东洋河流域土地利用及气候变化对径流的影响

Effect of land use and climate change on runoff in Dongyang River basin

为分析东洋河流域土地利用与气候变化对径流的影响,选用SWAT分布式水文模型,通过情景分析法模拟变化环境下流域的径流响应。结果表明:①SWAT模型在东洋河径流模拟过程中具有较好的适用性且不确定性较小。②按现有土地利用和气候变化趋势,单一因子和共同作用对径流均有削减作用(即水文负效应),将会造成下游用水形势更加严峻,并影响整个洋河流域的生态环境。③未来气候变化情景中,径流量与降雨变化呈正相关关系,与气温变化呈负相关关系。④极端土地利用情景中,增加耕地和林地使年均径流量减少,增加草地使径流量增加。⑤影响未来流域年均径流的主要因素是气候变化,土地利用变化的影响相对较弱。土地利用的变化对调蓄径流有一定作用,可缓解气候变化带来的水文负效应,有助于流域水资源的科学管理。

To quantify the effect of land use and climate change on runoff in Dongyang River basin, the distributed hydrological model SWAT was adopted to simulate runoff variation in the basin under changing environment by scenario analysis. The results showed that: ① The SWAT model had good applicability to runoff simulation in Dongyang River basin, and the uncertainties of simulation was acceptable. ② According to the current land use and climate change trends, both a single factor or two factors could reduce runoff(i.e., negative effect of hydrological change), which may cause a severe shortage of water supply in downstream and affect whole ecological environment in the basin. ③Under the future climate change scenario, there was a positive correlation between runoff and precipitation but a negative correlation between runoff and temperature.④ Under the extreme land use scenario,the increase of cultivated land and forest land could decrease the annual average runoff but the grassland increase could yield more runoff.⑤ The climate change was a key factor that affected the annual average runoff in the future, and the land use change had a relatively weak effect. However, the land use change also played a role in runoff regulation and storage, thereby alleviated the negative effect of hydrological change, which was conducive to scientific management of water resources.