CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
Erosion is the process by which the agents of soil erosion wear away, eat into, loosen, or carry away soil material and transport it from one locality to another where it is eventually deposited (Egboka, 1991). Soil erosion is a complex process caused by wind, water and physical disturbances, encompassing detachment, transport and deposition of weathered rock. Soil erosion reduces land productivity, challenges agricultural sustainability and degrades environmental quality through contaminants attached to the sediments.
Soil erosion is caused and complexed by a variety of factors such as natural phenomena of neotectonics and paleotectonics, soil/rock features (pedology/geology), wind/water dynamics; and human phenomena such as population density, anthropogenic activities including engihanic effects (Egboka and Nwankwor, 1985). In the execution of colossal or small scale projects of Industrial or engineering nature, the textural, coherence and plasticity characteristics of the soil are not considered. Irrigation schemes, major road network, small and large dams, urbanization, deforestation, sand and laterite mining are carried out without cognizance of the warnings of environmental experts and/or professionals. Similarly, sensitive drainage areas, wetlands and flood channels are encroached upon by hungry land developers. In view of these activities, sheet, rill and gully erosion are known to progressively develop over several years. All over the world man is a more important agent of environmental change than Nature (Press, 1990). Soil erosion problems are now endemic in many parts of southeastern Nigeria (Egboka, 1991). Increased awareness of erosion impacts on land, air, water quality and global climate, raises new challenges for erosion researchers. In some conditions, these impacts are so severe that they reduce the quality of life and economic well-being, and can threaten survival.
Chemical and physical deterioration of soil have major implication on agricultural productivity and housing development. In Nigeria agricultural production is the most important source of income to the people. Soil quality has a major impact on the capacity of the rural farmers to achieve food security. Soil erosion increment results in an unsustainable development of the living standard of the people. Sustainable development is the positive socio-economic change that does not undermine the ecological and social systems upon which communities and social systems are dependent. Land provides services to humans and other life forms as well as providing raw materials in production process. Land provides waste assimilation services as well as other ecosystem functions. Land provides utilities for recreation, health, cultural and ecological cycles and functions.
AN ASSESSMENT OF THE SOCIO-ECONOMIC IMPACTS (EFFECTS) OF AGULU-NANKA GULLY EROSION, ANAMBRA STATE, SOUTHEASTERN NIGERIA (ENVIRONMENTAL SCIENCE PROJECT TOPICS AND MATERIALS)