Evaluation Studies Of Urban Construction Land Suitability By Using The Geological Environment Factors Of Tianjin Binhai New Area

Coastal area is the front of our social and economic development.In China,such as coastal around Bohai sea,Yangtze River Delta and Pearl River Delta,etc.The five economic regions are playing an important role in driving national economic development.However,coastal area which located in the interchange zone of mainland and the sea,is the extremely active and sensitive area with complicated and various geological environment problems that does great harm.The future large-scale urban development and construction in coastal area should mainly based on geological environment for the rational planning and construction.How to scientifically and reasonably use valuable land resources and prevent the deterioration of geological environment during planning and construction of coastal cities has become an urgent problem which environmental geology is facing at present.Therefore,the evaluation studies of geological environment suitability of urban construction in coastal cities is imperative.This paper is based on the analysis of complex geological environment problems to build evaluation index system of geological environment suitability of every geological environment problem and urban construction in coastal city,selected AHP-entropy value method and sensitive factor-fuzzy comprehensive evaluation model to do evaluation studies of geological environment suitability of urban construction in Binhai newly-developed area,with the MAPGIS to do the distribution map of Binhai newly-developed area.According to the result,to make the grade classification of urban construction geological environment suitability,this paper divided the study area into" The most suitable region,suitable region,fairly suitable region,worse feasibility region and subsuitable region" four grades,to provide scientific evidence for the construction of Binhai newly-developed area.Through the research,this paper obtained conclusion and understanding as follows:(1)The thesis analysis the great influence of geological environment problem and suitability within development and construction activities of Tianjin’s Binhai newly-developed area.And find out that the development and construction of Binhai newly-developed area would lead to unfavorable influence of geological environment problem such as:Regional Crustal Stability,Natural Foundation,Soft Soil Foundation,first Pile Foundation,secend Pile Foundation,Sand Liquefaction,water and soil corrosion,land subsidence.(2)The AHP method is taken to analysis the suitability of urban construction according to different geological environmental conditions.The thesis establish a connection among hierarchy factors,construct AHP model through effect weight calculated by matrix,and use the entropy value method to make the final weight more reasonable.Therefore,the geological environment comprehensive evaluation of Tianjin’s coastal area is more than qualitative analysis,is reasonable and quantitative.(3)This evaluation classified the sensitive factor evaluation unit directly and selected important factors to do the fuzzy comprehensive evaluation by using sensitive factor-fuzzy comprehensive evaluation model.Not only considering all factors which impact on the environment,also can effectively reduce the effect of subjective factor on the evaluation results.Use the concept of fuzziness,can make the evaluation results more accurate and improve the evaluation precision.(4)According to the results of the urban construction land suitability evaluation of Binhai New Area of Tianjin,the suitable region of urban construction land is the most widely,the area is about 937.1 km2,accounts for 41.28%of the gross area in assessmental areas.fairly suitable region distribution area is 614.3 km2,accounting for 27.06%of the gross area in assessmental areas.The area of worse feasibility region and subsuitable region are respectively about 351.8 km2 and 366.8 km2,accounting for 15.50%and 16.16%of the gross area in assessmental areas.(5)This evaluation almost corresponds to the characteristics of the real geological environment in the assessed areas in Coast New Zone.It exactly reveals the current developing distribution of the geological environmental problems in all-round way,and is also able to reflect the matching suitability of assessmental areas to urban construction land.The accuracy and manifestation could be referred to for the planning management in Coast New Zone.(6)From the geological environmental point of view,combining with the evaluation results this study analyzed general land use planning of Binhai New Area of Tianjin,and put forward the corresponding prevention measures and Suggestions specific to the work of planning and construction of geological environmental problems.