Li Yuyi

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.

Distribution of Pressure Index of Agricultural Water Resources and Strategies in China Based on GIS

Pressure index of agricultural water resources(PIAWR) is the ratio of the amount of agricultural water use and 40 percent of total water resources. The PIAWR could reflect the status of pressure on agricultural water resources. The paper calculated the PIAWR at the municipal and regional scale in China using the pressure index model based on the statistical data of water resources in 2005. It was found that 42 municipalities had a water pressure of the ¢ñclass, accounting for 12.38% of the total, 50 had a water pressure of the ¢ò class, 14.75%; 83 had a water pressure of the ¢ó class,24.48%; 60 had a water pressure of the ¢ô class, 17.70%; 12had a water pressure of the ¢õ class, 3.54%; 7 had a water pressure of the ¢ö class, 2.06%; 18 had a water pressure of the¢÷ class, 5.31%; and 67 had a water pressure of the ¢ø class,19.76%. The difference of agricultural water resources pressure in 6 different administrative regions was also great and the PIAWR were ranked in the order of North China, Northwest China, East China, Northeast China, South China and Southwest China. Based on the above analysis, the paper gave some strategies and suggestions for alleviating the tension in the high pressure regions of North China, Northwest China, East China, Northeast China, such as developing water-saving agriculture, adjusting planting structure, strengthening irrigation water management and properly developing sewage irrigation.