Advances in Monitoring and Modeling of the Hydrologic Cycle and Meeting the Requirements from Flood Forecasting to Hydroclimate Predictions

Transcription

1 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

2 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

3 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

4 Two Primary Water Resources/Hydrology Challenges: Hydrologic Hazards ( Floods and Droughts) Water Supply Requirements ( Quantity and Quality)

5 Increasing Population: Number of Mega Cities Projected Global Population: 8.3 Billion by 2025 Global Urban population 1970: ~37% 2010: ~53%

6 Distribution of Fresh Water Use 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% % 60.0% % 33.4% 59.4% 49.5% 22.0% 17.1% 70.3 Iran 92% 6% 2%

7 Primary Solution To Satisfy Water Resources Needs and Address Hydrologic Extremes Engineering Approach: Control, Store, Pump and Transfer

8 A Century of Water Resources Development: Engineering success Hoover Dam Central Arizona Project Aqueduct

9 Colorado River: Great Source, But for How long? Discharge (1000 acf) 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 Colorado River Flow Below All Major Dams and Diversions Reservoir Salinity Measurement Year

10 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.

11 Groundwater Overdraft, land subsidence and sinkholes San Joaquin Valley, CA Eloy, Arizona 1952 In the US

12 Climate, Hydrology and Water Resources How will Climate effect water Availability? Can we predict the future changes which are responsive to user needs?

13 Global Climate: Past Decade and Prediction of End of 21 st Centaury

14 Intensification of the Hydrologic Cycle Consequences of Climate Change and Variability

15 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

16 Flood Frequency Analysis: Stationarity! Discharge (1000 cfs) Return Period (Years) Probability of Exceedance

17 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) Probability of Exceedance

18 Hydrologically-Relevant Climate Variables What Do Instrumental Records and Recent Experience Tell Us?

19 Changes in Precipitation: U.S.A From : 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

20 Los Angeles (1955)

21 GIS Role in Coupled Hydrologic-Hydraulic Flood Modeling System Houston Texas - Tropical Storm Allison 2001 (

22 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 Confidence 0 Index Based on Palmer Drought Index Moderate to Extreme Drought Source: Tom Karl NCDC-NOAA 2007

23 Lake Powell Glenn Canyon Dam Recent Droughts: Maximum of 30 Meters Drop

24 Hydrologically-Relevant Climate Variables What Do Pre-Instrumental Proxy Records Tell Us?

25 Reconstruction of Proxy Records: - From Tree Rings - Analysis of Salt Isotopes from Dry Lake Beds

26 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

27 Prediction Requirements for Water Resources Short Range Long Range hours days weeks months seasons years decades Short-range Mid-range Long-range Forecast Requirements

28 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

29 Hydrologically-Relevant Climate Variables What Do Climate Models Tell Us About the Future?

30 Aggregation Climate Model Downscaling to regional/watershed Scale Precipitation Vegetation Topography Climate Model Grid-Scale GCM RCM DS Downscaling Land

31 Ensemble Approach Generation of Future Precipitation Scenarios

32 Downscaled Precipitation to Runoff Generation Flow Precipitation prediction Generation of Future Runoff Scenarios Present Time (years) Future Present Time (years) Future

33 Seasonal-Scale Predictions Short Range Long Range hours days weeks months seasons years decades Mid-range Forecast Requirements

34 IRI 3-Month Multi-Model Probability Precipitation Forecast

35 Recent Assessment of Seasonal Climate Forecasts Quoting from Science, Vol. 321, 15 th August 2008 Livezey &Timofeyeva - BAMS, June About the only time forecasts had any success predicting precipitation was for winters with an El Nino or a La Nina

36 Climate-Scale approaches to addressing hydrologic extremes Short Range Long Range hours days weeks months seasons years decades Forecast Requirements Long-range

37 A Dryer Future for Southwest US?

38 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)

39 Recent Evaluation of RCM/GCM over Western U.S. Wei Chu 2011 Current period: Future period: 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

40 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 with )

41 Spatial Scales Drought Predictability Current Skill User Needs 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

42 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

43 Flow (m 3 /sec) Flow (m 3 /sec) Statistical Hydrology: synthetic stream flow Generation Time (years) Probability density function Past Present Time (years) Future

44 Statistical Hydrology Developed Based on Stationarity Assumption Reconstructed PDSI Sept 1951 Elephant Butte, NM Jan Middle Rio Grande Basin, NM AD Grissino-Mayer, Baisan, Morino, & Swetnam, Past - Present Future

45 Increase in Runoff not always due to Increase in Precip. After Before Undisturbed v.s. Urbanized

46 Wide-Range of Impacts on Infrastructure Design

47 A Page From the CalTran Highway Design Manual

48 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!

49 Required Hydrometeorological Predictions Short Range Long Range hours days weeks months seasons years decades Weather Scale: flood and River flow forecasting Short-range

50 River Discharge Common practice in Flood and River Flow Forecasting Observations (QPE) Current Time Animation Assisted by: Q. Xia & Gi-H. Park Forecast Time

51 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

52 Hydrologic Modeling: 3 Elements! DATA If the World of Watershed Hydrology Was Perfect! MODEL PARAMETER ESTIMATION

53 A Brief Review of Hydrologic Modeling NCEP Vision: First Choice First Alert Preferred Partner

54 Evolution of Hydrologic R-R Models A D API Model B C Lumped Conceptual Distributed (Mike SHE) VIC Model Distributed Physically-based

55 Big Challenge Adequacy of Hydrologic Observations for model Input, Calibration and Testing

56 Observation of Primary Hydrologic Variables Stream flow Precipitation

57 A Key Requirement! Precipitation Measurement is one of the KEY hydrometeorologic Challenges Push towards High Resolution ( Spatial and Temporal) Global Observations and Modeling

58 Precipitation Observations: Which to trust??

59 Coverage of the WSR-88D and gauge networks 12 3 km km AGL Maddox, et al., Daily precipitation - Gages (1 station per 600 km^2 ) - Hourly coverage even more sparse

60 Space-Based Observations Satellite Observations

61 Remote Sensing Systems (Spectral Signal) Reflectance ( % ) Human Eye Visible Range 40 Satellite 20 0 Bare Soil Healthy Vegetation Stressed Vegetation Fresh Snow Sea Water Center for Hydrometeorology Wavelength and Remote (µm) Sensing, University of California, Irvine

62 Satellite-Based Rainfall Estimation: Promising! Observations from space: Near-continuous, global coverage,

63 Satellite Data for Precipitation estimation Geostationary IR Cloud top data 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 )

64 Interpolation of 3-hour Precipitation T T+3hr T+6hr t-hr t+3hr

65 Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) PERSIANN System Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks

66 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.

67 PERSIANN-CDR: PERSIANN Climate Data Record

68 PERSIANN Satellite Product On Google Earth

69 Satellite-Based Precipitation: Very Promising for Hydrometeorological Applications a mpeg

70 GPM Mission: Target Date 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

71 GPM Animation Courtesy: NASA s ESE

72 GPM Animation Courtesy: NASA s ESE

73 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

74 Recently Released IPCC Report (AR5) - Sept 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

75 Thank You for the Invitation and Listening Somewhere in New Mexico, USA - Photo: J. Sorooshian