【摘要】 密怀顺地区是北京市重要的水源涵养区。2014年南水北调来水通过潮白河河道回补地下水，密怀顺地区地下水位抬升，包气带变薄。对区域地下水位回升情况和硝酸盐氮进行研究，结果表明：(1)2014—2019年研究区地下水位快速升高，升幅为12.31 m,其中密云区升幅为9.59 m,怀柔区升幅为15.17 m,顺义区升幅为12.50 m;(2)地下水位低升幅带面积为26.54 km~2,占研究区面积的5.45%,中升幅带面积为213.22 km~2,占研究区面积的43.79%,高升幅带面积为247.17 km~2,占研究区面积的50.76%,怀柔区以高升幅带为主；(3)2019年密云区包气带厚度为33.82 m,怀柔区包气带厚度为24.23 m,顺义区包气带厚度为33.30 m;(4)2015—2019年，密云区潮白河再生水回补河段地下水中硝酸盐氮平均质量浓度降低32.89%,研究区硝酸盐氮升高区域面积为312.98 km~2,占研究区面积的64.28%,分布于研究区西部和南部，是降低区域的1.80倍。地下水位升幅较快、包气带较薄的怀柔区地下水硝酸盐氮升高35.47%。更多还原

【Abstract】 Miyun-Huairou-Shunyi recharge area is an important water conservation area in Beijing. In 2014,the surplus water from the South-to-North Water Diversion Project was used to recharge groundwater through the Chaobai River channel. The groundwater level continued to rise, and the thickness of the vadose zone became thinner. Through the study of regional groundwater level rise and nitrate nitrogen, the results showed that:(1) the groundwater level in the recharge area rose rapidly from 2014 to 2019,with an increase of 12.31 m, of which Miyun District rose by 9.59 m, Huairou District rose by 15.17 m, and Shunyi District rose by 12.50 m.(2) The area of low rise zone of groundwater level was 26.54 km~2,accounting for 5.45% of the study area; the area of middle rise zone of groundwater level was 213.22 km~2,accounting for 43.79% of the study area; the area of high rise zone of groundwater level was 247.17 km~2,accounting for 50.76% of the study area. Huairou District was dominated by high rise zone.(3) In 2019,the thickness of the vadose zone in Miyun District was 33.82 m, the thickness of the vadose zone in Huairou District was 24.23 m, and the thickness of the vadose zone in Shunyi District was 33.30 m.(4) From 2015 to 2019,the average mass concentration of nitrate nitrogen in the groundwater of the Chaobai River reclaimed water recharge section in Miyun District decreased by 32.89%. The area of the nitrate nitrogen rose area in the recharge area was 312.98 km~2,accounting for 64.28% of the study area. It was distributed in the west and south of the recharge area, and the rise area was 1.80 times of the reduction area. The nitrate nitrogen concentration in the groundwater of Huairou District, where the groundwater level rose rapidly and the vadose zone was relatively thin, increased by 35.47%.更多还原