Climate Change: Risk Assessment
http://repository.pauwes-cop.net/handle/1/86
2024-03-29T01:23:20ZFlood Reduction through Flood Risk and Vulnerability Assessment and Mapping in Hadejia River Basin, Nigeria
http://repository.pauwes-cop.net/handle/1/432
Flood Reduction through Flood Risk and Vulnerability Assessment and Mapping in Hadejia River Basin, Nigeria
SHUAIBU, Abdulrahman
Floods are one of the most recurrent and devastating natural disasters that has enormous, widespread and ravaging negative impacts on lives, economy and infrastructures across the globe. Hadejia River Basin is known by its frequent flood occurrences which claims many lives and destroyed several infrastructures and vast hectares of farmlands. The purpose of this research was
to develop a GIS-based flood risk and vulnerability mapping integrated with Analytical Hierarchical Process (AHP) in order to reduce the risk and vulnerabilities associated with flood in Hadejia River Basin. The research employs an efficient and reliable methodology in preparing flood risk map for the Hadejia River Basin based on the concepts of integration of flood hazard
and socioeconomic vulnerability indicators. The risk map of the basin was generated by aggregating the geomorphological, hydrological, and socio-economic indicators namely; elevation, mean annual rainfall, slope, distance to rivers, soil type, drainage density, population density, female population density, literacy rate, land-use, and employment rate and road network in GIS framework using multi-criteria analysis technique called the Analytical Hierarchy Process (AHP). Accordingly, the northeastern and southeastern parts of the study area are prone to frequent floods which constitutes very high and high flood hazard zones of about 10.4% (3179.1 Km2) and 17.2% (5257.8 Km2) of the watershed while vulnerabilities levels are higher at the southeastern, central and extreme upstream parts of the study area which covers about 24.1% (7367Km2) of the study area. Moreover, combination of the flood hazard (FHI) and vulnerability (FVI) indices of Hadejia River Basin reveals about 43.4% of the basin is under high and very high flood risk covering about 13266.8Km2. The study also reveals that flood hazard and vulnerability indicators have different influence to flood risk. Furthermore, the results are validated and found to be in agreement with the historical records of flood distribution of the study area. This proves the reliability and applicability of the proposed methodology. This research has significant importance in developing strategic measures and plans through which government and relief agencies will reduce and/or prevent the negative impact of flood risk and socioeconomic vulnerability in the Hadejia River Basin.
2020-12-01T00:00:00ZFlood Inundation Modeling in the Gourou Watershed of Côte d’Ivoire, West Africa
http://repository.pauwes-cop.net/handle/1/342
Flood Inundation Modeling in the Gourou Watershed of Côte d’Ivoire, West Africa
Ulrich, Etche Attikora Kouadio
Nowadys, floods and droughts are becoming more and more frequent all other the world.
According to the Emergency Events Database, Africa is the third continent most affected by flood
events in terms of occurrence, total deaths, injured, affected and homeless. This report showed that
since 1989, Côte d’Ivoire has experienced floods in 1996, 2007, 2008, 2010, 2014, 2015, 2016,
and recently in 2017 and 2018. Those floods caused 169 deaths and around 40000 affected people.
Floods occur principally in Abidjan. Their occurrences and amplitudes will increase due to climate
change and the increasing urban population. The study was conducted to construct hydrological
and hydrodynamics models couple with GIS for flood inundation mapping in Gourou watershed
in Côte d’Ivoire. HEC-HMS and HEC-RAS models were used to achieve the specified objective.
The result of hydrological modeling showed that the HEC-HMS model simulated fairly well the
peak discharges. A sensitivity analysis of the HEC-HMS model parameters used in this study
showed that the model outputs are more sensitive to Curve Number compared to the percentage of
impervious area and lag time. From the result of hydrodynamics model, it was obvious that the
floodplain inundated areas increase with the magnitude of flow within the modeled network
confirming the high flood hazard level for settlements and activities near the main canal in Gourou
watershed. The WSE profile showed a great variability as water is moving from upstream toward
downstream. The obtained flood inundation map for 5-, 10-, 20-, 50-, 100-years illustrated that
most of the inundated areas are built-up areas. Thus, flood inundation maps developed in this study
can be used for decision making, along with strategies for flood preparedness
2019-10-01T00:00:00ZRainfall-Intensity Duration Frequency Analysis and Peak-flow Estimations for Flood Risk Management Options within Gountiyena basin in Niamey, Niger.
http://repository.pauwes-cop.net/handle/1/338
Rainfall-Intensity Duration Frequency Analysis and Peak-flow Estimations for Flood Risk Management Options within Gountiyena basin in Niamey, Niger.
Kavoo, Thomas Mutiso
Information on peak discharge and related probabilities is essential for engineering structure
designs. Many basins are ungauged and therefore, data for statistical analyses are missing and input
for sophisticated hydrological modeling is insufficient. Design storm estimations based on intensity
duration frequency analysis and peak discharge estimations is an essential component for planning
water management interventions. The study aims to contribute to flood risk reduction within the
Gountiyena basin in Niamey/Niger through intensity duration frequency analysis and peak
discharge estimations based on a 5-minutes interval rainfall from 1990 to 2017 for two stations.
The Gumbel distribution was applied for the intensity duration frequency analysis while the
Rational and the Soil Conservation Service-Curve Number methods were used for peak discharge
estimations. Short rainfall durations produced high rainfall intensities with increasing return period.
The intensities varied from 100mm/hr to 226mm/hr for both stations for 1-year and 50-years return
period respectively. Estimated average peak discharges vary from 84m3/s (1-year return period) to
290m3/s (50-years return period). The results can serve as basis for decision making for planning
water management interventions. Alternatives on appropriate flood management options were
summarized and described
2019-10-01T00:00:00ZSpatial and Temporal Drought Characterization in View of the Best Irrigation Practices in Central Malawi
http://repository.pauwes-cop.net/handle/1/306
Spatial and Temporal Drought Characterization in View of the Best Irrigation Practices in Central Malawi
Chikabvumbwa, Sylvester Richard
Recently, in Kasungu Agricultural Development Division (ADD), agricultural production has been challenged by uneven rainfall distribution spatially and temporally leading to constant dry spells and droughts resulting in economic losses. This study sought to characterize the temporal and spatial variations of drought from 1977 to 2017 and relate it to climate smart irrigation technologies that can be promoted and drought resistant crops that can be grown in the area. The previous studies done in Malawi did not look into drought characterization and only used the Percentile Index such that other indices were not considered for drought analysis. This study bridged this gap by using different monitoring drought indices in DMAP software. It was found that the ADD experiences mild and moderate meteorological droughts, frequent moderate agricultural droughts and extreme hydrological droughts. Based on the results on crop water requirements in CropWAT software, this study found that cassava should be promoted in the region as a drought resistant crop. Furthermore, the study found out that surface irrigation systems with low efficiencies are commonly used and that climate smart irrigation technologies are not largely practiced in the ADD. This study recommends the promotion of rainwater harvesting technologies and the adoption of drip and micro-sprinklers irrigation systems in the ADD.
2019-09-05T00:00:00Z