均衡法评价地下水可开采量的风险率

有限数据样本量所关联的不确定性因素,对水资源评价结果的可靠度有着显著影响。在地下水源地勘查与运行过程中,地下水位变幅是一个具明显缓变性质的随机变量。以山东省济宁市承压水源地为例,利用水均衡法评价方法,基于模糊-随机模型,定量研究缓变随机变量在先验分布与后验分布条件下对评价结果的风险影响。结果表明:受不确定性因素时变特性的影响,水源地按勘查成果形成的计划开采量运行,将导致水源地形成过量开采的风险率由13.67%增加至15.75%;考虑不确定性因素时变特性影响,随机变量的不确定性区间由5.64减小到3.60;利用后验信息及时调整开采计划,可保障水源地的供水安全。

Risk of Groundwater Allowable Withdrawal Evaluated Using Water Balance Method

Uncertain factors associated with limited samples have significant influence on the reliability of groundwater resources evaluation result.Groundwater table is a time-dependent stochastic variable during the well field exploration and operation.Therefore,take a confined aquifer of Jining City,Shandong Province as an example,the risk of prior probability distribution and posterior probability distribution are evaluated quantitatively with the fuzzy-stochastic model using Bayesian theory in this paper.The study results show that the fuzzy risk of groundwater over-drafted is increased from 13.67% to 15.75%.Considering the time-dependent uncertain factors,the uncertain interval spacing becomes smaller from 5.64 to 3.60.Consequently,the pumping plan should be adjusted to guarantee the safe supply.