SWAT模型对景观格局变化的敏感性分析——以丹江口库区老灌河流域为例

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 SWAT模型对景观格局变化的敏感性分析——以丹江口库区老灌河流域为例 DOI: 10.5846/stxb201303070366 作者: 作者单位: 郑州大学水利与环境学院,郑州大学水利与环境学院,郑州大学水利与环境学院 作者简介: 通讯作者: 中图分类号: P333 基金项目: 国家自然科学基金资助项目（40971128）；水体污染控制与治理专项课题资助项目（2011ZX07213-001） Sensitivity analysis of swat model on changes of landscape pattern：a case study from Lao Guanhe Watershed in Danjiangkou Reservoir Area Author: Affiliation: School of Environment and Water conservancy, Zhengzhou University,,School of Environment and Water conservancy, Zhengzhou University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:景观的空间配置与类型组成能够对流域的产流、产沙及非点源污染产生影响。在以往SWAT模型研究中，往往默认水文模型考虑了该影响。为分析SWAT模型对不同景观格局变化的敏感性，根据老灌河流域2000年土地利用在各子流域的组成，模拟研究区更为破碎、复杂的景观空间配置，通过设置多套试验参数，利用SWAT模型生成基于不同景观格局的模拟结果。结果表明，SWAT模型不能反映除坡度和面积变化之外的景观水平下各斑块之间因景观空间格局改变对流域产流、产沙以及非点源污染的影响；模型通过其他参数的调整，弥补了模型分析数据的不足，使实测数据与模型部分结果高度吻合。这表明，一个能够反映流域部分水文特征的SWAT模型，未必是对研究区真实情形的模拟，而是各个参数间平衡的结果。因此，在利用SWAT模型分析模拟景观变化时，不应默认模型能够模拟景观空间格局改变对流域水文过程的影响，同时研究者可以通过划分坡度带，提高模型对不同坡度土地利用的敏感性。 Abstract:A number of studies have demonstrated effects of the landscape composition and spatial configuration on the runoff, sediment yield and non-point pollution in a watershed. The SWAT model(Soil and Water Assessment Tool) was widely employed to explore the significance of land management practices on water, sediment, and agricultural chemical yields, which subdivides a watershed into sub-basins connected by a stream network and contain many Hydrologic Response Units (HRUs) characterized by unique combinations of land cover, soil and slope attributes. In a variety of the previous studies, the interaction between hydrographic features and landscape characteristics was taken for granted in the SWAT model, and calibrated model was frequently used to predict the eco-hydrological variation induced by possible land use changes without investigating sensitivity of model on changes of landscape pattern, and the results of model would be used to provide scientific foundation for decision-making in land use management. For a better understanding of SWAT model response to different landscape patterns, this study obtained a series of SWAT model outputs in Lao Guanhe watershed which is one of the head source of Danjiangkou Reservoir Area, by setting two land use scenarios with different landscape metrics, which are characterized by landscape composition and configurations, and proposed to quantify landscape pattern. By comparing the results of SWAT model using the real land-use data in 2000 to that using the simulated land use data, which have exactly same mean slope and area of each land use type in each sub-basin as the real land use map. It was found that, the SWAT model could display a substantial correlation between the runoff, sediment yields, non-point source pollutants and with slope and area of land use type, but failed to demonstrate the sensitivity of the results of SWAT model to the difference in landscape metrics. Perhaps because the model calculated each HRU separately, then summarized them for the output of the watershed. That is to say, if the SWAT model was applied to evaluate the effects of planting trees in the riparian strips on water quality of a stream, only the increase of forest land area and the descent of forest land slope would be taken in account. However, the interaction between forest land and other land use types, which might be more significant in eco-hydrological dynamics, could not play a part in water quality evaluation by using SWAT model. With further analysis, it is found that the runoff outputs of SWAT model, by using land-use data with different landscape characteristics, could not only match the measured data, but perfectly match each other, just by adjusting model parameters. Therefore, an outwardly reasonable output of SWAT model could be a perfect simulation of real situations, or come from shrewd calibration of model parameters. As a result, the SWAT model is not the default one to simulate the hydrologic process changed by the change of landscape spatial configuration, the sensitivity of SWAT model on changes of landscape pattern can be enhanced by defining slopes with different gradients. 参考文献 相似文献 引证文献