Debris flow hazards are an inherent but dangerous and costly element of mountainous environments in the lower Lancang River watershed.Conventional hazard map provide useful inventories of hazardous sites but provide little insight into the potential area of the hazards, this approach tends to rely heavily on subjective interpretation of the landscape.Assessing and predicting mountainous hazards potential using geographic information systems (GIS) are receiving increasing attention over years.Based on the spatial analysis of driving and triggering factors promoting the occurrence and development of debris flows in the Lancang River watershed a database and repository are constructed for assessing the area susceptible for debris flows in the area.A correlation of the occurrence of debris flows with slope gradient, vegetation cover and rainfall are also presented for providing multivariate statistical data available for assessing risk of the debris flows in the area.Using Arc/Info grid module all data in Arc/Info coverage, including contour, vegetation cover and rainfall are transformed into TIN data and DEM and further into raster gradient, vegetation and rainfall with raster of 100m X 100m .With the repository used for assessing the potential of the occurrence of debris flows, The classification of gradient, vegetation and rainfall with five ranks, in agreement with five risk ranks of debris flows :highest, high, moderate, less and none are implemented on Arc/info platform.A digital environmental model (DEM) to assess the debris flow risk in the lower Lancang river watershed.is employed to implement the processes of spatial algebra overlay.Raster gradient, vegetation and rainfall data with a weight of 0.5, 0.3 and 0.2,respectively are imported into same grid environment with to produce a new map, showing the potential zones of the debris flows with different risk ranks of the lower Lancang river watershed.With the overlay of conventional map of the debris flow hazards in history in the area with assessment result, it can be shown that the highest and high risk zones of assessment results are in agreement with the dense zones of debris flows in history and also indicate that the index selected and methods used for assessing the risk of debris flows in the Lancang river watershed are rational and credible for conducting the debris flow disaster control and mitigation in the area.and for helping mitigate the associated risk.
YAN Man-cun, WANG Guang-qian, LIU Jia-hong
. GIS-Based Risk Assessment of the Debris Flows in the Lower Lancang River Watershed[J]. SCIENTIA GEOGRAPHICA SINICA, 2001
, 21(4)
: 334
-338
.
DOI: 10.13249/j.cnki.sgs.2001.04.334
[1] 康志成主编.中国泥石流灾害与防治[M].北京:科学出版社,1996.27~28.
[2] Mantovani F,R Soeters,C J Van Westen.Remote sensing techniques for landslide studies and hazard zonation in Europe[J].Geomorphology,1996,15:213-225.
[3] 刘希林,唐川.泥石流危险性评价[M].北京:科学出版社,1995.62~79.
[4] Dikau R,Cavallin A,Jager S.Databases and GIS for landslide research in Europe[J].Geomorphology,1996,15 (3-4):227-239.
[5] Walsh S j,D R Bulter.morphometric and multispectral image analysis of debris flows for natural hazard assessment[J].Geocarto International,1997,12(1):59-70.
[6] Wadge G,A P Wislocki,E J Pearson.Spaial analysis in GIS for natural hazard assessment[A].Environmental Modellling with GIS[C].(M.F.,Goodchild,B.O.,Parks and L.T.Steyaert,editors) Oxford University Press,Oxford,1993.332-338.
[7] Gupta R P,joshi B.Landslides hazard zoning using the GIS approach:A case study from the Ramganga Catchment Himalayas[J].Engineering Geology,1990,28:119-131.
[8] Mejia-Navarro M,Wohl E E,Oaks S D.Geological hazards,vulnerability,and risk assessment using GIS; model for Glenwod Springs,Colorado[J].Geomorphology,1994,10(1):331-354.
[9] Van Westen C J,Rengers N,Terlien M T J,Soeters R.Prediction of the occurrence of Slope instability phenomena through GIS-based hazard zonation[J].Geologische Rundschau 1997,86(4):1-14.
[10] Terlien M T J,C J Van Westen,T W J Van Asch,Deterministic modeling in GIS-based landslide hazard assessment[A].Geographic Information Systems in Assessing Natural Hazards[C].(A.Carraa and F.Guzzetti,editors),Kluwer Academic Publishers,Dordrecht,1995,57-78.
[11] Binaghi E L,Luzi P Madella,F Pergalani,A Rampini.Slope instability zonation:A comparision between ceraainty factor and fuzzy dempster-shafer approaches[J].Natrial Hazards,1998,17:77-97.
[12] Dhakal A S,Amada A,Anlya M.landslide hazard mapping and its evaluation using GIS:An investigation of sampling schemes for a grid cell based quantitative method[J].Photogrammetric Engineering & Resote Sensing,1999,66(8):981-989.
[13] Dhakal A S.Lamdslide hazard mapping and the application of GIS in the Kulehani watershed Nepal[J].Mountain Research and Deveplopment.1999,19(1):3-16.
[14] 赵士鹏,周成虎,谢又予,等.泥石流危险性评价的GIS 与专家系统集成方法研究[J].环境遥感,1996,11(3):212~218.
[15] 丁永建.山区小流域洪水过程中泥沙搬运方式的初步研究[J].地理学报,1989,44(4):487-495.
[16] 中国科学院成都山地灾害与环境研究所.泥石流研究与防治[M].成都:四川科学技术出版社,1989.
[17] Dai Fuchu,C F Lee,Wang Sijing.Analysis of rainstorm-induced slide-debris-flows on natural terrain of Lantau island,Hong Kong[J].Engineering Geology,1999,52:279-290.
[18] Sidle R C,Pearce A J,O’loughlin C L.Hillslope stability and land use.Water Resources Monograph 11,Ameri-flows-an example from Marin County,California.Engican Geophysical Union[M].Washington,DC.1985.201-223.
[19] Greenway D R.Vegetation and slope stability[A].In:slides investigation and mitigation,Transportation Research Anderson,M.G.,Richards,K.S.(Eds.),Slope Stability[C].Wiley,New York,1987.187-230.
[20] 崔之久,谢又予.关于北京山区的泥石流爆发周期的初步探讨[A].北京市科委主编.首都圈自然灾害与减灾对策[C].北京:气象出版社,1992.158~165.
[21] 唐川,朱静.澜沧江中下游滑坡泥石流分布规律与此同时危险区划[J].地理学报,1999,54(增刊):84~92.
[22] 高志强,刘纪远,庄大方.基于遥感和GIS的中国土地资源生态环境质量同人口分布的关系研究[J],遥感学报,1999,3(1):66~70.
