土地利用/覆盖变化对永定河流域水文过程的可能影响模拟

SIMULATION OF THE POSSIBLE INFLUENCE OF LAND USE/COVER CHANGE ON THE HYDROLOGICAL PROCESS IN YONGDING RIVER WATERSHED OF CHINA

关键词:  土地利用/覆盖变化 水文 SWAT

Key words:  land use/cover change  hydrology  SWAT

摘要:

客观认识土地利用的空间配置对水资源空间变化的影响，揭示区域特殊的水土耦合关系，为流域水土资源合理利用提供重要的科学决策依据。文章利用1978、1987、2000和2005年土地利用类型图、土壤类型图和1970～2006年气候数据，基于SWAT模型，模拟了永定河流域的1981～1991年的月径流变化情况，并对模拟的结果进行了精度评价，在设定保持前一期气候不变情况下，根据不同土地利用/覆盖变化情景，模拟了径流过程，分析了土地利用/覆盖变化对平均流量的可能影响程度，结果表明：模型模拟结果精度已达到了模型应用的要求精度，而对土地利用/覆盖变化对水文影响研究中，1970s～2000s土地利用/覆盖变化对径流的可能影响程度最大，为23.33%，1980s～1990s影响程度最小，为9.69%，气候变化对流域的水文的可能影响程度达到了75%以上。总体看来，土地利用对流域的水文过程影响程度较低，制约水文变化的主要因素是气候。

Abstract:

Understanding the influence of spatial arrangement of land use on the spatial change of water resource objectively，and meanwhile revealing the special coupling relation between water and soil can provide an important basis for reasonable use of water and soil resource in the watershedBased on 1978，1987，2000 and 2005 land-use map，soil type maps and climate data from 1970 to 2006，this paper used SWAT model，a distributed hydrological model，to simulate the change of monthly average flow of Yongding River watershed and evaluate the accuracy of the simulation resultsKeeping the climate constant，it simulated runoff process and analyzed the influence of land use/cover change on surface runoff process within different land use/cover change scenariosThe results indicated that the model simulation accuracy had reached the requirements of the model application accuracyIn terms of the possible influence degree of land use/cover change on runoff，it was the largest with 23.33%from 1970s to 2000s，while it was the least with 9.69%from 1970s to 1980sThe possibility of climate change on hydrology of the watershed was more than 75%.Overall，the influence degree of land use on watershed hydrological processes was low，the climate was the main factor for the hydrological changes.