Contamination of trace elements in river ecosystem and source apportionment based on their relationship with landscape patterns

Abstract

Complex configuration of landscape types on different spatial scales and different slopes, such as entire basin and buffer zones, is a significant issue that affects contamination of trace elements in river ecosystem. Water and sediment samples were collected and analyzed to determine the concentration and spatial distribution of trace elements throughout various topographies and landscape types. The result demonstrated that landscape percentages (agricultural land, forest land, grassland, and built-up) would greatly affect concentration of trace elements in river, agricultural land and built-up percentage demonstrate significant positive correlation with concentration of trace elements. While forest land percentage appeared significant negative correlation with concentration of trace elements, but significant positive correlation areas are located on lower steepness slope and buffer zones with elevations of 0-500 m. As average slope steepness increases, more significant positive correlation exists between built-up percentage and trace elements concentration in river. Mining activities are a major potential source because the landscape types of mining land area in the upstream of the river are built-up on high steepness slope, and the relationships of built-up percentage in entire sub-basin with concentration of trace elements are more significant than that in river buffer zones.