Estimating spatial mean available water storage in a small catchment

黄土丘陵区特别是沟道复杂的地形为沟道小流域土壤有效储水量计算带来了困难。基于黄土丘陵区园则沟小流域2010—2012年土壤水分监测数据,采用时间稳定性分析和观测算子结合的升尺度方法,通过坡面单个监测点土壤有效储水量估算小流域不同尺度(坡面、沟道及小流域)土壤有效储水量。其中2010和2011年数据用于时间稳定性分析、观测算子构建以及坡面、沟道和小流域土壤有效储水量估算,2012年数据用于对其验证。结果表明通过坡面时间稳定点(单个点)土壤有效储水量不仅能够较为精确地估算坡面土壤有效储水量,也能通过构建观测算子较为精确地将其转换为沟道和小流域土壤有效储水量。验证结果表明,时间稳定点以及观测算子具有较高稳定性Abstract：The complex topography of the hilly area of the Loess Plateau （especially gullies） leads to thedifficulty of calculating watershed- scale available water storage （AWS）. Based on soil moisture datasetsfrom 2010-2012 in the Yuanzegou catchment of the Loess Plateau，this study attempted to estimate AWSof hillslopes，gullies and watershed from one single sampling location on the hillslopes for each layer，bycoupling time stability analysis with observation operators. The AWS datasets in 2010 and 2011 were usedfor time stability analysis，development of observation operators and estimation of AWS of hillslopes，gul⁃lies and catchment. The AWS datasets in 2012 were used for validation. The results show that the AWS ofhillslopes can be accurately estimated through that of one single hillslope time- stable location for eachdepth. Furthermore，the AWS of gullies and catchment are also well estimated from the hillslope time-sta⁃ble location by using the method of observation operators. The validation analysis indicates that the time-sta⁃ble location and the developed observation operators for various depths are temporally robust