UNCERTAINTY ANALYSIS ON ZONATION MAPS OF DEBRIS FLOW HAZARD IN YUNNAN PROVINCE,CHINA
- Received Date: 1999-08-10
- Publish Date: 2000-06-20
Abstract: Different researchers select different factors and use different methods to assess the regional hazard degrees of debris now.consequenily, even for the same region, tb..are often different hazard zonation maps, and there must be some uncertainty in the zonations.Thus the ceriainty analysis of zonation maps becomes obviously important.For debris now hazard, those zonation maps with a certainty analysis could provide most valuable information for land users, hazard managers and policy makers.By comparison of three researchers'findings in Yunnan Province, this paPer shows that seven to nine iafluential factors are chosen for the zonation maps.spatial density of debris flow ravines,regional average rock-weathering coefficient, yearly precipitation, days of≥50 mm daily rainfall, and proportion of sloping land with slope≥25℃ to the total land are the most acceptable factors.Mathemahcal methods of maximum-minimumvalues, upperlower limit values and Fuzzy values are used to quantify the factors.Step-by-step methodoogy is commonly used for the zonation maps.Research results show that mchmum uncedrinty is 66.6% and minimum uncertainty is 35.7% in debris now hazard maps of zhaotong Prefecture and Yunnan Province.Therefore there is still much work for us to improve the zonation methedology.
|Citation:||LIU Xi-lin. UNCERTAINTY ANALYSIS ON ZONATION MAPS OF DEBRIS FLOW HAZARD IN YUNNAN PROVINCE,CHINA[J]. Chinese Geographical Science, 2000, 10(2): 138-143.|