Population and land use/cover dynamics in the Volta River basin of Ghana, 1960-2010.
Abstract
The Volta River basin is one of the most economically deprived areas in Africa. Rain fed and some irrigated agriculture is the main economic activity of the majority of the population living in this region. High population growth rates have brought in its wake increasing pressure on land and water resources. Precipitation in the region is characterized by large variability as expressed in periodic droughts. Due to large variability in precipitation patterns, the development and optimum use of (near) surface water resources is the key to improved agricultural production in this region. As a result of the interplay between land/atmosphere, energy, water (vapor) and land use, significant shifts in land use patterns will bring about spatio-temporal changes in weather patterns and rainfall characteristics. There is the need therefore for a sustainable management of the water resources of the Volta River Basin. The Global Change in the Hydrologic Cycle (GLOWA) Volta Project therefore seeks to analyze the physical and socio-economic determinants of hydrological cycles, which will eventually lead to the development of a scientifically sound decision support system for the assessment, sustainable use and development of water resources in the Volta Basin of West Africa. It is a well-perceived notion that man and his activities are the major drivers behind land use/ cover change, and therefore become very central in any land use/cover change analysis. This study was therefore carried out as a sub-project of the GLOWA Volta Project, and it specifically looked at the relationship between population and other socio-economic dynamics, on the one hand, and agricultural and forest land uses on the other, and predicted the effect of changes in population on the two land uses in 2010. At the general basin level, population data were derived from population census reports of Ghana for 1960, 1970, 1984 and 2000, while forest cover information was derived from land cover and land use maps of 1990/91 and 2000, which were developed using LANDSAT Thematic Mapper (TM) satellite images. Agricultural land use data were obtained from the Ghana Ministry of Food and Agricultural Censuses of 1992 and 2000. Furthermore, a soil suitability map for 90-day maize was remapped into a binary layer of suitable and not suitable for agriculture, and used to predict the effect of population change on agricultural land use. At the district level, the main source of data was primary. A structured and open-ended questionnaire was administered between November 2001 and March 2002 amongst 252 households in 12 localities in the Kassena-Nankana District, and 252 households in 9 communities in the Ejura Sekyedumase District. Results show that the Bawku and Bolgatanga-Tongo Urban Councils in the White Volta, and the Kete-Krachi Local Council in the Daka will experience agricultural land shortfalls in the year 2010, as a result of changes in population. At the district level, years allowed for land to fallow and proportion of major farmers were statistically significant predictors of cropped area in the Kassena-Nankana District in 1984. However, the situation changed in 2000, since land fallow did not only cease to be a statistically significant predictor of cropped area in the Kassena-Nankana District, but also had a negative relationship with cropped area. In 1984, population of the locality was a statistically significant predictor of cropped area in the Ejura Sekyedumase District. In 2000, distance to farthest farm, off-farm income, and practice of agricultural extensification were predictors of cropped area in the Kassena-Nankana District, while population of the locality again predicted cropped area in the Ejura Sekyedumase District. Furthermore, the analysis shows that extra income earned off farm is not necessarily invested into farming activities. A spatio-temporal analysis of the relationship shows that land tenure arrangement (whether owned or hired), the presence of electricity as a source of household energy, affluence (items and livestock ownership), the use of tractors, inorganic fertilizer and improved seed variety as well as household size did not influence agricultural land use in both districts and in both years. On the effect of population change on forest cover between 1990 and 2000, predictions show that only the Jaman and Berekum Local/urban Council areas that fall within the Black Volta sub-basin will have depleted forest cover as a result of increases in population density. All the other areas within the sub-basin will have some amount of forest cover in 2010, irrespective of increases in population density that might occur. On the other hand, the Kete-Krachi Local Council in the Daka sub-basin will experience depleted forest cover in 2010 as a result of population density increase, while the Gushiegu-Chereponi, Bimbilla and Salaga Local Councils will have some forest cover in 2010 despite increases in population density. Finally, other indirect demographic factors, namely the farming systems, practices and inputs used, types of crops grown, consumption patterns of fuelwood as energy for cooking and other activities, and extensification of agricultural lands were all shown as indirect demographic causes of deforestation.
Cite this
APA
Codjoe, S. N. A. (2004). Population and land use/cover dynamics in the Volta River basin of Ghana, 1960-2010. Cuvillier Verlag.
Harvard
Codjoe, S. N. A. (2004) Population and land use/cover dynamics in the Volta River basin of Ghana, 1960-2010.. Gottingen: Cuvillier Verlag.
BibTeX
@book{codjoe2004population,
author = {Codjoe, S.N.A.},
title = {Population and land use/cover dynamics in the Volta River basin of Ghana, 1960-2010.},
year = {2004},
publisher = {Cuvillier Verlag},
address = {Gottingen}
}