A GIS Based Design of Groundwater Level Monitoring Network Using Multi-Criteria Analysis and Geostatistical Method

Abstract

Groundwater systems are dynamic and hence, an effective and optimally designed groundwater level (GWL) monitoring network is very essential to minimize monitoring, time and long term expenses. Groundwater scarcity is a big challenge in regions where excessive extraction takes place and GWL monitoring from observation wells (OWs) is the principal source of information. Hence, proper observation and management is necessary to ensure continual availability of water supplies. This study proposes a new and simplified approach using multi-criteria analysis (weighted overlay, analytical hierarchical process, fuzzy) and geostatistical (ordinary kriging) method to design GWL monitoring network of the Wainganga sub-basin, India. Several parameters considered for the analysis include command area (CA) and non command area (NCA), geology, geomorphologic unit, land use/land cover (LU/LC), lineament density, Groundwater level fluctuation (GWLF), recharge, slope and soil media. The study identifies representative or priority zones using multi-criteria analysis and optimum number of OW was determined within the representative zones using geostatistical method. Combination of two approaches helps overcome shortcomings of previously suggested methods of which analytical hierarchical process (AHP)-geostatistical approach gives more accurate results. Sensitivity analysis was carried out to identify importance of each parameter considered for analysis. The study concludes that minimum 80 wells are required for proper monitoring of GWL in the study area. It also reveals that a combination of these two approaches is effective and easy to implement in the regions where data availability is not constrained.