Abstract:
Thematic (GIS and remote sensing) data interpretation, field investigation, and laboratory analysis were carried out to investigate parameters influencing the debris flow and debris flood occurred on May 2006 in Amphoe Lablae, Changwat Uttaradit. The relationship between debris flow-flood and relevant parameters was analyzed for debris flow-flood susceptibility assessment. In Lablae sub-catchment, scar-scouring locations detected from remote sensing interpretation and field surveys were complied into a GIS database. Various maps were constructed from the flow-flood relevant parameters derived from the database. The parameters, univariant probability method, and calculation of debris flow-flood susceptibility were applied to analyze and produce a susceptibility map of debris flow-flood hazard in the sub-catchment. On the contrary to previous concludes, it was found that the disastrous event was not the work of the unusually heavy rainfall alone, the additional factors are distance from drainage less than 50 meters, slope more than 30°, water body and communities area. In Lablae sub-cachment that covering an area of 150.45 square kilometers, it can be divided into the very high-, high-, moderate-, low-, and very low susceptibility zone which have areas of 0.02, 3.12, 138.15, 6.52 and 2.64 square kilometers, respectively.