土地利用/覆被变化对区域径流的影响——以秦皇岛地区为例

Impacts of Land Use/Land Cover Change on the Runoff of Qinhuangdao Area

土地利用方式的变化是影响流域径流的重要因素。为定量研究土地利用/覆被变化对径流的影响,该文结合SWAT(Soil and Water Assessment Tool)分布式水文模型,分析了秦皇岛地区2000年、2005年、2010年和2014年不同土地利用/覆被变化对径流的影响,并在子流域尺度上分析径流的空间变化。研究结果表明:1)SWAT模型能够较好地模拟研究区流域的月径流过程。2000-2005年研究区耕地急剧增加,林地和裸地减少,导致多年平均径流量增加4.79%;2005-2010年林地明显增加,耕地和裸地减少,导致多年平均径流量减少3.32%;2010-2014年城镇建设用地增加明显,耕地和林地减少,导致多年平均径流量增加2.62%。2)耕地和城镇建设用地的增加在不同程度上会增加径流量,而林地具有涵养水源、减少径流量的作用。3)研究区年均地表径流变化空间差异较显著,整体呈增加趋势。研究结果可为合理规划土地利用格局、优化配置水资源提供参考依据。

Land use/land cover change is a predominant factor to influence the watershed runoff. In order to quantitatively evalu- ate the impacts of land use/land cover change on runoff, based on the Soil and Water Assessment Tool （SWAT）, combined with the land use, climate, soil and hydrographic data,we analyzed the runoff in 2000,2005,2010 and 2014 with land use/land cover changes in Qinhuangdao, and then investigated the spatial variation of runoff on watershed scale. Results showed that the SWAT model can simulate the monthly runoff process well in Qinhuangdao Area. From 2000 to 2005, the cropland increased sharply with the decrease of the forest and the bare land, causing an increase of the average annual runoff by 4.79 -. From 2005 to 2010, the forest grew significantly, while the cropland and bare land declined, these changes led to the average annual runoff reduced by 3.32 ;//0. From 2010 to 2014, the average annual runoff increased by 2.62 - due to the expansion of construction land and the reduction of the cropland and forest. Therefore, the expansion of cropland and construction land will increase the runoff to some extent,whereas the forest has the function of water conservation and runoff reduction. Moreover, the spatial difference of annual surface runoff was significant over the whole area. The results can provide a reference for the rational planning of land use pattern and optimal allocation of water resources.