Sonali Senaratna Sellamuttu/IWMI.

Ecological footprint of food security: monitoring and mapping of irrigated and rainfed areas in Asia and Africa

The maps of irrigated and rainfed areas in Asia, produced by the International Water Management Institute (IWMI), give a detailed view of the interface between food production areas and natural ecosystems. They also indirectly show the implications of this interface for water management, by distinguishing irrigated areas (where a single crop, double crop or continuous crop is grown) and rain-fed areas from other kinds of land cover. They maps were created by analyzing a series of time lapsed satellite images at a resolution of 250 meters using Moderate Resolution Imaging Spectroradiometer (MODIS) images, and are the first of such high resolution irrigated area maps to be created for Asia.

irrigated rainfed asia map iwmi
The irrigated and rain-fed area map of Asia for the years 2000 and 2010. http://waterdata.iwmi.org/irra/

Mapping irrigation coverage helps provide critical information on food production systems, which are the main fresh water users worldwide. These maps help those in research, development or conservation activities better pinpoint food production areas, estimate agricultural water uses, and identify hotspots of agriculture in the context of a healthy ecosystem. The maps might help improve decisions on land, water resources, and food security planning, policy making and private investments and, ultimately, benefit the farmers who are impacted by such decisions.

Tools like the irrigation maps can help monitor the footprint (extent) of food production systems at a given time interval.  This is especially useful for smallholder farms, which are difficult to monitor through traditional reporting systems. The ability to track current and future levels of development will be critically important for the successful implementation of the UN Sustainable Development Goals.

Scientists from IWMI have developed an irrigation map of Asia for the years 2000 and 2010 and are in the process of creating a similar map for Africa.

For more information, contact Xueliang Cai: x.cai [at] cgiar.org