大汶河流域陆面蒸发估算方法比较研究

区域陆面蒸散发的估算对于计算区域水资源总量,合理配置水资源具有重要意义。针对处于大汶河流域上游、受人类活动影响较小的雪野水库、黄前水库、东周水库控制子流域的实际特点,分别利用MODIS遥感方法、SWAT模型法、水面蒸发折算系数法对这三个子流域2000年-2008年的多年平均年陆面蒸发量及多年月平均陆面蒸发量进行估算,并基于水量平衡方程,结合各子流域的同期降雨与天然径流资料,对估算结果进行了分析比较。结果表明:在大汶河流域内,采用MODIS遥感方法估算实际陆面蒸散发的精度较低;水面蒸发折算系数法具有一定精度;SWAT模型法精度较高、适应性较好,估算误差仅在3%左右。研究结果可为半湿润区陆面蒸发估算方法的选择提供参考。

Comparative study on the methods of estimating land surface evaporation in Dawenhe River basin

The estimation of regional land surface evapotranspiration is of great significance to calculate the total amount of regional water resources and to allocate water resources reasonably. According to the characteristics of the sub river basins controlled by Xueye reservoir, Huangqian reservoir and Dongzhou reservoir in Dawenhe River basin, respectively using MODIS remote sensing method, SWAT model and conversion coefficient of water surface evaporation to estimate the average yearly and monthly land surface evaporation of the three sub basins from 2000 to 2008. Based on the rainfall and natural runoff data of each sub basin over the same period, the estimated results are analyzed and compared. The results show that: in Dawenhe River basin, the accuracy of the MODIS remote sensing method is low; the conversion coefficient method has a certain precision; the SWAT model method has higher calculation precision and better adaptability, and the estimation error is only about 3%. The results provide references for selecting good methods of estimating the land surface evaporation in the semi humid region.