| 摘要: | 我國在目前的災害防救體制下，對於水土災害雖然有相關的預警及風險評估概念，然而因為缺乏整體系統觀念的導入與落實，對於河川流域中人類社會、水環境、土地環境、氣候(氣象)在長期變遷趨勢下之相互影響作用並未有完整系統化之考量，所以導致在目前的水土災害預警與風險評估上，尚存在須改善之問題以及進一步強化之處，主要包括：(1)缺乏以系統角度進行水土災害風險評估與預警；(2)缺乏適當的水土災害風險評估方法；(3)缺乏水土災害未來長程性預警之機制。因此本計畫之目的在發展一套有效的水土災害預警及風險評估機制與系統，而且本計畫所發展之預警與目前災害防救體制中在颱風豪雨到來前之預警不同，而是屬於未來長程性之災害綜合風險評估與預警。本研究為三年計畫，在第一年首先針對水土災害風險評估制度進行檢討，然後將河川流域視為系統，以整體系統的觀點界定出河川流域水土災害風險評估體系架構，然後以風險評估(Risk assessment)、系統分析 (Systems analysis)、地理資訊系統(GIS)等方法與技術，並參考聯合國國際減災策略秘書處(Inter-Agency Secretariat of International Strategy for Disaster Reduction, UN/ISDR)所界定的風險評估與預警概念，界定河川流域水土災害因子間影響關係，進而發展河川流域水土災害風險評估與預警方法論。本研究針對我國河川流域特性，發展水土災害風險值計算式，包括以災害發生機率與強度為危害度指標，而以生命損失、經濟損失、就業環境損失、居住環境損失等做為損失指標，並以層級分析法(Analytic Hierarchy Process, AHP)界定各指標項目、指標值、權重等，因此本研究乃是考慮未來各種氣象條件，擬定為不同嚴重等級的情境，根據災害因子間影響關係而評估水土災害之危險度，以及所造成的社會經濟損失，以計算出風險值；然後推估各因子之未來趨勢，在河川流域尚未到達災害高風險值前，但可能將會到達災害高風險值時，先行提出預警，以讓主管機關與民眾能夠及早擬定因應措施，而進行後續之風險管理。第二年研究重點在發展河川流域水土災害預警與風險評估系統，將以Visual Basic、Microsoft Access、地理資訊系統等軟體進行系統開發，預計將包括風險評估、災害預警、資訊整合管理等3 個子系統。第三年研究重點在進行案例研究，預計以楠梓仙溪流域為案例地區，進行方法論與系統之驗證。本計畫所發展之河川流域水土災害預警與風險評估方法論及系統，預期可以協助主管機關有效減少水土災害風險(危害度及損失)。The concepts of warning and risk assessment for water-land disaster are applied in the current disaster prevention and response mechanism. However, the interactions among the human society, water environment, land environment, and climate (weather) of river basin under long-term change trend are not systematically considered. There are some defects of warning and risk assessment for water-land disaster need to be improved: (1) lacking of systematic considerations for warning and risk assessment for water-land disaster; (2) lacking of adequate methods for risk assessment for water-land disaster; and (3) lacking of the mechanism of long-term future warning for water-land disaster. The purpose of this study is to develop an effective mechanism and system for warning and risk assessment for water-land disaster. A three-year project is proposed as follows. The current system of risk assessment for water-land disaster will be reviewed in the first year. The river basin will be seen as a system in this study. The framework of risk assessment for water-land disaster of river basin will be identified. Based on the concepts of warning and risk assessment proposed by the Inter-Agency Secretariat of International Strategy for Disaster Reduction (UN/ISDR), the methods and technologies of risk assessment, systems analysis, and geographic information system (GIS) will be applied to identify the influence relationships among the factors of water-land disaster. The methodology of warning and risk assessment for water-land disaster of river basin then can be developed. Based on the characteristics of river basins in Taiwan, this study will develop an equation for calculating the risk value of water-land disaster. The hazard indicators consist of probability and intensity of disaster. The loss indicators include the losses of life, economy, employment environment, and resident environment. The Analytic Hierarchy Process (AHP) method will be used to identify the items, values, and weights of the indicators. This study will identify various scenarios based on different weather conditions to assess the hazards and losses based on the influence relationships among the factors of water-land disaster. The value of risk then can be calculated. Furthermore, the future trends of the indicators will be estimated. The warning will be announced when the river basin is possible to reach the high risk value. The authorities and people can prepare the responses for the possible disasters and generate the risk management plans. The system for warning and risk assessment for water-land disaster of river basin will be developed in the second year. The software of Visual Basic, Microsoft Access, and GIS will be applied to develop the system, which consists of three subsystems of risk assessment, disaster warning, and integrated information management. The methodology and system will be verified in the third year. The Nantzeshen River will be the case study area. The methodology and system for warning and risk assessment for water-land disaster of river basin developed in this study can be used to assist the authorities to effectively reduce the risk (hazards and losses) of water-land disasters. 研究期間：10008 ~ 10107 |
