The Impact Assessment Of Regional Geomorphology To The Sensitivity Of Debris Flow In The Upper Min River

The upper Min River is located in the transition area of the Qinghai-Tibet Plateau to the Sichuan Basin,and the influence of active seismic zones has made the upper Min River a typical area with complex geological environment and frequent debris flow disasters.Therefore,this paper selects the area's topography and debris flow as the analysis object,and comprehensively uses the analysis software such as ArcGIS and GRASS to analyze and compare the topographic characteristics and combination changes of different area topography.The Geomorphon method is used to deduct and identify the DEM in the upper Min River to obtain the upper Min River area Micro-landscape;use Bayesian model to evaluate debris flow sensitivity in the upper Min River;explore the relationship between micro-landscape and debris flow sensitivity and improve the fuzzy comprehensive evaluation and analysis of the river valley length used in single-ditch debris flow sensitivity;replace the valley area obtained from the micro-landscape To obtain the sensitivity of a single ditch of 244 debris flow ditches in the upper Min River,analyze the development degree of 244 debris flow ditches in the upper Min River,and use the valley area in the microtopography instead of the common watershed area to make the results more accurate.Trends in activity of typical debris flow ditch.The main research contents and results are as follows:(1)Micro-geographical zoning map of the upper Min RiverSome landforms are directly related to geological hazards.Various landforms can form strange natural landscapes,and they are also an important cause of geological hazards.It also determines the type of geological disaster.A certain geological feature will corr espond to a related geological disaster.This is also a method for domestic scholars to estimate the address disasters of each province through corresponding geomorphology,and to take corresponding measures to prevent related natural disasters.Corresponding geological disasters can be prevented in advance.At the same time,the accumulated experience can be analyzed and researched,and the analysis results with important value can be converted into research reports,providing reference value for academic research.However,there are few analyses on the relationship between natural landforms and debris flow.In this paper,thresholds are set based on parameter data inferred from DEM remote sensing images,and methods of combination setting and scene analysis are used to extract data from geomorphological features.Then,the obtained data is reconstructed in three dimensions,and the extracted data is converted into a format.After processing by computer,the geological features of the upper reaches of Min River are restored to obtain a microtopographic type map.(2)Debris flow distribution and sensitivity zoning map in the upper Min RiverTaking the type of regional geomorphology as one of the evaluation factors of debris flow sensitivity,a map of debris flow sensitivity in the upper reaches of the Min River was obtained.It can be seen that when no geomorphic factors are added,the sensitivity map obtained from the northern region of the Min River is more complex than actual ones There are some differences.After adding the geomorphological factors,the obtained debris flow sensitivity zoning map of the upper Min River is more realistic.The regions with higher sensitivity are Songpan County,Wenchuan County,and Mao County.According to the regional distribution of debris flows,See,the calculation results can truly reflect the situation of debris flow sensitivity.The debris flow in Maoxian,Wenchuan and Lixian is extremely sensitive,and the frequency of debris flow in recent years also agrees with the calculation results.(3)Sensitivity and regional geomorphology of 244 single-ditch debris flows in the upper Min RiverFirst,a classification map of the topographic elements of each debris flow was made.Then use the grey relational method to analyze the correlation coefficients of factors that affect the sensitivity of each debris flow ditch,replace the commonly used gully length with the valley area in the microtopography,and analyze the correlation between the influencing factors and debris flow activity.Then the fuzzy comprehensive evaluation is used to analyze the sensitivity of 244 debris flow ditches in the upper reaches of Min River.From the two perspectives of the region and the Shangou,the response relationship between regional landforms and debris flow activities is obtained.