摘要
泥沙连通性是表征泥沙在地貌单元间物理级联关系的重要参数,探讨其对土地利用变化的响应,对揭示流域内部水沙动态以及不同土地利用类型的水土保持效应具有重要意义。基于延河流域1990—2019年土地利用与径流输沙量等数据资料,结合连通性指数(index of connectivity,IC)分析土地利用变化对泥沙连通性时空分布的影响及与径流输沙量的关系。结果表明:1)近30年来,延河流域土地利用变化以退耕还林还草为主,加之少量的建设用地扩张。2)1990—2019年,延河流域IC整体呈下降趋势,截至2019年降低17.85%。退耕还林还草和建设用地扩张可有效降低泥沙连通程度,且退耕还林还草具有长期生态效益。3)IC存在明显的空间分异规律,呈现由南向北、由东向西的增加趋势。流域中部是主要退耕还林还草区和建设用地扩张区,也是泥沙连通性明显下降区;流域西北部泥沙连通性较高,且随土地利用变化降幅较小;流域南部泥沙连通性低。4)IC与输沙量之间存在显著正相关关系(P<0.05),适用于流域输沙预测。研究成果可为深入理解流域泥沙输移过程提供科学依据,并为布局和优化土地利用提供参考。
Sediment connectivity is an important parameter to characterize the physical cascade relationship of sediment between geomorphic units.It is of great significance to explore the response of sediment connectivity to land use change,which is helpful to reveal the dynamic of runoff and sediment load and evaluate the soil and water conservation capacity of different land use types.In this study,based on the data about land use,runoff and sediment load from 1990 to 2019,the index of connectivity(IC)was used to quantify the spatial and temporal variation characteristics of sediment connectivity and its relationship with runoff and sediment load under the background of land use change in Yanhe River Basin.The results showed that:1)In recent 30 years,the land use change has been dominated by the Grain for Green,coupled with a small amount of the expansion of construction land in this basin.2)From 1990 to 2019,the IC showed a downward trend as a whole,with a decrease of 17.85%in 2019.Grain for Green and the expansion of construction land could effectively reduce sediment connectivity,and the former also had long-term ecological benefits.3)IC had obvious spatial distribution characteristics,which showed an increasing trend from south to north and east to west.Among them,the middle of the basin was the main region of Grain for Green and construction land expansion,and thus significantly reduced sediment connectivity.The northwest of the basin had higher sediment connectivity,and its decreasing extent became smaller with land use change.The sediment connectivity in the south of the basin was lower.4)There was a significant positive correlation between IC and sediment load(P<0.05),and thus it was more suitable for the prediction of sediment load.The results can provide a scientific basis for the research of sediment transport process in the basin,and further provide a reference for the layout and optimization of land use.
作者
边熇
朱冰冰
黎珩
王蓉
唐馨怡
BIAN He;ZHU Bingbing;LI Heng;WANG Rong;TANG Xinyi(School of Geography and Tourism,Shaanxi Normal University,Xi an 710119,Shaanxi,China)
出处
《陕西师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第6期47-55,共9页
Journal of Shaanxi Normal University：Natural Science Edition
基金
陕西省重点研发计划(2021ZDLSF05-02)
国家自然科学基金(41601285)。
关键词
泥沙连通性
退耕还林还草
延河流域
水沙特征
连通性指数
sediment connectivity
Grain for Green Project
Yanhe River Basin
characteristics of runoff and sediment load
index of connectivity(IC)
