基于改进SWAT模型的区域蒸发蒸腾量模拟

运用改进的SWAT模型,以漳河灌区三干渠内杨树垱小流域为研究对象,针对"间歇灌溉"、"淹灌"、"薄浅湿晒"3种不同灌溉模式下的流域内ET模拟分析,结果表明该区域ET从大到小的顺序依次为"淹灌"、"间歇灌溉"、"薄浅湿晒",同种灌溉模式下ET随水稻种植面积比的增加而增大.对3种灌溉模式下的稻田ET分项(植株蒸腾、稻田水面蒸发、稻田土壤蒸发)模拟分析表明,3种模式下植株蒸腾比较稳定,维持在37%~40%;"间歇灌溉"和"淹灌"模式下的稻田水面蒸发占稻田ET的55%以上,而土壤蒸发只占6%和0.4%;"薄浅湿晒"灌溉模式下稻田水面蒸发和土壤蒸发分别占33%和27%.

Simulation of regional evapotranspiration in different irrigation methods based on adapted SWAT distributed hydrological model

Using the adapted SWAT distributed hydrological model on Yangshudang watershed in Third main canal district of Zhanghe Irrigation System (ZIS) for example, regional evapotranspiration(ET) in three different irrigation methods is analyzed. Simulation results suggestion that regional ET decreased successively with the irrigation methods "continuous flooding", "alternate wetting and drying (AWD)"and "thin, shallow, wet, dry ", and the larger area ratio of rice crop, the higher the regional ET. Analyzing the ET with different irrigation methods, crop transpiration, ranged from 37% to 40%, shows no difference, but water evaporation and soil evaporation in paddy field shows obvious difference. Water evaporation takes more than 55% of ET in paddy field with the irrigation methods "continuous flooding"and "AWD", but the soil evaporation only has 0.4% and 6%. Water evaporation takes 33% and soil evaporation takes 27% ET in the irrigation method "thin, shallow, wet, dry".