一、灌区内灌、排水量的依据 灌区用水量的增加与减少,影响地下水位的上升和下降。要使地下水位保持在适当深度,就必须使灌区的来水量和耗水量达到平衡。来水量大于耗水量,地下水位就升高,土壤就产生次生盐碱化;来水量小于耗水量,作物生长就受抑制。 I. Irrigation District, irrigation based on displacement Irrigation water consumption increases and decreases, affecting the rise and fall of groundwater levels. In order to keep the water table at the proper depth, it is necessary to balance the inflow and water consumption of the irrigation area. Water is greater than the amount of water consumption, the groundwater level rises, the soil produces secondary salinization; water is less than water consumption, crop growth is inhibited.