典型年份渭河流域蓝水绿水时空差异分析

以西北地区湿润/干旱过渡地带的渭河流域为例,采用降水距平百分率和标准化降水指数识别湿润年、正常年和干旱年,同时结合SWAT(Soil and Water Assessment Tool)模型的输出结果分析各典型年该流域蓝水绿水的时空分布差异。结果表明:(1)采用降水距平百分率和标准化降水指数两种方法确定1983、1997和2007年分别为湿润年、干旱年和正常年;(2)模型评价的结果表明,SWAT模型的月径流模拟的精度较高,可以准确描述渭河流域的径流变化过程;(3)在流域尺度上,绿水流的变化在湿润年、干旱年和正常年的变化相对稳定,绿水系数在湿润年、干旱年和正常年分别为82.06%、93.47%和87.72%;(4)从空间分布来看,蓝水绿水资源在渭河流域的分布呈现自东南向西北减少的趋势,绿水系数的空间分布表明在湿润年份(1983)或地区(东南部)绿水比重明显低于干旱年份(1997)或地区(北部)。

Spatiotemporal Variation of Blue-Green Water under Typical Reference Years in the Weihe River Basin

In order to understand the spatiotemporal pattern difference of blue-green water in typical reference years on a watershed scale, this study selected the Weihe River Basin in northwestern of China to analyze the spatiotemporal distribution pattern difference of blue-green water, and obtained the typical reference years by using standardized precipitation index(SPI) and precipitation anomaly index(Pa). The results showed that: (1)the years of 1983, 1997 and 2007 were determined as wet year, dry year and normal year, respectively. (2)Calibration and validation results showed a similar change trend between simulated and observed discharges, and the SWAT can be used to predict hydrological processes in Weihe River Basin. (3)Change of the green water was relatively stable in the typical reference years, and the green water coefficients were 82.06%, 93.47% and 87.72% in the wet year, dry year and normal year, respectively. (4)Spatially, the blue-green water decreased from southeast to northwest in Weihe River Basin. The spatial distribution of green water indicated that the proportion of green water in the wet year (1983) or areas (southeast) was lower than the normal and dry year (1997) or areas (north).