Impact assessment of sediment from watershed to accretion of Lap An lagoon in Thua Thien Hue province

Abstract

    Lap An lagoon located in Lang Co Town, is likely a large brackish water body moving further indland with water surface area is about 16.17 km2. In recent years, due to the socio-economic activities in the lagoon as well as in the upper watershed, the lagoon is rapidly accreted. This accretion is causing decreases in water exchange between the lagoon and the sea and also in water salinity, expanding environmental pollution, affecting seriously aquaculture and ecosystems in the lagoon. Therefore, it is necessary to conduct research on current status and causes of the lagoon's accretion and then proposing solutions to minimize the negative impacts. This paper presents an assessment of water discharge, sediment formation and transport from the watershed through river network to the Lap An lagoon by application of Soil and Water Assessment Tool (SWAT model). This assessment is one of the basis for quantifying sediment flowed into the lagoon and identifying the causes of the lagoon's accretion.