Advances in Monitoring and Modeling of the Hydrologic Cycle and Meeting the Requirements from Flood Forecasting to Hydroclimate Predictions Soroosh Sorooshian Center for Hydrometeorology and Remote Sensing University of California Irvine Water Institute of Texas 1 st Symposium on: Emerging Water Issues UTSA San Antonio Texas Oct. 4 th, 2013
University Research of Team: California Present Irvine and Recent (UCI) Past S. Sellars Center for Hydrometeorology and Remote Sensing, University of California, and Irvine many more
The Hydrologic Cycle Sublimation Evapotranspiration Evaporation Snow Accumulation Mountain Front Recharge Snowmelt Runoff Precipitation Discharge Infiltration Surface Runoff Surface Runoff Discharge Groundwater flow Recharg e Globally: 86% of Evap. and 78% of Precip. occur over the oceans
Two Primary Water Resources/Hydrology Challenges: Hydrologic Hazards ( Floods and Droughts) Water Supply Requirements ( Quantity and Quality)
Increasing Population: Number of Mega Cities Projected Global Population: 8.3 Billion by 2025 Global Urban population 1970: ~37% 2010: ~53%
Distribution of Fresh Water Use 467.34 460 USA China 380 India 7.0% 6.0% 4.0% 3.0% 41.7% 45.2% Water Source Fresh Water Use (10 9 Cubic Meters) Water Use 13.1% 87.0% 93.0% Agriculture Domestic Industry 117 Russia Japan Brazil 23.0% 36.47 17.0% 60.0% 90.8 18.6% 33.4% 59.4% 49.5% 22.0% 17.1% 70.3 Iran 92% 6% 2%
Primary Solution To Satisfy Water Resources Needs and Address Hydrologic Extremes Engineering Approach: Control, Store, Pump and Transfer
A Century of Water Resources Development: Engineering success Hoover Dam Central Arizona Project Aqueduct
Colorado River: Great Source, But for How long? Discharge (1000 acf) 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 The Colorado River is the most regulated stream in the world. Since 1962, the river flow has been fully utilized. Salinity levels increase 15 folds from mountain headwaters to the Mexican border 30000 25000 Colorado River Flow Below All Major Dams and Diversions 20000 15000 10000 5000 0 Reservoir Salinity Measurement Year
Salt loads continue to be an issue today The Central Arizona Project currently brings about 1.5 million tons of salt per year to the center of the state. This amount of salt would fill 50,000 railroad cars.
Groundwater Overdraft, land subsidence and sinkholes 1925 1955 1975 San Joaquin Valley, CA Eloy, Arizona 1952 In the US 1977 1985
Climate, Hydrology and Water Resources How will Climate effect water Availability? Can we predict the future changes which are responsive to user needs?
Global Climate: Past Decade and Prediction of End of 21 st Centaury
Intensification of the Hydrologic Cycle Consequences of Climate Change and Variability
Global Warming And Hydrologic Cycle Connection Drought Saturated Vapor Pressure Heating Flood t+20 t Temperature Evaporation Water Holding Capacity Atmospheric Moisture Green House Effect Rain Intensity Drought Flood Temperature of Created by: Gi-Hyeon Park
Flood Frequency Analysis: Stationarity! Discharge (1000 cfs) Return Period (Years) 1 2 5 10 20 50 100 200 500 1000 600 500 400 300 200 100 0 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 Probability of Exceedance
Discharge (1000 cfs) Potential Hydrologic Scenarios 1. Precipitation and Runoff Trends (e.g. increase/decrease) 2. Hydrologic Variability (e.g. magnitude/severity/duration) Return Period (Years) 1 2 5 10 20 50 100 200 500 1000 600 500 400 300 200 100 0 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 Probability of Exceedance
Hydrologically-Relevant Climate Variables What Do Instrumental Records and Recent Experience Tell Us?
Changes in Precipitation: U.S.A From 1908-2002: Total annual precipitation across the contiguous U.S. increased 7% Heavy daily Precipitation events have increased by 20% Facts from Observations Rainfall associated with warmer climates are more due to extreme events compared to colder climates 10 0 Confidence Index Source: Tom Karl NCDC-NOAA 2007
Los Angeles (1955)
GIS Role in Coupled Hydrologic-Hydraulic Flood Modeling System Houston Texas - Tropical Storm Allison 2001 (http://www.wxresearch.com)
Observed changes: Drought Drought activity during the 20 th and early 21 st Century U.S. droughts show pronounced multi-year to multi-decadal variability, but no convincing evidence for long-term trends toward more or fewer events. 10 5 Confidence 0 Index Based on Palmer Drought Index Moderate to Extreme Drought Source: Tom Karl NCDC-NOAA 2007
Lake Powell Glenn Canyon Dam Recent Droughts: Maximum of 30 Meters Drop
Hydrologically-Relevant Climate Variables What Do Pre-Instrumental Proxy Records Tell Us?
Reconstruction of Proxy Records: - From Tree Rings - Analysis of Salt Isotopes from Dry Lake Beds
2000-year Climate history of central U.S. The US Mid-West 1930 s dustbowl 2000 yrs. ago Today >100 year megadroughts 16th century megadrought Source: Overpeck 2004
Prediction Requirements for Water Resources Short Range Long Range hours days weeks months seasons years decades Short-range Mid-range Long-range Forecast Requirements
Climate-Scale approaches to addressing Regional hydrology Short Range Long Range hours days weeks months seasons years decades Use of climate models: down-scaling and ensemble schemes Traditional statistical hydrology methods: Forecast Requirements Long-range
Hydrologically-Relevant Climate Variables What Do Climate Models Tell Us About the Future?
Aggregation Climate Model Downscaling to regional/watershed Scale Precipitation Vegetation Topography Climate Model Grid-Scale GCM RCM DS Downscaling Land
Ensemble Approach Generation of Future Precipitation Scenarios
Downscaled Precipitation to Runoff Generation Flow Precipitation prediction Generation of Future Runoff Scenarios Present 20 40 60 80 Time (years) Future Present Time (years) Future
Seasonal-Scale Predictions Short Range Long Range hours days weeks months seasons years decades Mid-range Forecast Requirements
IRI 3-Month Multi-Model Probability Precipitation Forecast
Recent Assessment of Seasonal Climate Forecasts Quoting from Science, Vol. 321, 15 th August 2008 Livezey &Timofeyeva - BAMS, June 2008. About the only time forecasts had any success predicting precipitation was for winters with an El Nino or a La Nina
Climate-Scale approaches to addressing hydrologic extremes Short Range Long Range hours days weeks months seasons years decades Forecast Requirements Long-range
A Dryer Future for Southwest US?
Climate model Predictions about the future? globally DJF Precipitation Changes CM2 - Old model CM3 - Updated model Significant differences in regional outcomes! Source: Hadley Center (Climate Change Projections)
Recent Evaluation of RCM/GCM over Western U.S. Wei Chu 2011 Current period:1971-2000 Future period: 2041-2070 Spatial Res.: 50 km Temporal Res.: daily Outputs of six RCM/GCM sets: North American Regional Climate Change Assessment Program (NARCCAP) Emissions Scenario: A2: regionally oriented and fast economic growth study region
Recent Evaluation of RCM/GCM over Western U.S. Models indicate different signs and magnitudes of changes in the mean precipitation over the Western U.S. under the SRES A2 emissions scenario. Trend of area-average precipitation (comparing 2040-2070 with 1970-2000)
Spatial Scales Drought Predictability Current Skill User Needs 10000 km 1000 km 100 km 10 km 1 km Minute Day Week Season 1 yr 10 yrs 100 yrs Time Scales Provided by Siegfried Schubert 2011
Aggregation Climate Model Downscaling to regional/watershed Scale Precipitation Vegetation Climate Model Grid-Scale GCM RCM Topography A Valid Question to Ask: DS Given the Current State of Climate Models (especially at regional scales), What is the added-value of all the Downscaling Studies over traditional statistical hydrology methods in water resources studies? Downscaling Land
Flow (m 3 /sec) Flow (m 3 /sec) Statistical Hydrology: synthetic stream flow Generation 250 225 200 175 150 125 100 75 50 25 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Time (years) Probability density function -100-75 -50-25 0 Past Present 10 20 30 40 50 60 70 80 90 100 Time (years) Future
Statistical Hydrology Developed Based on Stationarity Assumption Reconstructed PDSI Sept 1951 Elephant Butte, NM Jan 2003 2.0 1.5 1.0 0.5 0 Middle Rio Grande Basin, NM AD Grissino-Mayer, Baisan, Morino, & Swetnam, 2001 - Past - Present Future -0.5-1.0-1.5-2.0 - - - - - - - 1250 1350 1450 1550 1650 1750 1 850 1950 2050 2150 2250 2350 2450 2550 2650 2750
Increase in Runoff not always due to Increase in Precip. After Before Undisturbed v.s. Urbanized
Wide-Range of Impacts on Infrastructure Design
A Page From the CalTran Highway Design Manual
What is the Message? Presently, the accuracy of Hydroclimate model predictions fall short of meeting the requirements of water resources planning. Hardly used for operational Purposes and unwise to push their use while highly uncertain. Therefore, Factoring in Resiliency in water resources system s design and planning is still the safest approach!
Required Hydrometeorological Predictions Short Range Long Range hours days weeks months seasons years decades Weather Scale: flood and River flow forecasting Short-range
River Discharge Common practice in Flood and River Flow Forecasting Observations (QPE) Current Time Animation Assisted by: Q. Xia & Gi-H. Park Forecast Time
River Discharge Efforts in Extending the Forecast Lead Time Observations (QPE) QPF NWP With improved QPF & hydrologic model accuracy Current Time Animation Assisted by: Q. Xia, Gi-H. Park & L. Bastidas Forecast Time
Hydrologic Modeling: 3 Elements! DATA If the World of Watershed Hydrology Was Perfect! MODEL PARAMETER ESTIMATION
A Brief Review of Hydrologic Modeling NCEP Vision: First Choice First Alert Preferred Partner
Evolution of Hydrologic R-R Models A D API Model B C Lumped Conceptual Distributed (Mike SHE) VIC Model Distributed Physically-based
Big Challenge Adequacy of Hydrologic Observations for model Input, Calibration and Testing
Observation of Primary Hydrologic Variables Stream flow Precipitation
A Key Requirement! Precipitation Measurement is one of the KEY hydrometeorologic Challenges Push towards High Resolution ( Spatial and Temporal) Global Observations and Modeling
Precipitation Observations: Which to trust??
Coverage of the WSR-88D and gauge networks 12 3 km km AGL Maddox, et al., 2002 - Daily precipitation - Gages (1 station per 600 km^2 ) - Hourly coverage even more sparse
Space-Based Observations Satellite Observations
Remote Sensing Systems (Spectral Signal) Reflectance ( % ) Human Eye Visible Range 40 Satellite 20 0 Bare Soil 40 20 0 Healthy Vegetation 40 20 0 Stressed Vegetation 80 40 0 0.4 5 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 4 3 2 1 0 0 2 4 6 8 10 12 14 16 Fresh Snow Sea Water Center for Hydrometeorology Wavelength and Remote (µm) Sensing, University of California, Irvine
Satellite-Based Rainfall Estimation: Promising! Observations from space: Near-continuous, global coverage,
Satellite Data for Precipitation estimation Geostationary IR Cloud top data 15-30 minute temporal resolution Passive Microwave (SSM/I) Some characterisation of rainfall ~2 overpasses per day per spacecraft, moving to 3-hour return time (GPM) TRMM precipitation RADAR 3D imaging of rainfall 1-2 days between overpasses ( S-35 N-35 )
Interpolation of 3-hour Precipitation - + + + - T T+3hr T+6hr t-hr t+3hr
Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) PERSIANN System Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks
Real Time Global Data: Cooperation With UNESCO 4km, Many 30 Features min. global provided Rainfall to Estimates users with from Public Multiple Domain Satellites Software.
PERSIANN-CDR: PERSIANN Climate Data Record http://www.ncdc.noaa.gov/cdr/operationalcdrs.html
PERSIANN Satellite Product On Google Earth http://chrs.web.uci.edu/
Satellite-Based Precipitation: Very Promising for Hydrometeorological Applications a000174.mpeg
GPM Mission: Target Date 2012-1014 OBJECTIVES 1 Main satellite + 8 Smaller Satellites \ Provide sufficient global sampling to significantly reduce uncertainties in short-term rainfall accumulations Future looks bright and will bring us more advances for precipitation Estimation
GPM Animation Courtesy: NASA s ESE
GPM Animation Courtesy: NASA s ESE
What is the Message? Despite advances to date, predicting the future Hydro-Climate variables will remain a major challenge: While investment in model development is fully justified, we must also improve the engineering approaches currently used in practice for operational and planning purposes. Long-term and sustained observation programs are critical, especially for model verification. Without some degree of verifiability, hard to expect their use
Recently Released IPCC Report (AR5) - Sept. 2013 It is likely that since 1950 the number of heavy precipitation events over land has increased in more regions than it has decreased. There is medium confidence that human influence on climate has affected stream flow and evapotranspiration in limited regions of middle and high latitudes of the Northern Hemisphere. In summary, there continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale
Thank You for the Invitation and Listening Somewhere in New Mexico, USA - Photo: J. Sorooshian