Comprehensive assessment of water balance, climatic tendencies and anthropogenic economic impact on the Tanganyika lake basin

Lake Tanganyika is a unique freshwater body of global importance, providing vital resources for millions of residents of four African countries. In conditions of increasing climatic and anthropogenic impact, the relevance of a comprehensive assessment of the state of its ecosystem is beyond doubt. The purpose of this study, the results of which are presented in this publication, is an integral analysis of the dynamics of the water balance of the Lake Tanganyika basin for the period 2003-2021, as well as an assessment of the impact of climatic trends and economic (business) activities on its hydrological regime and ecological condition. The methodological basis of the work is based on the joint use of satellite data from the GRACE/GRACE-FO gravimetric missions, Hydroweb altimetric measurements, reanalysis products (ERA5, IMERG), and hydrological modeling (GLDAS, MODIS). This approach allowed us to decompose the total water reserve into its main components and identify patterns in their distribution. The detailed and systematic analysis of the problem presented in this publication is based on a significant number of scientific studies that assess the hydrological changes in Lake Tanganyika, as well as the impact of climate and anthropogenic (technogenic) activities on these processes in the coastal areas. It has been established that the current hydrological dynamics of the basin are characterized by an increasing imbalance between the input and output components. The increase in surface water temperature enhances the thermal stratification of the lake, limiting vertical mixing and reducing the supply of nutrients to the photic zone, which leads to a decrease in primary productivity and a reduction in fish stocks. The high correlation between the total water supply and the lake level, identified using satellite data, opens up opportunities for predicting extreme floods, such as the 2021 flood in the Ruzizi Delta. Special attention is paid to the analysis of anthropogenic factors: it is shown that deforestation, urbanization, untreated discharges, agricultural runoff, and overfishing exacerbate climate-related changes, threatening the degradation of unique habitats for endemic species. The paper substantiates the need to integrate satellite monitoring into national water management systems and emphasizes the critical importance of developing adaptation strategies to preserve this unique ecosystem, which has a significant impact on the region's ecology and economy.