知识与财富的链接
石羊河流域是河西走廊水资源利用率最高、供需矛盾最突出的地区.本文选取石羊河中上游流域为对象,基于流域水文模型SWAT,研究1988年-2005年以及未来多种气候情景下出山口径流的变化特征,探讨气候变化对其中上游地区水文情势以及水资源的影响.研究表明:①采用SWAT模型对石羊河各条支流径流模拟已能够体现该流域中上游地区的降水径流特性,模拟精度满足未来气候变化对流域水文情势影响分析的要求;②通过调整历史降水和潜在蒸散发驱动SWAT模型对比分析未来A2和B2情景下2020s(2020年-2037年)、2050s(2050年-2067年)和2080s(2080年-2097年)三个时间段径流过程.未来A2和B2情景下石羊河流域降水和潜在蒸散发持续增加,但降水增幅略高.由此导致径流呈持续上升趋势,但增幅较小.A2与B2情景相比,A2情景下降水和潜在蒸散发的增幅均略高于B2情景.气候变化影响下未来石羊河流域径流量将略微增加,杂木寺断面增幅为1.37％～9.03％,而西营断面增幅为0.12％～5.04％.研究可为气候变化环境下的石羊河流域水资源综合管理规划提供技术支撑和依据.
The Shiyang River Basin has a highest utilization rate for water resources. In this study, a distributed hydrologic model (SWAT) of the middle and upper region of Shiyang River Basin was developed and validated to quantify the impact of climate change. Runoff variation characteristics in the four periods were simulated: 1990s(1988 to 2005), 2020s(2020-2037), 2050s(2050-2067) and 2080s(2080-2097) under different future scenarios and the impact of climate change on future hydrologic regimes and water resources quantified. We found that runoff in every tributary was better simulated based on SWAT and the accuracy supported the impact analysis of future climate change. For the unregulated stations (Zamusi and Jiutiaoling), the average efficiency coefficient was greater than 0.75 and the average relative coefficient was greater than 0.80. For regulated stations expect Shibalipu reservoir, the average efficiency coefficient was greater than 0.40 and average relative coefficient was greater than 0.60. Comparing A2 and B2 scenarios with baseline (1990s), future precipitation and potential evapotranspiration in the 2020s, 2050s and 2080s increase continuously. The rate of monthly precipitation is from -12% to 134% in A2 scenario, -2% to 98% in B2 scenario while the rate of monthly potential evapotranspiration is from 3% to 29% in A2 scenario, 1% to 19% in B2 scenario. The rate of precipitation is greater and the most significant month is April for precipitation and August for potential evapotranspiration. Thus, runoff also increases continuously, but the rate is lower. Comparing the precipitation and potential evapotranspiration under A2 with B2 scenarios, the rate of increase for both in A2 are higher than for B2. Runoff in the middle and upperstream of the Shiyang River Basin will increase slightly; at Zamusi station, it increases from 7.31m3/s in 1990s to 7.97m3/s (A2 scenario) and 7.45m3/s (B2 scenario) in 2080s. The increasing rate is between 1.37% and 9.03%. At Xiying station, it increases from 8.14m3/s in the 1990s to 8.55m3/s (A2 scenario) and 8.26m3/s (B2 scenario) in 2080s. The increasing rate is between 0.12% and 5.04%. The increasing rate in A2 is a greater than for B2 scenario. All studies are expected to support an integrated river basin water resource management system for the Shiyang River Basin under a changing climate.
