黄垒河流域气候与土地利用变化对径流的影响

Impact of climate and land use change on runoff in Huanglei River Basin

以山东胶东半岛黄垒河流域为研究区,构建了SWAT分布式水文模型,采用SUFI-2算法进行模型参数敏感性分析、率定与验证研究,对巫山水文站2011-2018年月径流量数据进行模拟,在此基础上设置3类变化情景,定量识别黄垒河流域内气候变化与土地利用变化下的水文响应情况.结果表明:1)SWAT模型在黄垒河径流模拟中具有较好的适用性,模型率定期的R2、ENS分别为0.74和0.71,验证期R2、ENS分别为0.69和0.72;2)综合型情景模拟分析得出,气候变化、土地利用变化及二者共同变化均引起流域内年均径流增加,分别使年均径流量增加0.14、0.05、0.19 m3·s^-1,径流量对气候变化比土地利用变化更敏感,径流变化由气候变化主导;3)气候变化情景模拟分析得出,流域内年均径流量与降水变化成正相关,降水增加比降水减少对径流变化作用更显著,气温升高对流量变化有负效应,流量对气温升高比气温降低更敏感;4)极端土地利用情景模拟分析得出,城市扩张情景、耕地保护情景、退耕还林情景、城市绿化情景下,年均径流变化率分别为5.04%、2.71%、-8.17%、-4.23%,居民地、耕地具有增流作用,且居民地增流作用大于耕地,林地则具有较显著的减流作用.需加强对流域内气温和降水,特别是强降雨的预测和防汛预警,并通过优化土地利用结构及空间布局减缓气候变化带来的水文负效应,实现流域水量平衡.

A soil and water assessment tool(SWAT)was developed to simulate monthly hydrograph from 2011-2018 in Huangleihe Basin in Jiaodong Peninsula,and to analyze impact on runoff by changes in land use and climate.R2 and ENS were found to be 0.74 and 0.71,0.69 and 0.72 respectively for calibration and validation periods,suggesting that the model was capable for runoff simulation in the watershed.Increases in runoff under integrated scenario were found to take place in response to changes in climate,land use and in both;climate was found stronger than land use in doing so.Analysis of climate change indicated that changes in runoff were positively correlated with changes in precipitation,negatively correlated with changes in temperature.Four extreme sub-scenarios of land use were found to increase annual runoff by 5.04%and 2.71%,or to decrease by 8.17%and 4.23%,suggesting that forest land intercepts rainfall ion,residential and cultivated lands do not.Strengthening prediction of rainfall and optimizing land use structure would mitigate negative hydrological effects due to climate change,thereby achieving water balance.