澜沧江中下游滑坡泥石流分布规律与危险区划

REGIONAL DISTRIBUTION AND HAZARD ZONING OFLANDSLIDES AND DEBRIS FLOWS IN THE MTODLE - LOWERREACHES OF THE LANCANG RIVER

澜沧江中下游地区滑坡泥石流灾害分布广泛,通过调查,研究区发育滑坡泥石流灾害点1152处,严重影响航道畅通、水利水电建设和城镇发展。本文分析了滑坡泥石流灾害分布规律、影响滑坡泥石流形成发展的静态环境因素组合和动态因素组合。开展滑坡泥石流危险区划评价,是为了进一步认识该地区滑坡泥石流活动规律和发展趋势,为流域区域开发提供科学依据。本文应用因子叠置法、极差分析法和模糊数学理论对研究区滑坡泥石流危险度进行综合区划,划分出高、中、低危险区和危险江段,为制定澜沧江中下游地区滑坡泥石流减灾防灾中长期规划提科学依据。

Landslides anddebris flows in Langcangriver basin have the characters of widespread distribution andfrequent occurrence. The navigation construction of hydroelectric power station and reservoir, cities andtowns, as well as mines and farmland in the basin, have been seriously affected. After detailed investigationsin detail in recent years, it has been confirmed that there are more than 490 landslides and 662 debris flowravines in the Laneang Watershed in Yunnan Provience. Among them, about 60% of landslides and debrisflow ravines conceny trates in the middle - lower reaches of Laneang River. Landslides and debris flows inthis area are the result of a complex interaction of geological and geographical environments, and have a vari-ety of causes; weak rocks, rugged topogtaphy, heavy rainfall, and human activities.In order to reduce landslide and debris flow disasters, earth - science technology has been applied wide-ly for the prediction. One of the most important work is hazard zoning of Landslides and debris flows, whichis concerned with establishing the general probability of slope instability and zones of differing grade of threatby evaluating the triggering factors and recorded landsliding. Therefore, hazard zoning of landslides and de-bris flows is significant to provide useful information for different applications, such as planning and construc-tion, as well as stabilization and maintenance in the Laneang River. In this paper the author discussed theapplication of three methods for assessing landslide and debris flow hazards in the study areas. Trie final zona-tion results show that the high hazard area takes up 19.3 % of total study area of 57 530 km2, the middle haz-ard area is 26.2% , and the low 25.8% .