Implications of Wet-Rice Farming on Human Health and Physical Environment in Kenya: A Comparative Study in Mwea Irrigation Settlement Scheme, Kenya

Abstract

This paper examines the implication of wet-rice farming or irrigated agriculture on the physical environment and human health. Environmental problems seem to have increased in the recent past posing a major threat to irrigation development. Several environmental problems created by irrigation development in Mwea Irrigation Settlement Scheme (MIS) could be attributed to improper understanding of the complex processes involved in the irrigation system. The main objective of this study was to examine cases and causes of some environmental and health problems and planning related issues in MIS. An environmental planning and management methodology is suggested which will attempt to minimize or at least mitigate against the environmental and health problems. 'Fool Proof' method of comparing the situation in an irrigation settlement with a neighboring off-scheme area where irrigation activities were absent, was utilized. The area selected for comparison has been earmarked for rice cultivation through irrigation and no environmental impact studies have been done. The results showed that there has been a dramatic increase in real and potential human health problems emanating from emergence of new diseases, the expansion of the vector base and the ease of spread of water borne- diseases. From the comparative method it was concluded that most of the problems observed were unique consequences of irrigation development since they were absent in the control region. It is recommended that an environmental plan should be instituted in the MIS management structure to ensure that the stress on the irrigation settlement ecosystem is within its carrying capacity. The management plan should incorporate and integrate baseline conditions, planned project activities, impacts anticipated and supportive and assimilative capacities of the system. Future irrigation development planning should therefore be holistic and multidimensional. K eywords: environmental problems, irrigation development, human health problems, comparative method.