水足迹分析中国耕地水资源短缺时空格局及驱动机制

为全面评估区域农业水资源供需关系,基于水足迹理论构建了耕地水资源短缺指数(arablelandwaterscarcity index,AWSI)。在分析1999-2014年中国AWSI时空分布格局的基础上,借助偏最小二乘法揭示了AWSI的主控因子。结果显示:中国AWSI的年均值约为0.413,总体上处于高度水资源压力状态,且有随时间加剧的趋势;各年份AWSI以华北平原为中心向外递减式扩散;面临极高水资源压力(AWSI0.800)的省区均分布在北方地区,长江以南省区均面临中度水资源压力(0.100AWSI0.400);降水量与日照时数是与耕地水短缺最为密切的气象因子,农业机械总动力、粮食面积比重以及人均GDP是影响AWSI的主要社会经济条件。农业生产水平较高的粮食主产区应以水足迹调控为重要内容进行农业水管理策略的制定。

Temporal-spatial distribution and driving mechanism of arable land water scarcity index in China from water footprint perspective

Efficient water use in agriculture production system is widely accepted as an important foundation of regional water resources management, water shortage alleviation and environmental sustainability. The arable land water scarcity index (AWSI) to describe relationship between crop production and potentially water resources was established based on water footprint framework in current study. AWSI was defined as the ratio of total water footprint in regional crops cultivation to available agricultural water resources, including blue and green water. AWSI in 31 provinces, municipalities and autonomous regions of China from 1999 to 2014 was calculated. Then, the spatial-temporal pattern and driving mechanism in the observed period were explored with the help of the methods of spatial autocorrelation analysis. A total of 10 potential factors such as relative humidity (RH), average temperature (AT), precipitation (P), sunshine hours (SH), chemical fertilizer per area (CF), pesticides per area (PP), power of machinery per area (MP), irrigation rate (IR), irrigation efficiency (IE), proportion of grain area (GA) and per capita GDP (GP) were selected in driving mechanism assessment. Given that the high co-dependence of these potential factors, partial least squares regression (PLSR) was used to elucidate the linkages between the ASWI and the selected factors. The results showed that, annual value of AWSI in China was estimated about 0.413, and the country faced high water stress during the studied period; AWSI in almost all of the provinces, municipalities and autonomous regions increased over time, indicating that water scarcity in agricultural production system of China was intensifying. Spatial autocorrelation analysis showed that the global Moran''s I was higher than 0 in all the calculated years, implying provinces, municipalities and autonomous regions with similar AWSI presented an obvious aggregation characteristic in agriculture production of China. Provinces with high AWSI was in the North China Plain and all the regions facing extremely high water stress (AWSI>0.800) were distributed in the north of China; most of the provinces located in south of the Yangtze River were classified as moderate water stress (0.100