The Spatiotemporal Distribution of Two Bacterial Indexes in a Small Tibetan Plateau Watershed

Abstract

Microbial contamination is now more common than chemical contamination in Tibet, and water-borne microbes can cause a number of diseases that threaten public health. Thus, in order to clarify the spatiotemporal distribution of bacteria in small watersheds for which there is no data in Tibet, four sampling points were set up along an upstream-downstream transect of the Xincang River Basin. A total of 239 water samples were collected in 2014 and 2015, and their total constituent numbers of bacteria (TB) and coliforms (TC) were evaluated. The results of this study show that the microbial contamination of the Xincang River Basin is mild-to-moderate in terms of TB and TC contents, and that these concentrations vary significantly in different seasons. The results show that in summer, TB and TC concentrations and microbial contamination are almost at the same level in upstream, midstream, and downstream sections; however, in the other three seasons, microbial contamination in the downstream section is more serious than in the upstream and midstream sections. The data also demonstrates that concentrated precipitation and local contamination sources are important factors underlying increases in TB and TC concentrations during the summer months. The results of this study are likely to reflect the basic characteristics of small watersheds for which there is no data to some extent, and are thus of significant practical importance for protecting their ecological environments and promoting sustainable development.

Hydrochemical characteristics and controlling factors of natural water in the border areas of the Qinghai-Tibet Plateau

“…In recent years, research regarding the water chemistry on the QT has focused on the major rivers and lakes and their catchments, including Yarlung Zangbo (Sarin and Krishnaswami, 1984;Wang, 2016), Senge Zangbo (Li et al, 2012;Wang et al, 2012), Three River Resource areas (Deng, 1988;Wu et al, 2008;Cao, 2013;Tan et al, 2016), Qinghai Lake (Hou et al, 2009;Jin et al, 2009;Xiao et al, 2012), Yamzhog Yumco Zhang et al, 2012;Sun et al, 2013;Zhe et al, 2017), Pumayum Co (Ju et al, 2010;Zhu et al, 2010), Nam Co (Gao et al, 2008;Wang et al, 2013), Mapam Yumco (Yao et al, 2015). Some scholars have also studied water chemistry in some areas of the QT (Zhang and Gustafsson, 1995;Guo and Wang, 2012;Tian et al, 2015), including microorganisms (Nie, 2011;Zhang et al, 2013;Zhao et al, 2017), heavy metals and trace elements (Cao et al, 2000;Grange et al, 2001;Li et al, 2006;Sheng et al, 2012;Tian et al, 2016).…”