Study On Shallow Groundwater Depth Exploration Using Ground Penetrating Radar

Groundwater is one of the most important natural resources in arid and semi-arid area. Changes of groundwater level distribution and its quality lead to environmental problems and hazards such as vegetation degradation, desertification and soil salinization, meanwhile, have an influence on the sustainable development of regional agriculture and eco-environment. Therefore, it is particularly important to obtain groundwater depth and its distribution information fast and accurately.The aim of this thesis is to explore shallow groundwater depth using ground penetrating radar (GPR), and to investigate the performance of GPR system over soil surface. Field data collected in eastern plain area of Oghan-Kucha river delta oasis using GPR equipment ZOND-12E with four different kinds of antennas (100 MHz, 38 MHz, 75 MHz and 150 MHz). The soil surface of research area is relatively coarse, and not suitable to collect GPR data directly, hence, GPR-sled is made for the stabilization of the equipment. Actual groundwater depth has acquired for later verification by hand digging.Shallow groundwater depth has acquired qualitatively and semiquantitatively by processing and analyzing EM wave Transmission and reflection characteristics and reflection frequency changes in the soil surface, and the depth is in good agreement with the actual measured value. Analyzing GPR signal reflection characteristics combining with the geological understanding of detecting points can accurate, fast and effective obtain to groundwater depth information. For extracting groundwater depth effectively, appropriate antenna frequency and type should be chosen based on physical characteristics of detection point, detection scheme, surface roughness, detecting depth and resolution requirement.