西辽河流域春玉米需水量变化趋势

Climate-induced changes in spring maize water requirement in Xiliaohe River watershed

西辽河流域在区域和国家粮食安全中地位重要,随着社会经济的发展,用水量增加导致水资源紧缺,作物需水量可为该区作物灌溉和区域灌溉需水量提供定量依据,采用Penman-Monteith模型和春玉米5～9月的作物系数计算了西辽河流域10个气象台站1951年～2005年春玉米需水量,采用Mann-Kendall法对全生育期需水量、生育期各月需水量和各气象要素变化趋势进行了分析,并对春玉米需水量和各气象因子进行了灰色关联分析.研究结果表明:(1)西辽河流域全生育期需水量增加和减少的站点各占1半,5月份需水量的增减对全生育期需水量的增减有重要影响;(2)最高气温、风速、日照时数或者平均气温与春玉米需水量的关联程度最高,风速和日照时数对西辽河流域春玉米需水量影响最大.

Xiliaohe River watershed plays an important role in regional and national grain security. With the development of society and economy, water consumption that increased dramatically causes water shortages. Crop water requirement can provide quantitative basis for making regional irrigation scheme. This study uses Penman-Monteith （PM） formula and spring maize coefficient from may to September to calculate the spring maize water requirement at ten meteorological station in Xiliaohe River watershed from 1951 to 2005, and uses Mann-Kendall method to analyze the variation trend of the spring maize water requirement during the whole growing period, every month water requirement, meteorological factors from May to September, and analyzes the degree of grey incidence between the water requirement and meteorological influencing factors. The results show： （1）： the spring maize water requirement increases at half of the stations and decreases at another half of the stations in Xiliaohe River watershed during the whole growing stages, water requirement increasing or decreasing in May has great impact on water requirement during whole growth stages. （2）： the mean monthly maximum air temperature, Wind speed, sunshine or mean air temperature have highest relevancy with crop water requirement. Wind speed and sunshine have great effects on spring maize water requirement in Xiliaohe River watershed.