Landscape influences on water quality in riparian buffer zone of drinking water source area, Northern China

Abstract

The riparian zone represents the interface between land and river and as such has an important influence on watershed export of nutrients, sediments and woody debris. Therefore, it is vital to identify the mechanisms underlying the impact of natural and anthropogenic landscape features on river conditions within this buffer zone. Here, we present data gathered between 2004 and 2010 from 50 sampling sites in a drinking water source area of Northern China. Spatial and multivariate statistical analyses revealed that the first 100 m of the riparian zone had the largest effect on river water quality. Generally, natural landscapes had positive effects. Due to intense anthropogenic disturbances close to rivers, most of the human-impacted land cover accounted for water quality deterioration. Landscape pattern metrics were also useful in explaining the water chemical variables. The covariation of natural and anthropogenic factors might be regulated by hydrologic conditions, which reached their peak influence during the rainy season. The impacts of anthropogenic variables were equal to those of natural variables before and during the rainy season, yet human landscape features had more effects beyond this season.