Flash floods and their effects on the development in El-Qaá plain area in South Sinai, Egypt

The arid regions are dominated to a much larger degree than humid regions by major catastrophic events. Although most of Egypt lies within the great hot desert belt; it experiences especially in the north some torrential rainfall, which causes flash floods all over Sinai Peninsula. Flash floods in hot deserts are characterized by high velocity and low duration with a sharp discharge peak. Large sediment loads may be carried by floods threatening fields and settlements in the wadis and even people who are living there. The extreme spottiness of rare heavy rainfall, well known to desert people everywhere, precludes any efficient forecasting. Thus, although the limitation of data still reflects pre-satellite methods, chances of developing a warning system for floods in the desert seem remote. The relatively short flood-to-peak interval, a characteristic of desert floods, presents an additional impediment to the efficient use of warning systems. The present thesis contains introduction and five chapters, chapter one points out the physical settings of the study area. There are the geological settings such as outcrop lithology of the study area and the deposits. The alluvial deposits of Wadi Moreikh had been analyzed using OSL dating to know deposits and palaeoclimatic conditions. The chapter points out as well the stratigraphy and the structure geology containing main faults and folds. In addition, it manifests the pesent climate conditions such as temperature, humidity, wind and evaporation. Besides, it presents type of soils and natural vegetation cover of the study area using unsupervised classification for ETM+ images. Chapter two points out the morphometric analysis of the main basins and their drainage network in the study area. It is divided into three parts: The first part manifests the morphometric analysis of the drainage networks which had been extracted from two main sources, topographic maps and DEM images. Basins and drainage networks are considered as major influencing factors on the flash floods; Most of elements were studied which affect the network such as stream order, bifurcation ratio, stream lengths, stream frequency, drainage density, and drainage patterns. The second part of this chapter shows the morphometric analysis of basins such as area, dimensions, shape and surface. Whereas, the third part points the morphometric analysis of alluvial fans which form most of El-Qaá plain. Chapter three manifests the surface runoff through rainfall and losses analysis. The main subject in this chapter is rainfall which has been studied in detail; it is the main reason for runoff. Therefore, all rainfall characteristics are regarded here such as rainfall types, distribution, rainfall intensity, duration, frequency, and the relationship between rainfall and runoff. While the second part of this chapter concerns with water losses estimation by evaporation and infiltration which are together the main losses with direct effect on the high of runoff. Finally, chapter three points out the factors influencing desert runoff and runoff generation mechanism. Chapter four is concerned with assessment of flood hazard, it is important to estimate runoff and tocreate a map of affected areas. Therefore, the chapter consists of four main parts; first part manifests the runoff estimation, the different methods to estimate runoff and its variables such as runoff coefficient lag time, time of concentration, runoff volume, and frequency analysis of flash flood. While the second part points out the extreme event analysis. The third part shows the map of affected areas for every basin and the flash floods degrees. In this point, it has been depending on the DEM to extract the drainage networks and to determine the main streams which are normally more dangerous than others. Finally, part four presets the risk zone map of total study area which is of high inerest for planning activities. Chapter five as the last chapter concerns with flash flood Hazard mitigation. It consists of three main parts. First flood prediction and the method which can be used to predict and forecast the flood. The second part aims to determine the best methods which can be helpful to mitigate flood hazard in the arid zone and especially the study area. Whereas, the third part points out the development perspective for the study area indicating the suitable places in El-Qaá plain for using in economic activities.

Mediterranean-type climate in the South Aegean (Eastern Mediterranean) during the Late Miocene: Evidence from isotope and element proxies

The present-day climate in the Mediterranean region is characterized by mild, wet winters and hot, dry summers. There is contradictory evidence as to whether the present-day conditions (“Mediterranean climate”) already existed in the Late Miocene. This thesis presents seasonally-resolved isotope and element proxy data obtained from Late Miocene reef corals from Crete (Southern Aegean, Eastern Mediterranean) in order to illustrate climate conditions in the Mediterranean region during this time. There was a transition from greenhouse to icehouse conditions without a Greenland ice sheet during the Late Miocene. Since the Greenland ice sheet is predicted to melt fully within the next millennia, Late Miocene climate mechanisms can be considered as useful analogues in evaluating models of Northern Hemispheric climate conditions in the future. So far, high resolution chemical proxy data on Late Miocene environments are limited. In order to enlarge the proxy database for this time span, coral genus Tarbellastraea was evaluated as a new proxy archive, and proved reliable based on consistent oxygen isotope records of Tarbellastraea and the established paleoenvironmental archive of coral genus Porites. In combination with lithostratigraphic data, global 87Sr/86Sr seawater chronostratigraphy was used to constrain the numerical age of the coral sites, assuming the Mediterranean Sea to be equilibrated with global open ocean water. 87Sr/86Sr ratios of Tarbellastraea and Porites from eight stratigraphically different sampling sites were measured by thermal ionization mass spectrometry. The ratios range from 0.708900 to 0.708958 corresponding to ages of 10 to 7 Ma (Tortonian to Early Messinian). Spectral analyses of multi-decadal time-series yield interannual δ18O variability with periods of ~2 and ~5 years, similar to that of modern records, indicating that pressure field systems comparable to those controlling the seasonality of present-day Mediterranean climate existed, at least intermittently, already during the Late Miocene. In addition to sea surface temperature (SST), δ18O composition of coral aragonite is controlled by other parameters such as local seawater composition which as a result of precipitation and evaporation, influences sea surface salinity (SSS). The Sr/Ca ratio is considered to be independent of salinity, and was used, therefore, as an additional proxy to estimate seasonality in SST. Major and trace element concentrations in coral aragonite determined by laser ablation inductively coupled plasma mass spectrometry yield significant variations along a transect perpendicular to coral growth increments, and record varying environmental conditions. The comparison between the average SST seasonality of 7°C and 9°C, derived from average annual δ18O (1.1‰) and Sr/Ca (0.579 mmol/mol) amplitudes, respectively, indicates that the δ18O-derived SST seasonality is biased by seawater composition, reducing the δ18O amplitude by 0.3‰. This value is equivalent to a seasonal SSS variation of 1‰, as observed under present-day Aegean Sea conditions. Concentration patterns of non-lattice bound major and trace elements, related to trapped particles within the coral skeleton, reflect seasonal input of suspended load into the reef environment. δ18O, Sr/Ca and non-lattice bound element proxy records, as well as geochemical compositions of the trapped particles, provide evidence for intense precipitation in the Eastern Mediterranean during winters. Winter rain caused freshwater discharge and transport of weathering products from the hinterland into the reef environment. There is a trend in coral δ18O data to more positive mean δ18O values (–2.7‰ to –1.7‰) coupled with decreased seasonal δ18O amplitudes (1.1‰ to 0.7‰) from 10 to 7 Ma. This relationship is most easily explained in terms of more positive summer δ18O. Since coral diversity and annual growth rates indicate more or less constant average SST for the Mediterranean from the Tortonian to the Early Messinian, more positive mean and summer δ18O indicate increasing aridity during the Late Miocene, and more pronounced during summers. The analytical results implicate that winter rainfall and summer drought, the main characteristics of the present-day Mediterranean climate, were already present in the Mediterranean region during the Late Miocene. Some models have argued that the Mediterranean climate did not exist in this region prior to the Pliocene. However, the data presented here show that conditions comparable to those of the present-day existed either intermittently or permanently since at least about 10 Ma.

The performativity of nonviolent protest in South Asia (1918 - 1948)

This study seeks to address a gap in the study of nonviolent action. The gap relates to the question of how nonviolence is performed, as opposed to the meaning or impact of nonviolent politics. The dissertation approaches the history of nonviolent protest in South Asia through the lens of performance studies. Such a shift allows for concepts such as performativity and theatricality to be tested in terms of their applicability and relevance to contemporary political and philosophical questions. It also allows for a different perspective on the historiography of nonviolent protest. Using concepts, modes of analysis and tropes of thinking from the emerging field of performance studies, the dissertation analyses two different cases of nonviolent protest, asking how politics is performatively constituted. The first two sections of this study set out the parameters of the key terms of the dissertation: nonviolence and performativity, by tracing their genealogies and legacies as terms. These histories are then located as an intersection in the founding of the nonviolent. The case studies at the analytical core of the dissertation are: fasting as a method in Gandhi's political arsenal, and the army of nonviolent soldiers in the North-West Frontier Province, known as the Khudai Khidmatgar. The study begins with an overview of current theorisations of nonviolence. The approach to the subject is through an investigation of commonly held misconceptions about nonviolent action, such as its supposed passivity, the absence of violence, its ineffectiveness and its spiritual basis. This section addresses the lacunae within existing theories of nonviolence and points to possible fertile spaces for further exploration. Section 3 offers an overview of the different shades of the concept of performativity, asking how it is used in various contexts and how these different nuances can be viewed in relation to each other. The dissertation explores how a theory of performativity may be correlated to the theorisation of nonviolence. The correlations are established in four boundary areas: action/inaction, violence/absence of violence, the actor/opponent and the body/spirit. These boundary areas allow for a theorising of nonviolent action as a performative process. The first case study is Gandhi's use of the fast as a method of nonviolent protest. Using a close reading of his own writings, speeches and letters, as well as a reading of responses to his fast in British newspapers and within India, the dissertation asks what made fasting into Gandhi's most favoured mode of protest and political action. The study reconstructs his unique praxis of the fast from a performative perspective, demonstrating how display and ostentation are vital to the political economy of the fast. It also unveils the cultural context and historical reservoir of body practices, which Gandhi drew from and adapted into 'weapons' of political action. The relationship of Gandhian nonviolence to the body forms a crucial part of the analysis. The second case study is the nonviolent army of the Pashtuns, Khudai Khidmatgar (KK), literally Servants of God. This anti-imperialist movement in the North-West Frontier Province of what is today the border between Pakistan and Afghanistan existed between 1929 and 1948. The movement adopted the organisational form of an army. It conducted protest activities against colonial rule, as well as social reform activities for the Pashtuns. This group was connected to the Congress party of Gandhi, but the dissertation argues that their conceptualisation and praxis of nonviolence emerged from a very different tradition and worldview. Following a brief introduction to the socio-political background of this Pashtun movement, the dissertation explores the activities that this nonviolent army engaged in, looking at their unique understanding of the militancy of an unarmed force, and their mode of combat and confrontation. Of particular interest to the analysis is the way the KK re-combined and mixed what appear to be contradictory ideologies and acts. In doing so, they reframed cultural and historical stereotypes of the Pashtuns as a martial race, juxtaposing the institutional form of the army with a nonviolent praxis based on Islamic principles and social reform. The example of the Khudai Khidmatgar is used to explore the idea that nonviolence is not the opposite of violent conflict, but in fact a dialectical engagement and response to violence. Section 5, in conclusion, returns to the boundary areas of nonviolence: action, violence, the opponent and the body, and re-visits these areas on a comparative note, bringing together elements from Gandhi's fasts and the practices of the KK. The similarities and differences in the two examples are assessed and contextualised in relation to the guiding question of this study, namely the question of the performativity of nonviolent action.