Evaluation for the Integration of a Virtual Evapotranspiration Sensor
Based on VIIRS and Passive Microwave Sensors into Annualized
Agricultural Non-Point Source Pollution (AnnAGNPS) Model
Rapid Prototyping Capability Project
2006
Lance Yarbrough (PI)
Dath Mita (Co-PI)
The University of Mississippi
Collaborators
Ronald Bingner (Ron)
USDA-ARS
National Sedimentation Lab
Robert Ryan
SSAI
John C. Stennis Space Center
Steve Running
The Numerical Terradynamic Simulation Group
University of Montana
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April, 2008
Presentation Outline
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Objectives
Background
Expected Impacts
Progress Report (April 2008)
Upcoming Major Tasks
Schedule
Future Science Questions
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Project Objectives
 To develop and evaluate a “Virtual” Evapotranspiration (ET)
Sensor (VETS) model for estimating ET using Moderate
Resolution Imaging Spectroradiometer (MODIS) data
 To evaluate the potential of applying VETS model with
Annualized Agricultural Non-Point Source Pollution Model
(AnnAGNPS)
 To evaluate the use of VIIRS data (simulation) as a potential
ET data source in place of MODIS
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
1
Study Area:
Lower Mississippi,
The Yazoo River Basin, Yalobusha Watershed
Yalobusha Watershed
0
12.5 25
50 Miles
4
Rationale:
-long history of hydrologic work
-extensive infrastructure
-long history of hydrologic data
-USDA-ARS NSL past & ongoing projects
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Background: AnnAGNPS
 AnnAGNPS is a watershed-scale simulation program
(developed by USDA)
 The model simulates point and non-point source quantities of:
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surface water,
sediment,
nutrients, and
pesticides
 The model output is expressed on an event basis for selected
stream reaches and outlets
 It is also used to evaluate Best Management Practices (BMPs)
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
AnnAGNPS Input Parameters
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Climate data
Hydrology – Daily soil moisture balance
Runoff – SCS curve number
Subsurface flow
Rill and sheet erosion – RUSLE
Sediment delivery – HUSLE
Gully Erosion
Channel Erosion
Chemical routing – Mass balance approach
Evapotranspiration (ET) – Penman equation
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
3
Project Overview
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Current AnnAGNPS ET input process involves:
1.
The use of climate data and the PENMAN equation to
estimate potential ET
2.
Estimates of potential ET and soil moisture are used to
generate actual ET
Wind
Solar Radiation
Humidity
Temperature
Penman
Equation
ETpotential
Soil
Moisture
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
ETactual
Problem definition:
 ET estimation:
Requires several climate data inputs (wind,
temperature, solar radiation, humidity etc.)
Not all weather stations collect and record a complete
set of the required climate parameters
 Certain regions have limited ground weather stations and
climate data
 Can lead to limited and generalized watershed ET estimates
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Project Outcomes
Enhancing AnnAGNPS as a Decision Support System by:
1.
Providing a more efficient and effective ET input process
a.
b.
2.
Increased spatial coverage
Reliable and consistent measurements
Performance evaluation of AnnAGNPS with satellite data
from current (MODIS) and next generation (VIIRS) sensors
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Expected Impacts
(Value and benefits to society)
1. Improvement in the accuracy of predicting non-point source
pollution loadings within agricultural watersheds
2. Improvements in the design and implementation of watershed
conservation programs.
3. Provision of short and long term improvements in water quality
management and human health.
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Progress Report
April 15, 2008
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April, 2008
Data Collection:
Ground weather station data:
Status: Complete
Research Application:
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To process ET data using the Penman equation
To run current AnnAGNPS watershed simulation process
To determine correlation and/or covariance with satellitebased ET
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Data Collection:
MODIS (2004) Satellite data:
Status: Complete
 Acquired and pre-processed:
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Surface Reflectance Daily L2G Global (MOD09GHK)
Surface Reflectance Quality L2G Global (MOD09GST)
Land Surface Temperature/Emissivity daily L3 (MOD11A1)
Landcover Types L3 Global (MOD12Q1)
 Research Application:
 To generate intermediate ET factors:
 LAI (leaf area index)
 FPAR (fraction of photosynthetically active radiation)
 EVI (enhanced vegetation index)
 ALBEDO
 To generating ET using the Virtual ET sensor
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Data Collection:
MODIS ET raw data (2004)
Status: Complete
 Acquired ET raw data (0.05 deg) processed using Revised RSPM algorithm
 In collaboration with The Numerical Terradynamic
Simulation Group, University of Montana
 Research Application:
 To apply in the Virtual ET sensor system
 Comparative analysis with Virtual sensor ET algorithm
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Data Collection:
Simulated VIIRS data (ITD-SSAI Stennis)
Status: In Progress
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Surface-Reflectance band I1 (MOD1) and band I2 (MOD2)
Emissivity M15 (MOD31)
Emissivity M16 (MOD32)
Land surface temperature (LST)
 Research Application:
 To generate intermediate ET factors:
1.
2.
3.
4.
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LAI (leaf area index)
FPAR (fraction of photosynthetically active radiation)
EVI (enhanced vegetation index)
ALBEDO
To generate ET using Virtual ET sensor algorithm and Revised RS-PM
algorithm
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Current Research Outputs
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
GIS layers of ground-based (2000-05) Climate Data:
(monthly and daily precipitation and temperature)
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Gridded ET GIS layers (Virtual ET Stations)
(2004, 8-day composites)
“Virtual” ET Stations
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
MODIS ET Surface Datasets (2004, 8-day)
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
AnnGNPS Climate Data Input Editor Modification
Current
AnnAGNPS
ET estimate
variable
inputs
MODIS
ET data
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Modified AnnGNPS Climate Data Input Editor
MODIS/VIIRS
ET data
AnnAGNPS ET executable code
-development
-testing
-implementation
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Challenge……
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Within AnnAGNPS, when the potential ET is combined with
the soil moisture in the soil profile, the actual ET is
determined.
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When Actual ET is supplied by the user, the interaction with
soil moisture still needs to be included in order to maintain
the water balance in the system that effects surface and
subsurface runoff as well as baseflow.
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Watershed Simulation
 Collection and preprocessing of AnnAGNPS ancillary variables
has been completed,
 topographic, soils, landcover, land management
datasets etc.
 Approximately 95% of the pre-simulation preparations have
been completed, including the incorporation of user defined
actual ET effects on simulating soil moisture throughout the
soil profile.
 Major Simulation Parameters: Peak Runoff, Sediment Yield,
and Nutrient Load
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Watershed Drainage Area Subdivision
by AnnAGNPS Cells
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Assignment of MODIS-ET Grid to
AnnAGNPS Watershed Cells
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Watershed RUSLE LS-Factor
(slope-length)
Subwta.shp
0.02 6 - 0.2 46
0.24 6 - 0.5 87
0.58 7 - 1.0 72
1.07 2 - 1.7 62
1.76 2 - 2.8 58
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Watershed Soil Variability
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
ET “Virtual” Sensor System
MODIS/VIIRS
Data
ET
Algorithm
Raw ET Data
GIS Protocol
-scaling factors
-coefficients
Grid Potential ET
Grid Actual ET
AnnAGNPS Climate Input Editor
-gridded ET
-watershed cells
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Remaining Major Tasks:
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Continue VETS Model Testing, Evaluation, and Validation
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Watershed simulation experiments:
1. Penman ET based (2)
2. MODIS ET (2)
3. VIIRS simulated ET (2)
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Analysis and evaluation of watershed simulation results
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Preparation of final report and publication manuscripts
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Project Schedule
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Future Science Questions
 How do watershed scale and the use of MODIS/VIIRS ET
observations in hydrologic modeling affect the accuracy and
precision of hydrologic assessments?
 Compare in-situ and expected observations of watershed flow,
sediment yield, and nutrient loading
 How can we most effectively estimate the tolerances and
optimization at local and regional scales?
 How can we account for natural variability in ecological
systems and allow for the most accurate and precise
assessments possible.
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008
Contact Information:
Greg Easson, Director UMGC
 662 915 5995
 [email protected]
Lance Yarbrough, PI
UMGC
 662 915 6598
 [email protected]
Dath Mita, Co-PI
UMGC
 662 915 5201
 [email protected]
The University of Mississippi Geoinformatics Center
NASA MRC RPC Review Meeting: 14-15 April 2008