黑河流域蓝绿水在典型年份的时空差异特征

蓝绿水研究目前主要集中在蓝绿水资源量及其时空分布评价方面,在流域尺度上考虑气候因素的蓝绿水时空差异研究甚少。本文选取中国西北干旱内流河地区的黑河流域,采用标准化降水指数(SPI)和降水距平指数(M)2个指标确定典型年份,并分析不同典型年份(干旱年、湿润年、平水年)的流域蓝绿水时空差异特征。结果表明:1)黑河流域的蓝水与绿水的合计深度从降雨量较高的上游到降雨量较低的下游呈现递减趋势;2)蓝绿水总量在湿润年份(1998年,252.72亿m3)明显大于干旱年份(1978年,167.73亿m3);3)绿水系数,即蒸散发占水资源总量的比例,在干旱年份(90.30%)明显高于湿润年份(85.41%)。同时,降水较低的年份(干旱年份)或地区(下游)绿水占水资源的比例明显高于降水较高的年份(湿润年份)或地区(上游)。黑河流域的典型年份蓝绿水数量与时空差异特征的分析可为探讨气候变化下蓝绿水演变及加强中国内陆河流域绿水资源管理提供参考。

Spatial and temporal pattern difference of blue-green water flows in typical reference years in the Heihe River Basin, northwestern China

In order to better understand the spatial and temporal pattern difference of blue-green water in typical reference years (dry years, wet years, and normal years) on a watershed scale, we chose the inland river (Heihe River Basin) in northwestern China to analyze the spatial and temporal distribution pattern difference of blue-green water in climate influence. We obtained the typical reference years by using two indicators firstly, namely standardized precipitation index (SPI) and precipitation anomaly index (M). The results showed: 1) the blue-green water of Heihe River Basin had a decreasing trend from upstream to downstream; 2) the blue-green water quantities in typical wet year (1998,25.272 billion m3) were more than in typical dry year (1978, 16.773 billion m3); 3) the green water coefficient, i.e. the percent of evapotranspiration in total water, was greater in typical dry years (90.30%) than in typical wet year (85.41%). Meanwhile, the percent of green water in total water resource was greater in typical dry year or dry region (downstream) than in typical wet year or wet region (upstream). The study carried out a comprehensive analysis of temporal and spatial difference of blue-green water in Heihe River Basin of northwestern China in typical years, and it can provide references for improving the management of inland river water resources in China.