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

Hydrology

Yacouba Yira¹  Bernhard Tischbein²  Kristian Näschen³  Mouhamed Idrissou³  Bernd Diekkrüger³  Thomas Poméon³  Boubacar Ibrahim⁴  Felix Op de Hipt⁵ 

[1] Applied Science and Technology Research Institute—IRSAT/CNRST, Ouagadougou P.O. Box 7047, Burkina Faso;Center for Development Research (ZEF), University of Bonn, Genscherallee 3, 53113 Bonn, Germany;Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany;Département de Géologie, Université Abdou Moumouni, BP 10 662, Niamey 8000, Niger;German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany;

关键词: WaSiM;    inland valley;    West African hydrology;    Land Change Modeler;    CORDEX-Africa;    land use change;   

DOI  :  10.3390/hydrology9010012

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown