摘要
泥石流危险性评估是风险分析和评估的基础步骤,气候变化增加了泥石流灾害发生的风险,研究未来气候变化下泥石流动态危险性对制定防灾减灾战略具有重要意义。本文利用CMIP5数据重建川西高原2021-2095年的年均温和日降水情景,并定量分析了气候变化下川西高原21世纪近期(2021-2045年)、中期(2046-2070年)、末期(2071-2095年)的泥石流的动态危险性响应。研究表明:(1)相对于基准期(1981-2005年),未来75年川西高原年均气温呈上升趋势,末期增温速度减缓,高海拔地区的增温幅度较大;年平均降水量呈增加趋势,末期增加速度减缓,空间上整体呈现“东增西减”的分布趋势;日最大降水量和暴雨日数呈现由东南部向西北方向增大的趋势。(2)在基准期,高度、较高泥石流危险性面积占26.77%,聚集在川西高原东部山地和金沙江等主要河流沿岸高山峡谷区;气候变化情景下,与基准期相比川西泥石流危险性普遍增加,西部、北部泥石流危险性增加更为明显;川西主要河流两岸泥石流危险等级均增加,如金沙江、大渡河、雅砻江等,高危险区不断向海拔高的区域扩散;泥石流中度及以下危险区难以转变为较高、高度危险区,表明与气候变化的影响作用相比,地质、地形和水文条件仍起主导作用。
The research on the dynamic hazard of debris flow with climate change is of great significance for designing disaster prevention and mitigation strategies due to the promotion of climate change to increase debris flow risk,in which the hazard assessment is a fundamental task for risk analysis and assessment of debris flows. Using the annual mean temperature and daily precipitation during 2021-2095,which was re-established according to climate projection data from the Coupled Model Intercomparison Project phase 5(CMIP5),this article analyzed quantitatively the dynamic hazard response to climate change during the near(2021-2045),middle(2046-2070)and late term(2071-2095)of the 21st century in the Chuanxi plateau,respectively. The study showed that:(1)Compared with the reference period(1981-2005),the annual mean temperature will increase in the next 75 years,and the warming rate will slow down at late term and be proportional to the height above sea level. The annual mean precipitation will also increase in the next 75 years,and slow down at late term,presenting the spatial distribution of "increasing in the east and decreasing in the west". The maximum daily precipitation and the number of rainstorm days will gradually increase from the southeast to the northwest.(2)In reference period,the area with very high and high hazard accounts for 26.77%,mainly located in the alpine valley areas on the eastern Chuanxi plateau. Affected by climate change,the debris flow hazard will generally increase,especially in the west and north of Chuanxi plateau. The hazard level tends to upgrade to high hazard level on both banks of the major rivers in Chuanxi plateau,such as the Jinsha River,the Dadu River,the Yalong River and so on,and the high altitude zones with lower hazard level will transform to higher hazard level. The finding that the zones with very low,low and moderate hazard level rarely will convert into the zones with high or very high hazard level shows that geological,topographic and hydrological conditions primarily control debris flow hazard compared with the impact of climate change on debris flow.
作者
周斌
邹强
蒋虎
李聪
ZHOU Bin;ZOU Qiang;JIANG Hu;LI Cong(Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Conservancy,Chinese Academy of Sciences(CAS),Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《自然灾害学报》
CSCD
北大核心
2022年第4期241-255,共15页
Journal of Natural Disasters
基金
国家自然科学基金项目(41790432)
四川省应用基础研究项目(2019YJ0006)
中国科学院战略性先导科技专项项目(XDA23090303)。
关键词
泥石流
气候变化
时空分布特征
动态危险性评估
川西高原
debris flow
climate change
spatial-temporal distribution characteristics
dynamic hazard assessment
Chuanxi plateau
