基于“源-汇”景观的永春县雨洪过程动态分析与风险评估

目的]探究雨洪过程中不同降雨重现期下“源—汇”景观的时空动态演变特征，并生成雨洪灾害分布格局，从而为“源—汇”景观单元规划与区域雨洪灾害预防提供科学参考。方法]以永春县景观因子指标数据为基础，引入可反映格局与过程关系的景观“源—汇”理论，基于最小累积阻力模型从景观因子阻力与径流动力平衡关系的角度重新划分“源”“汇”景观。结果]永春县初始“源”景观空间分布整体特征为“中部最高、西高东低”,且集中在戴云山脉附近，易成为山体径流的源头。永春县在自然排水状态下，易转化为“源”景观的土地利用类型排序为：草地>耕地>建设用地>林地>未利用地。草地一直具有较强的“源”作用，耕地在降雨重现期大于10年后“源”作用增强，建设用地与林地在降雨重现期小于20年时吸收雨水的能力较好，超过20年后建设用地的“源”作用偏强，林地的“汇”作用偏强，未利用地的“源”作用几乎无变化，其吸收雨水的能力有待后续的验证。当降雨重现期为100年时，永春西北部雨洪灾害风险较大，高风险区多集中在一都镇、桂洋镇、东关镇，需重点防患。结论]永春县雨洪灾害受到西北部山体径流影响，未来应从降低“源”景观、增...

Process Dynamic Analysis and Risk Assessment of Rainfall and Flood in Yongchun County Based on the Source-Sink Landscape

Objective] The spatio-temporal dynamic evolution characteristics of the source-sink landscape under different rainfall return periods in the process of rainfall and flood was explored, and the distribution pattern of rainfall and flood disasters was generated, so as to provide scientific reference for the source-sink landscape unit planning and regional rainfall and flood disaster prevention. Methods] Based on the landscape factor index data of Yongchun County, the landscape source-sink theory that can reflect the relationship between pattern and process was introduced. Based on the minimum cumulative resistance model, the source sink landscape was redefined from the perspective of the balance between landscape factor resistance and runoff dynamics. Results] The overall characteristics of the initial source landscape space of Yongchun County were the highest in the central region, high in the west, low in the east, which concentrated near the Dai yun Mountains, and was easy to become the source of the runoff of the mountain. Under the state of natural drainage, Yongchun County was easily converted into the source landscape land use type sorting: grassland>cultivated land>construction land>forest land>unused land; grassland always had a strong source effect. The source effect of cultivated land was enhanced after the rainfall return period was greater than 10 years. The construction land and forest land had better ability to absorb rainwater when the rainfall return period was less than 20 years. After 20 years, the source function of the construction land was stronger, while the sink function of the forest land was stronger. The source function of the unused land was almost unchanged, and its ability to absorb rainwater needs to be verified later. When the return period of rainfall is 100 years, the risk of rain and flood disasters in the northwest of Yongchun was relatively high. High risk areas mainly concentrated in Yidu Town, Guiyang Town and Dongguan Town, which need to focus on disaster prevention. Conclusion] The rain flood disaster in Yongchun County is affected by the mountain runoff in the northwest. In the future, it should be further studied from the perspective of reducing the source landscape and increasing the sink landscape.