基于BWSI与GWSI的江苏省农业生产水资源压力评价

为评价农业生产过程对区域水资源的影响,在核算江苏省农业广义水资源量和农作物生产水足迹的基础上,构建基于水资源消耗和水足迹的农业生产水资源压力指标BWSI和GWSI进行1999~2013农业生产水资源压力评价。结果显示,江苏省农业广义水资源约为1 034.6×10~8 m~3,绿水占70.4%,苏南地区相对丰富;农作物生产水足迹为1 069.5×10~8 m~3(5.9%蓝水、74.6%绿水、19.5%灰水),苏北地区占61.6%且有随时间增大趋势。全省BWSI和GWSI分别为2.60与1.09,水资源压力较大,且有随时间微弱增大的趋势;农业生产水资源压力由南向北呈增大态势,且在时间上呈现苏南减低、苏中稳定、苏北增大的整体态势。引江水缓解了全省及各分区水资源压力,对BWSI的影响大于GWSI。BWSI和GWSI可以用于区域农业生产水资源压力评价,BWSI能揭示缺水地区的水资源稀缺性,而GWSI适合全面反映水资源丰富地区的用水状况。

WATER STRESSES EVALUATION OF AGRICULTURAL PRODUCTION IN JIANGSU PROVINCE USING BWSI AND GWSI

The aim of this study is to evaluate water stress of agricultural production in Jiangsu Province of China.Two water stress assessment indices,i.e.,BWSI and GWSI,was established in the blue-green water framework base on regional generalized agricultural water resources and crop water footprint quantification.Then,we analyzed crop-water relationship and water stress of agricultural production for Jiangsu Province and its three sub-regions,i.e.,Northern Jiangsu,Central Jiangsu and Southern Jiangsu,during 1999-2013.Results showed that,the annual average of generalized agricultural water resources of the province in the observed period was 103.46 Gm3;green and blue water accounted for about 70.4％ and 29.6％ of the total water resources respectively;generalized agricultural water resources in the sub-region of Southern Jiangsu was more plentiful than the Northern Jiangsu and Central Jiangsu.Yearly water footprint for crop production was estimated to be 106.95 Gm3 during 1999-2013 and the proportion in total water footprint as a whole of blue,green and grey water footprint was 5.9％,74.6％ and 19.5％,respectively.Crop water footprint of the sub-region of Northern Jiangsu increased over time,and accounted for about 61.6％ of the provincial value in the study period.The annual average of BWSI and GWSI in 1999-2013 of Jiangsu province were calculated about 2.60 and 1.09,respectively,revealing a severe water stress facing the province in agricultural production.Both of the indices BWSI and GWSI showed a slight increase trend in the latest fifty years.From the perspective of spatial pattern,water stress of agricultural production increased from south to north.Temporal trend of the three sub-regions were found that three was a decrease in Southern Jiangsu,stability in Central Jiangsu and an increase in North Jiangsu.About 18.52 Gm3 of water diversion,mainly from Yangze River,was supplied for agricultural production in Jiangsu province.For all that,the BWSI and GWSI was reduced from to 2.65 and 1.09 to 2.02 and 1.01 during the period of 2001-2013.In addition to cross-regional water diversion,efficient use of green water resources and water footprint regulation should be emphasized for regional water stress relief.BWSI and GWSI can be used to evaluate the regional water stress of agricultural production.In addition,BWSI can reveal water scarcity in water-scarce areas,while GWSI is more suitable for fully reflecting water use in water-rich areas compared to the conventional water stress index (WSI).The findings of this study can supply some implications for regional water resources management.