广东稻田灌溉效益的时空变化分析

为合理进行稻田灌溉效益取值,对广东省不同地区32个样点46年的早稻、晚稻和双季稻的灌溉效益进行时空变化分析。结果发现:稻田灌溉效益在省内不同地区间大小差异悬殊,其变化与降雨量呈负相关关系,其中晚稻灌溉效益大于早稻,双季稻则介于两者之间;灌溉效益在多年时程中变化很大,其变异系数明显大于多年降雨量的变异系数,从多年灌溉效益的离散程度看,晚稻比早稻大,双季稻则比早稻和晚稻小;另外,灌溉效益在多年时程中的离散程度与平均相对减产量呈高度正相关关系,即平均相对减产量愈大,灌溉效益数值的离散度愈大。

Temporal and Spatial Variation Analysis of Rice Irrigation Efficiency in Guangdong

For the reasonable evaluation of rice irrigation efficiency,the temporal and spatial variation of irrigation efficiency of 32 samples of early rice,late rice and double-crop rice are analyzed,from different regions of Guangdong Province,in the past 46 years.The results show that the rice irrigation efficiency is so different between different regions,its variation is negatively correlated with rainfall,and the late rice irrigation efficiency is greater than the early rice,double-crop rice is somewhere in between;irrigation efficiency has changed dramatically in the years,and its coefficient of variation is significantly larger than that of the rainfall;in addition,degree of dispersion of irrigation efficiency in the years is positively correlated with the mean relative reduction of yield.