observed/lai/0_umd_landcover_readme.txt
author Forrest Hoffman <forrest@climatemodeling.org>
Tue, 27 Jan 2009 02:06:40 -0500
changeset 1 a3930ac0be17
permissions -rw-r--r--
Replaced EMDI Class A NPP 81 observational data with new revision from ORNL DAAC

The original EMDI Class A NPP 81 data provided by the ORNL DAAC contained
error as follows:

from Cook, Robert B. <cookrb@ornl.gov>
to jranders@uci.edu,
Forrest Hoffman <fmhoffman@gmail.com>,
"Hoffman, Forrest M." <hoffmanfm@ornl.gov>
cc "Hook, Leslie A." <hookla@ornl.gov>,
uso@daac.ornl.gov
date Fri, Oct 31, 2008 at 11:48 AM
subject revised EMDI data: please use this version
mailed-by ornl.gov

10/31/08 [NPP_EMDI_R1_20081028.html,EMDI_ClassA_NPP_81_R1.csv]

Hi Jim and Forrest,

We recently found out that the data we sent to you two years ago for
use in your model-data intercomparison activity has some problems.

One of our users discovered problems with the TNPP data for Class
A site tropical forest biomes. For a description of the problem
and what we've done to correct it are in the attached html file.

The attached csv file has the correct values. Please remove the
old file / data and use the new file.

We apologize for the inconvenience this may cause. We understand
that you have a paper in press that uses these data. Sorry about
this.

I am sending this note to you before we formally make the change
on our Web site, because you have a paper in press. When we place
the revision on our Web site, we will update the data set citation
and DOI.

Olson, R. J., J. M. O. Scurlock, S. D. Prince, D. L. Zheng,
and K. R. Johnson (eds.). 2008. NPP Multi-Biome: NPP and Driver
Data for Ecosystem Model-Data Intercomparison, R[evision]1. Data
set. Available on-line [http://www.daac.ornl.gov] from the Oak Ridge
National Laboratory Distributed Active Archive Center, Oak Ridge,
Tennessee, U.S.A. doi:10.3334/ORNLDAAC/xxx

Please let me know if you have any questions.

Thanks Bob

On Jan 26, 2009, I moved the original data.81 file to data.81.rev0.bad and
data.81.nc to data.81.rev0.bad.nc. Then I copied the file provided by the
ORNL DAAC, called EMDI_ClassA_NPP_81_R1.csv, to data.81 and re-generated
data.81.nc using the NCL script clamp/npp/01.read_ascii_81.ncl

Forrest Hoffman
Mon Jan 26 23:23:46 EST 2009
     1 
     2 ##############################################################################
     3 #     University of Maryland Global Land Cover Classifications               #
     4 #                 at 0.25, 0.5 and 1 degree (1992-1993)                      #
     5 ##############################################################################
     6 
     7 The files in this directory were provided by Drs. Ruth DeFries and Matt Hansen 
     8 from the Department of Geography at the University of Maryland, College Park. 
     9 These are global, coarse resolution (1/4, 1/2 and 1 degree spatial resolutions) 
    10 land cover classifications (dominant type and fractional cover) generated using 
    11 data from the Advanced Very High Resolution Radiometer (AVHRR) (see Hansen et 
    12 al. 2000).
    13 
    14 The objective of this study was to create a land cover map derived from 1 
    15 kilometer AVHRR data using all available bands and derived Normalized Difference 
    16 Vegetation Index (NDVI) and a full year of data (April 1992-March 1993). This 
    17 thematic map was resampled to 0.25, 0.5 and 1.0 degree grids for the 
    18 International Satellite Land Surface Climatology Project (ISLSCP) data 
    19 initiative II. During this re-processing, the original UMD land cover type and 
    20 fraction maps were adjusted to match the water/land fraction of the ISLSCP II 
    21 land/water mask. These maps were generated for use by modelers of global 
    22 biogeochemical cycles and others in need of an internally consistent, 
    23 global depiction of land cover. This 1km map was also one of the MODIS (Moderate 
    24 Resolution Imaging Spectroradiometer) at-launch land cover maps.  
    25 
    26 The data set describes the geographic distributions of 13 classes of vegetation 
    27 cover (plus water and unclassified classes) based on a modified International 
    28 Geosphere-Biosphere Programme (IGBP) legend (Rasool 1992). The data set also 
    29 provides the fraction of each of the 15 classes within the coarser resolution 
    30 cells. The data set is provided at three spatial resolutions of 0.25, 0.5 and 1 
    31 degrees in latitude and longitude. We refer the reader to the reference below 
    32 for more information on data processing of the original 1km data set.
    33 
    34 Please acknowledge Drs. DeFries and Hansen and the ISLSCP2 data collection when 
    35 these data are used. Please cite the following publications when these data are 
    36 used:
    37 
    38 Hansen, M. C., DeFries, R.S., Townshend, J.R.G., and Sohlberg, R., 2000, Global 
    39 land cover classification at 1km spatial resolution using a classification tree 
    40 approach, International Journal of Remote Sensing, 21, 1331-1364.
    41 
    42 Any problems encountered with the data set should be reported to Eric Brown de 
    43 Colstoun at ericbdc@ltpmail.gsfc.nasa.gov
    44 
    45 ##############################################################################
    46 
    47 File Name Convention
    48 --------------------
    49 The data sets in this directory are provided at three spatial resolutions of 
    50 0.25, 0.5 and 1 degrees lat./long. For each spatial resolution there is a land 
    51 cover type classification layer (with numbers from 0 to 14) and 15 associated 
    52 layers that provide the fraction, from 0 to 100, of each land cover type per 
    53 cell. The land cover type files are named umd_landcover_class_XX.asc, where XX 
    54 is qd, hd, or 1d, denoting a spatial resolution of 1/4, 1/2 or 1 degrees, 
    55 respectively. The fractional files are called umd_landcover_XX_cZZ.asc, where XX 
    56 is the same as above, and ZZ is a number from 00 to 14 which represents the land 
    57 cover type code as described below. As an example, the file named 
    58 umd_landcover_qd_c02.asc is the fraction of Evergreen Broadleaf Forest at a 
    59 quarter degree spatial resolution. This file is associated with the 
    60 umd_landcover_class_qd.asc land cover type file.
    61 
    62 ##############################################################################
    63 
    64 ASCII File Format
    65 ------------------
    66 All of the files in the ISLSCP Initiative II data collection are in the ASCII, 
    67 or text format. The file format consists of numerical fields of varying length, 
    68 which are delimited by a single space and arranged in columns and rows. The 
    69 values in the land cover class type files are written as integers from 0 to 14. 
    70 All values in the land cover fraction files are written as real numbers.
    71 
    72 The files at different spatial resolutions each contain the following numbers of 
    73 columns and rows:
    74    One degree: 360 columns by 180 rows 
    75    1/2 degree: 720 columns by 360 rows 
    76    1/4 degree: 1440 columns by 720 rows 
    77 
    78 All files are gridded to a common equal-angle lat/long grid, where the 
    79 coordinates of the upper left corner of the files are located at 180oW, 90oN and 
    80 the lower right corner coordinates are located at 180oE, 90oS. Data in the files 
    81 are ordered from North to South and from West to East beginning at 180 degrees 
    82 West and 90 degrees North. 
    83 
    84 The data files are PKZip compressed. On UNIX, they can be decompressed using the 
    85 "unzip -a" command. On Windows, they can be decompressed using WinZip or other 
    86 PKZip software. On the Macintosh, they can be decompressed using Stuffit 
    87 Expander.
    88 
    89 ################################################################################
    90 
    91 Land Cover Type Codes and Definitions
    92 -------------------------------------
    93 The following 15 classes are used. Note that here are no cells with a value of 
    94 13 (Urban and Builtup) in the 1degree land cover type file.
    95 
    96 0 = Water bodies: oceans, seas, lakes, reservoirs, and rivers.  Can be either 
    97     fresh or salt water. This class is derived from a land/water mask.
    98 
    99 1 = Evergreen Needleleaf Forests: lands dominated by trees with a percent canopy 
   100     cover >60% and height exceeding 5m. Almost all trees remain green all year. 
   101     Canopy is never without green foliage.
   102 
   103 2 = Evergreen Broadleaf Forests: lands dominated by trees with a percent canopy 
   104     cover > 60% and height exceeding 5m. Almost all trees remain green all year.  
   105     Canopy is never without green foliage.
   106 
   107 3 = Deciduous Needleleaf Forest: lands dominated by trees with a percent canopy 
   108     cover >60% and height exceeding 5m. Trees shed their leaves simultaneously in 
   109     response to cold seasons.
   110 
   111 4 = Deciduous Broadleaf Forests: lands dominated by trees with a percent canopy 
   112     cover >60% and height exceeding 5m. Trees shed their leaves simultaneously in 
   113     response to dry or cold seasons.
   114 
   115 5 = Mixed Forests: lands dominated by trees with a percent canopy cover >60% and 
   116     height exceeding 5m. Consists of tree communities with interspersed mixtures or 
   117     mosaics of needleleaf and deciduous forest types. Neither type has <25% or >75% 
   118     landscape coverage.
   119 
   120 6 = Woodlands: lands with herbaceous or woody understories and tree canopy cover 
   121     of >40% and <60%. Trees exceed 5m in height and can be either evergreen or 
   122     deciduous.
   123 
   124 7 = Wooded Grasslands/Shrublands: lands with herbaceous or woody understories and 
   125     tree canopy cover of >10% and <40%. Trees exceed 5m in height and can be either 
   126     evergreen or deciduous.
   127 
   128 8 = Closed Bushlands or Shrublands: lands dominated by bushes or shrubs.  Bush and 
   129     shrub percent canopy cover is >40%. Bushes do not exceed 5m in height. Shrubs 
   130     or bushes can be either evergreen or deciduous. Tree canopy cover is <10%. The 
   131     remaining cover is either barren or herbaceous.
   132 
   133 9 = Open Shrubland: lands dominated by shrubs.  Shrub canopy cover is >10% and 
   134     <40%. Shrubs do not exceed 2m in height and can be either evergreen or 
   135     deciduous. The remaining cover is either barren or of annual herbaceous type.
   136 
   137 10 = Grasslands: lands with continuous herbaceous cover and <10% tree or shrub 
   138      canopy cover.
   139 
   140 11 = Croplands: lands with >80% of the landscape covered in crop-producing fields.  
   141      Note that perennial woody crops will be classified as the appropriate forest or 
   142      shrubs land cover type.
   143 
   144 12 = Barren: lands of exposed soil, sand, rocks, snow or ice which never have more 
   145      than 10% vegetated cover during any time of year.
   146 
   147 13 = Urban and Builtup: land covered by buildings and other man-made structures.  
   148      Note that this class is not mapped from the AVHRR imagery but is developed from 
   149      the populated places layer that is part of the Digital Chart of the World (Danko 
   150      1992).
   151 
   152 14 = Unclassified: Points where the ISLSCP2 land/sea mask was labeled as land and 
   153      the UMD original data had sea and which could not be filled in from a 3 by 3 
   154      average of surrounding cells.
   155