Research On Visualization Technique Of Groundwater Level Red Line Management Based On GIS

"The groundwater level red line management" refers to the management of groundwater water level on red line index, to implement "the strictest water resource management system" and is a constraint and an important measure to regulate groundwater extraction activities. The existing management of groundwater level red line is relatively traditional and belongs to the pure attribute data analysis method. Using relational database technology has difficulties to accurately reflect the characteristics of the dynamic changes of the groundwater level temporally and spatially. At the same time, the simple use of relational database technology has many problems such as the complicated analysis process and the non-intuitive results. Hence, this thesis investigates the methods of using GIS technology in the groundwater red line management. First of all, use spatial database and spatial thematic mapping technology to reflect the temporal variation characteristics of the data that the red lines manage. Secondly, perform spatial analysis algorithms to carry out the groundwater level data red line analysis and delineate the over-exploited area boundaries. Thirdly, display the red line management processes and analyze the results intuitively and visually by improving the existing three-dimensional geological modeling and virtual simulation methods based on 3DGIS theory, combining with three-dimensional visualization technology. The results show that introducing GIS technology to the red line management applications has many benefits. Firstly, it can be intuitive, multi-levelled to reflect the temporal and spatial distribution of hydrogeological conditions and groundwater level of the study area. Secondly, it can effectively reduce the complexity of data management and groundwater level red line analysis.Specifically, the research contents and results of this paper are mainly as follows:(1) The analysis and management of the groundwater level red line management data. The groundwater level red line management involves complex spatial data and attribute data. For spatial data, covering the temporal information often makes it the spatio-temporal data. Therefore, it is necessary to launch the research in how these three-dimensional geographic elements with temporal and spatial attributes are generalized and modeled by visualization. Based on the GIS spatial database technology, these complex data can be presented in a concise, clear, and accurate manner, and can be data support for visualization of red water table management.(2) 2D research on visualization technique of groundwater level red line management. Improve the drawing method of water process curve based on GIS technology; Based on the hydrogeological profile, study drawing method of water level profile map; study on visualization of flow field, and focus on the drawing method of streamline. On this basis, to fully understand over exploitation and distribution of groundwater, analyze the groundwater level with red line and make the result quantization and visualization.(3) 3D research on visualization technique of groundwater level red line management. The geological environment of groundwater storage and migration is the basic factor influencing the groundwater dynamic change. So, it is necessary to visualize the hydrogeological environment and provide the accurate base model for red line management. The existing technology of 3D geological modeling has been relatively mature; however, the study of aquifer system modeling in hydrogeology field is still rare. Therefore, according to the storage characteristics and the movement rules of groundwater, and combining with the professional knowledge of hydrogeology, it is necessary to study the establishment of 3D geological model in hydrogeology field. The model can directly reflect the hydrogeological conditions in the study area, the characteristics of storage and movement, and the spatial position and the changing trend of groundwater red line warning surface from the three-dimensional perspective. The groundwater flow field is one of the most effective ways of describing groundwater movement. Therefore, generalize three-dimensional flow with stable and calculable direction from the pore seepage with unstable direction. The moving direction and the velocity of groundwater can be reflected in form of the arrow point. Then, analyze the groundwater level with red line and visualize the result.