Global Data Coverage
This page describes the coverage of the global variable datasets used in GLOBE.
LandScan 2007 population density was used as a land mask to select all Global Land Units (GLUs) that contained land. This created a base extent and resolution (30 arcsec) to which all global variable datasets were converted. If the native extent of a global variable was less than that of LandScan 2007 (typically small islands were not included), and it was appropriate and/or possible to extend the variable (e.g. mean temperature can be extrapolated, whereas world protected areas cannot), then the global variable was extrapolated to include as much land mass as possible. A tiered classification was developed that summarizes the final coverage (i.e. extent) and degree of extrapolation applied to the native data.
Coverage Code | Description | |
1 | GLUs containing LandScan 2007 cells covered by original data | |
2 | GLUs containing LandScan 2007 cells covered by extrapolating original data | |
3 | GLUs containing LandScan 2007 cells not covered by original or extrapolated data |
Any given GLU might contain native values for all global variables, extrapolated variable values, or no data. The smaller the amount of land covered by a GLU, the more likely it is that certain global variables were extrapolated and/or missing. A report of the percent of GLUs that contain data for the given number of global variables (for which global coverage is possible and/or appropriate) is given below.
Global Coverage Report
Variables Covered (#) | Frequency | Percent | Cumulative Percent |
5 | 26 | .0 | .0 |
6 | 137 | .0 | .0 |
7 | 292 | .0 | .0 |
8 | 682 | .0 | .1 |
9 | 477 | .0 | .1 |
10 | 339 | .0 | .1 |
11 | 394 | .0 | .2 |
12 | 751 | .1 | .2 |
13 | 1255 | .1 | .3 |
14 | 1462 | .1 | .4 |
15 | 1765 | .1 | .5 |
16 | 1664 | .1 | .6 |
17 | 1840 | .1 | .8 |
18 | 3689 | .3 | 1.0 |
19 | 9215 | .6 | 1.7 |
20 | 9577 | .7 | 2.3 |
21 | 6104 | .4 | 2.7 |
22 | 8315 | .6 | 3.3 |
23 | 14230 | 1.0 | 4.3 |
24 | 27208 | 1.9 | 6.2 |
25 | 20710 | 1.4 | 7.6 |
26 | 7882 | .5 | 8.2 |
27 | 25753 | 1.8 | 9.9 |
28 | 18147 | 1.3 | 11.2 |
29 | 40542 | 2.8 | 14.0 |
30 | 1242508 | 86.0 | 100.0 |
Total | 1444964 | 100.0 |
Nearly 90% of GLUs are missing data for 2 or fewer global variables, and 86% of GLUs have data for all variables intended to have global coverage.
Coverage reports for individual global variables are provided on each variable’s documentation page.