Using Erdas imagine model to determine suitable inland valleys for rice cultivation at selected sites in Brong Ahafo and Western Regions of Ghana

Loading...
Thumbnail Image
Date
2012-06-19
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Rice (Oryza sativa) has become one of the major food staples in Ghana. It is estimated that demand for rice in Ghana will increase at a compound annual growth rate of 11.8% from 939,920 - 1,644,221 metric tons from 2010 to 2015. Though there has been some increase in production it does not match the increase in consumption. This study seeks to determine the most suitable areas for inland valley rice cultivation using computer based models for selected sites (15km by 15km) in the Brong Ahafo Region and Western Region of Ghana. A sensitivity analysis was carried out using a stepwise exclusion method, excluding one parameter at a time from the model and the highly suitable area estimated. Parameters that caused least or no change in highly suitable area were completely taken out of the model. Weights of selected parameters were varied to see how changes in weight affect the highly suitable area. Finally, 12 most sensitive input parameters were identified from the initial 22 to include: rainfall, discharge, slope, stream order, length of rice growth, markets, roads, post harvest technology, land tenure, incentive net benefit, soil fertility and credit systems. These were used to model for five suitability classes namely: highly suitable, suitable, moderately suitable, marginally suitable and not suitable. The model results based on parameters having equal weights showed that 0.51% and 11.77% of the total study area were highly suitable and suitable respectively for the Brong Ahafo Region site and 1.42% and 21.41% of the total study area were highly suitable and suitable respectively for the Western Region site. Based on unequal weights, 0.77% and 7.64% were highly suitable and suitable respectively for the Brong Ahafo Region site and 0.86% and 13.57% were highly suitable and suitable respectively for the Western Region site. A 0.6% increase in highly suitable area was recorded whilst 7.84% decrease in area was recorded for suitable area when the results of the original model were compared with those of the modified one.
Description
A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirements for the award of the Degree of Master of Science in Soil and Water Engineering.
Keywords
Citation