Hydraulic Engineering of Land Reclamation

a system of measures for fundamental improvement of the poor water system of an area. In the USSR the following forms of hydraulic engineering of land reclamation are used: irrigation, found basically in the southern and southeastern regions; drainage, predominantly in the north and northwest; watering, in the arid and semiarid steppe and semidesert regions; flushing of saline lands; land protection, including measures against soil erosion, the washing away of slopes, and the formation of ravines; regulation of river channels and drainage; use of waste water for irrigation in areas near large cities and populated areas; and colmatage, used in fields with skeletal (having a large number of broken rocks) or poor soils, as well as in swampy or lowland areas.

Hydraulic engineering of land reclamation permits the control of the water conditions of the soil, gives stability to agricultural production, and makes possible the productive use of the land. The crop harvest yield on lands that are irrigated is several times greater than on nonirrigated lands (1.5 to two times greater for grain crops, four to five times greater for fodder crops). Harvests are high-yielding and stable on drained lands, especially in low-lying swamps. Hydraulic land reclamation is closely linked with agricultural forest reclamation, chemical land reclamation, and crop engineering works, forming a single complex for improving the natural conditions of agricultural production. Hydraulic land reclamation must be considered in the assimilation and correct usage of lands (including crop rotation, selection of crops and varieties, and a high level of agricultural technology). Only in this way can hydraulic land reclamation be economically effective and an important means of strengthening agriculture.

In order to implement hydraulic land reclamation, hydro-engineering projects are constructed. The complex of engineering structures and installations that supply and distribute water to irrigated lands (together with the irrigated territory) composes the irrigation system or, in the case of drainage, the drainage system. In irrigation, wells, ponds, channels, and water supply systems are constructed. In river control, the channels are deepened and widened, dams and embankments are built, and reservoirs are constructed to control flow. In highly saline soils the flush water containing salts is removed through drainage systems. In order to combat water erosion on slopes, water collecting channels and water control embankments are built, terracing is instituted, and flood-control structures are built in ravines and gullies. In some places hydraulic engineering of land reclamation is carried out by special construction-assembly administrations, machine-reclamation and meadow-reclamation stations, and machine-reclamation detachments, as well as by sovkhozes and kolkhozes. Most hydraulic land reclamation is done at the expense of the state budget.