Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, 606-8306, Japan.
Water Engineering and Management, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani, 12120, Thailand.
Environ Monit Assess. 2019 Sep 5;191(10):614. doi: 10.1007/s10661-019-7779-3.
Globally, rivers and streams are experiencing declining water quality. Anthropogenic activities largely contribute to surface water pollution. Understanding human-induced influence on river water quality remains a challenge owing to spatiotemporal variations. In this study, we assessed the influence of various land uses (LU) on 16 water quality parameters of the Mun River, a tributary of the Mekong River, at different scales. Water quality was statistically analyzed both spatially and temporally (1995-2010). Seasonal and annual effect of LU on water quality was evaluated at buffer zone scale and sub-basin scale (i.e., catchment scale) using multiple regression analysis. The result showed that urban LU extensively adds to the nutrient concentration [i.e., total phosphorus (TP), ammonia nitrogen (NH-N)] followed by agriculture LU at the sub-basin scale. Site-specific variability of TP is explained by urban LU and biological oxygen demand (BOD) by agriculture LU at the 5-km buffer in Upper and Middle Mun whereas at Lower Mun, the 20-km buffer explains the variability of suspended solids (SS) and total suspended solids (TSS), suggesting a more localized effect on the parameters upstream. The high concentration of parameters was noted in the dry season whereas the opposite was true for fecal coliform bacteria (FCB), SS, and TP. The maximum parameter concentration of NH-N, FCB, and total coliform bacteria exceeds the permissible surface water quality standards of the Pollution Control Department (PCD) of Thailand in all three sub-basins. The study suggests the need for multi-scale interventions and effective pollution control measures focusing on nutrient, pathogenic bacteria, and solids pollution to improve the river water quality of large river basin.
从全球范围来看，河流和溪流的水质正在不断下降。人为活动是造成地表水污染的主要原因。由于时空变化，了解人类活动对河水水质的影响仍然具有挑战性。在本研究中，我们评估了不同土地利用（LU）对湄公河支流芒河 16 个水质参数的影响，研究采用了不同的尺度。对水质进行了时空统计分析（1995-2010 年）。在缓冲区尺度和子流域尺度（即流域尺度）上，利用多元回归分析评估了 LU 对水质的季节性和年度影响。结果表明，在子流域尺度上，城市 LU 大量增加了营养物浓度[即总磷（TP）、氨氮（NH-N）]，其次是农业 LU。在芒河上游和中游的 5 公里缓冲区中，TP 的空间变异性由城市 LU 解释，BOD 由农业 LU 解释，而在芒河下游，20 公里缓冲区则解释了悬浮固体（SS）和总悬浮固体（TSS）的变异性，表明上游参数的局部影响更大。在旱季，参数的浓度较高，而粪便大肠菌群（FCB）、SS 和 TP 的浓度则相反。在所有三个子流域中，NH-N、FCB 和总大肠菌群的最大参数浓度均超过了泰国污染控制部（PCD）规定的地表水质量标准。研究表明，需要采取多尺度干预措施和有效的污染控制措施，重点关注营养物质、致病菌和固体污染，以改善大河流域的河水水质。
