Chesapeake Bay Program Models:

Transcription

1 Chesapeake Bay Program Models: A Guide to Better Understanding Modeling and Decision Support Tool Forum Penn State Harrisburg August 1,

2 Mark Dubin Agricultural Technical Coordinator University of Maryland Extension-College Park College of Agriculture and Natural Resources USDA-NIFA Mid-Atlantic Water Program EPA Chesapeake Bay Program Office

3 AGENDA Background Introduction to the Bay Models Land Change Model Airshed Model Scenario Builder Decision Support Tool Watershed Model Estuarine Model SPARROW Model Conclusions 3

4 Chesapeake Bay Background 4

5 Ratio of Areas Watershed : Estuary ~ 15:1 NY PA N, P, Sediment inputs WV DC MD DE Chesapeake Bay VA Bay Mouth 5

6 6 From Batiuk (2003)

7 Land use Forest 64% Agricultural 24% Urban 8% Other 4% 7

8 Main Sources of Bay Pollution Agriculture animal manure, commercial fertilizer Urban/suburban runoff a growing problem Air pollution tailpipes, power plants Wastewater sewage treatment plants 8

9 The Suite of Chesapeake Bay Models and Their Roles in Supporting Decision- Making 9

10 The Basic, Essential Purpose The basic, essential purpose of integrated modeling, research, and monitoring is to answer the questions of the decision makers: integrated models must be tailored to the nature of the decision and to the desired level of analysis. 10

11 Percent of Time Management Actions Roles of the Bay Models In Land Use Change Model Decision-Making Watershed Model Bay Model Criteria Assessment Procedures Airshed Model Scenario Builder CFD Curve Area of Criteria Exceedence Area of Allowable 30 Criteria Exceedence Percent of Space Sparrow Effects Allocations 11

12 An Overview of the CBP Integrated Models: Basic Chesapeake Bay Modeling Structure A Regression Model of 15 monitoring sites over 10 simulation years. Changes in air quality management simulated with the Regional Acid Deposition Model (RADM) with a domain covering the Eastern states and limited grid capabilities Watershed Model Phase model segments, 9 land uses, 20 calibration sites, 10 simulation years, fixed annual land use Chesapeake Bay Water Quality Model Hydrodynamic Model, Sediment Benthic Model, and Submerged Aquatic Vegetation, 10 simulation years, 13,000 model cells 12

13 An Overview of the CBP Integrated Models: Basic Chesapeake Bay Modeling Structure Nitrate and ammonia deposition from improved Daily Nitrate and Ammonium Concentration Models using 35 monitoring stations over 18 simulation years. Adjustments to deposition from the Community Multi-scale Air Quality (CMAQ) Modeling System Phase 5 Watershed Model Year-to-year changes in land use and BMPs; 899 segments; 24 land uses; 296 calibration stations; 21 simulation years; sophisticated calibration procedures; calibration demonstrably better in quality and scale Chesapeake Bay Estuary Model Detailed sediment input; Wave model for resuspension, Full sediment transport; Filter feeder simulation; Simulation of Potomac algal blooms; 54,000 model cells; simulation years

14 Chesapeake Bay Land Change Model 14

15 Chesapeake Bay Land Change Model Development History: first developed in 2006; latest Version 4 model Lead Developers: U.S. Geological Survey Shippensburg University Maryland Department of Planning Woods Hole Research Center Peer Review Status: CBP STAC independent review conducted in 2008 and 2010; USGS review of Phase 5.3 watershed model land use data 15

16 Population Chesapeake Bay Watershed Population Trends Data provided by state and local agencies 20,000,000 15,000,000 10,000,000 5,000, Year 16

17 Chesapeake Bay Land Change Model Version 3 WWTP Sewer Service Areas Watershed Model Segment Input Data COG and State Population Projections Growth Allocatio n Model GAMe Sewer Model Sewer population Septic Pop. Slope, Protected lands, Zoning, Sewer service areas Land Use/ Land Cover (RESAC) Calibration Metrics Cellular Automata Model CB-SLEUTH Future Urban Area Proportions of farm and forest converted to urban Impervious Surface Change 17 Source: U.S. Geological Survey Chesapeake Bay Land Data Team

18 Forecasted Urban Growth (2000 to 2030) Source: Chesapeake Bay Land Change Model Version 3 Management Applications Establish benchmark expectations of the magnitude, location, and impact of urban development in the Bay watershed through the year 2030 Inform Watershed Implementation Plans in the absence of alternative local or state forecasts. Starting point for considering and discussing the potential implications of urban growth on Bay water quality. 18

19 Forecasted Population Growth on Sewer vs. Septic (2000 to 2030) Source: Chesapeake Bay Land Change Model Version 3 19

20 Farmland and Forest Land Loss (2000 to 2030) Source: Chesapeake Bay Land Change Model Version 3 20

21 Chesapeake Bay Watershed Land Use Satellite Series: 1984, 1992, 2001, 2006 Satellite data: 1984, 1992, 2001, 2006 U.S. Census of Agriculture Square Miles

22 Montgomery County, Maryland Legend Open water Low Intensity Urban Medium, High Intensity Urban Barren Forest Shrub/grass Agriculture Wetlands 22

23 Chesapeake Bay Airshed Model 23

24 The Airshed Model Before: A Regression Model of 15 monitoring sites over 10 simulation years. Changes in air quality management simulated with the Regional Acid Deposition Model (RADM) with a domain covering the Eastern states and limited grid capabilities. Now: Nitrate and ammonia deposition from improved Daily Nitrate and Ammonium Concentration Models using 35 monitoring stations over 18 simulation years. Adjustments to deposition from the Community Multi-scale Air Quality (CMAQ) Modeling System.

25 The Airshed Model - CMAQ Combining a regression model of wetfall deposition... with CMAQ estimates of dry deposition for the base and using the power of the CMAQ model for scenarios. 25

26 Chesapeake Bay Scenario Builder Decision Support Tool 26

27 Scenario Builder A modeling program that simulates non-point source processes in order to enhance the accuracy and precision of the Phase 5 Chesapeake Bay Watershed Model 27

28 Scenario Builder Components Atmospheric Deposition Crop Max Uptake Crop Uptake Efficiency BMPs Crop Cover Transfer Source to Stage Database Landuse Change BMPs OR User File Upload and Validation Transfer Imported User Data Transfer Stage to Processing Database Pre BMP Landuse OR Apply crops on Post BMP Landuse Manure Production and Transformations Nutrient Application Transfer Nutrient Application Data to Database Nitrogen Fixation Create Model Files Transfer Processing to History Database Transfer History to Stage Database Post BMP Landuse File Septic Nutrient Application Rate Scenario Builder Sub-Systems March 1, 2010 SSIS packages Database Views C# modules Incomplete subsystems Waste Water Detached Sediment Summary of Processes: 1) Apply land use change BMPs to reported land use 2) Apply BMP efficiencies and then crops to land uses 3) Calculate: max crop uptake, crop cover, manure production and transformation, nutrient app rate, detached sediment 4) Calculate actual crop uptake 5) Apply nutrients and log application rates 6) Simulate N fixation 7) Make input files for watershed model and log history Documentation: Estimates of County-Level Nitrogen and Phosphorus Date for Use in Modeling Pollutant Reduction 28

29 29

30 Outputs to Chesapeake Bay Watershed Model BMPs Descriptions Acres Pounds nitrogen, phosphorus and sediment reduced Land uses Manure (nutrient species/land use/month) Septic system loads Cover crops uptake Fertilizer application Legumes (pounds nitrogen) Maximum crop uptake Uptake curve (monthly nutrient uptake by land use) 30

31 Chesapeake Bay Watershed Model 31

32 The Watershed Model Full States of Maryland, Delaware, and Virginia. Partial States of New York, Pennsylvania, and West Virginia Use for regional Chesapeake Bay assessment of water quality standards as well as assessment of water quality standards at the local watershed scale. Land Uses In Segment Segments Trib Basins

33 Chesapeake Bay Watershed Model Development History: First version in 1982 Current version is phase Peer Review Status: CBP STAC independent peer reviews of Phase 5 model conducted in 2007 and 2009 More Information: ftp://ftp.chesapeakebay.net/modeling/phase5/community/p52an/ 33

34 Co-Developers of the Chesapeake Bay Program s Phase 5 Watershed Model Chesapeake Bay Program Developers EPA U of MD USGS NRCS CRC VaTech Advisors and data suppliers NY, PA, MD, DE, VA, WV, DC Penn State $ ICPRB MDE VA DCR USGS $ 34

35 A Quarter Century of Watershed Model Development Phase 1 Phase 4 Phase 5 Completed in model segments 5 land uses 2 year calibration period (March- October) Completed in model segments 9 land uses 14 year calibration period ( ) May 2009 roll-out (Phase 5.1) ~ 1,000 model segments 25 land uses using time-varying land use & BMPs 21 year calibration period ( ) 35

36 Finer Segmentation and Longer Simulation Periods Increases the Calibration Sites By An Order of Magnitude Phase 4 Segmentation and Calibration Sites Calibration sites = 20 Land Segments = 94 River Segments = 94 Land uses = 9 Simulation Years = 10 Phase 5 Segmentation and Calibration Sites Calibration sites = 296 Land Segments = 308 River Segments= 1,063 Land uses = 25 Simulation Years = 20 36

37 How the Watershed Model Works Hourly Values: Rainfall Snowfall Temperature Evapotranspiration Wind Solar Radiation Dewpoint Cloud Cover HSPF Annual or Monthly: Land Use Acreage BMPs Fertilizer Manure Atmospheric Deposition Point Sources Septic Loads Daily output compared To observations 37

38 How the Watershed Model Works Each segment consists of separately-modeled land uses: High Density Pervious Urban High Density Impervious Urban Low Density Pervious Urban Low Density Impervious Urban Construction Extractive Combined Sewer System Wooded / Open Disturbed Forest Plus: Point Source and Septic Loads, and Atmospheric Deposition Loads Corn/Soy/Wheat rotation (high till) Corn/Soy/Wheat rotation (low till) Other Row Crops Alfalfa Nursery Pasture Degraded Riparian Pasture Manure Areas Fertilized Hay Unfertilized Hay Nutrient management versions of the above Each calibrated to nutrient and Sediment targets 38

39 How the Watershed Model Works Each land use type is divided into four soil layers: Composed of Water, Sediment, Nitrogen, and Phosphorus submodels 39

40 Atmospheric Deposition Denitrification Export How the Watershed Model Works Nitrate Solution Ammonia Trees Roots Particulate Labile Organic N Leaves Particulate Refractory Organic N Each submodel has a complex hydrologic or nutrient cycling structure. Export Export Export Export Export Export Adsorbed Ammonia Solution Labile Organic N Solution Refractory Organic N 40

41 Where do we calibrate? Automated Calibration Reasonable values of sediment, nitrogen, and phosphorus Observations of flow, sediment, nitrogen, and phosphorus 41

42 Calibration Strategy Match observations in rivers Match properties and trends Groundwater recession curve Crop uptake of Nitrogen Match literature and other models Reasonable rates of nutrient export USGS estimator and sparrow empirical models 42

43 Quick Overview of Watershed Model Scenarios Hourly Values: Rainfall Snowfall Temperature Evapotranspiration Wind Solar Radiation Dewpoint Cloud Cover Hourly output is summed over 10 years of hydrology to compare against other management scenarios HSPF Snapshot: Land Use Acreage BMPs Fertilizer Manure Atmospheric Deposition Point Sources Septic Loads Average Annual Flow-Adjusted Loads 43

44 Chesapeake Bay Water Quality/Sediment Transport (Estuarine) Model 51

45 Estuarine Water Quality Model This is the decision model for dissolved oxygen and chlorophyll water quality standards. Because of tight coupling of processes several of the integrated models are coupled to the Water Quality Model, i.e., interacting at every model timestep. The coupled models are the SAV, oyster, menhaden, and sediment transport models.

46 The Estuarine Sediment Transport Model The Water Quality Model combined with the Sediment Transport and filter feeder models will be the decision model for the clarity water quality standard. Clarity is influenced by chlorophyll, particulate and dissolved organics, and sediment. Achieving the clarity standard is necessary for restoring SAV.

47 Chesapeake Bay SPARROW Model 54

48 Current and Planned Watershed Monitoring Networks 55

49 Watershed Nitrogen/Phosphorus Flow-Adjusted Concentration Trends 56

50 Nutrient Impacts on Bay WQ 57 57

51 Conclusions 58

52 Why is Integrated Modeling Needed? Model integration creates: Cooperation between parties. More useful and accurate models. Better integration of EPA s programs providing better environmental protection at least cost. Results that are equitable and protective Model integration makes complete analysis of issues: Environmental fate and transport among different media. Improving environmental management by taking into account cross-media effects. More complete economic analysis of benefits and costs. Understand all impacts of actions and policies

53 Questions & Comments 60 60