![]() ![]() Temporary irrigation network means the network that carries out regulation within irrigated sites, composed of temporary, annually installed irrigation ditches, field (auxiliary) ditches and irrigation furrows and irrigation ditches, distribute water to fields and, when irrigating, transfer it into soil moisture of required extent. After farms’ boundaries and approximate boundaries of crop rotation sites are set and on-farm distributors are routed, they proceed to laying out crop rotation fields and irrigated sites within each crop rotation process. Then the routes of on-farm distributors are outlined according to the highest elevation of the relief with simultaneously setting crop rotation sites’ boundaries.Ĭrop rotation sites’ boundaries are marked so that they match higher-order canals, roads, boundaries of human settlements, natural boundaries and taking into account the hydrogeological conditions and the ease of use of the system. Permanent canals distribute water over the farm’s territory: they are designed on the maps to a scale of 1:10000 or 1:5000 with the contour intervals of 0.5 m, when the territory area, crop rotation pattern, irrigation regime, and method of irrigation of all crops are known.ĭesigning of the network begins from plotting farms’ boundaries on the map and determining the total irrigation area and the area usable for irrigation. On-farm irrigation networks consist of on-farm and delivery ditches as well as temporary irrigation network. On-farm canals are the ones that deliver water to each farm and, if a farm is big enough, to its separate large irrigated sites, without hampering the mechanization of farm operations and allowing treating of cultivated crops. To reduce seepage losses, the canals’ bottoms and walls are compacted, covered with facing from concrete, (cast-in-situ reinforced or precast structural) reinforced concrete, and shields from clay and polymer films are applied. Irrigation canals are laid through an excavation, cut-and-fill, or on a hillside. The routes of irrigation canals should pass along the boundaries of farms, crop-rotation sites, fields so that not to split the respective irrigated area, while the main canal – by the highest points of the irrigated area. ![]() ![]() Here a branch means a largest canal outgoing from the main canal, according to the significance (in terms of discharge, serviced area, length) of which it might be considered as an extension of the main canal.Ĭanals-distributors represent smaller sections of the inter-farm and farm irrigation network. The inter-farm canal is a branch of the main canal and distributes the water delivered through it among certain farms or crop-rotation sites. Canal routes are designed along the boundaries of farms, crop-rotation lands, fields, and so on in order to keep the integrity of the irrigated area. Water is supplied through the main canal from an irrigation source to the inter-farm distributors that deliver water to certain land users or crop-rotation lands on-farm distributors deliver water to fields or irrigated sites. In the open irrigation network, the conducting network is composed of the main canal, inter-farm, farm, and on-farm distributors of different orders. Inter-farm canals are the canals that distribute the water delivered to the main canal to all farms within the system. Command of the main canal (excess of the water level in it above the water level in lower-order canals) over the respective irrigated area and higher-order canals over lower-order canals) is essential for the irrigation network operation ensuring gravity irrigation. Irrigation canals are arranged so that to provide the following at minimum construction and operation costs: water supply of required volume and in due time highest efficiency of the canals (ratio of the flow rate at the canal tail to that at the canal head) and irrigated area use ration effective operation of the canals and structures in those. In some cases, the conducting network has no full set of canal structures. to inter-farm distributors which, in turn, deliver water to individual farms or crop-rotation sites on-farm distributors deliver water to crop-rotation fields or irrigated sites. The main canal delivers water from a river, reservoir, well etc. Conducting network in open irrigation systems is composed of the main canal, inter-farm, farm, and on-farm distribution canals (distributors) of different orders. ![]()
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