山东高青平原区浅层地下水资源合理开发利用

RATIONAL EXPLOITATION OF THE PHREATIC WATER IN GAOQING PLAIN, SHANDONG PROVINCE

高青平原是山东省重要的农业基地。长期以来,引黄灌溉为其水资源开发重点,而当地地下水则主要消耗于潜水蒸发。这种不合理的取水结构不但导致土地沙化和土壤盐碱化等环境效应,而且由于近年来黄河断流,使其用水供需矛盾日益尖锐。本文在定性分析地下水补、排条件的基础上,提出将无用的潜水蒸发转化为有用的可利用资源作为地下水资源评价的原则。同时根据实际资料选用合理的参数,用有限单元法定量地预测了不同开采方案的地下水水位及埋深。同时在保证水量平衡的前提下,着重对开采方案的合理性进行了评价分析。本文对于改良高青平原的土地沙化、土壤盐碱化以及缓解现今用水矛盾具有重要的现实意义。对于我国同类的平原区也有重要的参考价值。

On the basis of qualitatively analyzing the recharge, run-off and discharge conditions of ground water in Gaoqing Plain, authors propose that it should be regarded as a principle of ground water resource evaluation to transform useless evaporation of phreatic water into avail-able water resource. Then the mathematical model describing two-dimensional unsteady subsur-face flow in the heterogeneous aquifer was established in accordance with the hydrogeological conditions. Also rational parameters were selected in the light of a vast amount of actual materi-als. Meanwhile finite element method was employed to quantitatively predict the water table and buried depth after different exploitation schemes.On the premise of guaranteeing the water quantity balance and by comparing the different water table depths after all plans, the conclusions how to rather rationally extract water re-sources were reached based on the two different hypothetic precipitation series: (1) the precipi-tation series from 1975 to 1989; and (2) the average precipitation series coming from several decades.Subject to the hypothesis (1), the allowable exploitation in the phreatic aquifer is about 142. 5 millions cubic meters per year in case that the Yellow River keep flowing and can be chan-neled from it for irrigation, while 128. 0 millions cubic meters per year in case that the Yellow River dry up. Similarly, subject to the hypothesis (2), the allowable exploitation is about 168- 4 millions cubic meters per year in case the Yellow River keeps flowing, while 140. 0 millions cu-bic meters in case the Yellow River dries up.The research results manifest that the ground water is rather abundant and the extraction in current situation accounts for about one forth of the allowable exploitation of the phreatic wa-ter. As a result the phreatic aquifer has great potentialities for exploitation. At the same time, the water table would become lower and the evaporation discharge become smaller with the ex-ploitation of ground water, which would be bound to produce positive environmental effects.