Impact Assessment and Mitigation Strategy of Sediment Related Disasters under Climate Change in the Central Taiwan (I)

台灣中部山區多為年輕地質地層且因板塊活動擠壓而破碎，加以1999年集集大地震之衝擊，許多山區邊坡出露之地層屬於易崩滑的崩積土層或高度風化岩盤，暴雨更容易引發坡地及土石流災害，導致地貌變化劇烈，並重創觀光與農業及居民身家財產。近年來溫室效應造成全球氣候極端異常，造成降雨集中、降雨強度提高，也使坡地及土石流災害更雪上加霜。2008年辛樂克颱風及2009年莫拉克颱風，屢創各站之歷史降雨紀錄，高達200年以上重現期距之暴雨，也充分顯現極端氣候狀態下之土砂災害，是必須面對的課題。中興大學環境保育暨防災科技中心曾多次配合國家災害防治中心(NCDR)進行中部災害調查，八八風災發生後，中興大學防災中心於8月13日即組成一勘災團隊前往災區進行現地勘查。災後防災中心特別邀請中興大學水保系馮正一教授、土木系系主任陳豪吉教授、朝陽科技大學營建工程學系系主任徐松圻教授及林基源教授參與此份整合計畫之研究，其專長涵括材料結構、遙測工程、地理資訊、水土保持及防災技術等。根據此次勘災報告，中部山區重要點主要集中在陳有蘭溪流域及塔羅灣溪流域。本整合計畫即以濁水溪上游之陳有蘭溪及塔羅灣溪為研究地點，藉由探討中部山區最常發生災害的流域之土砂災害，針對土砂災害對住家、公路、河階農地與其他保全對象分別做探討，並分析土砂災害形成、影響範圍、危險度評估及監測技術，進而擬定土砂災害預警與防災體系決策程序，利用分工的方式進行課題探討後再由總計畫整合研究成果。其總計畫訂為極端氣候下之中台灣土砂災害影響評估與減災策略，包括子計畫一：以遙測技術輔助土砂災害調查與模擬及其保全策略研擬，子計畫二：霧社水庫淤泥再利用之研究，子計畫三：極端氣候下山區路基崩塌潛勢與災害防制，子計畫四：極端氣候狀態下沖積扇及河階地崩塌與致災因子研究，以及子計畫五：集水區崩塌地演化與崩塌潛勢之研究。本整合計畫之總體目標預估可分為下列3項:1. 土砂災害形成與影響：土砂災害之形成原因相當複雜，本計畫利用現地調查及3S技術、電腦試驗，探討土砂災害之形成機制及其影響範圍、分析崩塌潛勢，以估算土砂災害之土石堆積體積、遞移率分析、災害影響範圍及減災工程規劃。2. 崩塌區位潛勢分析、崩塌土體傳遞與淤泥之再利用：莫拉克風災在全臺造成超過20億立方米之崩塌，此土砂淤積於河道或水庫中，對中下游帶來嚴重影響。本整合型計畫研擬邊坡演化與崩塌土體傳遞控制方程式，藉由現地勘查結果進行驗證；並研究集水區邊坡高潛勢崩塌區位判釋、推估崩塌規模及崩塌機率、崩塌前兆。亦將淤泥再利用研究成果提供相關單位參考，可望有效解決淤泥淤積問題。3. 影響範圍與保全對象之防災管理：為減緩土砂災害發生對下游造成之災害，本整合型研究亦進行保全對象之風險評估。除保全對象風險評估系統之開發與整合應用外，亦提供土砂災害之減災策略，使未來土砂災害發生後能有一合宜災害治理策略。The geology of Taiwan mostly is weak shale and slate that causes a great potential of mud flow and landslide after heavy rainfalls, especially after Chi-Chi earthquake in 1999. In recent years, the global warming and the climate change make the sediment disasters even worse. Typhoon Sinlaku in 2008 and Typhoon Morakot in 2009 kept on breaking the rainfall record and brought a tremendous catastrophe in the central Taiwan.Center for Environmental Restoration and Disaster Reduction (CERDR) at National Chung Hsing University (NCHU) has been co-operating with National Science and Technology Center for Disaster Reduction (NCDR) to investigate disaster causes and assess damage loss at the central Taiwan for many years. Same as after every disaster event, an investigation group organized by CERDR went to field after typhoon Morakot. To understand the disaster causes and search the solution for the hot spots at the central Taiwan, this project is proposed for further research based on the investigation report. Five professors are invited to join this project as PIs, including Professor Yang (serve as the major leader, the chair of CERDR, NCHU), Professor Chen in (the chair of Department of Civil Engineering, NCHU), Professor Feng (in Department of Soil and Water Conservation, NCHU), Professor Hsu (the chair of Department of Construction Engineering, Chaoyang University of Technology (CYUT)), and Professor Lin (in Department of Construction Engineering, CYUT). This group has professional specialty in Material Structure, Remote Sensing, Geographic Information Systems, Geo-technology, Soil and Water Conservation, and Disaster Reduction. According to typhoon Morakot investigating report, the most serious disasters and hot spots occurred in Chenyulan River watershed and Truwan River watershed, which both are the tributaries of Jhoshei River. Therefore, the study area of this project is set as Chenyulan River watershed and Truwan River watershed. This project is to study the cause of landslide disasters, and the impacts of landslide disasters under hydrogeology and extreme weather conditions. Risk assessment and management of the landslides will also be established for further mitigation process.This project, named as “Impact assessment and mitigation strategy of sediment related disasters under climate change in the central Taiwan”, consists of five sub-project, such as Sub-project 1: “Application of remote sensing to debris disasters investigation and modeling and safety strategy planning”, Sub-project 2:”The research of mud reuse in Wushe reservoir”, Sub-project 3:” Slope Instability and Stabilization in Mountain Areas under Extreme Weather Conditions”, Sub-project 4:” Hazard assessment and induced factors of alluvial fans and terraces under extreme weather condition” and Sub-project 5:”The landslide evolution and hazard assessment in watershed.” We expect that the results of this research could be helpful for the government to set-up mitigation strategy and regulate rules in the future

Impact Assessment and Mitigation Strategy of Sediment Related Disasters under Climate Change in the Central Taiwan

台灣中部山區多為年輕地質地層且因板塊活動擠壓而破碎，加以1999年集集大地震之衝擊，許多山區邊坡出露之地層屬於易崩滑的崩積土層或高度風化岩盤，暴雨更容易引發坡地及土石流災害，導致地貌變化劇烈，並重創觀光與農業及居民身家財產。近年來溫室效應造成全球氣候極端異常，造成降雨集中、降雨強度提高，也使坡地及土石流災害更雪上加霜。2008年辛樂克颱風及2009年莫拉克颱風，屢創各站之歷史降雨紀錄，高達200年以上重現期距之暴雨，也充分顯現極端氣候狀態下之土砂災害，是必須面對的課題。中興大學環境保育暨防災科技中心曾多次配合國家災害防治中心(NCDR)進行中部災害調查，八八風災發生後，中興大學防災中心於8月13日即組成一勘災團隊前往災區進行現地勘查。災後防災中心特別邀請中興大學水保系馮正一教授、土木系系主任陳豪吉教授、朝陽科技大學營建工程學系系主任徐松圻教授及林基源教授參與此份整合計畫之研究，其專長涵括材料結構、遙測工程、地理資訊、水土保持及防災技術等。根據此次勘災報告，中部山區重要點主要集中在陳有蘭溪流域及塔羅灣溪流域。本整合計畫即以濁水溪上游之陳有蘭溪及塔羅灣溪為研究地點，藉由探討中部山區最常發生災害的流域之土砂災害，針對土砂災害對住家、公路、河階農地與其他保全對象分別做探討，並分析土砂災害形成、影響範圍、危險度評估及監測技術，進而擬定土砂災害預警與防災體系決策程序，利用分工的方式進行課題探討後再由總計畫整合研究成果。其總計畫訂為極端氣候下之中台灣土砂災害影響評估與減災策略，包括子計畫一：以遙測技術輔助土砂災害調查與模擬及其保全策略研擬，子計畫二：霧社水庫淤泥再利用之研究，子計畫三：極端氣候下山區路基崩塌潛勢與災害防制，子計畫四：極端氣候狀態下沖積扇及河階地崩塌與致災因子研究，以及子計畫五：集水區崩塌地演化與崩塌潛勢之研究。本整合計畫之總體目標預估可分為下列3項:1. 土砂災害形成與影響：土砂災害之形成原因相當複雜，本計畫利用現地調查及3S技術、電腦試驗，探討土砂災害之形成機制及其影響範圍、分析崩塌潛勢，以估算土砂災害之土石堆積體積、遞移率分析、災害影響範圍及減災工程規劃。2. 崩塌區位潛勢分析、崩塌土體傳遞與淤泥之再利用：莫拉克風災在全臺造成超過20億立方米之崩塌，此土砂淤積於河道或水庫中，對中下游帶來嚴重影響。本整合型計畫研擬邊坡演化與崩塌土體傳遞控制方程式，藉由現地勘查結果進行驗證；並研究集水區邊坡高潛勢崩塌區位判釋、推估崩塌規模及崩塌機率、崩塌前兆。亦將淤泥再利用研究成果提供相關單位參考，可望有效解決淤泥淤積問題。3. 影響範圍與保全對象之防災管理：為減緩土砂災害發生對下游造成之災害，本整合型研究亦進行保全對象之風險評估。除保全對象風險評估系統之開發與整合應用外，亦提供土砂災害之減災策略，使未來土砂災害發生後能有一合宜災害治理策略。The geology of Taiwan mostly is weak shale and slate that causes a great potential of mud flow and landslide after heavy rainfalls, especially after Chi-Chi earthquake in 1999. In recent years, the global warming and the climate change make the sediment disasters even worse. Typhoon Sinlaku in 2008 and Typhoon Morakot in 2009 kept on breaking the rainfall record and brought a tremendous catastrophe in the central Taiwan.Center for Environmental Restoration and Disaster Reduction (CERDR) at National Chung Hsing University (NCHU) has been co-operating with National Science and Technology Center for Disaster Reduction (NCDR) to investigate disaster causes and assess damage loss at the central Taiwan for many years. Same as after every disaster event, an investigation group organized by CERDR went to field after typhoon Morakot. To understand the disaster causes and search the solution for the hot spots at the central Taiwan, this project is proposed for further research based on the investigation report. Five professors are invited to join this project as PIs, including Professor Yang (serve as the major leader, the chair of CERDR, NCHU), Professor Chen in (the chair of Department of Civil Engineering, NCHU), Professor Feng (in Department of Soil and Water Conservation, NCHU), Professor Hsu (the chair of Department of Construction Engineering, Chaoyang University of Technology (CYUT)), and Professor Lin (in Department of Construction Engineering, CYUT). This group has professional specialty in Material Structure, Remote Sensing, Geographic Information Systems, Geo-technology, Soil and Water Conservation, and Disaster Reduction. According to typhoon Morakot investigating report, the most serious disasters and hot spots occurred in Chenyulan River watershed and Truwan River watershed, which both are the tributaries of Jhoshei River. Therefore, the study area of this project is set as Chenyulan River watershed and Truwan River watershed. This project is to study the cause of landslide disasters, and the impacts of landslide disasters under hydrogeology and extreme weather conditions. Risk assessment and management of the landslides will also be established for further mitigation process.This project, named as “Impact assessment and mitigation strategy of sediment related disasters under climate change in the central Taiwan”, consists of five sub-project, such as Sub-project 1: “Application of remote sensing to debris disasters investigation and modeling and safety strategy planning”, Sub-project 2:”The research of mud reuse in Wushe reservoir”, Sub-project 3:” Slope Instability and Stabilization in Mountain Areas under Extreme Weather Conditions”, Sub-project 4:” Hazard assessment and induced factors of alluvial fans and terraces under extreme weather condition” and Sub-project 5:”The landslide evolution and hazard assessment in watershed.” We expect that the results of this research could be helpful for the government to set-up mitigation strategy and regulate rules in the future