保定市主要作物需水量和缺水量特征分析

ANALYSIS OF THE WATER DEMAND AND WATER SHORTAGE IN MAIN CROPS IN BAODING CITY

[目的]对作物需水量及缺水量的研究是了解和合理配置农业灌溉用水的基础,对提高农业用水效率有重大意义。[方法]选取河北省保定市为研究区域,利用Penman-Monteith公式和分段单值平均作物系数法对冬小麦、夏玉米和棉花的作物需水量和缺水量等指标进行计算,通过Mann-Kendall检验法对保定市近60年来的作物需水量和缺水量等的变化趋势进行分析。[结果]3种主要作物的需水量、有效降雨量和缺水量的最大值均出现在作物发育中期;其中除冬小麦的有效降雨量以0.208mm/10年的速率呈不显著性增长趋势外,其他作物的各指标变化则均呈减少趋势;从突变现象来看,夏玉米和棉花的各指标发生明显变化的时期相近,需水量出现明显拐点的时刻在2008年以后,有效降水量在1968年以前和2014年两个时期,缺水量分别在2011年和2012年。[结论]该研究结果为保定市乃至河北省的农作物灌溉效率的提高及水资源规划与管理的完善提供了理论依据,具有一定的现实意义。

The research on water demand and water shortage of crops,which is the basis for understanding and rational allocation of agricultural irrigation water,is of great significance to improve the efficiency of agricultural water use.This paper took Baoding city of Hebei province as the research area,calculated indexes such as water demand,water shortage of winter wheat,summer corn and cotton in recent 60 years by Penman-Monteith model and Piecewise single-value crop coefficient method.At the same time we also analyzed the change trend of those indexes by Mann-Kendall test.The result showed that the maximum water requirement,the effective rainfall and the water deficit of the 3 main crops all appeared in the middle of crop development;Except that the effective rainfall of winter wheat showed no significant growth trend at the rate of 0.208mm/10a,the indexes of other crops showed a decreasing trend;In terms of mutations,indexes of summer corn and cotton changed abruptly in similar period,for example,the water demand of both crops showed an obvious inflection point after 2008.The effective precipitation changed largely in two periods of the prior to1968 and 2014,and water shortage changed largely in 2011 and 2012.The result of this article had practical significance by providing theoretical foundation to improve crop irrigation as well as to allocate and manage water resources for Baoding city and even Hebei province.