ABSTRACT

Groundwater is vital in Chennai Metropolitan Area, and thus its sustainable management is essential. This study aims to estimate groundwater recharge in the Chennai River basin (CRB) using an empirical method, a rainfall infiltration factor (RIF) method, a geographical information system (GIS)-distributed model, and the water table fluctuation (WTF) method. The average recharge estimates were 196 mm/year (empirical), 127 mm/year (WTF), and 122 mm/year (RIF). These results agree with the estimate of the GIS-distribution model, where 59% of the area has high recharge (>100 mm/year). The effective recharge from rainfall was around 10% with the RIF and WTF methods and 16% using the empirical method. All the estimates were statistically significant with confidence levels of over 98%, using a 95% confidence interval. The WTF method (with a 99.9% confidence level) was the most reliable of the four approaches. However, we suggest using multiple methods to cross-check the results and that measuring rainfall and water level is necessary for accurate recharge estimates in the future.

摘要

地下水在钦奈都会区至关重要，因此其可持续管理至关重要。本研究旨在使用经验方法、降雨入渗因子 (RIF) 方法、地理信息系统 (GIS) 分布模型和地下水位波动 (WTF) 方法估算钦奈河流域 (CRB) 的地下水补给量。平均补给估计为 196 毫米/年（经验）、127 毫米/年（WTF）和 122 毫米/年（RIF）。这些结果与 GIS 分布模型的估计一致，其中 59% 的区域具有高补给量（>100 毫米/年）。降雨的有效补给在 RIF 和 WTF 方法中约为 10%，在经验方法中为 16%。使用 95% 的置信区间，所有估计值均具有统计学意义，置信水平超过 98%。WTF 方法（带有 99. 9% 置信水平）是四种方法中最可靠的。但是，我们建议使用多种方法来交叉检查结果，并且测量降雨和水位对于未来准确的补给估算是必要的。