三江平原地下水脆弱性评价的熵权系数法模型

Entropy Weight Coefficient Model of Evaluationin Groundwater Vulnerability of the Sanjiang Plain

地下水脆弱性研究是保护地下水环境工作的基础。对地下水脆弱性进行评价,可为合理地保护、开发和利用地下水资源,实现地下水资源的可持续利用提供有益参考。地下水脆弱性评价的关键是指标体系的建立。结合三江平原实际情况,在传统的DRASTIC模型基础上,建立新的指标体系,包括以下7项指标：地下水埋深、含水层的净补给、含水层的介质类型、土壤介质类型、含水层水力传导系数、土地利用率和人口密度。根据相关性分析,该评价指标体系较为合理。传统的评价方法,如层次分析法或模糊数学方法,不能排除主观确定权重的人为干扰,评价结果往往带有一定程度的主观性误差。为了合理地对地下水脆弱性进行评价,首次将熵权系数法模型应用于地下水脆弱性评价之中。该方法的权重通过计算过程得出,排除了人为的主观性干扰,为地下水脆弱性评价提供了一种新的方法。将该方法应用于三江平原的地下水脆弱性评价,得到了满意的结果。该模型的评价结果与基于实数编码加速遗传算法的投影寻踪模型的评价结果完全相同,说明熵权系数法可以应用于地下水性评价,其评价结果可为有关决策部门提供参考。

The research of groundwater vulnerability is the basic work to protect the groundwater. For utilizing groundwater resource continuably, groundwater vulnerability evaluation is necessary . Useful reference to protect, exploit and utilize on groundwater resource are provided rationally. It is the key to establish the indexes system with the suited method to evaluate the vulnerability of groundwater. According to the real condition of Sanjiang Plain, the indexes system is established based on the traditional DRASTIC model. The new system includes 7 indexes as followings： Depth of Water, Net Recharge, Aquifer Media, Soil Media, Conductivity of the Aquifer, Land Utilizing Ratio and Population Density. The related analysis appears that the system is rather reasonable. Because traditional methods, such as analytic hierarchy process and fuzzy mathematics theory, can＇t be avoided human interference in selection of weights, they could lead to an imprecise result. In order to evaluate the groundwater vulnerability reasonably, entropy weight coefficient method is applied for the first time, which provides a new way to groundwater vulnerability evaluation. The method is a model whose weights are insured by the calculation process, so the artificial disturbance can be avoided. It has been used to evaluate the groundwater vulnerability in Sanjiang Plain. The satisfying result is acquired. Comparably, the .same result is acquired by the other method named projection pursuit evaluation based on real- coded accelerating genetic algorithm. It shows that entropy weight coefficient method is applicable on groundwater vulnerability evaluation. The evaluation result can provide reference on the decision-making departments.