2. Regional Assessment of Impacts of Climate Change: A Statistical Downscaling Approach

Water resource sectors are impacted by industrialization, urbanization, and climate change, making these vital resources more vulnerable and posing substantial challenges to water resources planners. Climate change significantly impacts agricultural production, and water will be a major constraint in the future for food production. Developing countries such as India are more vulnerable, and the ramification of climate change on rain-fed agriculture areas has been affecting the rural population because of their great dependency on agriculture for their livelihood. For understanding how the changes in cardinal and sensitive climate variables such as temperature and precipitation will affect natural resources, and for developing management policies for mitigation and adaption strategies, regional-scale assessments are crucial. This chapter showcases regional assessment of the impacts of climate change by the statistical downscaling technique, the Change Factor method, using the CMIP-5 General Circulation Model data in India with a case study in Bhima sub-basin. Spatial cross-correlation of maximum temperature and precipitation across the Indian Meteorological Department (IMD) gauge grids was captured adequately, and the downscaling satisfactorily captured the cross-correlation between rainfall grids of Bhima sub-basin. Future projections reports, average daily maximum temperature and rainfall are likely to increase in response to climate change under different representative concentration pathway (RCP) scenarios, with maximum changes in RCP 8.5.