@phdthesis{Mbachu2021, author = {Mbachu, Ikechukwu}, title = {Flood vulnerability assessment and adaptive capacity of smallholder farmers : a case study of the Orashi basin in the Niger Delta}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-57211}, school = {BTU Cottbus - Senftenberg}, year = {2021}, abstract = {In most studies on flood risk in Nigeria, priority is given to urban flood risk than rural flood risk. Smallholder farmers who mostly inhabit rural areas and flood plains are known to be at great risk of flooding, but to date, there have been no studies on the impacts they experience and how they cope with these impacts. To establish the existence of significant change in precipitation in the study area, statistical analysis of precipitation data was conducted using linear regression and non-parametric Mann Kendall test. Landsat satellite images for 1986, 2003 and 2016 were obtained from the United States Geological Survey's (USGS) website and used to collect and analyze data related to land use. To determine flood risk in the context of land use change, the HEC-HMS model version 3.5 was used. Land use maps corresponding to 1986, 2003, and 2016 LULC conditions were analysed and prepared for the calculation of CN values using Soil Conservation Service (SCS-CN) method. CN map was prepared by integrating the maps of hydrologic soil groups and land use in ArcGIS software. Based on selected morphological parameters, a flood risk map was developed for the study area. The morphologic flood risk showed that most parts of the basin face moderate flood risk. Higher runoff values were observed under 2016 LULC conditions mainly due to intense deforestation relative to those of 1986 and 2003. The results indicated that runoff and peak discharge are significantly affected by deforestation instead of changes in the rainfall pattern. Flood inundation maps of the study area were prepared for the flood events of 2012 and 2015. Maximum depth for the 2012 and 2015 flood events was calculated as 10.58m and 7.39m, respectively. The socioeconomic aspects of the research were conducted using household survey method. Using snowball sampling techniques, 400 flood-affected households were selected. The results show that the adaptive capacity of smallholder farmers in the study area remains very low and hampered by several factors such as poverty and weakened social networks. The synopsis of the examined variables leads to the following conclusion: Instead of climatic factors - as one indicator of vulnerability - it is social inequality and poverty in the region as well as the structural economic differences between various groups that mainly drives vulnerability in the study area.}, subject = {Vulnerability; Flood; Smallholder farmers; Climate change; Adaptive capacity; Hochwasserrisiko; Anpassungsf{\"a}higkeit; Kleinbauern; Klimawandel; Verletzlichkeit; Nigeria; Nigerdelta; Hochwasser; Kleinbauer; L{\"a}ndlicher Raum; Niederschlagsmessung; Anf{\"a}lligkeit; Klimawandel}, language = {en} }