Modeling the Impact of Climate and Land Use/Land Cover Change on Water Availability in an Inland Valley Catchment in Burkina Faso

Abstract

Water scarcity for smallholder farming in West Africa has led to the shift of cultivation from uplands to inland valleys. This study investigates the impacts of climate and land use/land cover (LULC) change on water resources in an intensively instrumented inland valley catchment in Southwestern Burkina Faso. An ensemble of five regional climate models (RCMs) and two climate scenarios (RCP 4.5 and RCP 8.5) was utilized to drive a physically-based hydrological model WaSiM after calibration and validation. The impact of climate change was quantified by comparing the projected period (2021–2050) and a reference period (1971–2000). The result showed a large uncertainty in the future change of runoff between the RCMs. Three models projected an increase in the total runoff from +12% to +95%, whereas two models predicted a decrease from −44% to −24%. Surface runoff was projected to show the highest relative change compared to the other runoff components. The projected LULC 2019, 2025, and 2030 were estimated based on historical LULC change (1990–2013) using the Land Change Modeler (LCM). A gradual conversion of savanna to cropland was shown, with annual rates rom 1 to 3.3%. WaSiM was used to simulate a gradual increase in runoff with time caused by this land use change. The combined climate and land use change was estimated using LULC-2013 in the reference period and LULC-2030 as future land use. The results suggest that land use change exacerbates the increase in total runoff. The increase in runoff was found to be +158% compared to the reference period but only +52% without land use change impacts. This stresses the fact that land use change impact is not negligible in this area, and climate change impact assessments without land use change analysis might be misleading. The results of this study can be used as input to water management models in order to derive strategies to cope with present and future water scarcities for smallholder farming in the investigated area.

Spatial modeling of soil loss as a response to land use-land cover change in Didessa sub-basin, the agricultural watershed of Ethiopia

“…In the African highlands of this agricultural watershed, however, high and intense soil erosion is one of the most distinctive characteristics. Studies highlight that high soil erosion from agricultural watersheds causes crop production losses [ [22] , [23] , [24] , [25] , [26] ]; (Thakuriah, 2023), sedimentation of reservoirs, resulting in severe economic losses to irrigation and hydroelectric projects [ [27] , [28] , [29] ]. As a result, a study confirmed that Africa lost 40% of agricultural productivity and covered an average of one-fifth of dam storage volumes with silt [ 30 ].…”

Future climate or land use? Attribution of changes in surface runoff in a typical Sahelian landscape

“…Likewise, Gbohoui et al [2021] showed that for varying nested watersheds scale, the control of environmental conditions (i.e., land use) is dependent on the size of the watershed. In contrast for example, in southwestern Burkina Faso, Idrissou et al [2022] projected to the 2050 horizon an increase in surface runoff (12% to 95%) and also a decrease (24% to 44%), primarily driven by land use changes in both cases.…”

Relationship between climate and land use land cover change over West Africa

“…Modeling tools have become useful to simulate the combined effects of climate-land interactions but also help to establish mechanisms leading to various environmental outcomes including biodiversity (Schulte to Bühne et al, 2021;Srinivasan and Wilcove, 2021), population (Molotoks et al, 2021), pathogens (Casazza et al, 2020), and food security impact of elevated CO 2 (J. , just to mention a few. Modeling tools have dominated climate-land related research due to their ability to model complex interactions and better represent environmental concerns such as stream ow and hydrological predictions, pollutant loading, water balance, and water quality (Achugbu et al, 2021;Alamdari et al, 2022;Boone et al, 2016;Cao and Dan, 2021;Chilukoti & Xue, 2021;Gabiri et al, 2020;Hung et al, 2020;Idrissou et al, 2022;Jain et al, 2021;Nyatuame et al, 2020;Ross and Randhir, 2022;Selwood et al, 2014;Srinivasan and Wilcove, 2021;Sylla et al, 2016;Tirupathi and Shashidhar, 2020;Tu, 2009), amongst others.…”