基于Budyko假设和SCS-CN模型的河源区水源涵养功能研究

Study on the Water Conservation Function Based on Budyko Hypothesis and SCS-CN Method in the Headstream Area of the Qinhe Basin

河源区作为一种重要生态功能区,具有重要的生态系统服务功能。以沁河源区为例,利用Budyko假设和SCS-CN模型研究了其水源涵养功能空间分布特征,并比较了不同土地利用类型、海拔和坡度下的水源涵养能力。结果表明:(1)沁河源区多年平均水源涵养量为306.48mm,水源涵养总量为4.19亿m^3;(2)不同土地利用类型水源涵养功能不同,落叶阔叶林和常绿针叶林的水源涵养贡献率和水源涵养量均值最大,贡献率分别为43.99%和42.00%,水源涵养量均值分别为330.41mm和364.53mm;(3)不同海拔高度上水源涵养功能不同,海拔1 000~1 500m地区是水源涵养功能的主体,水源涵养量均值在海拔1 500~2 000m地区最大,为401.71mm;(4)不同坡度上水源涵养功能不同,缓坡和斜坡的水源涵养贡献率最大,急坡、陡坡和险坡上水源涵养量均值分别为373.62mm,368.32mm和363.94mm。

The headstream area,as an important ecological function area,has important ecosystem services.The spatial distribution characteristics of water conservation function and water conservation capacity of different land use types,elevation and slope in the headstream area of the Qinhe basin were analyzed using Budyko hypothesis and SCS-CN method.The results indicated that:(1)the 306.48 millimeters of water depth and the 419 million cubic meters of water were conserved in the study area;(2)water conservation functions of different land use types were different;the deciduous broadleaf and evergreen coniferous forests conserving 330.41 mm and 364.53 mm of mean water were the main contributors to water conservation,of which contribution rates were 43.99%and 42.00%,respectively;(3)water conservation differred with attitudes;the areas with the elevation of 1 000~1 500 m were the main parts of water conservation function and the areas with the elevations of 1 000~1 500 m provided the largest water conservation which was 401.71 mm;(4)the different slopes also had different effects on water conservation;the mean values of water conservation on steep slopes,abrupt slopes and risk slopes were 373.62 mm,368.32 mm and 363.94 mm,respectively.