Research On Evaluation And Impact Factors Of Geological Environment Carrying Capacity In Fugu County

As an important part of territorial spatial planning,geological environment carrying capacity assessment has become a key link for the coordination between sustainable and highquality development of human economic and social activities and geological environment protection.Fugu County,Shaanxi Province,a fragile ecological environment area in the Yellow River Basin,was taken as an example.The assessment system and model of geological environment carrying capacity were established.Based on the results of comprehensive assessment,the effect and association rules of impact factors were further explored.The main achievements are as follows:(1)17 types of influencing factors such as surface cutting depth,slope angle and curvature were extracted from five aspects of natural geography and ecological environment to analyze single-factor geological environment carrying capacity.The study area was divided by 30m grid cells and the dimensional differences between data were eliminated by positive and negative range methods.After data multicollinearity was tested by variance inflation factors,the comprehensive assessment system of geological environment carrying capacity was established.(2)The unsupervised learning model was coupled with the supervised learning model and the semi-supervised learning model was introduced for the first time to evaluate the geological environment carrying capacity.The unsupervised learning model represented by principal component analysis was used for preliminary evaluation.Based on the assessment results,two supervised learning models(back-propagation neural network and gradient boosting decision tree model)were established to predict the geological environment carrying capacity index.Through comparative analysis,the semi-supervised learning model is more sensitive to geological environment carrying capacity and the principal component analysis-back propagation neural network model has the highest prediction accuracy.The geological environmental carrying capacity of the study area was divided into five regions by natural break model,which are high in the northwest and low in the middle and east.(3)Based on the results of regionalization,the impact factors of geological environment carrying capacity were analyzed.The main impact factors in the low carrying capacity area of geological environment are ground collapse susceptibility,collapse and landslide susceptibility and debris flow susceptibility.The main impact factors of high carrying capacity area are GDP density,proportion of available resources and distance to roads.The association rules based on the FP-Growth model showed the identification factors of the low and high carrying capacity regions of geological environment,which can provide reference for the identification of the geological environmental carrying capacity in the fragile eco-environment region of the Loess Plateau.