Land-use/land-cover changes are considered the dominant form of anthropogenic pressure on the environment, causing changes in ecosystem service patterns and affecting water supply services. Using the spatial econometric technique, we analysed the impact of land-use/land-cover change on water ecosystem services for domestic use upstream and downstream of the Wami River Basin. The results in terms of land-use/land-cover classes during the study period (2011–2016) indicate that cultivated land showed maximum positive changes in both sub-catchments, while bushland and woodland showed maximum negative changes upstream and downstream. The results showed that bushland, woodland, cultivated land, and grassland were significantly correlated with water point characteristics in both sub-catchments. For functionality characteristics, a significant effect was observed in bushland and grassland upstream and downstream, respectively, while sufficient water was found in woodland upstream and grassland downstream. Moreover, bushland was observed to have a significant number of water points with poor quality of water upstream, and a substantial number of water points with good quality of water were found in grassland downstream. We found that all measured land-use/land-cover changes and water point characteristic correlations were statistically significant; therefore, we concluded that land-use/land-cover change affects the water ecosystem in the basin. These results could facilitate decision-making and development of related policies and might support finding sustainable strategies for water ecosystem services for domestic use.

Understanding the hydrochemical composition of water resources in the Ngorongoro Conservation Area (NCA, Dodoma, Tanzania) related to climate variability is essential for sustainable development. Thus, the current study used the HYDRUS-1D model to assess the groundwater quality change due to the leaching of hydrochemicals from surface water under the climate variability of the NCA. This study observed that the area’s surface water had varying hydrochemical contaminants, whereas the groundwater is currently most suitable for drinking and domestic purposes. However, it is predicted that two anions (${\mathrm{Cl}}^{-1}$ and $\mathrm{PO}{4}^{-3}$ ) and two cations (${\mathrm{Na}}^{+}$ and ${\mathrm{K}}^{+}$ ) are expected to exceed the permissible limits from 2036 to 2050, considering the anticipated climatic conditions. Changes in groundwater quality for cations and anions are significantly correlated to evapotranspiration and temperature, with Pearson’s coefficient of determinations $r$ between 0.35 and 0.66. The findings of this study are necessary to benchmark better water resources management planning. Understanding the hydrochemical composition of water resources in the Ngorongoro Conservation Area (NCA, Dodoma, Tanzania) related to climate variability is essential for sustainable development. Thus, the current study used the HYDRUS-1D model to assess the groundwater quality change due to the leaching of hydrochemicals from surface water under the climate variability of the NCA. The hydrochemical assessment results for the composition of major cations and anions to the subsurface indicate the significant influence of future changes in the climate of the study area. The results indicate, two cations (${\mathrm{Na}}^{+}$ and ${\mathrm{K}}^{+}$ ) and two anions (${\mathrm{Cl}}^{-1}$ and ${\mathrm{PO}}_4^{-}$ ) would exceed the World Health Organization (WHO) and Tanzania Bureau of Standards (TBS) permissible limits between 2036 and 2050. Statistically, changes in groundwater quality for both cations and anions are significantly correlated with evapotranspiration and temperature. Therefore, apart from other factors such as volcanic activities and accelerated human interventions that could affect water quality, climate change can be considered the main driver for hydrochemical movements to the groundwater. Hence, a detailed climate change study should be conducted to precisely inform the impacts of future changes in climate parameters on water quality deterioration. The findings from such studies can be used for sustainable management of the water resources in this area.

Global croplands, pastures, and human settlements have expanded in recent decades. This is accompanied by large increases in energy, water, and fertilizer consumption, along with considerable losses of biodiversity. In sub-Saharan Africa, policies are implemented without critical consideration; e.g., agricultural expansions impair ecosystem services. We studied land use/cover and the associated rate of change for four time epochs, i.e., 1991, 2001, 2011, and 2021. This employed remote sensing and GIS techniques for analysis, while future projections were modeled using cellular automata and the Markov chain. The kappa coefficient statistics were used to assess the accuracy of the final classified image, while reference images for accuracy assessment were developed based on ground truthing. Overall change between 1991 and 2021 showed that major percentage losses were experienced by water, forest, woodland, and wetland, which decreased by 8222 Ha (44.11%), 426,161 Ha (35.72%), 399,584 Ha (35.01%), and 105,186 Ha (34.82%), respectively. On the other hand, a percentage increase during the same period was experienced in cultivated land, built-up areas, and grasslands, which increased by 659,346 Ha (205.28%), 11,894 Ha (159.93%), and 33,547 Ha (98.47%), respectively. However, this expansion of thirsty sectors has not reversed the increasing amount of water discharged out of the Kilombero River catchment. We recommend the promotion of agroforests along with participatory law enforcement and capacity building of local communities’ institutions.

In this study, land-use/cover pattern of the UNESCO world heritage site, Ngorongoro Conservation Area; is analyzed using the CA–Markov model with the help of RS and GIS. Hybrid classification techniques ware used to monitor land use/cover changes, using Landsat images for 1995, 2005 and 2016. The CA-Markov model is then used to predict the land use /cover maps for 2025 and 2035. The highest net gain from 1995-2016 observed in cultivated land (6.55%), grassland (2.68%), bare land (1.82%), bushland (0.48%) and built-up area (0.01%), and the net loss found in woodland (8.38%), forest (1.52%), wetland (1.41%), and water cover area (0.24%). However, reduction is expected in bushland (4.88%), forest (0.82%), water (0.77%) and woodland (0.07%) during 2025-2035 with increase in cultivated land (2.73%), grassland (1.19%), bare land (1.79%) and built-up area (0.14%). As per the current trend in land use management, forest cover is significantly declining; leading to the loss in the ecological values of the Ngorongoro Conservation Area and its surroundings. The results of this study can be used directly by the policymakers to plan appropriate conservation schemes to endorse improved land use management practices for ecological protection of the heritage site.

Global croplands, pastures, plantations, and human settlement areas have expanded in recent decades, accompanied by large increases in energy, water, and fertilizer consumption, along with considerable losses of biodiversity. In sub-Saharan Africa, policies are implemented without critical consideration e.g., agricultural expansions impair ecosystem services of the several river basins. The current study has studied landuse/cover and associated rate of change for four-time epochs i.e., 1991, 2001, 2011 and 2021. This employed remote sensing and GIS techniques for LULC analysis while future projection was modelled using cellular automata and Markov chain. The Kappa coefficient statistics were used to assess the accuracy of final classified image while reference images for accuracy assessment were developed based on ground truthing. Overall change results between 1991 and 2021, showed that major percentage loss in area were experienced by water, forest, woodland and wetland which decreased by 8,222Ha (44.11%), 426,161Ha (35.72%), 399,584Ha (35.01%) and 105,186Ha (34.82%). On the other hand, percentage increase in area during the same period were experienced in cultivated land, built up areas and grasslands which increased by 659,346Ha (205.28%), 11,894Ha (159.93%) and 33,547Ha (98.47%). However, even with the expanding thirsty sectors water discharged out of the catchment is on increment at a rate of 498.6 m3/s/year. For dualistic benefits, agroforest practices are recommended along with participatory law enforcement and capacity building of local communities through their institutions.