Harnessing earth observation (EO) capabilities in hydrogeology: an Indian perspective

Satellite remote sensing in conjunction with geographical information systems (GIS) offers great potential for water resources development and management (e.g., Bastiaanssen et al. 1999; Pietroniro and Prowse 2002). It will assist in the quantification of hydrologic parameters, in data collection and transmission to facilitate rapid analysis of various facets of water resources (Schultz and Engman 2000; Hoffmann 2005). However, utilization of remote sensing data by hydrologists is still rather low as the satellite sensors provide information restricted to a few centimeters below the Earth’s surface (Hoffmann 2005). Moreover, these datasets do not provide details of subsurface hydrology and also obscure the dynamic and minute information of the Earth’s surface due to the resolution limitations in both the spatial and temporal domain. Nevertheless, remote sensing has been used in many geological applications for the past few decades and as a high-end tool to address the surface mapping of the Earth (e.g., Erdelyi and Galfi 1988; Teeuw 1995; Schultz 2000; Navalgund 2002). It is being frequently applied for groundwater prospect mapping, snowmelt-runoff estimation, reservoir sedimentation assessment, studies on hydropower projects, assessment and monitoring of waterlogging and salinity in command areas (Jonna 1999). The extraction of hydrogeological parameters from multi-spectral satellite images and their interpretations in terms of groundwater potential, soil and water conservation and watershed development, has received great attention in India. This article highlights these experiences, including the present and future trends in satellite remote-sensing applications in India.