摘要:
针对华北粮蔬主产区滹滏平原浅层地下水位不断下降成因问题,基于大量实测资料和相关分析方法与MapGIS技术,通过对近50年来区内地下水位、粮蔬播种强度、有效灌溉面积变化特征和降水量、气温变化下地下水位下降对粮蔬播种强度响应机制研究,结果表明:1980年前粮蔬播种强度每增加0.01或夏粮和蔬菜播种面积每增加1万hm2,研究区地下水位下降幅度为0.36 m或0.43 m;1980年以来随粮蔬播种强度增大,地下水位下降幅度明显增大,粮蔬播种强度每增加0.01或夏粮和蔬菜播种面积每增加1万hm2,地下水位降幅分别达0.69 m和1.15 m。不仅与因播种强度增大导致农业开采量增加有关,而且还与1980年以来降水量不断减少密切相关。降水量减少100 mm,区内农业开采量增加35.7 mm。
Abstract:
Focusing onthe problems of continually declining shallow groundwater levels on the Hufu plain of North China, the variations and response mechanisms of groundwater levels, grain and vegetable planting intensity, effective irrigated areas and precipitation are studied.A large amount of observational data collected in the past 50 years is analyzed using statistical methods and the MapGIS technology.Results show that before 1980s, the magnitude of decline in groundwater levels is small in response to the increase in the grain and vegetable planting intensity.The decline would be 0.36 m and 0.43 m, respectively; should the planting intensity and the sown area of summer grain crops and vegetables increase 0.01 and 10000 hm2, respectively.However, a significant decline in groundwater levels has been observed since 1980s.The decline would be 0.69 m and 1.15 m, respectively, with the same changes in both planting intensity and sown area of summer grain crops and vegetables.Such a decline is not only the result of the increase in the grain and vegetable planting intensity, but the result of the decrease in annual precipitation on the plain.Should there be a reduction of 100 mm in annual precipitation; the groundwater exploitation for agricultural irrigation would be increased by 35.7 mm.
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