1997-2017年泰国蒙河流域水环境时空变化分析

蒙河(Mun River)流域是泰国东北部重要农业区,也是湄公河主要支流。随着流域经济社会发展,流域水环境难以避免受到扰动,研究其时空变化特征对于该区域及湄公河中下游的水生态环境保护具有重要意义。基于泰国污染管制署1997-2017年水质监测数据,应用季节性Kendall检验法分析代表性水质指标含量的变化趋势,并采用水质指数(water quality index)法分析流域整体水环境的时空分异特征。结果表明:尽管蒙河流域水环境总体质量尚好,近20年来水质总体上无趋势性变化,但存在明显的年内季节性变化以及空间差异。各监测站点非汛期水质状况一般好于汛期,而流域下游水质往往好于上游。推测土壤侵蚀、养分淋溶和城镇化进程是影响流域水环境的重要因素。

Spatiotemporal variations of water environment of the Mun River in Thailand during 1997 to 2017

The Mun River Basin is an important agricultural area in northeastern of Thailand and a major tributary of the Mekong River. With the economic and social development, the water environment of the basin has been disturbed, studying the spatiotemporal characteristics of water quality of the Mun River is hence of significance for the protection of the aquatic ecology of the basin and the lower and middle Mekong River. Based on the water quality monitoring data from the Pollution Control Department in Thailand from 1997 to 2017, the seasonal Kendall test method was used to analyze the temporal variation of representative water quality indicators. The water quality index (WQI) method was used to analyze the spatiotemporal characteristics of the water environment. The results indicate that the overall quality of the water environment in the Mun River Basin was good, and no trend has been detected for the water quality in the past two decades. Obvious spatial and temporal variations, however, exists. The water quality of each monitoring site in non-flood season was generally better than that in flood season, and the water quality in the lower reaches of the basin was often better than that in the upper reaches. It was speculated that soil erosion, nutrient leaching and urbanization were important factors affecting the water environment of the basin.