Evaluation Of Geological Environment Suitability In Ledu Area,Qinghai Province

Ledu district of Qinghai province is located in the transitional zone from the western end of the Loess Plateau to the Qinghai-Tibet Plateau.It is surrounded by gullies,grazing,excessive water and soil erosion,and frequent collapses,landslides,and mudslides.The contradiction between urban development and the environment is becoming increasingly prominent.Therefore,carrying out the analysis of the sensitivity of the eco-environmental environment can help to coordinate the relationship between the geological environment and the human engineering activities,so that the human engineering activities are within the environmental tolerance limits;at the same time,the evaluation of the geological environment suitability in the region can fully integrate the existing resources.To further promote the development of the local economy.This article is based on the field survey and remote sensing interpretation.The regional evaluation of the suitability of geological environment based on RS and sensitivity analysis is carried out on the basis of the field survey and remote sensing interpretation of the Ledu1:50000(J48E022002)in Qinghai Province,and the suitability of the project is given to the comprehensive planning of the study area.The following insights are mainly obtained:1.Data analysis and field surveys indicate that the landforms of the study area belong to the middle uplift zone of the Qilianshan geosyncline fold system and the Lajishan syncline fold belt and the Huangshui River valley.The landform types can be divided into three types:mid-high mountains,low hilly areas,and valley plains;The exposed stratum in the area from the old to the new,there are the former Quaternary strata(from old to new:Great Wall,Cambrian,Ordovician,Silurian,Triassic,Cretaceous,Tertiary)and Quaternary strata(Including the Middle Pleistocene(Q2),Upper Pleistocene(Q3)and Holocene(Q4)).There are three types of loose rock pore dives,clastic rock pore fissure water,and bedrock fissure water;poor dynamic geodynamic phenomena in the region and outside are more developed,mainly as unstable slopes,landslides,mudslides,and collapse.2.According to the inversion results of the vegetation coverage of the pixel two model method,the vegetation coverage in this area can be divided into three regions:vegetation,grassland and bare land.According to the integrated inversion results of geothermal inversion,OH~-,Si and surface temperature factors,the study area can be divided into 9 levels from low to high.At the same time,the fault structures are located in the geothermal anomaly area.3.Select the 9 first grade indexes,such as elevation,slope,vegetation coverage,urban atmosphere,engineering geology division,geological disaster,waterfront environment,convenient traffic and geothermal information,and make the study based on the suitability evaluation based on AHP method.The study area is divided into 5 types of areas.include more suitable residential area,suitable residential area,general suitable residential area,and less suitable area and unsuitable residential area.The area of the more suitable area is about108.6km~2,accounting for 26.1%of the total area;the suitable area is about 115.2km~2,accounting for 27.7%of the total area;the area of the general suitable area is about 104.4km~2,accounting for 25.1%of the total area;the area of the less suitable area is about 67km~2,accounting for 16.1%of the total area;and the area of the unsuitable area is about 20.8km~2,accounting for the research area.5%of the total area.4.Select training samples,according to Hopfield neural network to predict and predict,the accuracy rate is 78%and 88.776%respectively.Then suitability evaluation is carried out,and 5 categories are classified according to their suitability.An explanation of the anomalous region in the graph is given.The suitable area(I)is 74km~2,accounting for 17.8%of the total area;the suitable area(II)is 193.4km~2,accounting for 46.5%of the total area;the general suitable area(III)is 96.1km~2,accounting for 23.1%of the total area;the less suitable area(IV)is about 32km~2,accounting for 7.7%of the total area;and the unsuitable area(V)is about20.5km~2,accounting for 4.9%of the total area.5.Comparing the results of two suitability evaluation results based on the AHP method and the Hopfield neural network method,it is found that the evaluation results of the AHP method are relatively scientific and can reflect the radiation range of different factors.The Hopfield neural network method is based on the associative memory training sample,which is the evaluation price for single unit,and the unit statistics can be concluded and will be convenient to be concluded.The results are translated into the basis of urban planning.Finally,according to the results of the two methods,the study area is divided into 3 types of areas,such as suitable area,general suitable area and unsuitable area,and the corresponding suggestions for planning and utilization are given.Among them,the area of suitable area is 152.3km~2,accounting for 36.6%of the total area;the area of the general suitable area is 69.1km~2,accounting for 16.6%of the total area;the area of unsuitable area is 194.6km~2,accounting for46.8%of the total area.6.According to the six factors such as height,slope,vegetation cover,geological disaster,hydrology and biodiversity,the sensitivity analysis of ecological and geological environment is carried out,and the study is divided into low sensitive area,medium sensitive area and high sensitive area.The high sensitive area accounts for 21%of the total sensitive area,the low sensitive area accounts for 33.9%of the total sensitive area,and the middle sensitive area accounts for 45.1%of the total sensitive area.