An increase in extreme precipitation events due to future climate change will have a decisive influence on the formation of debris flows in earthquake-stricken areas. This paper aimed to describe the possible impacts ...An increase in extreme precipitation events due to future climate change will have a decisive influence on the formation of debris flows in earthquake-stricken areas. This paper aimed to describe the possible impacts of future climate change on debris flow hazards in the Upper Minjiang River basin in Northwest Sichuan of China, which was severely affected by the 2008 Wenchuan earthquake. The study area was divided into 1285 catchments, which were used as the basic assessment units for debris flow hazards. Based on the current understanding of the causes of debris flows, a binary logistic regression model was used to screen key factors based on local geologic, geomorphologic, soil,vegetation, and meteorological and climatic conditions. We used the weighted summation method to obtain a composite index for debris flow hazards, based on two weight allocation methods: Relative Degree Analysis and rough set theory. Our results showed that the assessment model using the rough set theory resulted in better accuracy. According to the bias corrected and downscaled daily climate model data, future annual precipitation(2030-2059) in the study area are expected to decrease, with an increasing number of heavy rainfall events. Under future climate change, areas with a high-level of debris flow hazard will be even more dangerous, and 5.9% more of the study area was categorized as having a high-level hazard. Future climate change will cause an increase in debris flow hazard levels for 128 catchments, accounting for 10.5% of the total area. In the coming few decades, attention should be paid not only to traditional areas with high-level of debris flow hazards, but also to those areas with an increased hazard level to improve their resilience to debris flow disasters.展开更多
荒野地是自然生态系统最后的避难所,对于区域生物多样性保护起到了关键作用.流域作为人类活动与经济发展的重心,探究流域尺度荒野地分布对于推动流域整体生态保护与高质量发展有着重要的意义.本研究以东南沿海地区的闽江流域为例,利用...荒野地是自然生态系统最后的避难所,对于区域生物多样性保护起到了关键作用.流域作为人类活动与经济发展的重心,探究流域尺度荒野地分布对于推动流域整体生态保护与高质量发展有着重要的意义.本研究以东南沿海地区的闽江流域为例,利用综合荒野制图法,识别流域范围内荒野地空间分布、格局特征、保护现状与保护空缺.研究结果表明:(1)闽江流域现存荒野地共计5922.33 km 2,占流域总面积的6.9%.荒野地主要位于植被覆盖密集、海拔较高、地形险峻的地区,总体表现为上游多、下游少的分布特征.(2)研究区域内荒野地破碎化情况严重.小型荒野地是主要的荒野地类型,大型荒野地目前仅存2处,位于武夷山自然保护地群内,且尚未被保护地范围所完全覆盖.(3)低质量荒野地、中质量荒野地、高质量荒野地面积比例分别为5.2%、51.7%、43.1%;中高质量荒野地是闽江流域荒野地的主要构成部分,高海拔区域分布有更多的高质量荒野.(4)闽江流域荒野地存在大面积保护空缺,约有74%的荒野地尚处于保护地范围之外,部分荒野地未能得到完整保护.研究揭示了闽江流域荒野地分布与保护空缺,以期为流域生态文明建设提供支持和政策建议.展开更多
数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The We...数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The Weather Research and Forecasting Model),交叉组合16套微物理过程和积云对流参数化方案,对闽江流域2021年5月17—24日的一场连续性暴雨过程进行敏感性对比模拟。结果表明,WRF模式基本可以再现本次降雨过程的时空分布特征,但明显高估了暴雨中心的强度和范围,EXP9(Lin-NT组合)整体表现较优。对于初始场质量敏感性试验,基于最优参数化方案组合的模拟结果表明,ERA5(The Fifth-generation Atmospheric Reanalysis of the European Center for Medium-Range Weather Forecasts)对各个量级降雨模拟效果均相对较好,与观测数据的时空特征最吻合,其次为GDAS/FNL(Global Data Assimilation System/Final Operational Global Analysis),而CFS(Climate Forecast System Operational Analysis)表现最差。可为提高极端降雨模拟和预报精度提供方法借鉴。展开更多
基金jointly funded by the 135 Strategic Program of the Institute of Mountain Hazards and Environment,CAS(Grant No.SDS135-1703)the National Key Basic Research Program of China(973 program)(Grant No.2015CB452702)
文摘An increase in extreme precipitation events due to future climate change will have a decisive influence on the formation of debris flows in earthquake-stricken areas. This paper aimed to describe the possible impacts of future climate change on debris flow hazards in the Upper Minjiang River basin in Northwest Sichuan of China, which was severely affected by the 2008 Wenchuan earthquake. The study area was divided into 1285 catchments, which were used as the basic assessment units for debris flow hazards. Based on the current understanding of the causes of debris flows, a binary logistic regression model was used to screen key factors based on local geologic, geomorphologic, soil,vegetation, and meteorological and climatic conditions. We used the weighted summation method to obtain a composite index for debris flow hazards, based on two weight allocation methods: Relative Degree Analysis and rough set theory. Our results showed that the assessment model using the rough set theory resulted in better accuracy. According to the bias corrected and downscaled daily climate model data, future annual precipitation(2030-2059) in the study area are expected to decrease, with an increasing number of heavy rainfall events. Under future climate change, areas with a high-level of debris flow hazard will be even more dangerous, and 5.9% more of the study area was categorized as having a high-level hazard. Future climate change will cause an increase in debris flow hazard levels for 128 catchments, accounting for 10.5% of the total area. In the coming few decades, attention should be paid not only to traditional areas with high-level of debris flow hazards, but also to those areas with an increased hazard level to improve their resilience to debris flow disasters.
文摘荒野地是自然生态系统最后的避难所,对于区域生物多样性保护起到了关键作用.流域作为人类活动与经济发展的重心,探究流域尺度荒野地分布对于推动流域整体生态保护与高质量发展有着重要的意义.本研究以东南沿海地区的闽江流域为例,利用综合荒野制图法,识别流域范围内荒野地空间分布、格局特征、保护现状与保护空缺.研究结果表明:(1)闽江流域现存荒野地共计5922.33 km 2,占流域总面积的6.9%.荒野地主要位于植被覆盖密集、海拔较高、地形险峻的地区,总体表现为上游多、下游少的分布特征.(2)研究区域内荒野地破碎化情况严重.小型荒野地是主要的荒野地类型,大型荒野地目前仅存2处,位于武夷山自然保护地群内,且尚未被保护地范围所完全覆盖.(3)低质量荒野地、中质量荒野地、高质量荒野地面积比例分别为5.2%、51.7%、43.1%;中高质量荒野地是闽江流域荒野地的主要构成部分,高海拔区域分布有更多的高质量荒野.(4)闽江流域荒野地存在大面积保护空缺,约有74%的荒野地尚处于保护地范围之外,部分荒野地未能得到完整保护.研究揭示了闽江流域荒野地分布与保护空缺,以期为流域生态文明建设提供支持和政策建议.
文摘数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The Weather Research and Forecasting Model),交叉组合16套微物理过程和积云对流参数化方案,对闽江流域2021年5月17—24日的一场连续性暴雨过程进行敏感性对比模拟。结果表明,WRF模式基本可以再现本次降雨过程的时空分布特征,但明显高估了暴雨中心的强度和范围,EXP9(Lin-NT组合)整体表现较优。对于初始场质量敏感性试验,基于最优参数化方案组合的模拟结果表明,ERA5(The Fifth-generation Atmospheric Reanalysis of the European Center for Medium-Range Weather Forecasts)对各个量级降雨模拟效果均相对较好,与观测数据的时空特征最吻合,其次为GDAS/FNL(Global Data Assimilation System/Final Operational Global Analysis),而CFS(Climate Forecast System Operational Analysis)表现最差。可为提高极端降雨模拟和预报精度提供方法借鉴。
