Abstract:The synergistic enforcement of the hydrographic behaviors of Kereke and Ukoghor river basins on the river Benue have been identified as the major contributors of the replete episodic flood hazard of Makurdi town. It is on this note that this study aims at analysing and comparing two categories of morphometric parameters; areal and linear/relief which influence runoff/discharge volumes and time lag of Kereke and Ukoghor river basins hydrograpghs respectively. This analysis provides a better understanding of their hydrographic characteristics and vulnerability to the flood hazard. The potential hydrographic variables examined include: runoff, peak flow, time to peak, infiltration, and overland flow. This was achieved using topographical maps of Makurdi sheet 251 NW and 251 SW on scale 1:50,000 published by Federal Survey of Nigeria (1965). These morphometric parameters were evaluated using ArcGIS 10.

This study was aimed at monitoring, mapping and characterisation of floodplain encroachment patterns on the River Kaduna floodplain in Kaduna metropolis, Nigeria,as part of the approach to flood hazard evaluation, flood risk assessment and effective flood and floodplain management. A Topomap of 1967 was used to extract the base built-up layer, while Landsat.TM, 1987, Spot.XS, 1995, Landsat.ETM, 2001 and Quickbird, 2006 were used to generate other built-up layers, which were extracted by digitization and converted to polygon shape files and later used for overlay analysis. A Digital Elevation Map (DEM) of the area was used for delineation of floodplain boundary. ArcGIS sorfware 9.0 operational tools was highly robust and flexible for mapping and analysis of urban growth patterns and characterisation of floodplain encroachment by communities. From the results, it was observed that the highest extents and rates of encroachment are recorded by communities in the proximity of the Central Business District (CBD) such as T/Wada, Ung. Rimi, Barnawa, Doka and the industrial layouts of Kakuri and Kudenda. These areas are the centers of highest socio-economic infrastructure which implies greater flood risk and damage potential in the event of flooding. Results also showed that about 52.83% of the urban segment of the River Kaduna total floodplain area of 48.55km², has been encroached by built-up. As a result of this pattern of encroachment, strong institutional framework and investment towards effective floodplain management is recommended

This study examines the contribution of Zobe dam to the socio-economic development of Makera Community Dutsinma LGA, Katsina State north-western Nigeria. The study identified types of socio-economic activities supported by the dam and their impact. Total of 392 questionnaires was administered to adults target population using stratified random sampling technique. Descriptive and inferential statistics were used to analyze the data. Findings revealed main economic activities supported by the dam are farming (60.46%), fishing (30.10%), domestic water supply (5.52%) and livestock watering (3.057). The positive contributions of the dam include an increase in the availability of social amenities and resident's standard of living. Specific impacts were increased income, increased crop yield, increased farm sizes, commercial fishing and increased access to water supply sources. The survey also revealed the dam is a major pull-factor with 79.59% respondent's decision to settle in the area influenced by the dam. The negative impacts were; occasional floods that erode crops, farmlands, the introduction of new pest and spread of water associated diseases (schistosomiasis, malaria, and typhoid in decreasing magnitude). ANOVA test showed no significant difference in literacy level, occupation and water use among residents. Analysis of water quality to determine the impact of activities was recommended.

Flooding is now an annual occurring event in Donga Town especially after heavy rainstorm which is further worsened by the nature of the topography of the area. The knowledge of how the public view flooding is considered a crucial aspect in modern flood management as it steers the development of effective and efficient flood mitigation strategies. This study therefore assessed public perception of flooding in Donga town. Two wards were purposively drawn out of ten wards (Gata Aure and Fada ward). The survey design method was employed in this study. Yamane (1967) method of sample size determination was used to arrive at a sample size of 130 for the study. Systematic random sampling was used in the administration of 130 questionnaires to respondents. Non parametric statistics of Spear Man rank correlation and descriptive statistics (percentages, tables, pie and bar charts) were used to analyze the data. The result of the findings showed that 95% of the respondents were male, 88.4% of the respondents were aware that the area was prone to flooding. Also, about 46.2% perceived that rainfall was the major cause of flooding in the study area. Correlation analysis result was insignificant which implied that in Donga town, educational level of respondents did not influence respondent's awareness level of flooding and that people's perception of flooding was influenced by factors other than respondent's literacy level. The conclusion from the study is that rainfall intensity and amount is the main cause of flooding in Donga town and also individual's response to flooding in the study area is poor. This study recommends the need to educate the people living in the flood plain on the dangers of continuous occupation of the area.