孙水河流域地质灾害时空分布及链式规律研究

20世纪90年代至今，我国先后以行政区为单元对地质灾害开展了1：50万至1：5万的调查工作，为我国地质灾害防治规划和土地利用规划提供了科学依据。近年来随着城镇化建设加快，小流域内地质灾害严重制约着城镇建设和发展。本文结合孙水河小流域地质灾害调查研究，研究了流域内孕灾环境条件、灾害演变模式、成灾规律等工作。取得以下几点认识：（1）2012年8月31日，孙水河流域遭遇两百年一遇特大暴雨，日降雨量达149.2mm，诱发大量的地质灾害，呈现出数量多、规模大、密度高等特点。（2）在空间上呈线-带-片状特性发育分布，表现为：沿重要交通干线成昆铁路、县级公路、乡村公路呈线状密集分布； 沿河流两岸呈带状密集分布等特点。（3）时间分布规律受降雨作用控制明显； 地质灾害形成与降雨强度、降雨历时和过程降雨量等呈正相关性。暴雨是地质灾害形成的主要因素之一，而且其连锁效应常形成灾害链，构成群发性灾害。（4）灾害链发生模式主要有：暴雨滑坡堰塞坝堆积坝溃决洪水； 暴雨泥石流堰塞体堆积坝溃决洪水； 暴雨弃渣滑坡、泥石流； 暴雨洪水岸坡失稳淤埋、雍高河道。

RESEARCH ON THE SPACE-TIME DISTRIBUTION AND CHAIN PATTERNS OF GEOHAZARDS IN SUNSHUI RIVER

Since the 1990s, we have act as a administrative district unit of geological disasters investigation in the 1:500000 to 1:50000,which provides the scientific proof for geological disaster prevention planning and land use planning. Geological disasters in small watershed have a serious threat to urban construction and development in recent years. This paper studies pregnant environment, disaster evolution pattern and rule of geohazads in combining with geohazads investigation in Sunshui river watershed. The main conclusions are as follows：(1)on August 31, 2012, once-in-two-century heavy rainfall hit Sunshui river basin, rainfall of 149.2mm, which induced a large number of geohazads and showed a large number, big size, high density and a line-belt-sheet space distribution characteristics.(2)Spatial distribution is shown as：linear concentrated distribution along the important traffic trunk, such as ChengKun railway, county roads, rural roads; strip concentrated distribution along both sides of the river; the distribution of geological disaster is group.(3)the precipitation effect is obvious by time distribution controlling; the formation of geological hazards and rainfall, rainfall duration, rainfall intensity and the process was a positive correlation. Heavy rain is one of the main factors for the formation of geological disasters, and the ripple effect often forms the disaster chain, and clusters of disasters.(4)Heavy rain disaster chain patterns mainly include：rainstormlandslidebarrier dambarrier dam failurefloods; rainstormdebris flowbarrier dambarrier dam failure floods; rainstorm abandon slaglandslide or debris flow; rainstormbank slope failure buried and high harmony channel.