气候自然变异与气候强迫变化对径流影响研究进展

Advances in studying impacts of climate natural variability and forced change on stream flow

在回顾IPCC自1990年至2007年4次关于气候变化对径流影响评价报告进展的基础上,将第一次与第二次评价报告归纳为第一代,主要以气候均值变化对径流影响及其适应为主要特征;第三次与第四次评价报告为第二代,主要突出人为强迫与气候自然变异变化对径流影响及其适应问题。分析了气候变化对水文水资源影响评价方法的发展过程与存在的问题,认为目前的气候影响评价反映了气候年代自然变异的影响,但未考虑与极端事件发生频次和强度变化密切相关的气候日、季和年际尺度变化的影响,从而低估了气候变暖对洪水、干旱以及农业灌溉需水的负面作用。在介绍国内外研究的基础上,为下次IPCC评价报告,提出了应加强水文、气候交叉学科研究气候变化与自然变异对水影响的后果及其适应等问题的建议。

Based on the review of the course of successive 4 Assessment Reports of the IPCC WGII on climate change impact on streamflow, started from 1990, it was summarized that the First （FAR） and Second （SAR） seemed as first generation studies, characterizing the impact of change in mean climate and adaptation to it, while the Third （TAR） and Forth（AR4）Assessment Reports as second generation study, which emphasized the impact of climate forced change and natural variability on streamflow and adaptation to them. The progress and issues in studying methodology of climate change on hydrology and water resources were analyzed. Therefore, it was pointed out that the impact of deeadal and multi-deeadal variability of climatic parameters on streamflow can be identified, but the changes in interannual and day to day variability were not taken into account in the conventional methodology of hydrological impact studies, hence as the results, the impact of climate change on extreme events, such as droughts and floods and irrigation water demands were underestimated. As for further studies, the paper came to conclusion suggesting to emphasize the cross cutting study between hydrology and climatology on the hydrological consequences of climate natural variability and climate forced change impacts during the next IPCC Assessment Report.