华北平原水资源合理开发利用的思路与举措

经过几十年的大量开采利用,华北平原地下水资源不仅表现为区域超采和局部严重超采,也暴露出地下水补给源严重萎缩的问题。其主要表现在中西部粗质平原的地下水易补给区,因汇流山地水库强力拦蓄,河道主体补给功能丧失,而在中东部细质平原的径流主产区,因水位埋藏浅和水质咸化,降水径流不能形成对地下水的有效补给,蒸发流失严重。以往实践强调山区水利工程建设而轻视了东部低平原区径流拦蓄利用,重视对高海拔咸水体的改造利用而忽视了对低海拔咸水体的改造利用,强化地表水库建设的重要性而忽略了地下水库的重要性。面对华北平原供水紧张的严峻形势,调整水资源开发战略势在必行,其具体思路是:以千方百计提高降水利用水平为中心,调整和改善水资源开发利用整体布局;以地下水补给调蓄为重点,大力集蓄雨洪水和改造利用浅层水,充分发挥地表水和地下水两大功能作用。其具体举措有:实施山前梯级水坝的地下水库"回灌"工程;实施中东部及滨海淡水蓄水利用工程;实施东部浅层地下水规模化改造开发利用工程。若上述措施得以实施,可使降水利用率从现状的20.65%提高到26%以上,则华北平原供水问题有望获得解决。

Idea and Action for the Rational Development and Utilization of Water Resource in North China Plain

After the large exploitation and utilization for the past several decades,the groundwater utilization in North China Plain not only showed regional and serious local overexploitation,but also exposed the problem of serious decrease of groundwater recharge source.Because of the powerful impoundment of confluence mountain reservoir,the recharge function of main river body,lost in the middle-west of North China Plain with coarse particles,which was easy groundwater recharge area;because of the shallow burial depth and water salinization,the rainfall-runoff could not be effective to the recharge of groundwater in the middle-east of North China Plain with fine particles,which was the main runoff area.The traditional practice showed that the hydraulic engineering construction was emphasized in mountain area while impounding and utilizing the runoff in the west low plain area was neglected;renovating and utilizing saline water was valued in high altitude area but ignored in low altitude area;the surface reservoir construction was strengthened while the ground water reservoir was overlooked.Facing the grim situation of intense water supply in North China Plain,it was necessary to adjust the development strategy of water resource.The idea was as follows: improving the utilization of precipitation should be the most important,and then the overall layout of development and utilization of water resource should be adjusted and improved;groundwater supply and store should be important,collecting the rain flood and transforming and utilizing the shallow water also should be paid attention to,giving full play to the function of surface and groundwater.The actions included the project of groundwater reservoir recharged by multi-level stone check dam in the piedmont,the project of storing fresh water in the middle-east and the coastal region and the project of utilizing the shallow water with large scale in the eastern.If the above actions could be carried out,the utilization rate of rainfall could increased from 20.65% to more than 26%,so the shortage of water supply in North China Plain could be solved.