Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Introduction to water resources impacts modelling Erika Coppola, ICTP, Trieste [email protected] • Impact modelling: Vulnerability and adaptation with respect to water resources • Hydrologic implications of climate change for water resources • Focus of the school • Uncertainty in a Climate Change scenario • Defining V&A assessment – Often V&A is analysis, not assessment – Why? Because the focus is on biophysical impacts, e.g., hydrologic response, crop yields, forests, etc. • However, assessment is an integrating process requiring the interface of physical and social science and public policy Examples of Adaptation – Water Supply • Construction/modification of physical infrastructure – Canal linings – Closed conduits instead of open channels – Integrating separate reservoirs into a single system – Reservoirs/mydroplants/delivery systems – Raising dam wall height – Increasing canal size – Removing sediment from reservoirs for more storage – Interbasin water transfers Examples of Adaptation – Water Supply (continued) • Adaptive management of existing water supply systems – Change operating rules – Use conjunctive surface/groundwater supply – Physically integrate reservoir operation system – Coordinate supply/demand Examples of Adaptation – Water Supply (continued) • Policy, conservation, efficiency, and technology – Domestic • • • • • Municipal and in-home re-use Leak repair Rainwater collection for nonpotable uses Low flow appliances Dual supply systems (potable and nonpotable) – Agricultural • • • • • Irrigation timing and efficiency Lining of canals, closed conduits Drainage re-use, use of wastewater effluent High value/low water use crops Drip, micro-spray, low-energy, precision application irrigation systems • Salt-tolerant crops that can use drain water Examples of Adaptation – Water Supply (continued) • Policy, conservation, efficiency, and technology (continued) – Industrial • • • • Water re-use and recycling Closed cycle and/or air cooling More efficient hydropower turbines Cooling ponds, wet towers and dry towers • • • • • • Reservoir re-operation Cogeneration (beneficial use of waste heat) Additional reservoirs and hydropower stations Low head run of the river hydropower Market/price-driven transfers to other activities Using water price to shift water use between sectors – Energy (hydropower) Tools in Water Resource V&A Studies • Hydrologic models (physical processes) – Simulate river basin hydrologic processes – Examples – water balance, rainfall-runoff, lake simulation, stream water quality models • Water resource models (physical and management) – Simulate current and future supply/demand of system – Operating rules and policies – Environmental impacts – Hydroelectric production – Decision support systems (DSS) for policy interaction • Economic models Studying the Hydrologic Cycle at Various Scales Evapotranspiration Sublimation Evaporation Snow Accumulation Mountain Front Recharge Precipitation Discharge Snowmelt Runoff Infiltration Groundwater flow Surface Runoff Surface Runoff Discharge Recharge Globally: 86% of Evap. and 78% of Precip. occur over the oceans Distribution of Freshwater Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Two Primary Water Resources/Hydrology Challenges: • Hydrologic Hazards ( Floods and Droughts) • Water Supply Requirements ( Quantity and Quality) “General” and Widespread Floods Illinois River August 14, 1993 Mississippi River Missouri River August 19, 1993 Bangladesh floods in 2004 MISSISSIPPI Floods 1993 Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Drought most visible in falling reservoir levels Normal Years Recent Southwest Drought 2004 Lake Powell, Colorado River, USA Source: J. Kane SRP 2004 Climate Change and Hydrologic Implications • Precipitation amount – Global average increase – Marked regional differences • Precipitation frequency and intensity – Less frequent, more intense (Giorgi et al., 2011;Trenberth et al., 2003) • Evaporation and transpiration – Increase total evaporation Climate Change and Hydrologic Implications (continued) • Changes in runoff – Despite global precipitation increases, areas of substantial runoff decrease • Coastal zones – Saltwater intrusion into coastal aquifers – Severe storm-surge flooding • Water quality – Lower flows could lead to higher contaminant concentrations – Higher flows could lead to greater leaching and sediment transport Global Warming And Hydrologic Cycle Connection Heating Drought Saturated Vapor Pressure Temperature Flood t t+20 Evaporation Water Holding Capacity Atmospheric Moisture Green House Effect Rain Intensity Temperature oF Drought Created by: Gi-Hyeon Park Flood How Extreme Can it Get ????? The Recent Drought in Historical Context: Reconstruction of Proxy records: - Analysis of Tree Rings and Stable Isotopes Recent US Southwest Drought in Historical Context Sept 1951 Elephant Butte, NM Jan 2003 Grissino-Mayer, Baisan, Morino, & Swetnam, 2001 Reconstructed PDSI Middle Rio Grande Basin, NM AD 2.0 - 1.5 - 1.0 - 0.5 - 0 - -0.5 -1.0 - Great -1.5 Drought -2.0 1250 Past 1350 Late 16th cent Megadrought 1450 1550 1650 1750 Highly variable 1 850 1950 2050 Present 2150 2250 2350 2450 2550 2650 2750 Future Two Primary Water Resources/Hydrology Challenges: • Hydrologic Hazards ( Floods and Droughts) • Water Supply Requirements ( Quantity and Quality) Projected Regions of Water Stress Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Distribution of Fresh Water Use 460 467.34 USA Water Source China 380 7.0% India 6.0% Fresh Water Use (109 Cubic Meters) 4.0% 3.0% 41.7% 45.2% Water Use 87.0% 13.1% Agriculture 93.0% Domestic Industry Russia 117 Japan Brazil 36.47 23.0% 17.0% Iran 70.3 60.0% 18.6% 90.8 33.4% 49.5% 59.4% 92% 22.0% 17.1% Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine 6% 2% Projected Population Growth Distribution 1995 world population 5.7 Billion 80% 71% 70% 2025 Projection 8.3 Billion 60% 52% 50% 40% 30% 36% 26% 33% 30% 17% 20% 10% -4% 0% -10% Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine 29% Cubic Kilometers per Year Our projections of future water use have been flawed. 14000 12000 10000 Projections 8000 6000 Actual Global Water Withdrawals 4000 2000 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 SOURCE: Dr. Peter H. Gleick, Pacific Institute for Studies in Development Rapid Change in Global Demographics Source: United Nations, 1996 Population Without Access to Improved Water Supply: 2000 800 693 700 Million people 600 Total: 1,100 million 500 400 300 300 200 78 100 3 0 Africa Asia Lat.Amer/Carib. Oceania SOURCE: Dr. Peter H. Gleick, Pacific Institute for Studies in Development 26 Europe The school focus Hydrology Model • Critical questions – How does rainfall on a catchment translate into flow in a river? – What pathways does water follow as it moves through a catchment? – How does movement along these pathways impact the magnitude, timing, duration, and frequency of river flows? Data Requirements • Prescribed supply (riverflow given as fixed time series) – Time series data of riverflows (headflows) cfs – River network (connectivity) • Alternative supply via physical hydrology (watersheds generate riverflow) – Watershed attributes • Area, land cover . . . – Climate • Precipitation, temperature, windspeed, and relative humidity Data Requirements (continued) • Water demand data – Municipal and industrial demand • Aggregated by sector (manufacturing, tourism, etc.) • Disaggregated by population (e.g., use/capita, use/socioeconomic group) – Agricultural demands • Aggregated by area (# hectares, annual water-use/hectare) • Disaggregated by crop water requirements – Ecosystem demands (in-stream flow requirements) Calibration and Validation • Model evaluation criteria – Flows along mainstream and tributaries – Reservoir storage and release – Water diversions from other basins – Agricultural water demand and delivery – Municipal and industrial water demands and deliveries – Groundwater storage trends and levels Final Aim of our exercise Uncertainty in climate change impact assessment in water resources • Global climate models (GCMs) use different but plausible parameterisations to represent the climate system. • Sometimes due to sub-grid scale processes (<250km) or limited understanding. Uncertainty in climate change impact assessment • Therefore climate projections differ by institution: 2°C Multiple ensembles for various prescribed temperature changes Simon Gosling, Walker Institute for Climate System Research, University of Reading 9 model runs Global Average Annual Runoff The ensemble mean Global Average Annual Runoff Change from Present (%) But what degree of uncertainty is there? Uncertainty in simulations Number of models in agreement of an increase in runoff Catchment-scale Seasonal Runoff The Liard The Okavango The Yangtze Seasonal Runoff Agreement of increased snowmelt induced runoff Less certainty regarding wet-season changes Agreement of dryseason becoming drier Large uncertainty throughout the year What can we do to decrease the uncertanty • Further downscaling: Regional climate modelling • Bias correction techniques • ENSEMBLE approach: Dynamical downscaling Statistical downscaling VALUE European COST project Ensuring Water in a Changing World Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine International Water Cycle Research Initiatives Addressing These Issues: - WCRP (GEWEX, CLIVAR, CLiC) - UNESCO Initiatives (PUB, HELP) - And Many National Programs GEWEX Role in Climate Research CLiC CLIVAR Water Resources Applications Coupled Ocean-Atmosphere Models Water resources management agencies Mesoscale Models E Hydrologic/Routing Models P Qs Monsoon ProcessesSVATs D Ss Ig D Sg Qg GEWEX Hydrologic Services Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Requirements and State of Hydrologic Forecasting DATA MODEL PARAMETER ESTIMATION If the “World” of Watershed Hydrology Was Perfect! Source: Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Thanks!