Appendix A. Present-day Drylands and Their Categories (Ecosystems and Human Well-being: Desertification Synthesis (full report))
Ecosystems and Human Well-being: Desertification Synthesis: Appendix A. Present-day Drylands and Their Categories
This is part of the Millennium Ecosystem Assessment report Ecosystems and Human Well-Being: Desertification Synthisis.
Core Writing Team: Zafar Adeel, Uriel Safriel, David Niemeijer, and Robin White
Extended Writing Team: Grégoire de Kalbermatten, Michael Glantz, Boshra Salem, Bob Scholes, Maryam Niamir-Fuller, Simeon Ehui, and Valentine Yapi-Gnaore
Review Editors: José Sarukhán and Anne Whyte (co-chairs) and MA Board of Review Editors
Appendix A. Present-day Drylands and Their Categories Drylands include all terrestrial (Ecosystems and Human Well-being: Desertification Synthesis: Appendix A. Present-day Drylands and Their Categories) regions where the production of crops, forage, wood and other ecosystem services are limited by water. Formally, the definition encompasses all lands where the climate is classified as dry subhumid, semiarid, arid or hyper-arid. This classification is based on Aridity Index values†.
† The long-term mean of the ratio of an area’s mean annual precipitation to its mean annual potential evapotranspiration is the Aridity Index (AI).
Notes: The map is based on data from UNEP Geo Data Portal (http://geodata.grid.unep.ch/ (Ecosystems and Human Well-being: Desertification Synthesis: Appendix A. Present-day Drylands and Their Categories) ). Global area based on Digital Chart of the World data (147,573,196.6 square km); Data presented in the graph are from the MA core database for the year 2000.
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