基于RCP情景的黄河流域未来气候变化趋势

Variation Trend of RCP-based Climatic Scenarios for Yellow River Basin

根据国家气候中心提供的7个气候模式的情景资料和黄河流域108个站点的实测气候要素资料,评估了不同气候模式对黄河流域历史（基准期1961～1990年）气候要素的模拟能力,在此基础上,采用较为适合黄河流域的气候模式资料,分析了不同RCP排放情景下黄河流域未来的气候变化趋势.结果表明,MPI-ESM模式能够较好地模拟黄河流域气温降水的历史变化.黄河流域未来气温将持续升高,线性升率约为0.28～0.45℃/10a,未来降水变化具有较大的不确定性,与基准期相比,未来黄河流域降水与基准期基本持平或偏少.气温降水变化的季节分配和空间分布差异明显,2、8、9月份升温幅度较大,5月份升温幅度较小;2、5、12月份降水普遍增多,6～8月份降水减少;黄河源头及宁夏内蒙河段升温幅度较大;黄河源头降水以增多或减少幅度较小为主,中游下段及下游地区降水以减少为主.

Based on historical simulations of 7 GCMs provided by CMA and the recorded climatic data from the 108 basic national meteorological stations within the Yellow River Basin, suitability of the 7 CMIP5 GCMs to the Yellow River Basin was assessed with three indices of mean, standard deviation, and linear trend rate. Variation trend of climate for the next decades over the Yellow River Basin was then analyzed with climatic projections of the most suitable GCM under the RCP emission scenario. The results show that MPI-ESM performs better for historical simulation of climatic variables as comparing to other GCMs. Temperature over the Yellow River Basin was projected a steady rising trend with linear rising rate of 0.28-0.45~C/10a, while precipitation will probably undergo a slight decline trend with high variability from 2021 to 2050, in which multi-year average is equivalent to or slight less than the baseline （1961-1990）. Under the three RCP scenarios, seasonal patterns as well as spatial patterns of temperature and precipitation during 2021-2050 were all changed relative to baseline. Higher temperature rise will probably occur in February, August, and September, and lowest rise occur in May. Precipitation in February, May, and December will likely get a higher increase while those in June to August are all less than baseline. Spatially, higher temperature rise will occur in source area of the Yellow River, and the reaches of Ningxia and Inner Mongolia autonomous regions, precipitation change is from positive in the source area to negative in the lower reaches of the Yellow River for RCP 26 and RCP85 scenario, RCP45scenario will probably make precipitation in most area of the Yellow River basin less than baseline.