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Abstract. Urban flooding has been and will continue to be a significant problem for many cities across the developed and developing world. Crucial to the amelioration of the effects of these floods is the need to formulate a sound flood management policy, which is driven by knowledge of the frequency and magnitude of impacts of these floods. Within the area of flood research, attempts are being made to gain a better understanding of the causes, impacts, and pattern of urban flooding. According to the United Nations office for disaster reduction (UNISDR), flood risk is conceptualized on the basis of three integral components which are frequently adopted during flood damage estimation. These components are: probability of flood hazard, the level of exposure, and vulnerabilities of elements at risk. Reducing the severity of each of these components is the objective of flood risk management under the UNISDR guideline and idea of "living with floods". On the basis of this framework, the present research reviews flood risk within the Lagos area of Nigeria over the period 1968-2012. During this period, floods have caused harm to millions of people physically, emotionally, and economically. Arguably over this period the efforts of stakeholders to address the challenges appear to have been limited by, amongst other things, a lack of reliable data, a lack of awareness amongst the population affected, and a lack of knowledge of flood risk mitigation. It is the aim of this research to assess the current understanding of flood risk and management in Lagos and to offer recommendations towards future guidance.

Traditionally, landforms have been measured using a combination of field survey techniques and analogue and analytical photogrammetry. With advances in computing power digital photogrammetric solutions are now seen as offering an affordable and cost effective way of mapping topographic features. This paper looks at the relative merits of each of these photogrammetric techniques, in terms of the practical considerations involved in data extraction and accuracies that can be achieved for a case study. The site investigated is Maiden Castle, situated southwest of Dorchester in Dorset, UK. This paper examines the relative accuracies of both digital and analytical photogrammetric techniques in relation to ground control points recorded using a global positioning system (GPS). Colour stereoscopic aerial photographs were taken of Maiden Castle, Dorset, in November 1999 at a scale of approximately 1 : 4000. Stereo models were constructed using pre-marked ground control points positioned using post-processed differential GPS. Subsequent analysis involved the calculation of residual values produced by comparing the computer-generated surface with a set of test points measured using differential GPS. This research demonstrates that the optimal digital system matched the performance of analytical photogrammetry for the collection of geomorphological data.

Coastal hazards are in the interface of human activities with natural coastal processes. The conflicts arising from this relationship require new approaches suitable for coastal management that consider the dynamic of coastal areas. A method to assess hazard in rock cliffs is presented, combining cliff evolution forcing mechanisms along with protection factors, according to a weighted factors system. This method provides a rapid evaluation of vulnerability for cliffed areas, supporting coastal management and hazard mitigation. The method was applied to the rocky cliffs of the densely populated coastal zone between Galé and Olhos de Água (Southern Portugal), where high and very high hazard values were found to be dominant. A method validation was made using the vulnerability areas and the recorded mass movements over a 45 year period in the same area.

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