Comparisons between Benggang development risk assessments in Jiangxi Province based on the information value model and frequency ratio model

Benggang is one of the most serious forms of erosion in the red loam hilly areas in southern China, and the risk assessment of Benggang based on GIS is carried out to provide support for the prevention and control of Benggang erosion and minimize the hazard of Benggang erosion. A case study was taken from the granite area of Jiangxi Province, we obtained 17,049 sample points of Benggang through remote sensing interpretation and field survey, 10 potential influence factors of Benggang, such as slope, aspect, elevation, topographic relief, rainfall erosion, temperature, lithological, soil type, land use type, and vegetation coverage, were selected to study the relationship between their characteristics and avalanche occurrence; applied gray correlation analysis and Pearson correlation analysis, the importance and correlation matrices of the influence factors were calculated for the screening of the influence factors, and the Benggang risk assessment index system was set up; Quantitative analysis of the relationship between environmental impact factors and the development of Benggang; used the information value, weighted information value and frequency ratio models to calculate the risk index of Benggang, and the risk index was calculated based on the natural breakpoint grading method. According to the natural breakpoint grading method, the accuracy of the risk assessment was quantitatively evaluated used the model accuracy test, and the method with the best performance was selected for the construction and application of the risk assessment model of Jiangxi Province. The results of the study show that: 1) The main factors influencing the development of Benggang in Jiangxi Province are temperature, elevation and land use type. 29 of the 67 graded indicators promote the development of Benggang, and 38 inhibit the development of Benggang. 2) The number and percentage of Benggang in the zoning results of the three models were positively correlated with the risk level, and the number of Benggang in the extreme high risk and high risk zones accounted for a higher percentage, and the three models selected were able to effectively assess the susceptibility of Benggang in Jiangxi Province. The test results of the model accuracy of the working characteristic curve of the subjects show that the AUC values of the information value model, the weighted information value model and the frequency ratio model were 0.860, 0.852 and 0.833, respectively, and the assessment accuracy of the three models was good, and all of them are suitable for the assessment of the risk of Benggang in Jiangxi Province. The accuracy of the information value model was slightly higher, enabling a more objective and accurate assessment of the risk of avalanche occurrence in Jiangxi Province. 3) The risk level of Benggang in Jiangxi Province shows a trend of gradual increase from the north to the south, and the extreme high risk area was mainly concentrated in the southern part of Jiangxi Province, and the high risk area was mainly distributed in the south and central Jiangxi Province. The results of the study can provide reference for the prevention and control of Benggang erosion in Jiangxi Province.