Exploring institutions, land use and water quality interactions with a socio-hydrological modelling approach in Burkina Faso

The variety of demands that people place on water resources, coupled with the dynamics of the natural system, make water resource management highly complex. Case studies provide research opportunities to advance our understanding of complex systems and examine different approaches to resource management. The "Participative Planning for a More Inclusive and Sustainable Water Management in Rural Areas of Burkina Faso" (www.pwgbf.iwmi.org) project ran from 2015-2019, and as part of this, we explored how a socio-hydrological model might support stakeholders to compare different levels of institutional support and different land management strategies for improving water quality. To create the conceptual model of how institutions, agencies, individuals, land and water management interact in the case-study region, literature review was coupled with interviews and field observations of agricultural practices and land and water management. The relationships in the model were described mathematically, and parameters were estimated based on the information collected. The resulting model could explore how the impacts of an increase in institutional capacity (e.g. greater enforcement of land-use regulations), local and regional resources (e.g. investment in irrigation infrastructure at locations far from the river), and individual (e.g. farmer willingness and capacity to reduce use of agro-chemicals, willingness and capacity to relocate or replace vegetable crops with tree crops) could lead to improvements in water quality (reduced concentrations of pollutants and sediments in rivers and reservoirs). Pathways to water quality improvements were modelled, and demonstrate relationships in a semi-quantitative way. For example, water quality can be substantially improved by doubling institutional support to the local water user groups and tripling their internal capacity (e.g. through capacity strengthening, more financial support, and raising gender balance/empowerment). Comparison of different management methods using the model also highlight how economic trade-offs are necessary to achieve improvements in water quality. The systems-dynamics modelling approach taken in this study offers considerable potential for exploring interactions and translating these into management recommendations. However, extensive engagement with stakeholders throughout the entire process is essential.