Hydrochemical Characteristics and Human Health Risk Assessment of Surface Water in the Danjiang River Source Basin of the Middle Route of China’s South-to-North Water Transfer Project

The Danjiang River basin is an important water source for the Middle Route of South-to-North Water Diversion Project. With shortage resources and increase in pollution pressure, it great significance to study hydrochemical characteristics surface risk human health posed by polluted bodies protection utilization resources. In this paper, 40 samples were collected analyzed innovatively adopting sampling principle “geological structure unit + landform small watershed unit”. Comprehensive mathematical statistical analysis, Piper trilinear diagrams, Gibbs ion ratio coefficients used analyze composition, spatial distribution influencing factors River. entropy weight comprehensive index method (EWQI) assessment model recommended United States Environmental Protection Agency (HHRA model) evaluate quality potential non-carcinogenic basin. results showed that pH area was 7.02~8.77, with average value 8.26; TDS ranged from 134 388 mg/L, 252.75 mg/L. main cations Ca2+ Mg2+, accounting 71% 20% total cations, respectively, while anions HCO3− SO42−, 74% 19% anions, respectively. type Ca·Mg. genesis mainly controlled weathering carbonate rocks, some ions influenced silicate activities also factor affecting chemical water. EWQI whole region 8.95~25.69, (HI) nitrate 0.0122 0.2118, which HI ranges children adults 0.0217~0.2118 0.0122~0.1333, indicating entire met Class I standards, low. However, its impact on significantly higher than adults, so monitor downstream urban areas reduce agricultural non-point domestic sewage discharge thereby risks young populations.