ABSTRACT
The objectives of the study were to: examine the nature and detect the change in flow regime; determine the most probable causes; describe the implication of the variable regime for flood recession agriculture; and identify endogenous coping strategies. Data was collected for twenty four (24) years on water level, rainfall, evaporation and temperature and index of urban expansion. Semi structured interview and participatory approaches were used to generate data on the implications for agriculture. Time series analysis using least square regression was used to examine the nature of change in temporal context, while step-wise regression was used to determine the most important cause(s) of the changing flow regime. Percentages, simple linear regression and chi square tools were adopted to examine the implications for agriculture. The result of the analysis showed that changing flow was significant, with 14.6 percent of the variation explained and predicted by time differential. The implication was that water level changed with time but this was accentuated by other explanatory variables. The second analysis result revealed that the changing flow regime was significantly related to and predicted by climate, with rainfall and evaporation being the most significant predictors. The implication of the small percentage(< 40%) explanation was that climate alone did not account for the variation in water level. The addition of an index of urbanization slightly increased the correlation and percentage explanation. This small increase, in percentage explanation indicated that other variables still accounted for the variation in water level over the years. Analysis of flow regime of the River Be, a tributary that is dammed, vis-à-vis rainfall, using regression analysis confirmed that water level was significantly predicted by rainfall. However, the low percentage explanation identified implied the involvement of other variables such as dam impoundment. The regime was observed to be playing more beneficial and complementary roles for agriculture through the enhancement of income mostly from flood recession practices. The implication is that the present flood regime is favourable to farming and this needs to be maintained through adequate watershed management. Where agricultural expansion, deforestation and urban expansion are allowed to continue unabated, the flood regime could be altered more significantly even with no significant change in climate. The endogenous coping strategy most common was recession/relay farming and this was recommended for the downstream farmers.