World dryland areas according to UNCCD and CBD defintions

ISO-19139 Metadata

Resource Identification Information:

Citation:
Title:  World dryland areas according to UNCCD and CBD defintions

Reference date - creation:  2011-07-14
Reference date - publication:  1997-01-01

Presentation format:  mapDigital

Other citation details: Full citation: UNEP-WCMC. (2007). A spatial analysis approach to the global delineation of dryland areas of relevance to the CBD Programme of Work on Dry and Subhumid Lands. Dataset based on spatial analysis between WWF terrestrial ecoregions (WWF-US, 2004) and aridity zones (CRU/UEA; UNEPGRID, 1991). Dataset checked and refined to remove many gaps, overlaps and slivers (July 2014). Cambridge (UK): UNEP-WCMC.

Party responsible for the resource - originator: 
Organization's name: UNEP-WCMC

Party responsible for the resource - custodian: 
Contact information:
Address:
Delivery point: Washington DC, USA
Place keywords:
Keywords:  global

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Theme keywords:
Keywords:  semiarid, dryland, dryland ecosystem, Condition and Trends, arid, chapter 22, aridity index, MA system, hyperarid, dry subhumid

Descriptive keywords:
Keywords:  Downloadable Data

Thesaurus name: ArcGIS Content Type
Abstract:  The original dataset developed by the MA is a subset of the aridity zone map created by CRU/UEA, UNEP/GRID for the World Atlas of Desertification. Aridity zones were derived from an Aridity Index (AI) which is calculated as the ratio of precipitation to potential evapotranspiration. Zones included in this dataset are: hyperarid, arid, semiarid, and dry subhumid. These are in accordance with the United Nations Convention to Combat Desertification (UNCCD) definition of Drylands. In the first instance, we compared the map published by Miles et al (2006) to show global distribution of tropical dry forests with the dryland map produced by Sörensen (2007). The dry forest areas were almost entirely included within the areas originally mapped as drylands. The only exception were some seasonally dry forests of continental southeast Asia, but these are climatically relatively moist, being mostly characterised by P/PET ratios well above 0.65 and having few other dryland features.In a second approach we reviewed the WWF ecoregions dataset. Sörensen (2007) had identified a number of additional ecoregions for possible inclusion. Based on expert knowledge, this resulted in the inclusion of the 13 additional ecoregions most likely to include dryland features and/or dry and subhumid tropical forests. (Table 1).Table 1. Ecoregions included in dryland area following reviewSelenge-Orkhon forest steppeTian Shan montane steppe and meadowsNorthwestern Himalayan alpine shrub and meadowsCentral Tibetan Plateau alpine steppeSoutheast Tibet shrublands and meadowsPamir alpine desert and tundraYarlung Tsangpo arid steppeHawaii tropical low shrublandsNorth Tibetan Plateau-Kunlun Mountains alpine desertHawaii tropical high shrublandsMaputaland-Pondoland bushland and thicketsAscension scrub and grasslandsDrakensberg alti-montane grasslands and woodlands

Purpose: The original drylands dataset was developed to define the Millennium Ecosystem Assessment (MA) dryland system boundary. Sörensen (2007) used this map to further delineate dryland areas of relevance to the CBD Programme of Work on Dry and Subhumid Lands. This current dataset builds on these maps to incorporate additional features to update the data to better reflect dry and sub-humid tropical forests in accordance with paragraph 13 of Convention on Biological Diversity (CBD) CoP Decision IX/17.

Dataset language:  eng
Dataset character set:  utf8

Status:  completed
Maintenance:
Update frequency:  notPlanned


Resource constraints:
Legal constraints:
Access constraints:  otherRestrictions

Other constraints: Access constraints: Unrestricted access and use of data without charge

Resource constraints:
Legal constraints:
Use constraints:  otherRestrictions

Other constraints: Use constraints: Users are restricted from any commercial or non-free resale of this data

Resource constraints:
Constraints:
Limitations of use: no conditions apply to access and use

Spatial representation type:  vector

Processing environment: Esri ArcGIS 12.7.0.26828

Extent:
Extent description: publication date

Geographic element - Bounding rectangle:
Extent contains the resource: true
West longitude: -166.734723
East longitude: 166.479019
North latitude: 72.438861
South latitude: -55.642017
1997
Credits: References: Miles, L., A.C. Newton, R.S. DeFries, C. Ravilious, I. May, S. Blyth, V. Kapos and J.E. Gordon. (2006). A global overview of the conservation status of tropical dry forests. J. Biogeogr. 33: 491–505. Sorensen, L. (2007). A spatial analysis approach to the global delineation of dryland areas of relevance to the CBD Programme of Work on Dry and Subhumid Lands. UNEP-WCMC, Cambridge. Full citation: UNEP-WCMC. (2007). A spatial analysis approach to the global delineation of dryland areas of relevance to the CBD Programme of Work on Dry and Subhumid Lands. Dataset based on spatial analysis between WWF terrestrial ecoregions (WWF-US, 2004) and aridity zones (CRU/UEA; UNEPGRID, 1991). Dataset checked and refined to remove many gaps, overlaps and slivers (July 2014). Cambridge (UK): UNEP-WCMC.

Point of contact - pointOfContact: 
Contact information:
Address:
Delivery point: 219 Huntingdon Road
City: Cambridge
Postal code: CB3 0DL
Country:  UK

Spatial Representation - Vector:

Level of topology for this dataset:  geometryOnly
Geometric objects:
Object type:  composite

Reference System Information:

Reference system identifier:
Value: 4326
Code space: EPSG
Version: 6.2(3.0.1)

Data Quality Information:

Scope of quality information:
Level of the data:dataset

Lineage:
Source data:
Level of the source data: The Aridity Index was derived from climate surface maps and calculated on a monthly basis as the ration of P/PET. Monthly values were average to create an mean annual potential moisture availability for the period 1951-80. Aridity classes were categorised as: i) dry subhumid (0.5 < P/PET < 0.65) ii) semiarid (0.2 < P/PET < 0.5) iii) arid (0.05 < P/PET < 0.2) iv) hyperarid (P/PET < 0.05) and v) cold climates (P/PET > 0.65)

Source citation:
Title:  Aridity Index

Reference date - publication:  1997-01-01

Party responsible for the resource - originator: 
Organization's name: CRU/UEA, UNEP/GRID as sited in the World Atlas of Desertification, Second Edition

Distribution Information:

Distributor:
Distributor information - distributor: 
Organization's name: UNEP-WCMC

Contact information:
Phone:
Voice: +44 (0) 1223 277314
Fax: + 44 (0) 1223 277136
Address:
Delivery point: 219 Huntingdon Road
City: Cambridge
Postal code: CB3 0DL
Country:  UK
e-mail address: info@unep-wcmc.org
Format:
Format name: Enterprise Geodatabase Feature Class

Transfer options:
Transfer size: 0.439

Metadata Information:

Metadata language:  eng
Metadata character set:  utf8


Last update:  2021-09-27
Maintenance:
Update frequency:  notPlanned


Other maintenance requirements: Some minor changes were made in July 2014 to fix some important topology and coding errors in the dataset.

Metadata contact - pointOfContact: 
Organization's name: UNEP-WCMC

Contact information:
Phone:
Voice: +44 (0) 1223 277314
Fax: +44 (0) 1223 277136
Address:
Delivery point: 219 Huntingdon Road
City: Cambridge
Postal code: CB3 0DL
Country:  UK
e-mail address: info@unep-wcmc.org
Scope of the data described by the metadata:  dataset
Scope name: dataset

Name of the metadata standard used: INSPIRE Metadata Implementing Rules: Technical Guidelines based on EN ISO 19115 and EN ISO 19119
Version of the metadata standard: V. 1.2