Study On Debris Flow Of The Jiaobangou Valley Characteristics And Monitoring And Early Warning Model In Dechang County

In the past 24 years, the Jiaobangou valley that had happened 6 different scale of the debris flow, has brought huge property losses to the local people. It is very necessary to conduct debris flow monitoring and early warning in the Jiaobangou valley. Based on the typical gully debris flow remote monitoring and early warning project,through field geological investigation and indoor test analysis,geological environment of the Jiaobangou valley is explored, the development characteristics of debris flow is studied in the Jiaobangou valley, the targeted monitoring and early warning program is designed and the monitoring and early warning model is studied. The following conclusions are obtained through the systematic study:(1) The Jiaobangou valley area is large, high in the west and low in the east. From west to east the narrow channel bencome wide, the slope of the channel steep slope also becomes smooth.There is large valley cutting depth, winding channel, fast flowing, developed drop. The mountain perfectly round and steep. The left bank slope steeper than the right bank overall. There are a lot of ditch and each ditch develop difference.(2) By means of the general characteristics of the source region, the circulation area and the accumulation area of the Jiaobangou valley, it is speculated that Jiaobangou valley develop a large ancient landslides. It is concluded that the static reserve of the material source is 5111.33 million m3,the dynamic reserves is 1026.1 million m3. Channel material source has unique start- circulation- accumulation phenomenon. The Jiaobangou valley happened many debris flow activity in the geological history and debris flow often exhibit multiple peak flow and the characteristics of the array flow.(3) In 1992 debris flow visible mud depth is up to 5m,mud maximum wide is 100 m in the Jiaobangou valley, debris flow always forward flow and meet Anning River. 5 times small or medium-sized debris flow occurred successively. The Jiaobangou valley is developing from the exuberant period to the recession stage.(4) According to the characteristics of the development of the Jiaobangou valley, the comprehensive research of the 1 program and the economic applicability of the 2 program are compared with the economic and long-term requirements, and ultimately determine the 2 program as the final solution.(5) Based on the hourly rainfall intensity I and total effective cumulative rainfall Rt rainfall starting index RTI si proposed. By means of logistic regression analysis method debris flow of the Jiaobangou valley rainfall warning model is established and debris flow of the Jiaobangou valley rainfall warning threshold is proposed.(6) According to the research and validation of the mud level warning, the sub sonic warning and the video warning, the threshold value and the classification of the early warning model are put forward.(7) According to the rainfall data of the 6 debris flows in recent years to verify, the effect is good.(8) Based on the highest alert level and expert evaluation, the monitoring and early warning method,such as rain, mud, infrasound and video,ared combined with together to joint early warning.