Spatiotemporal mapping of surface water variability for flood risk and water infrastructure management in the Gongola river basin (2000–2025)

This paper used multi-temporal geospatial data, satellite-based hydrological indicators, as well as rainfall data, land cover data, slope and drainage analysis, and flood hazard models to examine the Gongola River Basin in northeastern Nigeria in the period 2000-2025. The spatial and temporal dimensions were combined in the process of data acquisition, which allowed a comprehensive evaluation of ecological transformation, hydrological variability, and climate-related effects on water resources. Findings indicated that there was a gradual decrease in forest cover and an increase in farmland and cities, and this changed the hydrology by decreasing the infiltration and increasing the runoff. The relatively stable permanent water bodies were a result of controlled hydraulic structures as opposed to seasonal flows, which were sharp in nature, given that the basin relied on the variability of rainfall. There was a steady southwest to northeast gradient of rainfall distributions with increased interannual variability directly affecting water supplies and risk of flooding. Slope and drainage analysis illustrated the effects of the terrain on the runoff velocity, erosion, and groundwater recharge, and the model of flood hazard forecasted that the percentage of the areas at risk would increase gradually with time, with a range of 33.22% in 2000 to 34% in 2025. The originality of the study is the fact that it combines land cover, hydrology, rainfall, topography, and flood hazard, which is a single analytical framework that connects both the science and engineering of the environment. The fact that there is an increasing need for climate-resilient infrastructure and adaptation to water management in semi-arid areas highlights its role. The study connects ecological change and rainfall variability with hydrological outcomes and engineering implications, which are practical information to policy-makers and engineers to protect the water security, reduce the risks of floods, and enhance sustainable development in the Gongola Basin. Received: 23.04.2026 Received in revised form: 14.07.2026 Accepted: 21.07.2026