The Content Level, Spatial and Temporal Distribution Characteristics, and Health-Risk Assessment of Trace Elements in Upper Lancang River (Changdu Section)

Abstract

Evaluation of trace elements in the water of Lancang River during the wet season (October) and dry season (December) was carried out to analyze the content of trace elements in the water, spatial and seasonal variations, enrichment, and health risks of dissolved trace metal. The results showed that the content of trace elements in the main stream of the upper Lancang River met the “Environmental Quality Standard for Surface Water” (GB3838-2002) Class I water-quality standard, but the Fe content in sampling points during the wet season exceeded the limit value of water-quality standard. Compared with other rivers in Tibet, the contents of As, Fe, and Pb in the study were relatively high. While Pb, As, and Zn were the mainly enriched trace elements. The water temperature, dissolved oxygen, conductivity, As, Cr, and Cu in the main stream of the upper Lancang River with significant seasonal variations. The content of trace elements in the front of the dam was lower than that in the tail and under the dam. The trace elements in the water of the reservoir area increased with an increase in the depth, and the reservoir had a certain interception effect on the trace elements. The As content in the main stream of the Lancang River was greatly affected by the branch of Angqu with high content of As. The HQingestion and HI of As in the part of the river in the study exceeded 1, and the water-quality health risks of the Guoduo reservoir tail and urban reaches were higher than those of other reaches, which should be paid more attention.

Geochemistry and Sources Apportionment of Major Ions and Dissolved Heavy Metals in a Small Watershed on the Tibetan Plateau

“…The DO concentrations of river waters in the LR and DLQ ranged from 6.3 to 6.6 mg•L −1 (DO saturation ranged from 94.7% to 100.1%). The DO concentration of river water in the DLQ was higher when compared with rivers at the same altitude on the TP, such as the Requ River (6.0 mg•L −1 ) and the Chumaer River (5.6 mg•L −1 ), which may be caused by the accelerated mixing of water and oxygen in ambient air due to the fast flow rate of the river water in the DLQ [47]. The EC value of the water in YBJ was 2.9 mS•cm −1 , and the TDS was 1422 mg•L −1 , which belonged to brackish water (1-3 g•L −1 ) [48].…”

Construction and Application of a Seasonal River Health Evaluation System in Arid and Semi-Arid Areas

“…Seasonal rivers play a crucial role in providing social services, and their flood control function during the flood season is an important indicator in assessing their health. Additionally, due to the susceptibility to flood disasters during the high-water period, the flood control compliance rate of seasonal rivers serves as a significant indicator for health evaluation [21][22][23].…”