SWAP和SWAT在柳园口灌区的联合应用

以河南柳园口灌区为背景,利用SWAP和SWAT分别建立模型,并进行了率定和验证.利用SWAT模型提取各水文响应单元的水平衡要素作为SWAP的输入,实现作物产量的空间分布式模拟.联合应用SWAP和SWAT模型模拟分析了不同灌溉水源及作物种植结构下灌区水平衡要素、作物产量和水分生产率的变化规律以及水分生产率随尺度的变化规律.结果表明,区域平均蒸发蒸腾量、产水量、土壤含水量变化、渗漏量都随着井灌面积比的增加而减少,合适的井灌面积比有利于控制适宜的地下水埋深,从而减少潜水蒸发损失,防止由于地下水埋深过深而导致取水困难;现有水稻种植区改种旱稻,区域平均蒸发蒸腾量、产水量、土壤含水量及渗漏量都减少,但变化幅度较小,同时水分生产率降低;现状条件下随着尺度的增大,灌溉水分生产率增大,蒸发蒸腾量水分生产率稍微降低,毛入流水分生产率变化不大.

Combined application of SWAP and SWAT to Liuyuankou irrigation system

SWAP and SWAT were combined to simulate distributed water balance and crop yield for Liuyuankou Irrigation System. The two models were calibrated and verified with measured data. SWAT model was run first ,then water balance elements for each hydrological response units were extracted and used as SWAP inputs. The validated models were used to simulate responses of water balance, crop yield and water productivity to irrigation water sources and crops planting structure changes. Results show that average evapotranspiration, water yield, variation of soil water content, seepage decrease as well irrigation area increases. Appropriate well-canal irrigation ratio can maintain reasonable groundwater depth and decrease groundwater evaporation losses; thus avoided difficulty of pumping. If all lowland rice is replaced by aerobic rice, evapotranspiration, water yield, variation of soil water content, seepage will decrease slightly, and water productivity indices also decrease. Irrigation water productivities increase prominently as scale increase; and evapotranspiration productivities decrease as scale increase; while gross in flow productivities keep stationary at all scales.