Vol. 5 Num 865 Fri. November 03, 2006  

SPARRSO works for food security

Food security is the ensured access of all people at all times to enough food for an active, healthy life. Food security includes, at a minimum, ready availability of nutritionally adequate, and safe, food. It also assures the ability to acquire acceptable food in socially acceptable ways. It is a great and important work to ensure food security to the people of a country. Increasing food security in developing countries through increased and subsidised food production in an economically and environmentally sustainable way is also very important

Food security is linked to the consumption, production, and marketing of food, and survey and monitoring of food production, specially food grains. For the scientific management of food security in the country SPARRSO is providing support to the Government of Bangladesh through the estimation and forecasting of rice yield, using satellite technology in the Boro and Aman seasons.

Bangladesh Space Research and Remote Sensing Organization (SPARRSO) is a multidisciplinary research and development organization of the Government of the People's Republic of Bangladesh under the Ministry of Defence. It is devoted to applying space technology and Geographic Information System (GIS) for surveying, mapping and monitoring natural resources, as well as monitoring the environment and disasters in the country. It is the focal point of all space and remote sensing related activities in the country. As a multidisciplinary organization, SPARRSO activities are related to a large number of fields like agriculture, water resources, fisheries, forestry, oceanography, meteorology, environment, land use, cartography, geology and geology.

SPARRSO has carried out a number of studies on cropping pattern determination, rice area and yield estimation using satellite remote sensing. Enumeration area mapping, vegetation index mapping, coastal zone monitoring and change detection mapping, monitoring of river course changes, inventory of forest resources, mapping and monitoring of natural hazards like cyclones, storm surges, floods, tornadoes, nor'westers, droughts etc. are being done more or less on a regular basis. The information and knowledge gathered through analysis of satellite data are being supplied to concerned ministries and user agencies in the form of maps, reports, articles and papers, with recommendations. As a part of resource inventory SPARRSO has been making all-out efforts for exploitation of space science and remote sensing technology toward food security in the country.

Bangladesh is an agricultural country with high density of population. The lands are mainly used for rice cultivation to fulfill the demands of the main cereal food. Agriculture is one of the most important fields where satellite technology can be used effectively, specially in the field of rice crop inventory and forecasting. SPARRSO estimates crop area and rice yield on a regular basis, particularly for Aman and Boro rice, using NOAA AVHRR data.

The NOAA satellite receives AVHRR imagery of the earth and its atmosphere in five spectral channels of which channels 1 and 2 are situated in the visible and near infrared regions respectively. The data values in these channels are used to calculate the area and state of crops. In fact, the data from these two channels are used to calculate the Normalized Difference Vegetation Index (NDVI) using the equation: NDVI = (Channel 2 Channel 1)/Channel 2 + Channel 1). The NDVI image efficiently represents the green vegetation and other properties of the earth's surface. A correction algorithm developed by SPARRSO has been employed to take into account the fractional coverage and spatial heterogeneity of rice area.

In order to estimate the Boro rice area in April-May the NOAA images of March 31 have been corrected geometrically, geo-referenced and analyzed. An Arc/Info based administrative boundary layer of the country has been used to obtain the crop statistics from the NOAA AVHRR data and NDVI product. The following photomap prepared from the NOAA picture shows the Boro rice area in the country. The Boro rice area has been extracted from the crop statistics of this map.

Some sample field surveys, fairly distributed over the country, have been carried out for verifying the different identified classes in the field, and to collect corresponding yield data. The rice area has been multiplied by the average rice yield/ ha to obtain the total yield of the country. Later the estimated result was ratified by Bangladesh Bureau of Statistics, Department of Agriculture Extension and Ministry of Food for national use.

It is known to the scientists that that NOAA satellite provides very low resolution ( 1. 1 km) picture. It has a number of constraints in estimating rice crop area. Moreover we cannot estimate precisely other crops like potato, jute, sugarcane and many other vegetables because of its extremely low resolution picture. In fact NOAA is a weather satellite. For this kind of survey and monitoring we need high resolution picture of Earth Resources Satellite like Landsat, IRS etc. But, ironically, we do not have any Earth Resource Satellite in Bangladesh. Bangladesh should have her own high resolution satellite. It will provide us high resolution pictures for this kind of study for food and disaster forecasting, and for scientific management of natural resources on the sustaining yield basis. We need, and it is high time to develop, satellite technology in the country. It will help us to build a happy and prosperous nation. The nation will be scientifically and technologically sound and will be consistent with the rest of the world. This is our national expectation.

Dr. Jinnahtul Islam is a remote sensing, forest and environment specialist.
NOAA satellite Phoptomap of 31 March 2006 showing the BORO Rice Crop area of Bangladesh