Water Resources under the changing climate and adaptation ACCC Project, 2010 Water Resources under the changing climate and adaptation ——气候变化对水资源的影响及适应 Dr. Guoqing WANG / 王国庆教授 Nanjing Hydraulic Research Institute, MWR Research Center for Climate Change, MWR 南京水利科学研究院 March 5, 2010, Beijing

Contents Observed Changes /观测到的气候变化 Assessment model /气候变化影响评价模型 Effect Assessment for Water / 水资源影响评价 Adaptative strategies / 气候变化的适应对策 Scientific Issues / 需进一步研究的科学问题

Global Temperature / 全球气温变化 Global annual mean temperature: +0.74℃ /年均气温升高0.74 The warmest decade: 1990s / 20世纪90年代是最热的10年 Recent 11 years rank among the 12 warmest years / 1860年以来最热的12年有11年发生在1995～2006

Temperature change in China / 中国气温变化 Similar rising trend to global temperature / 趋势与全球相似 Temperature rise during the last 100yrs: 0.5~0.8℃ / 近100年气温升高0.5~0.8℃ Rising rate during the last 50yrs: 0.22℃/10a / 近50年气温平均升率0.22℃/10a

Precipitation change in China（降水变化） Increasing Decreasing Trend ratios of precipitation during 1951-2002 Western: Increase 西部增加 Southern: Increase 南部增加 Northern: Decrease 北部减少 Northeastern: Decrease东北减少

Changes of extreme rainstorm events /暴雨变化 Changes in 60mins rainfall before and after 1980 Trend rate of rain days of extreme rainstorms Short duration rainfall intensity: Increasing /暴雨强度增加 Kuanping, Shanxi: 1998.07，1300mm/6-7hr Zhanjiang, Guangdong: 2007.08，1188mm/24hr Rain days of extreme rainstorms: Increasing / 极端降水日数增加

Water Resources in China / 中国水资源 667mm 118mm 35mm 84% 12% 4% Mountain Areas（山丘区） Plain areas（平原区） 677.2 bm3 176.5 bm3 82% 18% Overlap: 31.8 bm3 Annual runoff depth: 288mm 年径流深288mm Surface water: 2737.5bm3 地表径流量：2737.5bm3 Ground water: 821.9bm3 地下径流量：821.9bm3

Temporal distribution Characteristics of WR /水资源特点 多年平均降水量 Spatial distribution 空间分布 Temporal distribution 时间分布 Uneven distribution in time and space/时空分布不均: 80% Low water occupation per capita/人均水资源量低：< 30% Serious shortage：400/668 cities， 水资源严重短缺: Gap=40bm3, in Normal Year Huge losses due to flooding and drought / 洪涝、干旱灾害损失巨 大：>GDP1％

Water Issues in China / 四大水问题 Flooding / 水多 Decreasing / 水少 Polluting /水脏 Losing / 水混

Changes in Recorded Runoff / 实测径流变化 黄河 海河 Decreasing rate of runoff during 1980-2004 comparing to that before 1980 Significant decreasing : Haihe River, Yellow River 显著减少：海河，黄河 Slight changing: other rivers 轻微变化：其它河流

Sustainable utilization Climate change and Hydrological cycle 气候变化与水文循环 Sustainable utilization Global Warming （水资源的可持续利用） Hydrological cycle Changes in rainfall

Contents Observed Changes / 观测到的气候变化 Assessment model / 气候变化影响评价模型 Effect Assessment for Water / 水资源影响评价 Adaptative strategies / 气候变化适应对策 Scientific Issues / 需进一步研究的科学问题 12

National Key Project (85-913-03-03 ) Study Catchments/研究区域：Tributaries of six big rivers Assessment Models/评价模型: Lumped Water Balance Models / 集总式水量平衡模型 Assessment / 评价: The future water resources, based on outputs of 7 GCMs

National Key Project (96-908-03-04 ) Study basins / 研究区域: 4 big river basins Assessment Models / 评价模型: 30×30km grid based hydrologic model Assessment / 评价: sensitivity analysis

Xin’anjiang Model 新安江模型 Simplified model structure 5 parameters / 5个参数 Extension Water Wm , B R Free water storage, Sm Rapid Q, Cs Slow Q, Cg Discharge Q E Simplified model structure 5 parameters / 5个参数 Applied to Huaihe River / 应用到淮河流域

Two Parameters Water Balance Model两参数水量平衡模型 Humid river basins / 湿润地区 Hanjiang River, Gangjiang River / 汉江和赣江流域 DC>80% P EP Q E SOIL MOISTURE

Snowmelt-based WBM 考虑融雪的水平衡模型 Semi-arid or arid river basins / 干旱半干旱流域 P T Rain/Snow EP Snowfall Rainfall Accu- SRunoff SMRunoff GFlow Soil moisture Q E Semi-arid or arid river basins / 干旱半干旱流域 Consider snowmelt flow / 考虑融雪径流

National Key Project (2001-BA611B-02-04) Study area: China 研究区域：中国 Assessment Model：VIC Assessment：vulnerability 18

Key Technology1：PUB 关键技术：缺资料地区的水文模拟 GIS-based distributed hydrological model / 基于GIS的分布式水文模型 Relationship between parameters and catchment indices / 下垫面要素 Hydrological modeling for poorly gauged river basins / 无资料地区的应用 Flow generation： Flow concentration： 19 19

Key technology2：Parameters optimization 关键技术：参数优化识别技术 Auto-optimization combining experts knowledge / 数学自动优化与专家知识结合 Simulation accuracy and optimization efficiency / 模拟精度与优化效率 X2 X(1) X(0) X(2) A X(3) Rosenbrock method X1 单纯形法 20 20

Key technology3：downscaling 关键技术：情景降尺度技术 Two statistical approaches / 两种统计降尺度途径 Double linear interpolation method / 双线性降尺度插值方法 Non-linear Lagrange interpolation method / 不等距拉格朗日三点插值方法 Similar temperature fields before and after downscaling from RCMS 21

Key technology 4: Contribution identification 关键技术：径流归因识别技术 Baseline Human-disturbed Two key issues Determination of baseline / 基准期的确定: Cluster analysis method, Mann-Kendall method, etc Runoff naturalized method / 天然径流还原方法: Hydrological simulation approach, VIC model, WB model 22 22

Contents Observed Changes /观测到的气候变化 Assessment model / 气候变化影响评价模型 Effect Assessment for Water / 水资源影响评价 Adaptative strategies /气候变化的适应对策 Scientific Issues / 需进一步研究的科学问题 23

Assessment approach 气候变化影响评价途径 Vertically integrated Projected Horizontally integrated Scenario / 情景 Projected Hypothetical Assessment / 评价 Model Impacts Adaptation / 适应 Policy Technology 24

Climate Scenario / 气候情景模式 More environmental 侧重环境保护 More regional 侧重区域 More global 侧重全球 B1 B2 A1 A2 More economic 侧重经济发展

Temperature trends in 21th Century 21世纪全球气温变化趋势 ( IPCC AR4, 2007 ) 6.4℃ 1.1℃ Temperature rise: 1.1－6.4℃ / 21世纪末气温升高1.1－6.4 Warmer globe / 一个更加温暖的地球 26

Possible climate change in China 21世纪我国可能的气候变化 Precipitation：Increase in most areas, Decrease in Northern China and North-eastern China before 2040 / 大多数地区降水增加，但华北和东北可能减少 Temperature / 气温变化：2030，1.7℃；2050，2.2℃ 27

Projected water resources distribution 未来水资源分布变化 A2 scenario Change in runoff distribution under the scenario A2 2071-2100年A2情景下的径流分布变化 Probability of flood and drought hazards would increase / 洪涝干旱灾害可能增加 The pattern of south-flood and north-drought would aggravate.

Projected water resources distribution 未来水资源分布变化 Change in runoff distribution under the scenario B2 2071-2100年B2情景下的径流分布变化 B2 scenario Similar to that under scenario A2, exacerbating the instability of water system / B2情景下的水资源类似A2， 水资源系统可能更加不稳定

Sensitivity of WR to Climate Change 水资源系统对气候变化的敏感性 Sensitivity /敏感性 Sensitivity of hydrology to climate change is response degree of hydrological variable to climate change. High response under the same climate change means more sensitive to climate change Study basin 研究流域 Cold region：Yilihe River 高寒山区：伊犁河 Semi-arid region：Yellow R 半干旱区：黄河 Semi-humid region：Huai R 半湿润区：淮河 Humid region：Dongjiang R 湿润区：东江 30

Sensitivity of WR to Climate Change 水资源系统对气候变化的敏感性 Yellow River 黄河 Yilihe River 伊犁河 T RISE: increases Spring discharge, decreases runoff in other seasons 气温升高降增加春季径流，减少其它季节径流量 Surface runoff: more sensitive to climate change 地表径流对气候变化更为敏感 Human activities: could decrease sensitivity of runoff 人类活动能够在一点程度上降低水资源对气候变化的敏感性 31

Sensitivity of WR to Climate Change 水资源系统对气候变化的敏感性 Huaihe River 淮河 Dongjiang River 东江 Precipitation change: result in larger runoff change than T does 对降水变化比对温度变化的响应更为敏感 Same change range: P+ result in larger runoff change than P- 降水增加比减少对径流的影响更显著 Arid region: more sensitive; while humid region less 干旱区对气候变化响应比湿润区更敏感 32

Sensitivity comparison of Hydro-variables 不同水文变量敏感性比较 ACTUAL EVAPORATION 实际蒸发 SOIL MOISTURE 土壤湿度 RUNOFF 径流 Response Law：similar between actual evaporation and soil moisture 实际蒸发和土壤湿度对气候变化的响应规律类似 P changes：Runoff, actual evaporation, soil moisture, (bigger->less) 径流、蒸发和土湿对降水变化的响应依次降低 T changes：Soil moisture, runoff, actual evaporation, (bigger->less) 土湿、径流和实际蒸发对气温变化的响应依次降低

Identification of CC contribution (YRB) 气候变化对径流历史变化的贡献评价 Periods Reco-ed (108m3) Simu-ed Total redu Climate-induced Human-induced 108m3 (%) Baseline 237.5 1970-1979 148.5 198.5 89.0 39.0 43.82 50.0 56.18 1980-1989 172.7 217.6 64.8 19.9 30.67 44.9 69.33 1990-2000 95.3 181.1 142.2 56.4 39.64 85.8 60.36 1970-2000 138.8 199.5 98.7 38.0 38.53 60.6 61.47 Human activities are main reasons of runoff reduction in YR 人类活动是径流减少的主要原因 Contribution of Climate change accounts for 39％ 气候变化影响占径流减少总量的39％ 34

Contents Observed Changes / 观测到的气候变化 Assessment model / 气候变化影响评价模型 Effect Assessment for Water /水资源影响评价 Adaptative strategies / 气候变化的适应对策 Scientific Issues / 需进一步研究的科学问题 35

Climate Change, IWRM and Resilience 气候变化与水资源一体化管理 Many challenges not new, nor product of climate change alone. /目前水资源短缺不是气候变化单一作用的结果 Water resources are already stressed due to economic growth, population pressure and lifestyles. 经济发展、人口增加、生活方式改变，已经使得水资源利用面临着巨大的压力 Many climate change impacts are just extreme examples of existing challenges. /气候变化的影响只是目前水资源压力基础上的极端情形

Integrated WR Management / 水资源一体化管理 Flooding Flood management 水 多 洪 水 管 理 Water saving W Shortage 水 少 节 水 技 术 W Pollution Green economic 水污染 绿 色 经 济 W Losing Self restoration + engineering 水土流失 自我修复与水土保持

Water-Saving Society / 节水型社会 Index of water usage China Developed Countries Consumed Water/ 10000GDP(RMB) 537 m3 4×World Mean value The effective-utilization coefficient of agricultural irrigation water（灌溉水利用系数） 0.4－0.5 0.7～0.8

Non-Traditional water sources / 非传统水源 High cost / 高费用. Technology Support / 技术支持 Waste water treatment 污水处理 Storm water harvest 雨洪资源利用 Sea water desalination 海水淡化 水 窖 北京市高碑店污水处理厂

Water Controlling Projects / 控制性工程 JingJiang dyke Embankment Reservoirs / 水库 River dikes / 堤防 Flood retention areas / 滞洪区 Water transfer projects / 调水工程 Three Gorge Reservoir Reservoirs: 87,000 已建水库：87,000 Total storage capacity: 600 billion m3 总蓄水容量： 6000亿 m3

Water transfer project / 调水工程 中线 工程 ML 海河Haihe river 东 线 工 程 EL 黄河 Yellow river 西 线 工 程 WL 淮河Huaihe river 长江Yangtze river

Soil and water conservation / 水土保持 Perfect policy, laws, and regulations / 完善法律、法规和政策 Public education / 公众教育 Re-grass / 退牧还草 Reforestation / 更新造林 Terrace construction / 梯田建设 Check dams / 淤地坝

Regional adaptation strategies / 区域适应对策 Principle / 原则 Different issues for different regions / 不同区域面临不同问题 Different adaptation strategies for different regions / 不同区域的适应措施存在差异 东北粮食主产区 黄淮海国家重点发展区 东南沿海经济发达区 三江源我国主要水源区 西北生态脆弱干旱区 Key Regions 43 43

Contents Observed Changes / 观测到的气候变化 Assessment model / 气候变化影响评价模型 Effect Assessment for Water / 水资源影响评价 Adaptative strategies /气候变化的适应对策 Scientific Issues / 需进一步研究的科学问题 44

Scientific issues and further study 进一步需要研究的科学问题 Uncertainty in Assessment /不确定性 Emission Scenario GCMs RCMS HM Assessment Improvements / 改进 New scenario / 新情景 Assessment model, especially for ungauged areas / 改进模型 Limitation of adaptation / 适应的局限性 More strategies at state level / 多集中在国家层面 Lack of regional adaptation strategies / 缺少区域有效措施

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