Relative erosion potential (REP) for all land areas within the wider Caribbean (1 km)

Source: Lauretta Burke and Jon Maidens and contributing authors: Mark Spalding, Philip Kramer, Edmund Green, Suzie Greenhalgh, Hillary Nobles, Johnathan Kool. 2004. Reefs at Risk in the Caribbean.

Relative erosion potential (REP) for all land areas within the wider Caribbean (1 km)

Metadata also available as

Identification_Information:

Data_Quality_Information:

Attribute_Accuracy:

Positional_Accuracy:

Horizontal_Positional_Accuracy:
Vertical_Positional_Accuracy:

Lineage:

Process_Step:

Process_Description:

The first step of the analysis involves estimating likely erosion rates for each 1km resolution grid cell using a modified, simplified form of the Revised Universal Soil Loss Equation (RUSLE) (USDA, 1989). Information on slope, land cover type, precipitation, and soil porosity were integrated to develop an indicator of relative erosion potential (REP) for all land areas within the wider Caribbean.

Data Sets Used REP relies upon four input data sets: a) Percent slope (derived from USGS HYDRO1K digital elevation model, 2000), (1000m resolution) b) Relative erosion rate by land cover type. The Global Land Cover Characteristics Database (USGS / Loveland, 2000) using International Geosphere-Biosphere Program land cover categories was reclassified to relative erosion rates, ranging from 15 (for forest) to 200 for croplands. (See Table 1 below) These relative erosion rates are based on published work involving conversion factors. (Nyborg, 1995; FAO, 1979; Berner and Berner, 1987) (1000m resolution) c) Precipitation for the peak rainfall month (mm), based on monthly precipitation surfaces (0.08 DD resolution.) This variable was chosen instead of mean annual precipitation because it is more indicative of the extreme rainfall events and because it captures more of the rainfall variability in the area. (9342m resolution) d) Soil porosity. A polygon database on soil type (FAO, 1995) provided soil texture and porosity attributes. Soil porosity is the soil characteristic used in calculations because of its relationship with infiltration capacity of the soil. (5000 m resolution)

REP (by 1 km grid cell) = pct_slope * Land_cov_eros_rate * Precip_mm * porosity / 1,000

Within this analysis, slope is the most influential input variable, followed by land cover, precipitation, and soil porosity. The most influential areas in the landscape in terms of high relative erosion rates are steep slopes with land converted to agriculture.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 6000
Column_Count: 5750
Vertical_Count: 1

Spatial_Reference_Information:

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Planar:

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Map_Projection_Name: Lambert Azimuthal Equal Area

Lambert_Azimuthal_Equal_Area:

Longitude_of_Projection_Center: -76.000000
Latitude_of_Projection_Center: 16.000000
False_Easting: 0.000000
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Planar_Coordinate_Encoding_Method: row and column

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Abscissa_Resolution: 1000.000000
Ordinate_Resolution: 1000.000000

Planar_Distance_Units: meters

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Horizontal_Datum_Name: D_Sphere_ARC_INFO
Ellipsoid_Name: Sphere_ARC_INFO
Semi-major_Axis: 6370997.000000
Denominator_of_Flattening_Ratio: infinity

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: rep_1km

Attribute:

Attribute_Label: ObjectID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:: Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Value
Attribute_Definition: relativer erosion rate
Attribute_Domain_Values:

Attribute:

Attribute_Label: Count

Distribution_Information:

Resource_Description: Downloadable Data

Standard_Order_Process:

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Transfer_Size: 25.932

Metadata_Reference_Information:

Metadata_Date: 20041221

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: World Resources Institute

Contact_Address:

Address_Type: 10 G Street, NE Suite # 800
City: Washington, DC
State_or_Province: District of Columbia
Postal_Code: 20002
Country: United States

Contact_Voice_Telephone: 202 729 7600

Contact_Facsimile_Telephone: 202 729 7775

Contact_Electronic_Mail_Address: reefsatrisk@wri.org

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

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Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Generated by mp version 2.8.6 on Tue Dec 21 12:49:30 2004

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