基于SWAT模型的张家口清水河流域土地利用情景变化对径流影响研究

Study on the Effect of Different Land Use Scenarios on Runoff in Qingshuihe Basin of Zhangjiakou Based on SWAT Model

土地利用是区域气候和环境变化的重要影响因素。以3S技术为依托,分析25年来张家口清水河流域土地利用类型变化特征,建立了流域SWAT模型并评价了其在张家口清水河流域的适用性,通过设置5种土地利用变化情景,定量分析了张家口清水河流域主要土地利用类型对流域径流的影响。结果表明:SWAT模型在张家口清水河流域具有很好的适用性。1990—2015年,张家口清水河流域的土地利用类型以林地、草地和耕地为主,3种土地利用类型面积总和均占流域总面积的96%以上。其中林地对径流量的影响系数为1.908 m^3/(km^2·h),草地对径流量的影响系数为1.836 m^3/(km^2·h),说明林地和草地都具有截留径流的作用,且林地的作用大于草地;耕地对径流量的影响系数为3.168 m^3/(km^2·h),说明耕地对径流起增加作用。因此,合理开发耕地资源,保护林草资源有利于促进张家口清水河流域生态环境质量的改善。

Land use is an important factor affecting regional climate and environmental change.Based on 3 S technology,we analyzed the characteristics of land use types change in Qingshuihe basin of Zhangjiakou over the past 25 years.The SWAT model was established and its applicability in the Qingshuihe basin of Zhangjiakou was evaluated.Five land use change scenarios were set up to quantitatively analyze the impact of main land use types on runoff in the Qingshuihe basin of Zhangjiakou.The results showed that SWAT model had good applicability in Zhangjiakou Qingshuihe basin.From 1990 to 2015,the main land use types of Qingshuihe basin in Zhangjiakou were woodland,grassland and cultivated land.In the meanwhile,the sum of the three types of land use area accounted for more than 96%of the total basin area.The influence coefficient of woodland on runoff was 1.908 m^3/(km^2·h),and the influence coefficient of grassland on runoff was 1.836 m^3/(km^2·h),showing that both woodland and grassland had the function of intercepting runoff,and the role of woodland was greater than that of grassland.The influence coefficient of cultivated land on runoff was 3.168 m^3/(km^2·h),indicating that cultivated land played an important role in increasing runoff.Therefore,reasonable development of cultivated land resources,protection of forestland and grassland resources are conducive to improving the ecological environment quality of Zhangjiakou Qingshui River basin.