Master thesis in Sustainable Development 2018/13 Examensarbete i Hållbar utveckling Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi Jieying Shi DEPARTMENT OF EARTH SCIENCES INSTITUTIONEN FÖR GEOVETENSKAPER Master thesis in Sustainable Development 2018/13 Examensarbete i Hållbar utveckling Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi Jieying Shi Supervisor: Rickard Petterson Evaluator: Veijo Pohjola Copyright © Jieying Shi and the Department of Earth Sciences, Uppsala University Published at Department of Earth Sciences, Uppsala University (www.geo.uu.se), Uppsala, 2018 Contents 1. Introduction ...................................................................................................................... 1 2. Aim and research questions ............................................................................................ 2 3. Background ...................................................................................................................... 3 3.1. Study Area .............................................................................................................. 3 3.2. The Importance of Ürümqi River and UG1 ........................................................... 3 4. Method and Data ............................................................................................................. 5 4.1. Distributed Enhanced Temperature Index Model ................................................... 5 4.2. Data ........................................................................................................................ 6 4.3. Model Setup ........................................................................................................... 7 4.4. Calibration .............................................................................................................. 8 4.5. Future Scenarios ..................................................................................................... 9 5. Result ............................................................................................................................... 11 5.1. Calibration Result .................................................................................................. 11 5.2. Future Scenario Correction Result ....................................................................... 12 5.2.1. Temperature Correction ............................................................................ 13 5.2.2. Precipitation Correction ............................................................................ 15 5.2.3. Discharge Correction: ............................................................................... 17 5.3. Scenarios Result ................................................................................................... 18 5.3.1. Temperature .............................................................................................. 18 5.3.2. Precipitation .............................................................................................. 19 5.3.3. Discharge .................................................................................................. 21 6. Discussion ....................................................................................................................... 23 6.1. Model and Uncertainty ......................................................................................... 23 6.2. A broad perspective on CMIP5 climate model biases .......................................... 23 6.3. Human-water System ........................................................................................... 24 6.4. Further Study Based on Future Monitoring.......................................................... 25 6.5. Delimitation .......................................................................................................... 25 7. Conclusion ...................................................................................................................... 27 8. Acknowledgement .......................................................................................................... 28 9. Reference ......................................................................................................................... 29 Appendix ................................................................................................................................ 37 Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi JIEYING SHI Jieying, Shi., 2018: Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi. Master thesis in Sustainable Development at Uppsala University, No. 2018/13, 44 pp, 30 ECTS/hp Abstract: Glaciers are known to be prone to climate change. The Xinjiang Uyghur Autonomous Region, China, has approximately 20,000 glaciers, which accounts for half number of glaciers in China. One of important function of glacier is that it provides meltwater, therefore, the glacier response to a warming temperature in this area is becoming critical to be investigated in relation to water sustainable development. The Ürümqi Glacier No.1 (UG1), as one of the most important glaciers, has a dominant role of providing meltwater for the capital city, Ürümqi. In this thesis, the Distributed Enhanced Temperature Index Model (DETIM) was employed, and calibrated to perform UG1’s historical discharge pattern. Then the calibrated discharge model was grafted to future climate projection of four Representative Concentration Pathways (RCPs) from fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), in order to investigate UG1’s water supply potential in the future. Moreover, UG1’s water supply role was discussed under a dynamic interaction between water supply and human society in the end. The result showed that the computation meltwater volume is between 121 million m³ to 131 million m³ in 35 years, from 2016 to 2050. Keywords: sustainable development, climate change, glacier, discharge model, water supply Jieying Shi, Department of Earth Sciences, Uppsala University, Villavägen 16, SE- 752 36 Uppsala, Sweden Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi JIEYING SHI Jieying, Shi., 2018: Modeling response of glacier discharge to future climate change, Glacier No.1, Ürümqi. Master thesis in Sustainable Development at Uppsala University, No. 2018/13, 44 pp, 30 ECTS/hp Summary: Glaciers are an important source of fresh water and have gained increasing study interests worldwide. Currently, climate change has posed a long-lasting effect on glaciers, and glacier recession has been discussed and investigated from a water sustainable development perspective as never before. Many studies have been conducted on a global and regional scale with the aim to explore the glacier response to climate change, especially in areas that are relatively depending on seasonal glacier meltwater as the main source of water supply. This study picked up the Glacier No.1 (known as “UG1, located in Ürümqi, China), as the study area, and provided a comprehensive investigation starting from the calibration of discharge model to future discharge projection, and then the projected discharge was discussed in a dynamic interaction between water supply and human society. The Distributed Enhanced Temperature Index Model (DETIM) was employed to compute discharge, and calibrated with measured climate and discharge data of UG1. The future climate projection of four Representative Concentration Pathways (RCPs) were extracted and dynamically downscaled to UG1 location from ESM2G model, belonging to fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). Keywords: sustainable development, climate change, glacier, discharge model, water supply Jieying Shi, Department of Earth Sciences, Uppsala University, Villavägen 16, SE- 752 36 Uppsala, Sweden 1. Introduction Glaciers are important to humans and other beings as it is one of the major sources storing fresh water on earth (Brown et al. 2010; Fry 2010). Glacier can be found not only in vast ice sheets polar regions, but also in mountainous regions on every continent (Miller 1961). Approximately, glaciers cover about 10 percent of Earth's land surface. However, glaciers are rather sensitive to climate change and has been continuously exposing to an increasing global temperature (Cazenave & Remy 2011; Lawson 2007; Steinegger et al. 1993). Some glaciers’ recession speed has exceeded its forming speed which often takes decades or even centuries of long-term snow accumulation (Grinsted 2013; Favier et al. 2014; Jenkins et al. 2010; Casassa 1987). Moreover, climate change has also significantly weakened the snowing process, which contributes to a faster glacier recession progress worldwide (Hock et al. 2005; Marshall 2007; Marshall 2014). There are approximately 20,000 glaciers in Xinjiang Uyghur Autonomous Region, China, which account for roughly half of all glaciers in China. Since the 1950s, glaciers in Xinjiang have retreated by between 21 percent to 27 percent due to a globally warming temperature (Sun et al. 2013). In recent decades, a visible recession of Ürümqi Glacier No.1 (UG1) has been observed (Ye et al. 2005; P. Wang et al. 2014; Jing et al. 2006). This situation is becoming critical because a significant amount of water supply to the capital city (Ürümqi) is highly depending on the glacier meltwater (Sun et al.