近20年我国有效灌溉面积动态分析

The Change of Effectively Irrigated Land Area in China during the Past 20 Years

有效灌溉耕地是我国粮食安全的重要保障。本文在全面分析近20年有效灌溉面积变化情况及其原因的基础上，提出保护有效灌溉面积的相关建议。研究表明。1986年～2004年我国年均已有灌溉面积减少量为81．81×10^4hm^2，占年均有效灌溉面积的1．60％。2000年以后有效灌溉面积减少的主要原因是灌溉设施损坏、建设占地和退耕。我国每年因有效灌溉面积减少至少导致粮食减产48．90×10^8kg。建议水利部门抓住2006年将开展的土地利用总体规划修编前期工作和第二次全国农业普查的机会，会同有关部门开展调研，提出保护有效灌溉面积的具体对蒙。

Effectively irrigated land is playing a very important part in China＇ s food production and food security. This paper gives some suggestions for protecting effectively irrigated land based on the analysis of dynamic change of effectively irrigated area land and driving forces of the change. The result shows that the annual average decrease of effectively irrigated area of land during the periods of 1986 ～ 2004 is 81.81 × 10^4ha, taking for 1.60 percent of annual average total area of effectively irrigated land. In general, the annual decrease area of effectively irrigated land in the 1990＇s is sustained stably in about 66 × 10^4ha. However, the annual decrease was accelerating after 2000 and hit 118.34 × 10^4ha in 2003, accounts for 2.12 percent of total area of effectively irrigated land in 2003. A dozens of reasons contribute to the decreased area of effectively irrigated land including outdated irrigation facility, inappropriate management of pump and well, water shortage, occupation of farmland by construction purposes and farmland conversing into forestry land. The decreased area of effectively irrigated land is mainly distributed over the important regions for food production out of 13 provinces. Therefore, the decrease of effectively irrigated farmland has a great impact on food production and food security in the country. The research shows that the decrease of effectively irrigated farmland during the periods of 2000 - 2003 contribute directly to a decrease of 4.89 billion kg of food production yearly, which is far more than the annually average amount of tbod imported from foreign countries. If the reduced part of food products were replenished through food import it would cost over 900million US Dollars each year. So it is suggested that water resource management agencies take the chanco of remediation of land use planning and second national agricultural survey in cooperation with relevant government departments to conduct in - depth investigation and research into the problems, formulating effective measures and strategies to prevent farmland from declining continuously.