Study On Suitability Assessment Of Build Landuse In Yinchuan City Based On GIS

In recent years,China's urban geological survey results service system is becoming increasingly perfect,especially for urban planning evaluation reports and maps increasing.In 2017,the Overall Plan for Urban Geological Survey(2017-2025)pointed out that geologists should provide layout suggestions and geological suitability opinions for planners at the urban planning stage.Based on the survey data of Yinchuan city,a three-dimensional geological structure model of Yinchuan city is established in this paper.By analyzing the engineering geological conditions of the construction suitability of Yinchuan city,the evaluation index system was established and the weight of each index was determined by the analytic hierarchy process.The multi-factor comprehensive evaluation model was used to evaluate the suitability of build landuse in Yinchuan city.Based on the development trend of the build landuse suitability evaluation in our country and the engineering geological characteristics of Yinchuan,this study constructs the evaluation index,11 are: the terrain slope,geomorphic types,rock compressibility,3 m,2 m,6m section bearing capacity,groundwater depth,soil liquefaction grade,distance from the active fault,distance from rivers and lakes and traffic convenience.The grade zoning map of build landuse suitability in Yinchuan city was obtained by GIS spatial analysis and other tools.According to the code,the suitability of build landuse in Yinchuan city is divided into four levels,which are: suitable build landuse,buildable landuse,unsuitable landuse and unbuildable landuse.The following conclusions are drawn after compiling the suitability zoning map of build landuse in Yinchuan city:(1)suitable build landuse accounts for about 27.17% of the whole evaluation area,which is generally non-liquefied or slightly liquefied with good site stability.It can be used as the natural foundation for low-rise and multi-storey buildings.And some areas can be used as the natural foundation for high-rise buildings.In most areas,the groundwater depth is more than 10 m,and the compressibility of rock and soil is not uniform,which is easy to cause the uneven settlement of foundation.Therefore,attention should be paid to the treatment of foundation soil during construction.It is suggested to plan land for residential use and land for commercial services.(2)buildable landuse accounts for 28.94% of the total area of the evaluation area.Part of this area can be used as the natural foundation for low-rise and multi-storey buildings,which does not meet the bearing capacity requirements of high-rise buildings.The site has a good stability.The groundwater depth in most areas is less than 5m.And the compressibility is high.The foundation soil should be treated to improve its bearing capacity in the project construction.It is suggested to plan land for residential use and land for commercial services.(3)unsuitable landuse accounts for about 27.17% of the whole evaluation area.The very few areas can be used as the lower and the natural foundation of multistory buildings.It did not meet the requirements of the bearing capacity of the high-rise buildings.Its groundwater depth,high compressibility.There are many medium liquefied area and serious liquefaction area.The construction should be considered when the drainage,liquefied area treatment,compressibility of foundation soil treatment and so on.It is suggested that land use planning,warehousing logistics,green space and square,etc.(4)unbuildable landuse accounts for about 9.26% of the total area of the evaluation area.The natural foundation of the area does not meet the bearing capacity requirements of any building.The groundwater is buried in shallow depth and has high compressibility.It is suggested to plan green land and square land.