近45年元江干热河谷灌溉需水的变化趋势分析

基于元江、巍山及禄丰3个站1955~2000年的逐月气象数据及作物种植、农业耕作等资料,采用Mann-Kendall法和R/S分析法,研究了元江干热河谷近45年来的干湿变化及农业灌溉需水量转折变化趋势。结果表明:元江河谷的气温下降、降水量增多、湿度增大,导致ET0显著降低,干湿指数、水稻及农业综合灌溉需水定额都呈下降的趋势。元江河谷的气象因子转折变化集中在20世纪70年代初和80年代末,而农业综合灌溉需水定额的转折变化期则在90年代初与气象因子的第二个转折期基本相同。

Analysis on evolution of agricultural water requirement in Yuanjiang River valley in recent 45 years

Based on the monthly climate records of three observation stations in Yuanjiang River from 1955 to 2000 and the crop pattern as well as cultivate data in the year of 2000,the Mann-Kendall trend and Rescaled Range Analysis(R/S) method was adopted to study the tendency of aridity-humidity and irrigation water requirement in the xerothermal valley of Yuanjiang River.The results show that the temperature tends to decrease and precipitation as well as humidity tends to increase,thus,result in decrease of ET_0 in river basin.Furthermore,the aridity-humidity index,paddy irrigation quota and total agriculture irrigation quota decrease.It is found that the turning points of climate factors are focused at the beginning of 1970's but the changing period of irrigation quota is happened to the beginning of(1990's) which is coincided with the second turning point of climate factors.