IWMI Global Irrigated Area Map (GIAM)

 

GIAM and GMRCA V2.0 Release update (May, 2007)

Global irrigated area map (GIAM) web portal update

With new addition of Global Map of Rainfed Croplands (GMRCA) statistics

 

We recently (May 10th, 2007) updated the Global Irrigated Area Map (GIAM) and Global map of Rainfed Cropland (GMRCA) web portals (http://www.iwmigiam.org). First, the GIAM 10 km V2.0 area statistics are re-computed using slightly adjusted irrigated area fractions (IAFs). There is a very minor change in areas compared to earlier version. The method for calculating GIAM areas is presented here. The GIAM areas are increasingly becoming attractive and acceptable to user’s.  For complete Methodology on GIAM; please click here.

 

Second, the area statistics for the Global map of Rainfed Cropland Areas (GMRCA) has been released for the first time. The GMRCA maps and area statistics are made available for 175 countries, just like GIAM.

 

This enables a complete accounting of the GIAM and GMRCA areas leading to total cropland area statistics for every country.

 

Important note: We urge the users to use the areas calculated by the GIAM team which are provided in the GIAM web portal.  This is because to avoid inconsistencies that may arise if users use different projection parameters.

 

 

Your comments are always welcome. If you have further questions, please contact: Prasad S. Thenkabail (p.thenkabail@cgiar.org) or Chandrashekhar M. Biradar (c.biradar@cgiar.org).

 

 

References

Biggs, T., Thenkabail, P.S., Krishna, M., GangadharaRao, P., and Turral, H., 2006.. Vegetation Phenology and Irrigated Area Mapping Using Combined MODIS Time-series, Ground Surveys, and Agricultural Census Data in Krishna River Basin, India. International Journal of Remote Sensing. 27(19):4245-4266.

 

Brown, L.R. 2003. Plan B: Rescuing a Planet Under Stress and  Civilization in Trouble. Earth Policy Institute. 266 p

 

Flavin, C., Gardner, G. 2006. China, India, and the New World Order. Chapter 1. State of the World 2006. The World Watch Institute. 244 p

 

Kurz, B and Seelan, S. K. 2007. Use of Remote Sensing to Map Irrigated Agriculture in Areas Overlying the Ogallala Aquifer, United States. Book Chapter in Global Irrigated Areas. IWMI. Under Review.

 

Ozdogan, M. and Woodcock, C.E. (2006). Resolution dependent errors in remote sensing of cultivated areas. Remote Sensing of Environment 103 (203-217).

 

Thenkabail, P.S., GangadharaRao, P., Biggs, T., Krishna, M., and Turral, H., 2007. Spectral Matching Techniques to Determine Historical Land use/Land cover (LULC) and Irrigated Areas using Time-series AVHRR Pathfinder Datasets in the Krishna River Basin, India. Photogrammetric Engineering and Remote Sensing. (accepted, in press).

 

Thenkabail, P.S., Biradar, C.M., Turral, H., Noojipady, P., Li, Y.J., Vithanage, J., Dheeravath, V., Velpuri, M., Schull M., Cai, X. L., , Dutta, R. 2006. An Irrigated Area Map of the World (1999) Derived from  Remote Sensing. Research Report # 105. International Water Management Institute. Pp. 74. Also, see under documents in: http://www.iwmigiam.org.

 

Thenkabail, P.S., Schull, M., Turral, H. 2005. Ganges and Indus River Basin Land Use/Land Cover (LULC) and Irrigated Area Mapping using Continuous Streams of MODIS Data. Remote Sensing of Environment, 95(3): 317-341.

 

Tucker, C.J., Grant, D.M., Dykstra, J.D. 2005. NASA’s Global Orthorectified Landsat Dataset. Photogrammetric Engineering & Remote Sensing. 70(3), 313-322.