NLCD and MODIS Landuse NLCD and MODIS Landuse Processing Tools and Projection Processing Tools and Projection

Issues in ModelingIssues in Modeling

Limei Ran and Alison EythLimei Ran and Alison EythCenter for Environmental Modeling for Policy DevelopmentCenter for Environmental Modeling for Policy Development

Institute for the EnvironmentInstitute for the EnvironmentUniversity of North Carolina at Chapel HillUniversity of North Carolina at Chapel Hill

Outline of the PresentationOutline of the Presentation

• Landuse Data

• New Release of Spatial Allocator (SA) 3.5

• Projection Issues in Modeling

• Future Enhancements for SA

• Acknowledgements

Landuse Data in WRF and MM5Landuse Data in WRF and MM5

• USGS Global Land Cover Characteristics (GLCC) 30-second (around 1km) landuse data are used in:

• WRF GEOGRID• MM5 TERRAIN

• GLCC database was developed from:• NOAA 1km AVHRR satellite images spanning

04/1992 through 03/1993

2001 NLCD and MODIS Landuse Data2001 NLCD and MODIS Landuse Data• Two new land cover data sets are available:

• 2001 30m NLCD for US (Landsat 7 and 5 TM images) • 2001 1km MODIS for the Globe (TERRA MODIS satellite images)

• 30m NLCD data can be obtained from two places:USGS for US• 21-classes USGS Land cover data• Imperviousness• Tree Canopy

NOAA Coastal Change Analysis Program (C-CAP) for coast regions• 30-classes USGS Land cover data

• MODIS land cover database can be obtained from:– Department of Geography, Boston University

• 20-classes IGBP land cover data

2001 NLCD Data2001 NLCD DataUSGS NOAA

2001 NLCD Classification2001 NLCD Classification

11 - Open Water12 - Perennial Ice/Snow21 - Developed - Open Space22 - Developed - Low Intensity23 - Developed - Medium Intensity24 - Developed - High Intensity 31 - Barren Land (Rock/Sand/Clay)32 - Unconsolidated Shore 41 - Deciduous Forest42 - Evergreen Forest43 - Mixed Forest 51 - Dwarf Scrub52 - Shrub/Scrub71 - Grassland/Herbaceous72 - Sedge/Herbaceous

73 - Lichens74 – Moss

75 - Tundra81 - Pasture/Hay82 - Cultivated Crops90 - Woody Wetlands

91 - Palustrine Forested Wetland92 - Palustrine Scrub/Shrub Wetland93 - Estuarine Forested Wetland94 - Estuarine Scrub/Shrub Wetland

95 - Emergent Herbaceous Wetlands96 - Palustrine Emergent Wetland97 - Estuarine Emergent Wetland98 - Palustrine Aquatic Bed99 - Estuarine Aquatic Bed

MODIS 2001 Land Cover DataMODIS 2001 Land Cover Data

MODIS Land Cover IGBP MODIS Land Cover IGBP ClassificationClassification

0 - water1 - evergreen needleleaf forest2 - evergreen broadleaf forest3 - deciduous needleleaf forest4 - deciduous broadleaf forest5 - mixed forests6 - closed shrublands7 - open shrublands8 - woody savannas 9 - savannas10 - grasslands

11 - permanent wetlands12 - croplands13 - urban and built-up14 - cropland/natural vegetation

mosaic15 - permanent snow and ice16 - barren or sparsely vegetated17 - IGBP Water Bodies (recoded to

0 for MODIS Land Product consistency).

254 - unclassified255 - fill value

New Release of Spatial New Release of Spatial Allocator 3.5Allocator 3.5

• New release is organized into three parts:• Vector Tools to process shapefiles• Raster Tools to process NLCD/MODIS landuse data • Surrogate Tools to compute surrogates

• Uses PROJ4.6 to project between spherical earth R and ellipsoid:

• PROJ4.6: no datum transformation. Matches WRF,MM5 projections..

• PROJ4.5 or older versions: performs datum transformation automatically and results in mismatches..

NLCD and MODIS 2001 Data NLCD and MODIS 2001 Data ProcessingProcessing

• Two steps to generate modeling grid land cover data from NLCD and MODIS data:

1. Pre-process original NLCD data sets to get rid of overlaps. 2. Compute modeling grid land cover information from:

• USGS NLCD land cover• USGS NLCD imperviousness• USGS canopy• NOAA coastal NLCD land cover• NASA MODIS land cover data

• Two output files produced: • WRF landuse NetCDF file• CSV text file

NC 1km Grids, NLCD and MODISNC 1km Grids, NLCD and MODIS

NLCD and WRF Land CoverNLCD and WRF Land Cover NC 1km GridsNC 1km Grids

NLCD and WRF Land CoverNLCD and WRF Land Cover NC 1km GridsNC 1km Grids

NLCD and WRF Land and WaterNLCD and WRF Land and Water

Projection Issues in ModelingProjection Issues in Modeling• Map projection can be: Map projection can be:

Forward:Forward: P(x,y) = F { Projection, Parms(Earth_Model), P(long,lat) } P(x,y) = F { Projection, Parms(Earth_Model), P(long,lat) } Reverse:Reverse: P(long,lat) = F { Projection, Parms(Earth_Model), P(x,y) }P(long,lat) = F { Projection, Parms(Earth_Model), P(x,y) }

Projection: LCC, AEAC, UTMProjection: LCC, AEAC, UTMEarth model (datum): sphere R, ellipsoid WGS84 or NAD83, NAD27Earth model (datum): sphere R, ellipsoid WGS84 or NAD83, NAD27

• Datum transformation is needed when projecting a GIS data set to a Datum transformation is needed when projecting a GIS data set to a projection that uses a different earth model.projection that uses a different earth model.

NLCD AEAC with NAD83 to LCC with R=6370000mNLCD AEAC with NAD83 to LCC with R=6370000m

Forward projection to Forward projection to x/y file in LCC with Rx/y file in LCC with R

transform datum?

Transform to Transform to lat/long file in lat/long file in

sphere Rsphere R

Reverse projection to Reverse projection to lat/long file in NAD83lat/long file in NAD83

Yes

No

Conclusion:1. Make sure that spatial data are in WGS84 datum (USGS GLCC data).2. No Datum transformation from WGS84 to WRF or MM5 sphere (PROJ4.6).

Future Enhancements for Future Enhancements for Spatial AllocatorSpatial Allocator

• Develop programs to extract preprocessed GOES satellite data for a modeling grid.

• User defined domain to extract GOES data• Output in WRF NetCDF format

• Add variable grid option to:• Surrogate computation• BELD3 data processing • Land cover computation

AcknowledgementsAcknowledgements

• This project is fully funded by US EPA under the Contract No. EP-W-05-045, “Operation of the Center for Community Air Quality Modeling and Analysis”.

• We gratefully acknowledge the support of William Benjey, Jonathan Pleim, and Robert Gilliam from US EPA.