KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 气候变化对中国天山雪冰流域水文过程的影响及不确定性分析 | |
| 冉思红 | |
| Subtype | 硕士 |
| Thesis Advisor | 罗毅 |
| 2018-06-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 新疆乌鲁木齐 |
| Degree Discipline | 理学硕士 |
| Keyword | 气候变化 气候模式 水文模型 冰川 径流 climate change general climate model hydrological model glacier runoff |
| Abstract | IPCC 第五次气候评估报告 (AR5) 指出，近 20 年来全球冰川整体处于退缩状态；冰川覆盖流域的水文过程对气候变化响应更为敏感。发源于亚洲高山地区的大部分河流，冰川和积雪融水对径流有重要贡献。天山广泛分布冰川，是众多流入中国新疆和中亚五国(哈萨克斯坦、土库曼斯坦、吉尔吉斯斯坦、塔吉克斯坦、乌兹别克斯坦)河流的发源地。研究表明，受气候变暖影响，天山冰川面积退缩，河川径流量及其年内分布发生变化。气候变化情景数据驱动水文模型是预估未来气候变化对水文过程影响的常用方法。 CMIP5 (Coupled Model Intercomparison Project Phase 5) 发布了 50 多个气候模式， 其结果可作为预估未来时期流域水文水资源变化的驱动数据。近年来已有较多研究利用 CMIP5 气候模式数据驱动水文模型，预估中亚天山、喀喇昆仑山、青藏高原、喜马拉雅山上雪冰流域未来雪冰水文过程变化。然而，不同气候模式输出的气温和降水等气象要素存在较大差异；驱动水文模型预估未来水文过程的结果必然存在差异； 通常采用多模式驱动水文模型，讨论预估结果的集合平均和不确定性区间。气候模式及其数目如何影响集合平均和不确定性值得讨论。本文研究了天山河源区五个不同冰川覆盖率的流域(台兰河， 32%；库玛拉克河， 22%；玛纳斯河， 11%；托什干河， 4 %；库车河， 0.4%；以 1960 年/1970 年的冰川数据为依据)未来水文过程的变化，以及气候模式选取对预估结果不确定性的影响。在 CMIP5 中，选取了总共 39 个的气候模式的 RCP2.6, RCP4.5, RCP8.5 三个情景，将气候模式数据降尺度处理，驱动分布式冰川水文模型 SWAT-RSG，模拟 1960s-2100 期间的流域水文过程，比较 2016-2045 年(未来近期)、 2066-2095 年(未来远期)与 1966-1995(历史时期)的变化；同时，在 RCP4.5 情景下以 38 个气候模式为母本，其中分别随机抽取 5 个、 10 个、 20 个气候模式，对预估的水文过程模拟结果进行统计分析，研究气候模式数目对预估结果的影响。得到如下认识：(1) 预估结果的不确定性区间随流域冰川覆盖率减小而增大；冰川融水具有对预估结果不确定性的缓冲作用； RCP4.5 情景下，从 38 个模式中选取不同数目的气候模式模拟结果集合，不同的组合方式预估的未来远期气温变化的不确定性范围大于未来近期；不同的组合方式预估的未来时期降水变化的不确定性范围在各流域存在差异。受气温的影响，在冰川覆盖率大的流域，径流变化范围和冰融水变化一致，不同的组合方式得到的未来近期径流变化范围表现出未来近期大于未来远期。(2) 38 个气候模式预估结果的集合平均表明，在 RCP2.6、 RCP4.5、 RCP8.5 三种情景下，各流域冰川融水的变化趋势均表现出先持续增加达到峰值，然后减小的变化趋势；在库车河流域，未来时期的总产流量在未来时期较历史时期均有增加；在玛纳斯河流域和托什干河流域，总产流量先增加再减小，且未来远期的产流量较历史时期有减少。 |
| Other Abstract | The IPCC fifth climate assessment report (AR5) pointed out that the globalmountain glaciers have retreated significantly, and the snow area in the northernhemisphere has continued to shrink in the past 20 years. Runoff in glacier covered basinsis more sensitive to climate change. Runoff from the rivers is supplied by glaciers andsnow-melting water in Asia's high mountain. They are important water source for humanto surviving and development in the downstream regions. The Tianshan Mountains withwidely distributed glaciers are the source of numerous rivers that flow into China'sXinjiang and five Central Asian countries (Turkmenistan, Tajikistan, Kyrgyzstan,Uzbekistan and Kazakhstan). Previous studies have shown that the glacier area hasshrunk, and the distribution of runoff within the year has changed due to the impact ofglobal warming in the Tianshan Mountains.Hydrological models driven by climate model data are commonly used to predict theimpact of future climate change on hydrological processes. The CMIP5 (Coupled ModelIntercomparison Project Phase 5) has published more than 50 climate models. The outputis the main source of data for estimating hydrological changes in the basin during thefuture period. In recent years, many studies have used data of CMIP5 climate models todrive hydrological models. The changes of runoff and snowmelt water or area of glaciersin the snow-ice basins in the future have been predicted, which are located in CentralAsia, such as the Tianshan Mountains, Karakoram, Tibetan Plateau or Himalayas.However, the meteorological elements such as temperature and precipitation output bydifferent climate models are quite different; the results of driving hydrological models topredict future hydrological processes are necessarily different; usually, multi-modeldriven hydrological models are used to discuss the collective and uncertainty of theprediction results. It is worthy to discuss the ensemble number of climate models affectaggregate mean and uncertainty.We selected five different glacial watersheds( Tailan River, 32%; Kumaric River,22%; Manas River, 11%; Toxkan River, 4%; Kuche River, 0.4%; based on glacier datafrom 1960s or1970s ) to study the hydrological processes changes in the future. And the impact of climate model selection on uncertainty of projected results. First, selected theclimate model data from CMIP5 is downscaled to drive the SWAT-RSG hydrologicalmodel under the scenarios of RCP2.6, RCP4.5, and RCP8.5. Simulate watershedhydrological processes during the 1960s-2100s and compared the changes in 2016-2045s(the near future), 2066-2095 (the far future) and 1966-1995 (history). What’ more, 38climate models were used as female parent in RCP4.5. And 5, 10, and 20 climate modelswere randomly selected. Statistical analysis was performed on the estimated hydrologicalprocess simulation results to study the number of climate models. The main researchresults and achievements were as follows:(1)The uncertainties of the predicted result increase with the decreasing area of theglaciered basins. Glacier melt has a buffer effect on the uncertainties of the predictedresults. Under the RCP4.5 scenario, different numbers of climate model ensemble whereselected from the 38 models. The predicted uncertainty range of the far futuretemperature changes by different combinations is greater than the near future. Thepredicted uncertainties ranges of the precipitation changes by different combinations aredifferent across basins. Affected by temperature, the range of runoff changes is consistentwith the changes in ice melt water in the watersheds with large glacier coverage. Therange of runoff changesinduced by different combinations shows that the future runoffwill be greater in the far future than that in the near future.(2) The ensemble average of 38 climate model projections under the three scenariosof RCP2.6, RCP4.5, and RCP8.5 shows that the trends of glacial melt water in each basinexperience a continuous increase to peak, and then decreased. In the Kuche River Basin,the total production flow will increase in the future compared with the historical period.In the Manas River Basin and the Toxkan River Basin, it will increase first and thendecrease. The far future production flow will decrease compared with the historicalperiod. |
| Subject Area | 自然地理学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14982 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 冉思红. 气候变化对中国天山雪冰流域水文过程的影响及不确定性分析[D]. 新疆乌鲁木齐. 中国科学院大学,2018. |
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