School of Hydraulic Engineering, Dalian University of Technology, Dalian, Liaoning Province 116024, China.
School of Hydraulic Engineering, Dalian University of Technology, Dalian, Liaoning Province 116024, China.
Sci Total Environ. 2020 Jun 20;722:137863. doi: 10.1016/j.scitotenv.2020.137863. Epub 2020 Mar 14.
Lancang River, the upstream reach of Mekong River, is a hotspot region in the sustainable management of water resources and environment as it is currently facing the deterioration of aquatic ecosystems. Nutrient balance (i.e., Phosphorus) in the Lancang-Mekong River Basin has become a highly disputed issue in recent years due to the construction of cascade hydropower stations. However, the estimation of the total phosphorus (TP) load faces great difficulties and challenges due to the absent measured water quality data. This study estimates the TP load based on the social economic data, analyzes the spatial distribution of TP and the contribution of different TP sources in the Lancang River basin under the level of social-economic development in 2014. Results show that the annual average TP load in the Lancang River Basin is 1.6 × 10-3.9 × 10 tons, which is at a very low level compared with other large-scale basins in China. The TP load from natural soil erosion dominates all other sources, accounting for 69%, followed by agricultural production and fertilization. In general, the TP load increases from upstream to downstream, but heterogeneity also exits in different regions under the influence of various factors, such as rainfall intensity, soil properties and human activities. The results reveal a holistic picture of TP load in the Lancang River Basin, which could provide a new perspective on the trans-border international river management.
澜沧江是湄公河上游，在水资源和环境可持续管理方面是热点区域，因为其水生态系统正不断恶化。由于梯级水电站的建设，澜沧江-湄公河流域的养分平衡（即磷）成为近年来极具争议的问题。然而，由于缺少实测水质数据，总磷（TP）负荷的估算面临着巨大的困难和挑战。本研究根据社会经济数据估算 TP 负荷，分析了 2014 年社会经济发展水平下澜沧江流域 TP 的空间分布及不同 TP 源的贡献。结果表明，澜沧江流域年平均 TP 负荷为 1.6×10-3.9×10 吨，与中国其他大型流域相比处于很低的水平。自然土壤侵蚀产生的 TP 负荷占所有其他源的 69%，其次是农业生产和施肥。总的来说，TP 负荷从上游到下游逐渐增加，但在不同地区，由于降雨强度、土壤特性和人类活动等各种因素的影响，也存在着不均匀性。该研究结果揭示了澜沧江流域 TP 负荷的整体情况，为跨境国际河流管理提供了新视角。
