Urban runoff is an effective alternative water resource, particularly in arid and semi-arid regions. Urban runoff exploitation permits cities to have a significant amount of water, but without assessing the runoff quality, harvesting of this resource is complicated and requires further investigations. Due to the lack of a specific method, in this study, a new index method (WLTR) was developed for assessing the urban runoff vulnerability to contamination. The WLTR index is based on rating different sub-factors of wastewater (W), land use (L), transportation (T), and rainfall runoff (R) factors. The efficiency of the WLTR index was investigated in 12 sub-catchments of the Ardabil city in Iran. The priority of sub-catchment vulnerability was determined via WLTR index value. The efficiency of the developed method was investigated using direct measurement of several water quality parameters (pH, EC, TDS, TSS, TH, and SO₄) in the sub-catchments outlet. A Water Quality Index (WQI) was calculated for each sub-catchment. The quality priority of sub-catchments was determined based on the WQI value. According to the measured data, an acceptable efficiency was observed for WLTR index. According to the results, the most vulnerable sub-catchments (Nos. 4, 11, and 12) had the lower runoff quality among studied sub-catchments, whereas the least vulnerable sub-catchments (Nos. 2, 9, and 8) had the higher runoff quality.

城市径流是一种有效的替代水资源，特别是在干旱和半干旱地区。城市径流的开采允许城市拥有大量的水，但是在不评估径流质量的情况下，这种资源的获取十分复杂，需要进一步调查。由于缺乏特定的方法，在这项研究中，开发了一种新的指数方法（WLTR）来评估城市径流对污染的脆弱性。WLTR指数基于对废水（W），土地使用（L），运输（T）和降雨径流（R）因素的不同子因子进行评级。在伊朗的阿尔达比勒市的12个子集水区调查了WLTR指数的效率。通过WLTR索引值确定了子集水区脆弱性的优先级。₄）在子汇水出口。计算了每个子汇水区的水质指数（WQI）。根据WQI值确定子集水区的质量优先级。根据测得的数据，对于WLTR指数观察到了可接受的效率。根据结果​​，最脆弱的子集水区（第4、11和12号）的径流质量较低，而最不脆弱的子集水区（第2、9和8号）的径流质量较低。更高的径流质量。