基于SWAT模型的无定河流域水供给服务空间流动模拟

Simulation of water provision services flow in Wuding River Basin based on the SWAT model

利用SWAT(soil and water assessment tool)水文模型,在子流域尺度上探究了2005—2018年无定河流域水供给服务供给与需求的时空关联特征,并定量模拟了水供给服务的空间流动过程。结果表明:(1)2005年、2010年、2015年和2018年无定河流域水供给服务的供给量呈现逐年增多趋势;在空间分布上,流域中下游水供给量较多,上游地区水供给量不足;2005—2018年流域用水需求量也逐年增多,在空间分布上,榆阳区、绥德县、子长市等城镇所在子流域的水需求量较大,上游林地、草地、沙地广布,需水量较少。(2)2005—2018年水供给服务安全格局显示,流域仅有48.67%的面积为服务安全等级,服务安全存在风险,脆弱、易危和濒危地区需要加以关注并采取相关措施。(3)结合供需关系,模拟了流域内3个主要受益区(榆阳区、靖边县、沙尔利格镇及其周边区域)水供给服务流流向与流量的变化。

To clarify the supply and demand state and spatial flow process of water provision services in the Wuding River Basin,the SWAT hydrological model is used to explore the spatial and temporal correlation between supply and demand of water provision services in the Wuding River Basin at the sub-basin scale,and the spatial flow process of water provision services is simulated quantitatively.The results show that:(1)The supply of water provision services in the Wuding River Basin in 2005,2010,2015 and 2018 appeared an increasing trend year by year,and in terms of spatial distribution,there was more water supply in the middle and lower reaches of the basin and insufficient water supply in the upstream areas.The water demand in the basin also increased year by year from 2005 to 2018.In terms of spatial distribution,the Yuyang district,Suide county,Zichang city and other towns are located in the sub-basin where the water demand is higher,and the upstream woodland,grassland and sandy land are widely spread where less water is required.(2)The water provision service security pattern during 2005-2018 showed that only 48.67%of the basin area is at service security leve l.Hence,service security is at risk and fragile,vulnerable and endangered areas need to be concerned and relevant measures should be taken.(3)The changes in flow direction and flow rate of water provision services flow in three major beneficiary areas in the basin,namely Yuyang district,Jingbian county,Sha'erlige town and its surrounding areas,were simulated in conjunction with the supply and demand relationship.