Colorado Vegetation Classification Project White Paper

July 2003

 

 

 

Project Background and Development

 

The Bureau of Land Management (BLM) initiated a cooperatively funded project in 1992 to map land cover within and immediately adjacent to their Montrose District within the regional boundaries of Southwestern Colorado.  The objective of this initial phase was to provide a vegetation dataset for all of southwestern Colorado using Landsat TM imagery.  At the time, the BLM lacked a comprehensive vegetation map for public lands within its boundaries and had no data on non-public lands.  This data would be for interagency use in the development of landscape-level ecosystem management activities.  The dataset could be used as a reference for change detection studies, ecosystem modeling, regulatory compliance issues, and interagency land management policy-making.

 

In 1994, the participants agreed the project should be expanded to include the entire state which would establish the cooperative acquisition and development of a landscape level vegetation dataset for the remaining areas within the State of Colorado using Landsat TM imagery.  A Memorandum of Understanding  (MOU) was developed and put in place between the Colorado Division of Wildlife (CDOW), U. S, Forest Service (USFS), and BLM for data acquisition, data development, data sharing, and the incorporation of the ancillary data for data verification.   The project had four primary objectives:  1) Develop current, classified and rectified vegetative data for Colorado derived from satellite imagery and formatted for GIS use; 2) Maintain requirements, standards, and procedures used by the SW Colorado Project to ensure a seamless database across the state; 3) Utilize the varied resources of the participating agencies to create a common hierarchical vegetation data structure conducive to the needs of all parties; and, 4) lay the foundation for future cooperation among the contributors for ecosystem management initiatives through data sharing and resource inventory.   

 

A project plan was developed in 1996 which established methods, products, and projected costs for completion of a comprehensive and standardized, classified vegetation database for the State of Colorado.  This plan expanded the scope of the original efforts initiated in southwest Colorado.  The CDOW, in cooperation with the Canon City office of the BLM, came on board in 1997 as part of The Colorado Vegetation Classification Project (CVCP) to administer the project for southeast Colorado.  The CVCP truly became a statewide effort in 1998 with its expansion into northeastern Colorado and the participation of northwestern Colorado through the cooperation of the BLM’s Craig District Office.  (Classification efforts by the CDOW and BLM beginning in 1992 to expand the SW effort through contracts with university personnel/students in southeastern and northeastern Colorado and private contractors in the northwest were redone under the CVCP)

 

The BLM is providing equipment and services required for centralized data processing, field training and coordination of field crews, and transfer of data to cooperating agencies.  Data is processed at the National Applied Resources Service Center (NARSC), now known as The National Science and Technology Center, Geographic Information Lab at the Denver Federal Center in Lakewood Colorado.  The CDOW provided a majority of the funding for this project along with some partner contributions by the BLM and USFS.  CDOW contributed funds have primarily been from the Great Outdoors Colorado Trust Fund (GOCO). 

 

There have been four Remote Sensing Analysts for this project contracted through the BLM:  Suzie Noble, Ed Chine, Randy Simpson, and Thom Curdts.  BLM representatives who have assisted in administration of this project have been Melinda Walker, Debra Dinville, and Pam Clemmer,  NSTC/Denver Federal Center, John Carochi, Canon City, Jim Ferguson, Montrose, and Greg Goodenow, Craig.  The CDOW representative administering this project is Amy Cade, Ft. Collins.  Prior to 1998, Don Schrupp (Denver Headquarters) was the CDOW coordinator for classification efforts related to the initial phases of this project.  Other CDOW employees integral to the success of the CVCP include the Wildlife Resource Information System (WRIS)/habitat biologists from each CDOW region:  Francie Pusateri, Dawn Brownne, Dave Lovell, Seth McClean, Jim Garner, Pam Schnurr, and Scott Strain

 

 

 

Data Processing

 

Landsat TM imagery was acquired from spring and fall dates of the years 1993-95 for each of the 16 scenes covering the State.  The imagery was purchased terrain-corrected and geo-referenced to the UTM coordinate system, zone13, NAD 27, from EOSAT Corporation at the EROS Data Center in Sioux Falls, S.D.  The imagery was resampled to a pixel size of 25 meters.  Bands 1-5 and 7 from the spring imagery were merged with bands 1-5 and 7 of the fall imagery and subset into individual watersheds to create a 12 banded image.  The number of signatures used in the unsupervised classification was determined through analysis of signature divergences and visual assessment of the watershed.  This number varied from 35-70 depending on the spectral complexity of the given watershed.  The ERDAS IMAGINE program ISODATA was used to generate the signatures, which were then entered into a maximum-likelihood classifier to produce a preliminary classification (the specified number of “spectral clusters”).

               

Field crews collected point data, including species composition, percent cover, GPS coordinates and a photograph.   Each field form was entered into an Informix database.  An ArcView Avenue script was written to query the database, and create a shapefile of the field data points for a specified watershed.  The shapefile was then converted into an IMAGINE image for use in the class labeling process.  The IMAGINE image of field points was then compared to the spectral clusters created during the classification process and a summary text file was produced.  The summary file lists all the points that are coincident with each spectral cluster.  The photographs were linked with each field point using ArcView’s HotLink function. 

 

An “all criteria” model was developed using ERDAS Imagine’s Spatial Modeler.  This model refined the spectral clusters derived from the Landat TM data with several ancillary data layers.  Ancillary data layers included DEM-derived (digital elevation model) datasets (150-foot elevation zones, slope, aspect), 100K DLG hydrography line coverage, and land cover data from the US Forest Service, Colorado State Forest and National Park Service.  Criteria related to elevation, slope, aspect, distance from streams, and forest cover type were applied to each spectral cluster by the imaging processing specialists, based on field data and visual analysis of the TM imagery. 

               

There has not been a statistically valid accuracy assessment performed on this data set due to lack of funding and the logistics of such an effort for a project of this size.  After a first draft classification has been completed for a particular basin, a field crew is sent out to review the basin and is directed to obtain additional field data based on questions the analysts may have regarding confused class-types or other uncertainties.  Additionally, first draft classification maps are sometimes sent to BLM or CDOW personnel (WRIS Biologists and DWM’s) for review and field checking.  This information is used to complete the 2^nd draft or final classifications.

 

 

Data Availability

 

The CVCP is scheduled for completion in 2003.  Completed classification data for each basin are posted on a CDOW ftp site housed at:  www.ndis.nrel.colostate.edu.  Data available on this site include:  ARC grid export files, .avl, .clr, and an FGDC metadata file.  In addition, the following data files are available for each completed basin but are  not posted on the ftp site:  final classification in Imagine .img format, 12 band image of basin (.img), ARC points coverage with associated field attributes, points .dbf file, hot link procedures document, final classification document with comments specific to that basin, and the photos (.jpg).

 

 

Distribution Liability

 

This land use/land cover map is a product and property of the Colorado Division of Wildlife, a division of the Colorado Department of Natural Resources.  Care should be taken in interpreting these data.   It is strongly recommended that careful attention be paid to the content of the metadata file associated with these data.

 

The Colorado Department of Natural Resources is not responsible and shall not be liable to the user for damages of any kind arising out of the use of data or information provided by the Department, including the installation of the data or information, its use, or the results obtained from its use.

 

ANY DATA OR INFORMATION PROVIDED BY THE DEPARTMENT OF NATURAL RESOURCES IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 

Data or information provided by the Department of Natural Resources shall be used and relied upon only at the users sole risk, and the user agrees to indemnify and hold harmless the Department of Natural Resources, its officials, officers and employees from any liability arising out of the use of the data or information provided.

 

 

Classification Scheme Development

 

The original classification scheme for this project was adapted from the scheme developed for the Colorado Gap Analysis Project (Schrupp, et al).  The BLM was using a more detailed vegetative scheme that was cross-walked to best fit the classes delineated by the CDOW.  As we expanded the scope of this project to include the entire State of Colorado, the scheme was modified as different cover types were added.  Eventually, we developed the final classification scheme which is a hierarchical form based on the classification system devised by Anderson et al (1976).  Every classification completed contains a list of attributes uniquely defined for that particular basin(s).  The names of the cover types are standardized throughout all the basins, but the descriptions may vary slightly, in terms of individual species that may or may not occur within that type for that particular basin(s

 

 

CVCP Codes, Cover Types, and Descriptions

 

Cover type categories are listed in hierarchical form based on the classification system devised by Anderson et al (1976) titled A Land Use and Land Cover Classification System for Use with Remote Sensor Data and modified for this project.  This is not intended to be a complete species list, but rather an overview of the most common species associated with each cover type. When several different species types occur in a cover type, species are generally listed in order of greatest occurrence.  Co-dominance is defined as two species with each having > 25 and < 75% crown cover over the same site.   Codes in parentheses are the original codes used before a more hierarchical coding scheme was created.

 

1   URBAN/BUILT UP: High density commercial or high density residential areas.

 

2   AGRICULTURE: Row crops, irrigated pasture and hay fields, dry farm crops.

 

3   RANGELAND: Consists of grass/forb range, shrub/brush range, or mixed range.

 

4   WOODLAND: Consists primarily of pinyon/juniper, oak or PJ/oak mixed.

 

5   FOREST LAND: > 25% forested land (deciduous, coniferous, and mixed forests).

 

6   BARREN LAND: Less than 10% vegetation.

 

7   SUBALPINE/TUNDRA: Areas both above and below timberline consisting of alpine tundra and subalpine grass/forb meadow species.

 

8   RIPARIAN: Riparian areas along waterways or standing wetlands.  Principal woody species include Narrowleaf and Common Cottonwood, Russian Olive, various willow    species, and tamarisk.  Herbaceous species include various sedges, Scouring Rush, and cattails.

 

9   WATER: Open water such as lakes, streams, and rivers.

 

11  RESIDENTIAL: High density residential areas, consisting of homes, lawns, and planted trees, or parks and golf courses.

 

12  COMMERCIAL: High density urban areas with little vegetation, parking lots, buildings, etc.

 

21  DRYLAND AGRICULTURE: Dryland crops and fields.

 

22  IRRIGATED AGRICULTURE: Irrigated crops and fields.

 

23  ORCHARD: Agricultural areas consisting of orchards.

 

31  GRASS/FORB RANGELAND: Perennial and annual Grasslands.  Low elevation (< 6,000') species include Blue Gramma, Needle & Thread, Sand Drop Seed, and brome species. Mid elevation (> 6000' and < 9500') species include Wheatgrass, Smooth Brome, Blue Gramma, Cheatgrass, dandelion, Spearleaf Buckwheat, and clover.  In the southeast plains region of Colorado, grasslands are often associated with yucca and various cacti species, such as cholla, and prickly pear.

 

      3101 (310) SNAKEWEED/SHRUB MIX: Desert and low elevation shrubland dominated by Snakeweed but heavily associated with Greasewood, sagebrush, and saltbush.

 

      3102 (311)  GRASS DOMINATED: Rangeland dominated by annual and perennial grasses.  Example species include:  Needle & Thread, Western Wheatgrass, Crested Wheatgrass, Kentucky bluegrass, Bluebunch wheatgrass (POPR), or Galleta grass.

 

      3103 (312)  FORB DOMINATED: Rangeland dominated by forbs.  Example species include: arrowleaf balsamroot (BASA3), ligusticum (LIGUS), meadowrue (THALI2), false hellebore (VETE4), and mulesears wyethia (WYAM).

 

      3104 (313)  GRASS/FORB MIX: Rangeland codominated by grasses and forbs.  Example species include:  Arrowleaf balsamroot (BASA3), Gumweed (GRIND), Mule’s ear-wyethia) WYAM, Prairie junegrass (KOMA), Western wheatgrass (PASM), lupine, or Kentucky bluegrass.

 

      3105 (314)  TALL-GRASS PRAIRIE: Grassland present in the eastern plains region.  Species include Big Bluestem (ANGE), Indian grass (SONU), Little bluestem (SCSC) and Switchgrass (PAVI).

 

      3106 (315)  MID-GRASS PRAIRIE: Grassland present in the eastern plains region.  Species include Sideoats grama (BOCU), Galleta (HIJA), Foxtail barley (HOJU), Western wheatgrass (PASM), Bluebunch wheatgrass (PSSP), Little bluestem (SCSC), New Mexico feathergrass (STNE), Green needlegrass (STVI) and Needle-and-Thread (STCO).

 

      3107 (316)  SHORT-GRASS PRAIRIE: Grassland  present in t he eastern  plains  region.  Species

            include Blue grama (BOGR) and Buffalograss (BUDA).

 

     3108 (317)  SAND DUNE COMPLEX: Grassland present in the eastern plains region.  Species include Prairie sandreed (CALO), Sand bluestem (ANHA), Sand dropseed (SPCR), Sandhill muhly (MUPU), and Common reed (PHAU), Blowoutgrass (REFL) and Lemon scurfpea (PSLA).

 

     3109 (318)  FOOTHILL/MOUNTAIN GRASSLANDS: Grassland present primarily on the western slope.  Species include Parry oatgrass (DAPA), Arizona fescue (FEAR), Idaho fescue (FEID), Thurber fescue (FETH), Slimstem muhly (MUFI), Mountian muhly (MUMO), Bluebunch wheatgrass (PSSP), Needle-and-Thread (STCO), Junegrass (KOMA), wildrye (ELYMU) and Slender wheatgrass (ELTR).

 

     3110 (319)  DISTURBED RANGELAND: Disturbed or overgrazed rangeland in the NW region. Species include Broom snakeweed (GUSA2), Cactus (Opuntia spp.), Yucca (Yucca spp.), Cheatgrass (BRTE), Medusahead rye (TAAS), Halegeton (HAGL),  Russian thistle (SAKA), and tumble mustard (SIAL2).

 

      3111 (320)  SPARSE GRASS/BLOWOUTS:  Sparsely vegetated grasslands, 10 – 40% vegetation, indicative of blowouts.

 

32  SHRUB/BRUSH RANGELAND: Consists primarily of sagebrush (ARTR2), saltbrush (ATCA2), greasewood (SAVE4), and snakeweed (GUSA).

 

      3201 (321)  SAGEBRUSH COMMUNITY: Shrubland principally dominated by ARTR2, ARNO4, and/or ARFI2.  Often associated with Rabbitbrush (CHNA2), Bitterbrush (PUTR2), Broom Snakeweed (GUSA2), various grasses, and mixed cacti.  Greasewood (SAVE4), Serviceberry (AMAL2 or AMUT), Snowberry, or  Winterfat (KRLA2) may also be present as secondary species.

 

      3202 (322)  SALTBUSH COMMUNITY: Shrubland found on upland, alkaline soils, principally dominated by Shadscale (ATCO), Four-Wing Saltbush (ATCA2), and Mat Saltbush (ATCO4).  Community sometimes codominated by Basin or Wyoming Big sagebrush (ARTRT or ARTRW8). Often associated with Snakeweed, Bud Sagebrush (ARSP5), Spiny Hopsage (GRSP), Spiny or Spineless Horsebrush (TESP2 or TECA2), and Gardners/Nuttalls Saltbush (ATGA).  Greasewood may occur here, but in some basins it may just be a minor component.

 

      3203 (323)  GREASEWOOD: Desert and low elevation shrubland dominated by SAVE4. Associated with ATCA2, ATCO, GUSA2, ARTR2, various rabbitbrush species and various grasses.

 

      3204 (324)  SAGEBRUSH/GAMBEL OAK MIX: Shrubland co-dominated by Big Sagebrush and Gambel Oak.  Patchy distribution of both species, with mixed grass/forb understory.

 

      3205 (325)  SNAKEWEED: Desert and low elevation shrubland dominated by GUSA2.  Associated with ATCA2, SAVE4 and various grasses in low densities.

 

      3206 (326)  SNOWBERRY:   Deciduous shrubland dominated by Mountain Snowberry (SYOR2).

 

      3207 (327)  SNOWBERRY/SHRUB MIX: Mountain deciduous shrubland dominated by Mountain Snowberry.  Often associated with Saskatoon Serviceberry, sagebrush, Squawbush, Rabbitbrush and Gambel Oak.

 

      3208 (328)  BITTERBRUSH COMMUNITY: Shrubland principally dominated by Bitterbrush (PUTR2).  Often associated with Rabbitbrush, Sagebrush, Greasewood, various grasses, and mixed cacti.

 

      3209 (329)  SALT DESERT SHRUB COMMUNITY:  Low-elevation shrublands found on alluvial salt fans or flats.  Component species may include:  saltbushes, greasewood (SAVE4), sagebrushes, horsebrushes, and spiny hopsage (GRSP).

 

      3210 (330)  SAGEBRUSH/GREASEWOOD:   Shrubland codominated by sagebrush and greasewood.   Secondary species may include rabbitbrush,

 

33  SHRUB/GRASS/FORB MIX: Mixed grass/forb and shrub/grass rangeland.  Example species include:

 

      3301 (331)  SAGEBRUSH/GRASS MIX: Codominant sagebrush shrubland and perennial Grassland.  Principal shrub species include Big Sagebrush, 3-winged Sage, and Black Sage.  Principal grass species include Crested Wheatgrass, Bluebunch Wheatgrass, and Blue Gramma.

 

      3302 (332)  RABBITBRUSH/GRASS MIX: Co-dominant Rabbitbrush and perennial Grassland. Principal shrub species include Rubber Rabbitbrush (CHNAN3), Sticky Rabbitbrush (CHVI8), and Small Rabbitbrush (CHDE2).  Grassland species are the same as cover type Sagebrush/Grass.

 

      3303 (333)  SAGEBRUSH/MESIC MOUNTAIN SHRUB MIX: Co-dominant sagebrush Mesic mountain shrubland consisting of Mountain Big Sagebrush (ARTRV) and any combination of Mountain Snowberry (SYOR2, SYRO), Service Berry (Utah AMUT or saskatoon AMAL2), Squaw apple (PERA4) or bitterbrush (PUTR2), often with a grass/forb understory.  Understory species may include, among others, Elk Sedge (CAGE2), Bluegrass, Needlegrass, arrowleaf balsamroot, lupines, penstemons, Indian paintbrush, and Mariposa lily.  Often found at the higher elevations of the sagebrush zone, on north facing slopes, in basins, or on other mesic sites.

 

      3304 (334)  GRASS/MISC. CACTUS MIX: Low elevation perennial Grassland codominate with cacti shrubland.  Grass species include Blue Gramma, Needle & Thread, Sand Drop Seed, and brome species.  Cholla cactus dominant, but other species and shrubs present in low density include Prickly Pear Cactus, Yucca, and Hairy Sage.  No Cholla cactus is present north of the Palmer Divide.  Prickly Pear and Yucca become dominate in the NE region.

 

      3305 (335)  WINTERFAT/GRASS MIX: Codominant shrubland and perennial Grassland.  Eurotia species of winterfat mixed with Blue Gramma.  Rabbitbrush often present.

 

      3306 (336)  BITTERBRUSH/GRASS  MIX:  Codominant shrublamd and perennial grassland. Principal shrub species include Bitterbrush with some Rabbitbrush.  Sagebrush and Greasewood present.  Principal grass species include Crested Wheatgrass, Bluebunch Wheatgrass, and Blue Gramma.

 

      3307 (337)  GRASS/YUCCA MIX:  Codominant perennial grassland and cactus shrubland. Principal grass species include Crested Wheatgrass, Bluebunch Wheatgrass, and Blue Gramma.  Principal cactus species include Yucca potentially mixed with Prickly Pear.

 

      3308 (338)  SAGEBRUSH/RABBITBRUSH MIX:  Co-dominant Sagebrush and Rabbitbrush shrubland.  Principal shrub species include Basin Big Sagebrush (ARTRT), Wyoming Big Sagebrush (ARTRW8), Rubber Rabbitbrush (CHNAN3), Sticky Rabbitbrush (CHVI8), or Small Rabbitbrush (CHDE2).

 

41  CONIFEROUS WOODLAND: Woodlands of pinyon/juniper (PIED/JUSC2).

 

      4101 (411)  PINYON-JUNIPER:  Coniferous woodland principally co-dominated by Pinyon Pine (PIED) and Utah juniper (JUOS) or Rocky Mountain Juniper (JUSC2).  Understory is sagebrush, mixed mountain shrubs, or grasses, usually at less than 25% cover.

               

      4102 (412)  JUNIPER: Woodland principally dominated by Utah Juniper (JUOS) or Rocky Mountain Juniper (JUSC2).  Understory may be sagebrush, grass, or bare soil.

 

42  DECIDUOUS WOODLAND: Woodlands of Gambel oak (QUGA) and mountain shrub mix.  Example species include:

 

      4201 (421)   GAMBEL OAK: Deciduous woodland (or tall shrubland) dominated by Gambel Oak. Primary associated shrub species include Mountain Mahogany (CEMO2), Utah Serviceberry (AMUT), Saskatoon Serviceberry (AMAL2), Big Sagebrush, and to a lesser extent, Mountain Snowberry (SYOR2).

 

      4202 (422)  XERIC MOUNTAIN SHRUB MIX: Deciduous woodland (or tall shrubland) dominated by Mountain Mahogany (CEMO2) or Curlleaf Mountain Mahogany (CELE3).  Associated species may include sagebrush, rabbitbrush, Mormon tea, or scattered Pinyon pine or Utah juniper.

 

      4203 (423) MESIC MOUNTAIN SHRUB MIX: Deciduous woodland (or tall shrubland) codominated by Gambel Oak, Serviceberry, and/or Mountain Mahogany.  Primary associated shrub species include Snowberry, sagebrush, or chokecherry.  Secondary shrub species may include Skunkbush sumac (RHTR), Antelope bitterbrush (PUTR2), and Squawapple (PERA4).