Research On Land Use Comprehensive Disaster Prevention Planning And Its Spatial Decision Support System

Urban Comprehensive Disaster Prevention Planning(UCDPP) consists of multiple kinds of disasters and urban systems.Based on the present research and practical experience,the components of UCDPP are constructed,in which the Land Use Comprehensive Disaster Prevention Planning (LUCDPP) is the important precondition of the succeeding components of this system.The LUCDPP's conception,functions and characteristics are discussed,and the research contents are summarized accordingly as:1) combining each disaster's hazard analysis result and the land attributes to estimate the land's disaster resistance suitability(e.g.Land's seismic resistance suitability evaluation),2) combining all the disasters' hazard analysis results,the land attributes and the attributes of the whole urban system built on the land to research the Land Use Comprehensive Disaster Risk(LUCDR).The research contents have three features:firstly,most data processed are spatial data,secondly,the relevant factors of LUCDR are nonlinear and with randomicity,thirdly the data's temporal-spatial scope and amount are both great,which limit this problem as a complex unstructured process.With the rapid development of Spatial Technology(ST) and Information Technology(IT),the constructing process for the mathematical model of Spatial Analysis(SA) and Spatial Decision Support System(SDSS) is more professional,modularized,and intelligentized.The following aspects of LUCDPP are researched in details with the combination of LUCDPP theory analysis and SDSS.(1) The seismic disaster is chosen to research the LUCDPP's first research contents,i.e.the research of Construction Land Seismic Resistance Suitability(CLSRS) evaluation.Based on the present research and practical experience in Urban Seismic Resistance and Hazardous Prevention Planning(USRHPP),seismic disaster prediction and other relevant fields,four indexes(site classification index,liquefaction index,seismic hazard index and ground stability index) are selected to evaluate the CLSRS synthetically.The SA mathematical model of each index and the synthetic evaluating model are built to support the CLSRS evaluation process.●The SA mathematical model for site classification index is based on the geostatistical analyzing process of regionalized variables,Soil Equivalent Shear Wave Velocity (SESWV) and Cover Soil Thickness(CST),which mainly include the fitting model analysis of spatial trend and semivariogram to simulate their spatial distribution raster maps.With the spatial distributive result of SESWV and CST as input,the deterministic and Fuzzy Synthetic Evaluation(FSE) approaches are used separately to calculate the site classification raster map.Practical project data are adopted to illustrate this process.●The probabilistic approach,based on the statistical simulation method(Monte Carlo simulation algorithm),is applied to calculate each bored pile's liquefaction index.Then the geostatistical analyzing model is used to simulate the spatial distribution of the liquefaction index,i.e.to create each liquefaction grade's probability raster map.●The Seismic Hazard Analysis(SHA) method FSHASA is constructed on the FSE approach and SA to support the UCDPP and USRHPP,based on the research of present SHA methods.The basic spatial database includes fault,earthquake,geology,bouguer gravity anomaly etc.The models-base includes 11 models for the corresponding 11 indexes of the FSHASA evaluating system and FSE model.The methods-base includes Analytic Hierarchy Process(AHP) for indexes weights,Levenberg-Marquardt for data processing etc.Six districts are selected to test the FSHASA method.●The conception of ground stability is defined first to distinguish from lithosphere stability and foundation stability.The multi-level evaluation indexes system is built, whose first hierarchy indexes include tectonic background,geological disaster,human engineering activities influence,and topographic feature.The FSE approach is used to analyze this indexes system.Based on the results of four indexes for CLSRS,the AHP method is used to synthesize them to get the CLSRS raster map.Considering the limiting factor theory,the raster map is modified.This process is illuminated with practical project data.(2) LUCDR research,i.e.the second research contents of the LUCDPP,is based on each disaster's hazard analysis result,the land features and various features of the whole urban system built on land to identify the potential synthetic disaster risk.In most cites each disaster's hazard zonation or other forms of hazard analysis results are available before the UCDPP work.So the emphasis of LUCDR should be the synthetic approach that combines the influencing factors of disaster hazards, land features,various urban system features.The multi-level evaluation indexes system(three levels) is constructed considering every aspect of disaster-inducing factors,disaster-influencing factors and disaster's bearing-body factors.The first hierarchy includes 5 indexes and the last hierarchy includes 38 indexes.Most of these indexes are qualitative,which are vulnerable by subjective ideas.The multi-level FSE method is adopted to reduce the error caused by subjective factors.The expert appraisal system is built to support the expert appraisal process,and calculate the membership degree value vector.Combined with the weights vector got from AHP method and weighted average fuzzy arithmetic operator,every soil unit's membership degree value for each LUCDR grade is calculated, and the final LUCDR grade is determined by the principle of maximum membership degree.(3) The GIS,DSS,and SDSS technologies are indispensable for these researches mentioned above.The advantage for the application of SDSS is elaborated.UML and Model Builder(embedded in ArcGIS 9.0) are utilized to build the spatial analysis mathematic model.AO developing technology in VB language is used to develop these models.Finally the LUCDP-SDSS application is built on the ArcInfo 9.0 platform and Oracle 9i RDBMS.Its functions,user interfaces etc.are introduced.