未来气候变化对黄土高原黑河流域水资源的影响

气候变化对黄土高原的水资源有重要影响,对其影响进行评估可以为区域发展提供重要的决策依据.基于分布式水文模型SWAT和4种全球环流模式的各3种排放情景,评估了2010～2039年黄土高塬沟壑区黑河流域水资源对气候变化的潜在响应.结果表明,黑河流域2010～2039年的年均降水变化-2.3%～7.8%,年均最高和最低温度分别升高0.7～2.2 ℃和1.2～2.8 ℃,年均径流量变化-19.8%～37.0%,1.2 m剖面年均土壤水分含量变化-5.5%～17.2%,年均蒸散量普遍增长0.1%～5.9%;水文气象变量变化趋势复杂,但T检验表明年降水、径流、土壤水分和蒸散增长的概率较大.对于季节变化,降水可能在12～7月份和9月份增长,8月份和10～11月份减少;径流在4～7月份和9～10月份增加,11～3月份和8月份减少;土壤水分在各月都增长;蒸散11～6月份普遍增长,7～10月份减少的可能性较大.未来气候将发生显著变化并对水资源有重要影响,需采取必要的措施来减缓其不利影响.

The impacts of future climate change on water resources in the Heihe Watershed on the Loess Plateau

Climate changes can influence the water resources in the Loess Plateau greatly, and evaluating the impacts will provide helpful information for decision-making of regional development. Based on the SWAT (soil and water Assessment Tools) model and four GCMs (General Circulation Models) under three emission scenarios, this study assessed the potential impacts of climate change on water resources in the Heihe watershed on the Loess Plateau during 2010-2039. Climate models predicted a -2.3% to 7.8% change in annual precipitation, 0.7℃ to 2.2℃ rises in maximum temperature, and 1.2℃ to 2.8 ℃ rises in minimum temperature. Climate change will affect the hydrologic situation of Heihe watershed; SWAT model predicted a -19.8% to 37.0% change for annual runoff, a -5.5% to 17.2% change for annual soil water content, and a 0.1% to 5.9% increase for annual evapotranspiration. Though the change trends of hydro-meteorological variables are complex, T-test showed that annual precipitation, runoff, soil water and evapotranspiration would increase with a high probability. For seasonal change, precipitation would possibly increase from December to July and in September while decrease in August and from October to November, runoff would increase from April to July and September to October while decrease in August and from November to March, soil water would possibly increase all the year, evapotranspiration would increase from November to June while decrease from July to October. Overall, the results showed that climate would change significantly and some countermeasures were necessary to reduce the adverse effects.