摘要
为降低洪涝灾害影响、提高对洪水灾害的防御能力,评估极端土地利用变化和降雨类型对洪水特征的影响至关重要。基于分布式水文-土壤-植被模型DHSVM对浙江省汤浦水库上游流域20场洪水进行入库洪水建模,并采用模糊决策树法将洪水划分为快速洪水、短历时降雨洪水和长历时降雨洪水3种类型,研究极端土地利用和降雨类型对各类型洪水的特征指标影响。结果表明:DHSVM模型模拟效果较好,率定期和验证期各场次洪水纳什效率系数均值大于0.7。受区域内耕地面积影响,退耕还林和退耕还草对洪峰和洪量的消减作用皆小于2%。快速洪水的洪峰对下垫面变化最敏感,在退林还耕和城市扩张的极端土地利用变化下其洪峰平均增长率分别为12.87%和60.88%。下垫面变化对长历时降雨洪水的洪量影响最大,在退林还耕和城市扩张情境下其洪量平均增长率分别为10.48%和20.70%。城市扩张情景使得峰现时间平均提前2.10 h,降雨类型改变使得快速-短历时洪水开始时间平均延迟3.63 h,洪峰减小34.73%;短历时-快速洪水开始时间平均提前7.11 h,洪峰增大22.87%。
In order to reduce the impact of flooding and improve the management of flood disasters,it is crucial to assess the impact of extreme land use changes and rainfall types on flood characteristics.The distributed hydrological soil vegetation model was used to simulate 20 floods in the upper watershed of Tangpu Reservoir,Zhejiang Province.And then the fuzzy decision tree was adopted to categorize flood types into flash flood,short duration rainfall flood and long duration rainfall flood,so as to investigate the effects of extreme land use and rainfall types on the characteristic indices of flood.The results showed that the model simulation was effective,with Nash efficiency coefficients in both calibration period and validation period greater than 0.7.Due to the limited area of cropland in the region,the reduction of flood peaks and flood volumes by both returning farmland to forest and restoring farmland land to grassland was less than 2%.The flood peak of the flash flood was the most sensitive to land use change,its growth rate reached 12.87%and 60.88%under the extreme scenarios of deforestation and urban expansion respectively.Changes in subsurface had the greatest impact on the flood volume of long duration rainfall floods,with flood volume growth rates of 10.48%and 20.70%under the deforestation and urban expansion scenarios,respectively.The urban expansion scenario advanced the flood peak onset time by 2.10 h on average;changes in rainfall type advanced the onset of flash-short duration rainfall floods by an average of 3.63 h,and reduced the flood peak by 34.73%;while the onset of short duration rainfall-flash floods were delayed by an average of 7.11 h,and increased the flood peak by 22.87%.
作者
梁霄
许继良
许月萍
周焕
刘甜
LIANG Xiao;XU Jiliang;XU Yueping;ZHOU Huan;LIU Tian(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Zhejiang DesignInstitute of Water Conservancy and Hydroelectric Power,Hangzhou 310002,China)
出处
《水资源与水工程学报》
CSCD
北大核心
2024年第3期1-10,共10页
Journal of Water Resources and Water Engineering
基金
浙江省重点研发项目(2021C03017)。
关键词
极端土地利用变化
雨型
DHSVM模型
洪水分类
洪水特征
extreme land use change
rainfall type
distributed hydrological soil vegetation(DHSVM)model
flood classification
flood characteristics
