Global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000)

MIRCA2000 is a global dataset with spatial resolution of 5 arc minutes (about 9.2 km at the equator) which provides both irrigated and rainfed crop areas of 26 crop classes for each month of the year. The crops include all major food crops (wheat, maize, rice, barley, rye, millet, sorghum, soybean, sunflower, potato, cassava, sugarcane, sugarbeet, oil palm, canola, groundnut, pulses, citrus, date palm, grape, cocoa, coffee, other perennials, fodder grasses, other annuals) as well as cotton. For some crops no adequate statistical information was available to retain them individually and these crops were grouped into ‘other’ categories (perennial, annual and fodder grasses).

Text files indicate for each 5-minute grid cell,  each irrigated crop and each related sub-crop the growing area in hectares and additionally the month in which the growing period starts and the month in which the growing period ends. The dataset is therefore both spatial and temporal, allowing extraction of crop areas and calendars.

Users are able to obtain from MIRCA2000, after import into GIS software and appropriate format conversion, the following global datasets: (i) number of crops (rainfed, irrigated and total), (ii) the maximum area (%) occupied by the individual MIRCA2000 crops and  totaled for rainfed and irrigated crops, (iii)  the most important, second most important, third most important, fourth most important, and fifth most important rainfed and irrigated crops and areas (%) occupied by each of these crops, (iv)  the areas occupied by other rainfed and irrigated crops and the ratios of rainfed and irrigated crops in the crop mix, (v) the crop calendars for individual crops as defined by the start and end month of the crop cycles. For some crops (e.g. rice) several crop calendars are provided.

The methodology for generating the MIRCA2000 dataset is described in detail by Portmann et al.(2010). Given its reliance on the integration of census-based statistical with remote sensing-derived information, the MIRCA2000 dataset is based on a solid methodology and probably the best database currently available for high-resolution mapping of crop distributions and calendars. In addition to its high spatial resolution, the MIRCA2000 datasets has the advantage that, in contrast to other datasets that represent only dominant crops, it contains in each 5 arc-minute grid cell the shares of each of the 26 rainfed and irrigated crop classes. This makes it possible to represent better the spatial distribution of crops at sub-national level and is therefore a very important benchmark for re-defining and mapping farming systems. The main drawback of the MIRCA2000 dataset is that it shows a situation that is nearly 15 years old, which in a rapidly evolving continent like Africa may require regular updating of the information, perhaps using the same methodology.

References:

Monfreda, C., N. Ramankutty, and J.A. Foley. 2008. Farming the planet: 2. Geographical distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Global Biogeochemical Cycles, Vol. 22, GB1022, doi: 10.1029/2007GB002947, 2008                             

URL: http://onlinelibrary.wiley.com/doi/10.1029/2007GB002947/pdf

Portmann, F.T., S. Siebert, and P. Döll. 2010. MIRCA2000 - Global monthly irrigated and rainfed crop area around the year 2000: a new high-resolution data set for agricultural and hydrological modeling. Global Biogeochemical Cycles, Vol. 24, GB1011, doi: 10.1029/2008GB003435, 2010                   

URL: http://onlinelibrary.wiley.com/doi/10.1029/2008GB003435/pdf