Overview on methods and theories of remote sensing monitoring and exploration of groundwater

Remote sensing of groundwater is one of the challenging tasks in the remote sensing application research. This paper describes the development and progress of remote sensing application research on the ground water exploration, as well as summarizes the domestic and international remote sensing theories and methods of ground water monitoring and puts forward relevant definition. These ways and means include geological and hydro-geomorphological remote sensing analysis, environmental remote sensing information analysis, thermal infrared remote sensing method and quantitative exploration modeling. At last, the future prospects of groundwater remote sensing are put forward. The quantitative exploration modeling based on the establishment of experimental model by combination of mathematical, physical reflective factors of ground water has been found to be most effective in monitoring, delineation and detection of regional ground water. Overseas, air-borne remote sensing data have been used to investigate ground water resources since the latest 1960's; Thermal infrared data and multi-spectral, multi-temporal images generally used in 1980's while satellite remote sensing of groundwater was initially started in China. During this time, visual interpretation of hydromorphic features, water-bearing structures and environmental factors had been the mainly approach of detection work; The combination of RS, GIS and GPS technology became the useful method in the end of 1990's in both overseas and China. Bands ranged from visible, thermal infrared and microwave have been coming into widespread use since the latest 1990's. Due to its ability to penetrate to a certain depth into soil and sensitivity to water content, microwave remote sensing is becoming the most promising tool to demarcate and map out ground water resources with the development of handling and imaging techniques.