SAMPLING DESIGN FOR GLOBAL SCALE MAPPING AND MONITORING OF AGRICULTURE

摘要

In the changing global environment there is a need for an operational system for monitoring of world food crop production using satellite observations. It is useful in two primary missions - food security in developing countries, and forecasting production available for global market of agricultural crops. In the present study, grids of size (i) 5 deg X5 deg (ii) 1 deg X1 deg (iii) 30'X30' (iv) 15'X15' (v) 7.5'X7.5' and (vi) 5'X5' were generated and percent crop area was calculated for each grid of all sizes using MERIS landuse/landcover data of 300 m resolution. The grid size of 15'X15' was found to be optimum for global monitoring, as there is not much change in the distribution of the grids after reducing the sample size. Using the 'cumulative square-root of frequency method five stratas was defined, which reduces the variance of the population estimate by sampling.