Landuse/Landcover Update for the Attoyac Bayou Watershed

June 16, 2011

attoyac.tamu.edu

Neil BoitnottCastilaw Environmental Services, LLCnboitnott@castilawenvironmental.com

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LULC Map

Legend

Open Water

Developed (Open Space)

Developed (Low Intensity)

Developed (Medium Intensity)

Developed (High Intensity)

Barren Land

Forested Land

Pine Plantation

Mixed Forest

Near Riparian Forested Land

Rangeland

Managed Pasture

Cultivated Crops

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attoyac.tamu.edu

LULC Percentages

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Methods

ArcGIS 9.3 software was utilized for LULC mapping.

Started with watershed boundary with no LULC features.

Cut features by LULC class based on 2008-2009 leaf-off aerial photography.

Final product was entire watershed with over 12,000 individual LULC features.

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Methods Cont.

Watershed Boundary With No LULC Features

Clipping LULC Features within Watershed Boundary

LULC Features Clipped from Watershed Boundary

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Accuracy AssessmentTotal Average Accuracy = 86%Accuracy by LULC Class:

Open Water – 100% Developed (Open Space) – 100% Developed (Low Intensity) – 76% Developed (Medium Intensity) – 70% Developed (High Intensity) – 100% Barren Land – 82% Forested Land – 100% Pine Plantation – 90% Mixed Forest – 67% Near Riparian Forested Land – 70% Rangeland – 100% Managed Pasture – 86% Cultivated Crops – 75%

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Accuracy Assessment Cont.

Field Assessment Methods

Upload GPS points from mapping software to mobile GPS unit.

Drive to GPS point in the field.

Record LULC type for GPS point and compare to mapped LULC.

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Accuracy Assessment Cont.

Managed Pasture Pine Plantation

Open Water Near Riparian Forested 8

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Accuracy Assessment Cont.

Office Accuracy AssessmentPrimarily Used for Developed ClassesMethods:

Using ArcGIS software, place grid over developed area in question.

Count number of grid intersections occurring over developed surfaces vs. number of grid intersection occurring over undeveloped surfaces.

Get a total percentage of developed area and classify to appropriate LULC class

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Accuracy Assessment Cont.

Developed area (Garrison) with Grid for Office Assessment.

Developed area (Garrison) Classified.

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Any Questions?

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Neil BoitnottCastilaw Environmental Services, LLCnboitnott@castilawenvironmental.com