Land Systems Impacts of Hydropower Development

Hydropower is often seen as the low-cost, low-carbon, and high-return technology for meeting rising electricity demand and fueling economic growth. Despite the magnitude and pace of hydropower expansion in many developing countries, the potential land use and land cover change (LULCC), particularly indirect LULCC, resulting from hydropower development is poorly understood. Hydropower-driven LULCC can have multiple impacts ranging from global and local climate modification (e.g., increased extreme precipitation events or increased greenhouse gas emissions), ecosystem degradation and fragmentation, to feedbacks on hydropower generation (e.g., increased sedimentation of the reservoir). As a result, a better understanding of both direct and indirect LULCC impacts can inform a more integrated and low-impact model for energy planning in countries with transitioning or growing energy portfolios. This study uses multi-scale remote sensing imagery (Landsat, MODIS, fine-resolution commercial imagery) to estimate LULCC from past hydropower projects intended primarily for electricity generation in 12 countries in Africa, South and Central America, South Asia, and Southeast Asia. It is important to examine multiple locations to determine how socio-political and environmental context determines the magnitude of LULCC. Previous studies have called for the need to scale-up local case studies to examine "cumulative impacts" of multiple development activities within a watershed. We use a pre-test/post-test quasi-experimental design using a time series of classified images and vegetation indices before and after hydropower plant construction as the response variable in an interrupted time series regression analysis. This statistical technique measures the "treatment" effect of hydropower development on indirect LULCC. Preliminary results show land use change and landscape fragmentation following hydropower development, primarily agricultural and urban in nature. These results suggest that indirect land use change should be considered in the energy planning process and design of environmental impact assessments. The large-scale land system impact assessment method used in this study can be extended to examine other intensive development projects such as road construction and mining.