| 摘要: |
| 近40年,由于土地利用变化及水库调控影响,赣江上游下垫面条件变化,洪水形成过程受到影响。本文以平江流域为例,将1981－2021年流域土地利用情况划分为1985时期、2005时期及2020时期,采用情景分析法设置不同时期土地利用和水库调控情景,构建MIKE SHE模型并模拟各种情景下的洪水过程的洪峰、洪量及峰现时间,探究水库调控及土地利用变化对洪水的影响程度。结果表明:平江流域的土地利用变化是草地、耕地转化为林地及建设用地；其中草地、耕地各减少3.49%和1.72%,林地、建设用地分别增加3.98%和1.41%；土地利用变化下,洪水过程洪峰减少2.33%、洪量减少2.13%,峰现时间延后2h,土地利用变化下洪峰的变化大于洪量,在下垫面变化对洪峰、洪量及峰现时间影响中占39%、40%及54%；1985时期到2020时期水库调控对洪水过程主要发挥削峰错峰作用,降低洪峰3.59%,峰现时间增加8.06%,洪量削弱3.25%,在下垫面变化对洪峰、洪量及峰现时间变化中占61%、60%及46%；对大洪水、中洪水及小洪水模拟结果比较,发现水库调控主要影响大洪水、其次是中洪水,小洪水的敏感性相对弱,而土地利用变化下大洪水、中洪水响应程度低于小洪水,小洪水洪量、峰现时间相对洪峰对于土地利用变化更敏感,而大洪水及中洪水的洪峰对土地利用变化更敏感。本研究分析了变化环境下水库调控与土地利用变化分别在下垫面变化期间的洪水响应,可以为流域洪水预报提供科学参考,对水土保持有重要意义。 |
| 关键词: 土地利用变化 水库调控 洪水过程 MIKE SHE 平江流域 |
| DOI： |
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| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Effects of land use change and reservoir regulation on flood process: A case study in Pingjiang River Basin |
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Chen Junlin1, Wen Tianfu1, Li Guofang2, Xiao Yong3, Zhang Jingwen3, Lu Xiangyu3
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1.Jiangxi Academy of Water Science and Engineering;2.Hohai University;3.: Jiangxi Academy of Water Science and Engineering
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| Abstract: |
| During past 40 years, due to the influence of land use change and reservoir regulation, the underlying surface conditions of the upper reaches of Ganjiang River have changed, with the flood formation condition affected. Taking Pingjiang River Basin as an example, dividing the land use situation of the basin from 1981 to 2021 into 1985, 2005 and 2020 periods, this study adopted scenario analysis to set the land use and reservoir regulation scenarios in different periods. To explore the impact of reservoir regulation and land use change on flood, MIKE SHE model was constructed and simulated from the flood peak, flood volume and peak time of the flood process under various scenarios. The results show that the land use change tendency in Pingjiang River Basin is transforming the grassland, cultivated land into forest land and construction land. Grassland and cultivated land decreased by 3.49% and 1.72% respectively, while forest land and construction land increased by 3.98% and 1.41% respectively. With the land use changing, flood peak and flood volume decreased by 2.33% and 2.13%, the peak time was delayed by 2h, the change of flood peak was larger than the flood volume, and the influence of underlying surface change on flood peak, flood volume and peak time accounted for 39%, 40% and 54%. From 1985 to 2020, reservoir regulation and control mainly play a role in the flood process, the flood peak was reduced by 3.59%, the peak time was raised by 8.06% and the flood volume was weakened by 3.25%. The changes of underlying surface account for 61%, 60% and 46% of the changes of flood peak, flood volume and peak time. Simulation results of major flood, medium flood and small flood indicated that reservoir regulation mainly affects major flood, followed by medium flood, and the sensitivity of small flood is relatively weak. Under land use change, the response of major flood and medium flood is lower than that of small flood, the flood volume and peak time of small flood are more sensitive to land use change than flood peak. The flood peak of large flood and medium flood is more sensitive to land use change. This study analyzed the flood response of reservoir regulation and land use change during the change of underlying surface under changing environment, which can provide scientific reference for watershed flood forecast and has an important significance for soil and water conservation. |
| Key words: Land use change reservoir regulation flood process MIKE SHE Pingjiang River Basin |
