Evaluation of Agricultural Water Use Efficiency and Regional Irrigation Strategies in China Based on GIS

Enhancing agricultural water use efficiency (AWUE) is the key way for water saving in China. In this paper, the evaluation method for AWUE was established based on the concept of agricultural standard yield and total consumed agricultural water. Through taking province as analysis unit, the relationship between AWUE and irrigation intensity (irrigation amount per acre), irrigation extent (ratio of effective irrigation area), standard yield and cropping index was analyzed. It was found that the difference of AWUE was great and changed from 1.70 kg/hm2·mm to 7.40 kg/hm2·mm in the different provinces of China in 2007. There was a significantly negative correlation between irrigation intensity and AWUE. A positive correlation between irrigation extent, standard yield and AWUE was also observed, but the correlation coefficient did not reach significant level, and no correlation between cropping index and AWUE was observed. According to the distribution of AWUE in China, three different types of regions were divided, the first type regions (AWUE≤3.0kg/hm2·mm) were located at Gansu, Ningxia, Yunnan, Guizhou, Hainan, Fujian, Guangdong and Guangxi. Second type regions (3.0 kg/hm2·mm≤AWUE≤5.0kg/hm2·mm) included Shanghai city, Heilongjiang, Jiangxi, Qinghai, Xinjiang, Shaanxi, Tibet, Hubei, Hunan, Anhui, Jiangsu, Zhejiang, Sichuan and Shanxi, and third type regions (5.0 kg/hm2·mm≤AWUE≤7.5 kg/hm2·mm) mainly included Chongqing city, Tianjin city, Beijing city, Liaoning, Jilin, Shandong, Hebei, Henan and Inner Mongolia. Lastly, different regional irrigation strategies were put forward.