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CSISS Center for Spatial Information Science and Systems
Remote-sensing-based Post-flood Crop Loss Assessment for Supporting Agricultural Decision
Making—Requirements, Methods, and Gaps
Liping Di
Center for Spatial Information Science and Systems George Mason University
4400 University Drive, MSN [email protected]
Phone: 703-993-6114http://www.csiss.gmu.edu
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CSISS Center for Spatial Information Science and Systems
Contents
• Post-flood crop decision making activities at USDA– NASS– RMA
• Requirements and Remote Sensing methods
• Resolution gaps– Spatial– Temporal
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CSISS Center for Spatial Information Science and Systems
Introduction
• Flood is one of the worst natural disasters in the world. Flooding often causes significant crop loss over large agricultural areas in the United States.
• Two USDA agencies, the National Agricultural Statistics Service (NASS) and Risk Management Agency (RMA), make decisions on flood crop loss assessment and recovery– NASS has the mandate to report crop loss after all flood events– RMA manages crop insurance policy and uses crop loss
information to guide the creation of the crop insurance policy and the aftermath compensation.
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CSISS Center for Spatial Information Science and Systems
Agricultural decision activities after a flood disaster
Decision activity Requirements Existing Services/Systems
Gaps
Collecting and archiving flooded acreage and flood duration
Complete coverage; duration of flood; annual records.
None. Annual records of flooded acreage
Recording annual crop loss due to flood
Crop loss due to flooding; yield reduction by county; annual records.
None. Annual records of crop loss by county
Assessing the crop insurance rating areas
Reliable flooding frequency information
Investigating crop policy compliance
Cause of loss; reported loss vs. actual loss
Manual survey Crop condition profile and crop growth dates; flood duration; high resolution crop type
Spot checking of crop loss claims
Prevent planting claim validation
Manual survey Annual crop condition profiles; high resolution cropland map
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CSISS Center for Spatial Information Science and Systems
Shortcomings of current approaches
• Sparse samplings due to limited number of field investigators
• Subjective results due to the uneven knowledge of field investigators
• Slow response due to the length sample data collection and analysis process
• Difficulty in data integration due to data-interpolation and data-interpretation problems
• Lack of effective decision support tools to manage and integrate the diverse information.
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CSISS Center for Spatial Information Science and Systems
The Proposed Remote Sensing Approach
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CSISS Center for Spatial Information Science and Systems
Extraction of flood duration and frequency from surface water records
•1. Cloud affected data
•2. Missing data (“gap”)
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CSISS Center for Spatial Information Science and Systems
Crop Loss Seen in Remote Sensing Images
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CSISS Center for Spatial Information Science and Systems
Yield loss
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CSISS Center for Spatial Information Science and Systems
Compliance investigation
• Compliance investigation determines if a claim of crop loss meets the policy requirements. – (1) did the flood occur during the crop growing season? – (2) was there crop actually planted? – (3) how much is the crop loss?
• To answer these questions, we need the following information from remote sensing– (1) crop growing season – (2) flood event duration,– (3) crop condition profiles
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CSISS Center for Spatial Information Science and Systems
Spot Check
• Spot check is to verify the appraisal for the loss. One of the major questions is to determine if the claim satisfies the condition “prevent planting”. Is the clause of prevent planting satisfied? Is replanting prevented? Does the farmer grow anything after the flood?
• To answer these questions, we need to have knowledge of the crop conditions after a flood event. – determine if the crop development actually affected by the flood.
• The information sought to support the decision are crop type, and crop condition profile against the normal crop condition profile.
• Need high-resolution images
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CSISS Center for Spatial Information Science and Systems
Scale dependency
• It is found that the information requirements for decision-making have a range of scales depending on the level of decision-making. – For the state-level and federal-level overview, decision makers
require complete information of flooded area, flood duration, affected crop area, and crop loss.
– For specific crop loss claims or field investigation, decision makers need detailed information on flood frequency, crop history, and crop development. Information on historical floods specific to the interested spots and the crop development beyond the current flood is required for making better appraisal on crop loss and prompt fair compensation to insured farmers.
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CSISS Center for Spatial Information Science and Systems
Gaps on Spatial Resolution
• For the federal and State-level decision making– MODIS/VIIRS + Landsat OLI should be enough.
• For spot check of individual claims,– Landsat OLI barely meets the requirements.– Resolution around 5-15 meters multiple spectral images are
better
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CSISS Center for Spatial Information Science and Systems
Gaps on temporal resolution
• The decision making requires the use of temporal profile
• Because of frequent cloud cover, even the daily temporal coverage of MODIS data has problems, for example, in determining flood frequency and duration
• Landsat’s 16-day coverage is difficult to establish the temporal profile
• Considering to integrate with SAR data
