Abstract

Author:
Robert Asaanbilla Awini, Steve Ampofo, Melvin Guy Adonadaga, Boateng Ampadu

Doi: 10.26480/efcc.01.2026.17.29

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Tamne catchment has a river system, a reservoir, and fertile arable land, making it a valuable landscape in the northern part of Ghana. Tamne catchment’s water flow is crucial, and long-term spatio-temporal assessment from 1992 to 2022 to understand inter-decadal variability is essential for supporting water management and agriculture in the catchment. The study used geospatial and climate data and applied the SWAT model and Mann-Kendall test with Sen’s slope to assess key climatic and LULC variables. The results showed that water increased by 1%, built/bare soil areas increased by 26% while grass/shrub land decreased by 31% from 1992-2022, and agricultural land saw a decline by 37% and 28% between 2002 and 2022. Climate and LULC shifts increased evapotranspiration and led to decreasing trends in groundwater and surface discharge. Trend analysis of rainfall indicated a troubling decline in rainfall with a Sen’s slope of – 5.24, highlighting variability in the annual rainfall but insignificantly affects the catchment hydrology. The SWAT model performed well, supported with an NSE of 0.71 and robust P- and R-factor values of 0.75 and 0.78, respectively.