艾比湖流域植被生态需水量

Vegetation Ecological Water Requirement of Ebinur Lake Watershed

基于遥感数据,通过SEBAL模型估算蒸散量,计算艾比湖流域不同植被类型下植被生长季(5—9月)的生态需水量。结果表明:研究区植被主要为牧草地、灌木林地、耕地、乔木林地,面积分别为13 944km^2(50%)、8 071km^2(29%)、5 022km^2(18%)、566km^2(2%)。SEBAL模型估算的日蒸散量7月最大,为4.36mm。5、6、8、9月日蒸散量分别为4.26、4.07、4.24、4.15 mm。SEBAL模型估算结果整体相对误差在10%以内,在允许范围内。2000—2015年生长季植被生态需水量整体上呈现出增加-减少-增加的变化趋势,2000、2005、2010、2015年分别为151.003×10~8、149.611×10~8、144.431×10~8、136.374×10~8 m^3。各植被类型下的生态需水量相比,牧草地>灌木林地>耕地>乔木林地,牧草地约占总生态需水量的53%~55%,而灌木林地、耕地的生态需水量分别占21%~25%、19%~20%,乔木林地的生态需水量所占比例最小,仅为2%~3%。

The ecological water requirement of different vegetation types within growing season in the Ebinur Lake watershed is calculated with SEBAL model and remote sensing data.The results show that the vegetation area is classified into 4 kinds,which are grassland,shrub land,farmland,timber forest,and the area are 13 944 km^2,8 071 km^2,5 022 km^2,566 km^2,respectively,occupying 50%,29%,18%,2% respectively.Based on SEBAL model,the daily evapotranspiration is estimated from May to September.The results indicate that the daily evapotranspiration in July reach highest with 4.36 mm,and it is 4.26 mm,4.07 mm,4.24 mm,and 4.15 mm in May,June,August,September respectively.The whole error of the SEBAL model results is less than 10%.There was an increase-decrease-increase tendency for the calculation results of vegetation eco-water demand during the growing season from 2000 to 2015.The ecological water requirement of different vegetation types indicates as grassland〉shrub land〉farmland〉timber forest.The ecological water requirement of grassland accounts for 53%-55%,shrub land and farmland occupied 21%-25%,19%-20%,respectively.The least is timber forest,only 2%-3%.