气候变化已成为目前全球最为重要的环境问题之一, 气候变化将通过加速水文循环进而对区域水资源产生重要影响。采用统计分析和数学模拟方法, 分析了气候变化对中国华北粮食主产区水资源的可能影响。结果表明: 过去50年黄河中下游地区和海河流域河川径流呈现显著性减少趋势, 淮河流域及黄河上游河川径流为非显著性变化；其中, 1980年以来海河流域实测径流量较前期减少超过50%。未来30~50年华北粮食主产区气温将持续上升, 降水的不确定性更大, 总体呈现弱增加趋势。受气温升高和降水变化影响, 未来几十年水资源总体以略微偏少为主, 但存在区域性增多的可能; 在RCPP2.6、RCP4.5和RCP8.5排放情景下, 区域水资源较基准期(1961-1990)分别变化?1.3%、1.0%和?2.3%。在空间分布上, 黄河中游水资源可能略有增多, 但淮河和海河流域水资源很可能进一步减少, 华北粮食主产区水资源供需矛盾可能会因气候变化而更为突出。加强节水型社会建设、水利工程建设以及充分利用非传统水源是该地区未来适应气候变化的核心工作。
Climate change, as one of the important global environmental issues, distorts the hydrologic cycle and therefore has significant implications for regional water resources. The grain production belt of the North China mainly consisting of the Yellow River Basin, Hai River Basin and Huai River Basin is the region most vulnerable to climate change in China. The major water issues in this region (including severe shortage of water resources and increasing regional flooding) have attracted significant attentions from both the central government and local communities. It is therefore critical to analyze future trends in water resources and seek for adaptive strategies to climate change in the region. Using statistical methods such as the Mann-Kendall test, variations of historical runoff recorded during the period 1950-2010 at ten key hydrometric stations on the main streams of the Yellow River, Hai River and Huai River were analyzed. Based on seven GCM projects under the three emission scenarios of RCP2.6, RCP4.5 and RCP8.5, the VIC (Variable Infiltration Capacity) model was used to simulate future water resources in these basins. Using 1961-1990 as the baseline period, changes in future water resources were analyzed for each decade. The results suggested that the recorded runoffs in the middle and lower reaches of both the Yellow River Basin and the Hai River Basin significantly decreased in the last 50 years. There was a insignificant change in the Huai River Basin and in the upper Yellow River Basin. For the Hai River Basin in particular, recorded runoff after 1980 deceased by over 50% compared to the value in 1961. While projected temperature steadily rose in the next 30-50 years, precipitation slightly increased over the period. Changes in water yields under the RCP2.6, RCP4.5 and RCP8.5 climate scenarios were estimated to change by ?1.3%, 1.0% and ?2.3%, respectively, distorting the spatial distribution of water resources in the region. Water resources in the middle Yellow River Basin increased while those in both the Hai River Basin and the Huai River Basin decreased, particularly under the RCP8.5 climate scenario. The degree of water shortage in the main grain production belt of the North China was aggravated by the simulated climate change. The core activities of adaptation to climate change included enhancement of the construction of water-saving society, the full use of non-traditional water resources and also the speeding up of the planning and implementation of water conservancy projects in the region.