Geomorphological processes, forms and features in the surroundings of the Melka Kunture Palaeolithic site, Ethiopia

The landscape of the surroundings of the Melka Kunture prehistoric site, Upper Awash Basin, Ethiopia, were studied intensively in the last decades. Nonetheless, the area was mainly characterized under a stratigraphic/geological and archaeological point of view. However, a detailed geomorphological map is still lacking. Hence, in this study, we identify, map and visualize geomorphological forms and processes. The morphology of the forms, as well as the related processes, were remotely sensed with available high-resolution airborne and satellite sources and calibrated and validated through extensive field work conducted in 2013 and 2014. Furthermore, we integrated multispectral satellite imagery to classify areas affected by intensive erosion processes and/or anthropic activities. The Main Map at 1:15,000 scale reveals structural landforms as well as intensive water-related degradation processes in the Upper Awash Basin. Moreover, the map is available as an interactive WebGIS application providing further information and detail (www.roceeh.net/ethiopia_ geomorphological_map/)

Climate Change and the Global Pattern of Moraine-Dammed Glacial Lake Outburst Floods

Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and regularity – rather unexpectedly – have declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From an assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine-dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century

Floods In the context ot natural hazards and risks

The worldwide methodology for gathering data about natural disastrous processes is still missing. Consequently it is hard to confirm the theory about increase of natural hazards due to the global warming. Nevertheless data about impact on human lives and property exist. Several specific statements about time and space distribution of floods, effects on different groups of the society allow us to evaluate the risk. The position of floods among various natural hazards is discussed from the point of view of predictibility or occurrence regularity. Internal links between different types of hazardous processes and the role of complexity help to understand the fundaments of floods51

Serengeti

11

Následky El Niňa v Peru

6

Kláštery Meteora

11211

Ostrov Théra

11811

Přírodní katastrofy

303