Cost-effectiveness of soil and water conservation measures on the catchment sediment budget:the Laaba watershed case study, Burkina Faso

In the Sahelian region, the high precipitation intensity and the daily rainfall extreme values are currently the main cause of soil erosion and land degradation. In addition, solid transport often leads to reservoir siltation and reduction of the amount of water available for agriculture. To cope with these issues, Soil and Water Conservation (SWC) measures have been regularly employed in the Sahelian area. However, a proper cost-effectiveness analysis of the impact of SWC interventions on the catchment sediment budget normally requires quantitative surveys on erosion and sedimentation processes. Where data for calibration and validation of models are scarce, an overall methodology to evaluate the economical sustainability of a proposed intervention can be of paramount importance. The study herein proposed aims to assess the monetary sustainability of SWC measures in limiting the reservoir siltation of the Laaba dam (Yatenga District, Northern Burkina Faso). In particular, the catchment sediment budget was estimated by means of morphological and pedologic parameters and dam sedimentation rates; a cost-effectiveness analysis was then performed to assess the economic sustainability of a possible SWC intervention. The proposed methodology showed interesting potentials for land and water management in Burkina Faso, particularly when data and financial resources are limited and where the application of detailed process-based models is not possible