- There are three drainage systems within the state.
The drainage of marshes and marshy lands has considerably extended.
The drainage of Manitoba is entirely northeastward to Hudson Bay.
In extent, characterized by wholly interior drainage, a peculiar mountain system and extreme aridity.
Below the confluence the Kabul becomes a rapid stream with a great volume of water and gradually absorbs the whole drainage of the Hindu Kush.
The suggested causes are (I) reduction of insects by drainage, (2) reduced population, (3) the use of quinine.
Excellent examples of the indecisive drainage of a new land surface, on which the river system has not had time to impress itself, are to be seen in northern Canada and in Finland, where rivers are separated by scarcely perceptible divides, and the numerous lakes frequently belong to more than one river system.
These basins of internal drainage are calculated to amount to 22% of the land surface.
The general slope of the plateau is toward the N., and the drainage of the state is chiefly through the above-named rivers - the principal tributaries of the Araguaya being the Grande and Vermelho, and of the Upper Tocantins, the Manoel Alves Grande, Somno, Paranan and Maranhao.
The drainage system here, including a water-closet, is of the most complete and modern kind.
The Bebedero, in San Luis, and Porongos, in Cordoba, and others, are shallow, saline lakes which receive the drainage of a considerable area and have no outlet.
The unhealthiness of the city is chiefly due to want of proper drainage, impure drinkingwater, miasma from the disturbed rubbish heaps, and contaminated dust from the uncleansed roads and streets.
Corner of the state is the third drainage system.
On the western frontier a northern extension of the great central chain of Goyaz forms the water-parting between the drainage basins of the Sao Francisco and Tocantins, and is known at different points as the Serra do Paranan, Serra de Sao Domingos and Serra das Divisoes.
North of the Murchison, Mount Augustus and Mount Bruce, with their connecting highlands, cut off the coastal drainage from the interior; but no point on the north-west coast reaches a greater altitude than 4000 feet.
In the case of a large hollow in a very dry climate the rate of g evaporation may be sufficient to prevent the water from ever rising to the lip, so that there is no outflow to the sea, and a basin of internal drainage is the result.
The river was also canalized, a telephone service introduced, and extensive drainage works carried out.
A considerable part of southern Goyaz, however, slopes southward and the drainage is through numerous small streams flowing into the Paranahyba, a large tributary of the Parana.
The water supply and drainage systems were introduced by the United States government, which controls the sanitation of the city, but has no other jurisdiction over it.
This upheaval - the consequences of which have been felt even within the historic period, by the drainage of the formerly impracticable marshes of Novgorod and at the head of the Gulf of Finland - together with the destruction of forests, contributes towards a decrease of precipitation over Russia and towards increased shallowness of her rivers.
Drainage finding no outlet through the thick clay, the soil of the forest region is often hidden beneath extensive marshes, and the forests themselves are often mere thickets choking marshy ground; large tracts of sand appear in the W., and the admixture of boulders with the clay in the N.W.
The shortness of the summer, the deficiency of drainage and the depth to which the soil freezes in winter, are the circumstances which determine the characteristic features of the vegetation of the tundras.
Of the Colorado river; the northern edge being formed by the divide of the drainage basin of the Columbia river, the eastern by that of the Colorado, the western by the central part of the Sierra Nevada crest, and by other high mountains.
Such drainage as had at one time existed was allowed to get choked up, giving rise to typhoid fever of a virulent type.
Above the sea, which receives the drainage of the eastern slopes of the Sierra and what little drainage there is in the northern half of Nevada.
The Sao Francisco forms its northern boundary, and the drainage of the northern part of the state is northward and eastward to that river.
For instance, the swampy character of malarial areas is explained by their breeding in stagnant water; the effect of drainage, and the general immunity of high-lying, dry localities, by the lack of breeding facilities; the danger of the night air, by their nocturnal habits; the comparative immunity of the upper storeys of houses, by the fact that they fly low; the confinement of malaria to well-marked areas and the diminution of danger with distance, by their habit of clinging to the breeding-grounds and not flying far.
Put comprehensively, it involves the control of the subsoil and surface waters by drainage, the regulation of rivers and floods, suitable agriculture, the clearing of forests or jungles, which tend to increase the rainfall and keep the ground swampy.
The city of Rome is an example of what can be done by drainage; situated in the midst of malaria, it is itself quite healthy.
I Drainage works begun.
The Pontotoc ridge separates the drainage system of the Mississippi from that of the Tombigbee; extending from the northeastern part of the state southward, this ridge divides in Choctaw county, the eastern branch separating the drainage basin in the Pascagoula from that of the Pearl, and the western branch separating the drainage basin of the Pearl from that of the Big Black and the Mississippi.
North and parallel with its course is a low watershed, which separates its drainage basin both from that of the Sao Francisco and from that of the Parnahyba, the northern confluent of the Parana.
The southern outfall works of the London main drainage system are at Crossness in the neighbouring lowland called Plumstead Marshes.
The greater part of the state belongs to the western extension of the Brazilian plateau, across which, between the 14th and 16th parallels, runs the water-shed which separates the drainage basins of the Amazon and La Plata.
Annually, but the drainage from the eastern slopes of the Andes is large enough to meet the loss from evaporation and keep these inland lakes from drying up. At an early period this depressed area drained southward to the Colorado, and the bed of the old outlet can still be traced.
The rivers belonging to this inland drainage system are the Vermejo, San Juan and Desaguadero, with their affluents, and their southward flow can be traced from about 28° S.
The three great rivers that form the La Plata system - the Paraguay, Parana and Uruguay - have their sources in the highlands of Brazil and flow southward through a great continental depression, two of them forming eastern boundary lines, and one of them, the Parana, flowing across the eastern part of the republic. The northern part of Argentina, therefore, drains eastward from the mountains to these rivers, except where some great inland depression gives rise to a drainage having no outlet to the sea, and except, also, in the " mesopotamia " region, where small streams flow westward into the Parana and eastward into the Uruguay.
The so-called rivers have a strong flow only after heavy rains, and some of them do not ever reach the main drainage line.
Broad, believed to encircle a large portion of the inland country, with drainage at one end by a marsh into Spencer Gulf.
Although not the most extensive of the great oceans, the Atlantic has by far the largest drainage area.
It collects nearly all the drainage of the Udaipur plateau with that of the eastern slopes and hill-tracts of the Aravallis, and joins the Chambal a little beyond the northeastern extremity of the Bundi state, after a course of about 300 m.
The results areaa lack of water-supply and of water-power, the streams becoming mere torrents for a short period and perfectly dry for the rest of the year; lack of a sufficient supply of timber; the denudation of the soil on the hills, and, where the valleys below have insufficient drainage, the formation of swamps.
Proper drainage and improvement of the (generally fertile) low-lying and hitherto malarious plains.
Drought and consequent defoliation result in the same, and these considerations help us to understand how old-established trees in parks, &c., apparently in good general health, become stag-headed by the necrosis of their upper twigs and smaller branches: the roots have here penetrated into subsoil or other unsuitable medium, or some drainage scheme has deprived them of water, &c., and a dry summer just turns the scale.
Differences in land forms do not exert great influence on the distribution of living creatures directly, but indirectly such land forms as mountain ranges and internal drainage basins are very potent through their action on soil and climate.
Murray, " Drainage Areas of the Continents," Scot.
Hanoi resembles a European city in the possession of wide well-paved streets and promenades, systems of electric light and drainage and a good water-supply.