Long-term trend analysis of climate factors and their impacts on flows in some river basins in Viet Nam

Abstract

Basins in Vietnam recently, have experienced the changes in climate that could have impacts on water resources in these basins. Therefore, it is important to study long-term trends in water flows as well as their influencing factors, such as temperature and precipitation. This study focuses on analyzing long-term trends of water flows in three basins of Vietnam including: Dong Nai, Ca, and Hon -Thai Binh rivers. Water flows data from 44 hydrological stations provided by the national hydro-meteorological forecasting center were analyzed using the Mann-Kendall test and Sen’slope. Additionally, climate data were analyzed for the period 1990–2019. Trend analysis was performed on water flow data at monthly, seasonal, and yearly scales. Overall temperatures and precipitation across the basins have increased since 1990, whereas stream-flows have tended to decrease across the three basins. However, this trend pattern may not be consistent across all monitoring stations within each basin.