Impact of anticipated climate change on direct groundwater recharge in a humid tropical basin based on a simple conceptual model (pages 1655–1671)

摘要

A simple conceptual semi-distributed modelling approach for assessing the impacts of climate change on direct groundwaternrecharge in a humid tropical river basin is investigated. The study area is the Chaliyar river basin in the state of Kerala, India.nMany factors affecting future groundwater recharge include decrease or increase in precipitation and temperature regimes, coastalnflooding, urbanization and changes in land use. The model is based on the water-balance concept and links the atmospheric andnhydrogeologic parameters to different hydrologic processes. It estimates daily water-table fluctuation and is calibrated andnvalidated using 10 years of data. Data for the first 6 years (2000 to 2005) is used for model calibration, and data for the remainingnfour years (2006 to 2009) is used for validation. For assessing the impact of predicted climate change on groundwater rechargenduring the period 2071–2100, temperature and precipitation data in two post climate change scenarios, A2 and B2, werenpredicted using the Regional Climate Model (RCM), PRECIS (Providing Regional Climates for Impact Studies). These datanwere then corrected for biases and used in a hydrologic model to predict groundwater recharge in the post climate changenscenario. Due to lack of reliable data and proper knowledge as to the magnitude and extent of future climatic changes, it may notnbe possible to include all the possible effects quantitatively in groundwater recharge modelling. However, the study presents anscientific method to assess the impact of predicted climate change on groundwater recharge and would help engineers,nhydrologists, administrators and planners to devise strategies for the efficient use as well as conservation of freshwater resources.nCopyright © 2011 John Wiley & Sons, Ltd.