地下水污染风险评价作为地下水资源合理开发利用和土地规划管理中的一项基础性工作，已经成为规划决策者的一种管理手段。地下水污染风险评价应从含水系统的固有脆弱性、污染源的可能危害性和污染受体预期损害性三方面进行评价，是三方叠加的结果。针对不同的受体，地下水污染风险略有差异，但固有脆弱性和污染源损害性是各种受体风险评价的基础和关键，因此本文在已有固有脆弱性评价体系基础上，着重研究污染源量化方法，并将其应用于地下水污染风险评价，为后续开展不同受体的地下水污染风险评价奠定基础。地下水污染源对地下水环境的危害性主要通过特征污染物的属性特点和数量累积效应表达出来；但鉴于地下水污染物来源难以确切识别追溯，污染源释放污染物的量并非是直接进入地下水系统的量，且通量难以计算等特点，本文拟将地下水系统上覆包气带土壤层作为地下水污染的直接来源，建立半定量的估算地下水污染源强的估算方法，定量描述进入地下水系统的污染物通量（源强），叠加特征污染物的属性危害，进而达到污染源量化的目的。源强的量化可采用数值法和指标法。数值法可采用HYDRUS-1D模型，模拟预测污染物通过包气带进入地下水界面的通量；本文以指标法研究为主，指标法进行污染源量化主要步骤是：（1）识别地下水中土壤源的特征污染物；（2）计算包气带土壤中同源物质的总量，作为可能进入含水层系统的污染物总量（T）；（3）引入土壤衰减指数指标（A），定量描述包气带对污染物的耗损；（4）通过将表征污染物总量的量化值扣除包气带耗损量，得出进入地下水系统的污染物通量的量化值；（5）从污染物的毒性、迁移性和可降解性三方面表征污染物的属性危害；（6）污染源危害量化值等于通量值与属性危害值的乘积。以浑河冲洪积扇为应用区，识别出总硬度（TH）、Al、Cr、Pb、As 五种指标为该地区土壤源的特征污染物，针对该5种污染物对应的包气带土壤这一污染源的危害性进行量化表征，基于ArcGIS地理信息系统，得出污染源风险图，再对该地区含水层系统固有脆弱性进行评价，脆弱性等级图叠加污染源风险图，得出浑河冲洪积扇地下水污染风险等级图。对比分析土壤源的危害性等级分布图与土壤中5中特征污染物的含量分布范围，研究区东北部污染源危害性等级高的范围与土壤中Pb含量高的分布范围相似，而中部高危害区则与Pb和TH的高含量区相似程度最大，再结合各特征污染物的属性危害值，可推断出土壤中砷和钙、镁化合物（构成地下水中的总硬度）进入地下水界面的通量较大，而As的通量相对较低。而最终得出的地下水污染风险性分区范围与污染源危害性分区图相近。

The groundwater pollution risk assessment has been used as a kind of effective means in land planning management and groundwater resources utilization for policy makers. Groundwater pollution risk assessment should take three aspects into condition, there are as follows: the inherent vulnerability of the groundwater system, potential hazards from pollution source, and the damage the receptor received. The evaluation results are superposition of three aspects of the forehead. According to different receptors, the results of the groundwater pollution risk are slightly different, but the inherent vulnerability assessment and pollution sources damage risk are still the basis and key link in the whole. Therefore this paper emphasizes on the method of quantization of the pollution source basing on the existing system of inherent vulnerability assessment, and applied it into the groundwater pollution risk assessment, aiming to lay the foundation of the different receptors of groundwater pollution risk evaluation.The dangers, groundwater pollution source put on groundwater environment, conveyed by feature attribute characteristics and quantity accumulative effect of pollutants. As a result of difficulties existing in identifying and tracing the direct source and the quantity it released then into the groundwater table, etc this article would take the soil overlying the vadose as the direct source of the groundwater system, set up a series of estimation methods for estimating the flux released by the soil and then run into the groundwater system. Aiming to quantitative describing the hazards from pollutants source, contaminant flux entering the groundwater and property damage need to be superimposed. Numerical method and index method are the two mainly methods in quantization the contaminant strength. HYDRUS-1D model can be used as the numerical method to simulate and predict pollutant flux released by soil through vadose zone into the groundwater. The main steps of the index method are as follows: (1) Identify the characteristic pollutants from the soil source in groundwater; (2) Calculate the total amount of pollutants in the soil corresponding with substances in groundwater as the possible amount of pollutants into the aquifer system; (3) Introduce the soil attenuation index (A), to quantitative describe the pollutants lost through vadose zone; (4) Determine the flux of pollutants entering into the water system by deducting vadose consume amount from the total amount; (5) Qualify hazards of the source caused by toxicity, migration and biodegradability of the pollutants; (6) Pollution quantitative value is equal to the product of flux size and the attribute hazards of the contamination.Taking Hun River alluvial fan as a case area, identify the total hardness (TH), Al, Cr, Pb and As five indicators as the region characteristic pollutants from soil source, quantify the harmfulness of the soil. Based on ArcGIS geographic information system, pollution risk map can be concluded. And then superimpose the inherent vulnerability evaluation of region aquifer system, groundwater pollution risk map of Hun River alluvial fan can be drawn.