the gap receives the rainfall of the south-west monsoon; and during the north-east monsoon ships passing Beypur meet with a stronger wind from the land than is felt elsewhere on the Malabar coast.
In the strip of low country that fringes the peninsula below the Ghats the rainfall is heavy and the climate warm and damp, the vegetation being dense and characteristically tropical, and the steep slopes of the Ghats, where they have not been artificially cleared, thickly clothed with forest.
In Lower Burma the western face of the Arakan Yoma hills, like that of the Western Ghats in India, is exposed to the full force of the south-western monsoon, and receives a very heavy rainfall.
But higher up the valley, and especially north of Pegu, the country is drier, and is characterized by a less luxuriant vegetation and a retarded and more scanty rainfall.
But the distribution of the rainfall is very uneven.
On the face of the Western Ghats, and on the Khasi hills, overlooking the Bay of Bengal, where the mountains catch the masses of vapour as it rises off the sea, the rainfall is enormous.
Rainfall rapidly diminishes to the north-west from that belt.
The north-western area is best marked in Sind and the Punjab, where the climate is very dry (the rainfall averaging less than 15 in.), and where the soil, though fertile, is wholly dependent on irrigation for its cultivation.
It occupies a comparatively dry area, with a rainfall under 75 in.
In Bombay and Madras almost all the irrigation systems, except in the deltas of the chief rivers, are dependent on reservoirs or " tanks," which collect the rainfall of the adjacent hills.
The heaviest rainfall occurs in April, and is accompanied by violent storms.
The rainfall varies greatly in different parts of the island.
Cluny in the Grand Port (south-eastern) district has a mean annual rainfall of 145 in.; Albion on the west coast is the driest station, with a mean annual rainfall of 31 in.
The rainfall is about 38 in.
The total rainfall in 1905 was 41.30 in.
The mean annual rainfall in this city is about 76 in., and nearly three-fourths of it is from the middle of June to the middle of October, when the winds blow from the south-west.
During the period from 1865 to 1902 the annual rainfall varied from 35.6 in.
In the year ending August 1903 the amounts of rainfall at 41 observation stations widely distributed throughout the archipelago varied from 16.2 in.
The rainfall is abundant, and the soil of the heavily wooded valleys and lower mountain slopes is exceptionally fertile and productive.
The Himalayan districts of course are cool, and have a much greater rainfall than the plains.
The rainfall 'varies from 30 to 44 in.
The rains come in July and August on the west and north-east coasts, and from April to July on the south coast, the approximate mean annual rainfall of these localities being 30, 35 and 42 in.
The great height of the snow-line, 14,000 ft., is due to the small rainfall and the upward rush of dry air from the plain of the Araxes.
On the 31st of May 1889, during a heavy rainfall, the dam gave way and a mass of water 20 ft.
California has the highest land and the lowest land of the United States, the greatest variety of temperature and rainfall, and of products of the soil.
Along both the Coast Range and the Sierra considerable rainfall is certain, although, owing to the slight snow accumulations of the former, its streams are decidedly variable.
The extreme variability in the amount of rainfall is remarkable.'
The effects of a season of drought on the dry portions of the state need not be adverted to; and as there is no rain or snow of any consequence on the mountains during summer, a succession of dry seasons may almost bare the ranges of the accumulated stock 1 During the interval from 1850 to 1872 the yearly rainfall at San Francisco ranged from 11.37 to 49.27 in.; from 1850 to 1904 the average was 22.74, and the probable annual variation 4 in.
In some sections a system of dry-farming, by which the scanty rainfall is protected from evaporation by deep ploughing and mulching the soil, has proved profitable.
This river, of volume varying with the tide and the amount of rainfall, is normally navigable by small steamers and native prahus, of a draught of 4 to 5 ft., for 300 to 400 m., that is to say, from Pontianak up to Sintang, and thence as far as Benut.
Even at Banjermasin, near the south coast, the north-west wind brings annually a rainfall of 60 in., as against 33 in.
The rainfall is steady and not usually excessive.
Nicaragua comes within the zone of the wet northeast trade-winds, which sweep inland from the Atlantic. The rainfall is heavy along the west side of the lacustrine basin, with an annual mean at Rivas of 102 in., but this figure is sometimes greatly exceeded on the east coast, where rain is common even in the dry season.
It is notable as having the heaviest known rainfall in the world.
This excessive rainfall is caused by the fact that Cherrapunji stands on the edge of the plateau overlooking the plains of Bengal, where it catches the full force of the monsoon as it rises from the sea.
The rainfall is scanty in average years, and only an insignificant proportion of the land is irrigated, while the rest is devoted to pasture, or covered with thin bush and forest.
The average rainfall for the year is about 55 in.
It can be said, however, that the south-east is the warmest portion of the state, lying as it does without the mountains; that the north-central region is usually coldest; that the normal yearly rainfall for the entire state is about 15.5 in., with great local variations (rarely above 27 in.).
The maximum number of "rainy" days (with a rainfall of more than o oi in.) rarely approaches ioo at the most unfortunate locality; for the whole state the average of perfectly "clear" days is normally above 50%, of "partly cloudy" above 30, of "cloudy" under 20, of "rainy" still less.
The rainfall is ample for their needs, but no other reserves in the country showed in 1900 such waste by fire and pillage.
Because of the small amount of rainfall, agriculture is confined chiefly to the river valleys.
The mean annual rainfall is about 19 ins.
The soil is extremely fertile, and, with a fair rainfall, say 13 in., between November and April, yields magnificent crops, but the improvements in agriculture are scarcely satisfactory.
The annual rainfall is about 68 inches.
The climate is temperate, and the rainfall very slight.
Although the annual rainfall, owing to the situation of the town towards the western flank of the Pennine Hills, is about 49 in., the air is particularly dry owing to the high situation and the rapidity with which waters drain off through the limestone.
The average annual rainfall for Sweden is 19.72 in., locally increasing on the whole from north to south, and reaching a maximum towards the south-west, precipitation on this coast greatly exceeding that on the south-east.
It is sometimes called the " Vale of Chile," and is the richest and most thicklypopulated part of the republic. It is a highly fertile region, is well watered by numerous streams from the Andes, has a moderate rainfall, and forms an agricultural and grazing region of great productiveness.
It is an alluvial plain for the greater part, but contains some sandy tracts, as in Ruble and Arauco; in the north very little natural forest is found except in the valleys and on the slopes of the enclosing mountain ranges, but in the south, where the rainfall is heavier, the plain is well covered with forest.
The heavy and continuous rainfall throughout this region, especially in the latitude of Chiloe, gives rise to a large number of rivers and lakes.
Some of the smaller islands of these groups are also inhabited, though the excessive rainfall of these latitudes and the violent westerly storms render them highly unfavourable for human occupation.
The high altitudes of the Andean region also introduce vertical zones of temperature, modified to some extent by the rainless plateaus of the north, and by the excessive rainfall of the south.
Going south the temperature slowly falls and the rainfall gradually increases, the year being divided into a short rainy season and a long, dry, cloudless season.
In southern Chile the climate undergoes a radical change - the prevailing winds becoming westerly, causing a long rainy season with a phenomenal rainfall.
It is wet and stormy all the year through, though the rainfall is much less than that of Ancud and Valdivia.
These conditions subsist with but few modifications, if any, from the Straits northward to the 42nd parallel, the extreme humidity, abnormal rainfall and dark skies being unfavourable to the development of insect life, while the Andes interpose an impassable barrier to migration from the countries of the eastern coast.
The northern part of this region has a sub-tropical climate, light rainfall and a long, dry summer, but with irrigation it produces a great variety of products.
Although wheat is produced in the northern part of this region, it is grown with greater success in the south, where the rainfall is heavier and the average temperature is lower.
The mean annual temperature is 59.9 and its annual rainfall is 115 in.
In no other part of West Africa is the rainfall so heavy.
The eastern escarpments (the Drakensberg, &c.) of the plateau intercept the rain-bearing winds from the Indian Ocean, so that over the greater part of the interior the rainfall is slight (5 to 24 in.).
Only along the south-eastern coast and in some of the river valleys is the climate of a markedly tropical character; here the rainfall rises to 50 in.
In consequence of the deficient rainfall over the greater part of the country the flora is not luxuriant and there are no large forests.
The scanty rainfall in many parts of South Africa and its unequal distribution necessitates a system of artificial irrigation unless much of the land be allowed to remain uncultivated.
The rainfall is very heavy, amounting to 121 in.
The rainfall is 24 in.
Being fed by tributaries which for the most part drain narrow valleys where gradual denudation has washed bare the flat-backed slopes of limestone ridges, and which consequently send down torrents of rapidly accumulating rainfall, both these central lines of water-course are liable to terrific floods.
North of Bhutan, between the Himalayan crest and Lhasa, this formation is approximately maintained; farther east, although the same natural forces first resulted in the same effect of successive folds of the earth's crust, forming extensive curves of ridge and furrow, the abundant rainfall and the totally distinct climatic conditions which govern the processes of denudation subsequently led to the erosion of deeper valleys enclosed between forest-covered ranges which rise steeply from the river banks.
The great mass of the Himalaya exhibits the same structure, due to the same conditions acting for longer periods and on a much larger scale; but the structure is varied in the eastern portions of the mountains by the effect of different climatic conditions, and especially by the greater rainfall.
Instead of wide, barren, wind-swept valleys, here are found fertile alluvial plains - such as Manipur - but for the most part the erosive action of the river has been able to keep pace with the rise of the river bed, and we have deep, steep-sided valleys eating their way northwards owing to the greater rainfall on the southern than on the northern slopes.
Diurnal currents of wind, which are established from the plains to the mountains during the day, and from the hills to the plains during the night, are impqrtant agents in distributing the rainfall.
The yearly rainfall, which amounts to between 60 and 70 in.
Speaking broadly, the general type of the flora of the lower, hotter and wetter regions, which extend along the great plain at the foot of the Himalaya, and include the valleys of the larger rivers which penetrate far into the mountains, does not differ from that of the contiguous peninsula and islands, though the tropical and insular character gradually becomes less marked going from east to west, where, with a greater elevation and distance from the sea and higher latitude, the rainfall and humidity diminish and the winter cold increases.
This equability of temperature is partly caused by the very heavy rainfall precipitated on Portugal as one of the westernmost countries of Europe and the one most exposed to the Atlantic. The rainfall has been as heavy as 16 ft.
The rainfall is heaviest in the north and on the Serra da Estrella; it is least in Algarve.
The average rainfall was 22.5 in., falling mostly from November to March.
These have been deeply cut by rivers, especially on the north-east, where the rainfall is heavier.
This vertical arrangement of climatic zones is modified to some extent (less than in Argentina) by varying rainfall conditions, which are governed by the high mountain ranges crossing one corner of the republic, and also by the prevailing winds.
On the west side of the Cordillera, which extracts the moisture from the prevailing easterly winds, the elevated plateaus have a limited rainfall in the north, which diminishes toward the south until the surface becomes absolutely barren.
In general, the sub-tropical (valle) and temperate (cabezera de valle) regions of Bolivia are healthy and agreeable, have a plentiful rainfall, moderate temperature in the shade, and varied and abundant products.
The climate is mild and relaxing and the rainfall averages about 40 in.
The rainfall varies between 13 and 20 in.
The scanty rainfall is distributed from July to April, with marked excess from July to September and a lesser maximum in December.
From ' At Yuma, Phoenix and Tucson, the records of twenty-six, eighteen and fifteen years respectively show a rate of evaporation 35.2, 12.7, and 7.7 times as great as the mean annual rainfall, which was 2.84 in., 7.06 in.
There are fine indigenous grasses that spring up over the mesas after the summer rains, furnishing range for live-stock; some are extraordinarily independent of the rainfall.
Rainfall varying with the altitude, the lower timber line below which precipitation is insufficient to sustain a growth of trees is about 7000 ft., and the upper timber line about I I,Soo ft.
The climate of the plains is hot and malarial, and the rainfall heavy.
The mean annual rainfall for the entire state in 1903 was 16.60 in.; the highest amount recorded was at Murray, Shoshone county (37.7 0 in.) and the lowest was at Garnet, Elmore county (5.69 in.).
The rainfall varies also according to the districts, the rainy season being the summer.
Thus the mean annual rainfall in the interior of Bohemia is 18 in., in the Riesengebirge 40 in., while in the Bohmerwald it reaches 60 to 70 in.
The general appearance of the surface is arid and desolate, partly because of the volcanic remains, and partly because of the scanty rainfall, which is insufficient to support vegetation other than that of the desert except in the deeper mountain valleys.
The surrounding district is fertile, and the rainfall about 22 in.
In 1903 a heavy rainfall caused a flood which continued from the 8th to the 19th of October and destroyed not less than $7,000,000 worth of property.
The rainfall is greatest at the sea-board, diminishing inland; the fall also diminishes from north to south.
West of the tableland the amount of rainfall decreases as the distance from the Pacific increases, and in a large area west of the Darling the average annual rainfall does not exceed io in.
The soil in that part of the country is, for the most part, suitable for cultivation, and there are large areas of rich land, but the rainfall is too light and irregular for the purpose of agriculture.
The District Of Ahmednagar is a comparatively barren tract with a small rainfall.
The very heavy rainfall of the district, which is the wettest in England, has led to the utilization of Thirlmere as a reservoir for the water supply of Manchester, over 80 m.
The numerous streams of the region carry off the rainfall down long valleys or dales to the east and the south, and by shorter and steeper valleys to the west.
The heavy rainfall of the upper valleys unfits them for agriculture, and the farms are poor.
The Carboniferous rocks of the centre form a soil which produces rich pasture under the heavy rainfall and remarkably mild and equable temperature, forming a great cattle-raising district.
The rainfall of England, being largely due to passing cyclones, can hardly be expected to show a very close relation to the physical features of the country, yet looked at in a general way the relation between prevailing winds and orographic structure is not obscure.
There are few places in the Western Division where the rainfall is less than 35 in., while in Wales, the Cornwall-Devon peninsula, the Lake District and the southern part of the Pennine Region the precipitation exceeds 40 in., and in Wales and the Lake District considerable areas have a rainfall of over 60 in.
In the Eastern Division, on the other hand, an annual rainfall exceeding 30 in.
In the Western Division there is a tendency for the annual maximum of rainfall to occur later than October.
Attention has been called to the fact that the bare rocks and steep gradients which are common in the Western Division allow of the heavy rainfall running off the surface rapidly, while the flat and often clayey lands of the Eastern Division retain the scantier rainfall in the soil for a longer time, so that for agricultural purposes the effect of the rainfall is not very dissimilar throughout the country.
The climate of the islands is oceanic, with moderate and fairly uniform temperatures and heavy rainfall.
The average annual amount of rainfall is about 80 in., and Unalaska, with about 250 rainy days per year, is said to be the rainiest place within the territory of the United States.
To the warmth and moisture brought by this means the coastal region owes its high equable temperature, its heavy rainfall (80-110 in.) and its superb vegetation.
In passing from the Sitkan district westward toward Kodiak and the Aleutians the climate becomes even more equable, the temperature a little lower and the rainfall somewhat less; 1 the fogs at first less dense, especially near Cook Inlet, where the climate is extremely local, but more and more persistent along the Aleutians.
The rainfall is light, from io to 25 in.
All these ranges are shorn through transversely by numerous glens and gorges, and, the rainfall being heavy and the exposure favourable, they are densely clothed with vegetation.
The southern exposure of this littoral region, the shelter afforded against the bitter winds of the north by the lofty Caucasus range, and the copious rainfall all combine to foster a luxuriant and abundant vegetation.
The amount of the rainfall shows great variations in different years, the records at Banana showing a total fall of 16 in.
From May to August, the period of the south-east monsoon, the climate of Banka is dry and hot; but the mean annual rainfall reaches 120 in.
The heavy rainfall is of great importance to the tin-streaming industry.
Turfor meadowformation depends upon uniform rainfall.
The rainy season is of great importance not only to Abyssinia but to the countries of the Nile valley, as the prosperity of the eastern Sudan and Egypt is largely dependent upon the rainfall.
The rainfall varies from 37 in.
Aman rice is much more extensively cultivated than dus, and in favourable years is the most valuable crop, but being sown in low lands is liable to be destroyed by excessive rainfall.
The climate of Backergunje is one of the healthiest in Eastern Bengal, owing to the strong south-west monsoon, which comes up directly from the Bay of Bengal, and keeps the atmosphere cool; but the heavy rainfall and consequent humidity of the atmosphere, combined with the use of bad water, are fruitful sources of disease.
The average rainfall is about 20 in., March and April being the rainy months.
The average annual rainfall on the coast is 10o 8 in.; it increases to about 120 in.
The rainfall, which is heaviest in summer, averages about 15-20 in.
The average yearly rainfall for the state as a whole is about 39 in., ranging from 53.7 in.
Rainfall comes from the Gulf of Mexico.
In the south and toward the great lower basin of the Amazon, where the rainfall is continuous throughout the year, the plains are heavily forested.
The Pacific coast rivers are numerous, and discharge a very large volume of water into the ocean in proportion to the area of their drainage basins, because of the heavy rainfall on the western slopes of the Coast range.
The great Andean barrier which crosses the republic from the south to north acts as a condenser to the prevailing easterly winds from the Atlantic, and causes a very heavy rainfall on their eastern slopes and over the forested Amazon plain.
The rainfall is heavy in the wet season, causing many of the rivers to spread over extensive areas, but in the dry season the inundated plains become dry, the large rivers fed by the snows and rainfall of the Andes return within their banks, the shallow lagoons and smaller streams dry up, vegetation disappears, and the level plain becomes a desert.
The low ridges of the Sierra de Perija do not wholly shut out these moisture-laden winds, but they cause a heavy rainfall on their eastern slopes, and create a dry area on their western flanks, of which the Vale of Upar is an example.
Farther south the coast ranges cause a very heavy rainfall on their western slopes, which are quite as uninhabitable because of rain and heat as are the coasts of southern Chile through rain and cold.
The rainfall on this coast is said to average 73 in., though it is much higher at certain points and in the Atrato Valley.
There is no satisfactory record of temperatures and rainfall in these widely different climatic zones from which correct averages can be drawn and compared.
Thus while the coast-lands, especially in the southeast, enjoy an ample rainfall, the winds as they advance west and north contain less and less moisture, so that over the larger part of the country drought is common and severe.
The western coastlands and the Little Karroo have a rainfall of from io to 20 in.; the Cape peninsula by exception having an average yearly rainfall of 40 in.
Along the south coast and in the south-east the mean annual rainfall exceeds 25 in., and is over so in.
The hot westerly winds of summer make the air oppressive, though violent thunderstorms, in which form the northern districts receive most of their scanty rainfall, occasionally clear the atmosphere.
The surface of the earth is rarely impermeable, and the structure of the rocks largely determines the direction of flow of so much of the rainfall as sinks into the ground and is not evaporated.
This cannot be determined from the rainfall; it entirely depends upon the power of the soil and rock to store water in the particular area under consideration, and to yield it continuously to the stream by means of concentrated springs or diffused seepage.
In such a case the first essential in determining the yield is to ascertain the rainfall.
Unqualified reliance upon single gauges in the past has been the cause of serious errors in the estimated relation between rainfall and flow off the ground.
The greatly varying distribution of rainfall over that length of 1600 ft.
Such examples show the importance of placing any rain-gauge, so far as possible, upon a plane surface of the earth - horizontal, or so inclined that, if produced, especially in the direction of prevailing winds, it will cut the mean levels of the area whose mean rainfall is intended to be represented by that gauge.
It has been commonly stated that rainfall increases with the altitude.
At the extreme left the rain-clouds are thrown up, and if this were all, they would precipitate a larger proportion of the moisture Since the above was written, this work has been taken over by the " British Rainfall Organization."
The neglect of these facts has led to many errors in estimating the mean rainfall on watershed areas from the fall observed at gauges in particular parts of those areas.
In the simplest case of a single mountain valley to be used for the supply of an impounding reservoir, the rainfall should be known at five points, three being in the axis of the valley, of which one is near the point of intersection of that axis with the boundary of the watershed.
The gauge in the bottom of the valley farthest from the source will in a wide valley generally record the least rainfall, and one of those on the south-west side, the highest.
Symons, F.R.S., of the Meteorological Office and of the Royal Meteorological Society, has resulted in the establishment of a vast number of raingauges in different parts of the United Kingdom, and it is generally, though not always, found that the mean rainfall over a long period can be determined, for an area upon which the actual fall is known only for a short period, by assigning to the missing years of the shortperiod gauges, rainfalls bearing the same proportion to those of corresponding years in the long-period gauges that the rainfalls of the known years in the short-period gauges bear to those of corresponding years in the long-period gauges.
Rainfall is proverbially uncertain; but it would appear from the most trustworthy records that at any given place the total rainfall during any period of 50 years will be within i or 2% of the total rainfall at the same place during any other period of 50 years, while the records of any period of 25 years will generally be found to fall within 32% of the mean of 50 years.
It is equally satisfactory to know that there is a nearly constant ratio on any given area (exceeding perhaps 1000 acres) between the true mean annual rainfall, the rainfall of the driest year, the two driest consecutive years and any other groups of driest consecutive years.
Apart altogether from the variations of actual rainfall produced by irregular surface levels, the very small area of a single rain-gauge is subject to much greater variations in short periods than can possibly occur over larger areas.
If, therefore, instead of regarding only the mean rainfall of several gauges over a series of years, we compare the relative falls in short intervals of time among gauges yielding the same general averages, the discrepancies prove to be very great, and it follows that the maximum possible intensity of discharge from different areas rapidly increases as the size of the watershed decreases.
Of the total quantity of rainfall a very variable proportion is rapidly absorbed or re-evaporated.
In the eastern counties the rainfall is lower and the evaporation approximately the same as upon the Thames area, so that the percentage of loss.
They show generally that, as the rainfall increases on any given area evaporation increases, but not in the same proportion.
Again, the loss from a given rainfall depends greatly upon the previous season.
Thus the actual yield of rainfall to the streams depends largely upon the mode of its time-distribution, and without a knowledge of this it is impossible to anticipate the yield of a particular rainfall.
In estimating the evaporation to be deducted from the rainfall for the purpose of determining the flow into a reservoir, it is important to bear in mind that the loss from a constant water surface is nearly one and a half times as great as from the intermittently saturated land surface.
Even neglecting the isolated and local discharges due to excessive and generally unrecorded rainfall, the variation in the discharge of all streams, and especially of mountain streams, is very great.
Adopting this general minimum as the unit, we find that the flow from such areas up to about 5000 acres, whose mean annual rainfall exceeds 50 in., may be expected occasionally to reach 300 cub.