农业种植规模与降水量变化对农用地下水开采量影响识别

Impact Identification of Planting Scale and Precipitation Variation on Agricultural Groundwater Exploitation

以石家庄平原区作为研究区域,运用相关分析及回归分析阐明农用地下水开采量与降水量及小麦—玉米种植规模之间的关系。降水量与农用地下水开采量之间的相关系数较小,但作为农作物需水的重要水源,降水量通过影响农业地下水开采强度影响地下水开采总量。农业地下水开采强度在丰水年时明显减小,在枯水年时明显增大。小麦和玉米作为主要的耗水型作物,其种植面积与农用地下水开采量关系密切,随小麦—玉米种植面积的增加(减小),农用地下水开采量表现出明显的增加(减小)趋势。1981年之前,小麦—玉米种植面积每增加1×104 hm2,农用地下水开采量平均增加0.69×108 m3;1981年之后,小麦—玉米种植面积每增加1×104 hm2,农用地下水开采量增加0.23×108 m3。

Groundwater is the main water resources for agricultural irrigation in Shijiazhuang Plain and there is a very close relationship between groundwater exploitation and agricultural planting scale.Besides,groundwater exploitation is also affected by precipitation because precipitation can influence water consumption intensity of agriculture.In order to identify the impact of agricultural planting scale and precipitation variable quantity on agricultural groundwater exploitation,this paper used correlation analysis and regression analysis to study the relationship among agricultural groundwater exploitation and precipitation and agricultural planting scale.For winter wheat and summer maize are the main water consuming crops there,the paper used total winter wheat and summer maize area to replace agricultural planting scale.The results showed that the correlation between precipitation and agricultural groundwater exploitation was not significant.The partial correlation coefficient was-0.431.But as water resources of crops requirement,precipitation can affect groundwater exploitation by influencing groundwater consumption intensity.In wet years,groundwater consumption intensity was smaller than that of the year before and after it.In dry years,groundwater consumption intensity was obviously bigger than the adjacent years.For total wheat and maize area,the partial correlation coefficient was 0.873,which showed that there was a better correlation between total wheat and maize area and agricultural groundwater exploitation.When wheat and maize area increased,groundwater exploitation increased.Before the year of 1981,groundwater exploitation increased to 0.69×108 m3 while wheat and maize area increased to 1×104 hm2.After 1981,while wheat and maize area increased to 1×104 hm2,groundwater exploitation increased to 0.23×108 m3.The relationship between total wheat and maize area and agricultural groundwater exploitation,as well as the correlation coefficient calculated,showed that total wheat and maize area was the main factor that induced agricultural groundwater exploitation changing.