The groundwater quality of the Upper Pearl River Watershed (UPRW) and surface water quality of the basin’s outlet, Ross Barnett Reservoir (RBR), are critically important because of growing demands for drinking, agriculture, and industrial use in the region. To identify factors affecting water quality and characterize the surface water outlet and the watershed’s groundwater, geochemical and statistical analyses were performed using results from various hydrogeochemical parameters. Based on surface geology, groundwater samples analyzed (n = 51) within the watershed were partitioned into three recharge zones: North, Mid, and South. Precipitation and rock-water interactions were identified to dominantly influence the groundwater chemistry in the region. The chemistry of the surface water samples (n = 9), on the other hand, was influenced more by precipitation with minor contribution from the proximal aquifer system. Principal component analysis (PCA) revealed that two groundwater recharge zones and RBR samples exhibited significant clustering. The groundwater had a complex array of parameters influencing its chemistry owing to diverse properties, including Na, Ca, Mg, alkalinity, and conductivity. Comparing land use at the sub-watershed level with the water quality parameters showed that agriculture and development could have contributed nitrate, especially to the groundwater in the south zone. However, a general lack of distinct relationship between land use and water quality, along with detection of excess nitrate in select wells suggested that the water in the region was likely affected by point sources, such as poultry farms. The research recommends evaluating point sources of pollution to cater to future water management in the region.

珠江上游流域（UPRW）的地下水水质和流域出口Ross Barnett水库（RBR）的地表水水质至关重要，因为该地区对饮用水，农业和工业用途的需求不断增长。为了确定影响水质的因素并表征地表水出口和流域的地下水，使用了各种水文地球化学参数的结果进行了地球化学和统计分析。根据地表地质，将流域内分析的地下水样本（n = 51）划分为三个补给区：北，中和南。降水和岩水相互作用被确定主要影响该地区的地下水化学。地表水样品的化学成分（n= 9），另一方面，降水受到的影响更大，而近端含水层系统的贡献较小。主成分分析（PCA）显示，两个地下水补给区和RBR样品表现出明显的聚类。由于Na，Ca，Mg，碱度和电导率等多种特性，地下水具有一系列影响其化学性质的参数。将小流域水平的土地利用与水质参数进行比较表明，农业和发展可能贡献了硝酸盐，特别是南部地区的地下水。但是，土地利用与水质之间普遍缺乏明显的联系，加上在选定的水井中检测到过量的硝酸盐，这表明该地区的水很可能受到诸如家禽养殖场等点源的影响。