Academic literature on the topic 'Geomorphological processes'

AbstractThe objective of the present study is to evaluate the relation between the spatial and temporal dynamics of Land Use and Land Cover (LULC) and the hydro-geomorphological processes and their impacts. The study area is the city of Leiria, in central Portugal, within the period 1958–2018 based on the historical record of floods and landslides disasters. The LULC analysis shows an accentuated increase in the artificial areas and a continuous decrease in the agricultural areas. With regard to hydro-geomorphologic disaster occurrences, a total of 124 occurrences were identified, having caused a set of impacts. The obtained results allow one to characterize the artificialization process, its intensity and territorial dispersion, as a consequence of urban sprawl and peri-urbanization, along with its consequences in exposure to hydro-geomorphological processes. The analysis concludes that changing the risk drivers resulted in an increase in frequency and spatial dispersion of hydro-geomorphologic disasters over the analysed period.

Main issues related to the geomorphological mapping of quarries are discussed. The stages of creating these maps are characterized. The first stage is the analysis of raw materials and prefield mapping. The relief in contours with a relatively small value of horizontal crossing (2 m) is depicted in surveying and topographic maps and plans of mines (scale 1:500–1:5000). According to topographic maps and plans of mining the boundaries of main elements of relief can be quite easy to distinguish, and sometimes their genesis can be set. Space photos help to identify not only the major but also the minor (small) elements and forms of relief and micro-relief surfaces (flat, hilly etc.). As a result of preparatory (prefield) the geomorphological map-hypothesis (preliminary geomorphological map) is worked out, the main morphological elements of relief are highlighted there to the most possible extent. The second most important, phase is field mapping. The main task is to identify the complete and final elements and landforms. Four major components of the quarry relief, which are represented on geomorphic maps (its morphology, genesis, age and dynamics) are analysed. The relief morphology is the most essential part of the content of geomorphologic maps of quarries. The morphological criteria define the boundaries of cells and landforms, and confirm or deny the previously allocated limits, specify them (including changes in the relief that have occurred in recent years) and circumstance them. The genesis of quarries relief, in general, is purely anthropogenic. Depending on the relief forming factor (anthropogenic denudation or accumulation) the main genetic categories of relief are distinguished respectively: excavated (or denudational) and accumulative. The age of the relief is determined by the fund and literary sources, topographic and surveying maps, remote materials. Additional criteria that can be found in field studies can also be used, such as: 1) herbage (amount of turf); 2) forestry (approximate age of trees); 3) the severity of morphological forms. Contemporary geomorphological processes in quarries are the natural and anthropogenic processes that occur in man-made terrain, but act as natural. From the experience of personal research, the most common processes include landfall-landslides processes, linear erosion, sheet erosion, upheaval, suffusion. Some other characteristics that are represented on geomorphological maps include geological structure, vegetation, hydrological features. The main geological characteristic is the lithology of deposits, first and foremost the lithology of career ledges (loam, sand, marl, limestone, sandstone etc.). Vegetation on geomorphic maps of quarries is of secondary importance. Its presence indicates the relative maturity of the human terrain, insignificant activity of modern exogenous processes. Hydrological features of quarries usually consist in the amount of water on separate areas (bottoms of quarries) and waterlogging. The last stage is drawing the legend and mapping of the geomorphological map. Legend to the geomorphological map consists of the following components: 1) the types of human terrain, which are divided into key elements (rarely forms) of relief; 2) small (minor) elements and landforms; 3) the contemporary geomorphological processes (contemporary morphodynamics); 4) other markings. The most essential in the legend is the first part that actually describes the main elements and landforms of quarry relief grouped according to genetics and further divided by age and morphology, topography, geological and hydrological characteristics, vegetation. There are no specific standards as to geomorphological maps mapping. There are black and white and colour versions of the maps. Key words: quarry, anthropogenic relief, geomorphological mapping, geomorphological maps stages of construction, contemporary morhpodynamics

The article is conceived as an introduction to the study of the floodplain. It deals with the delimitation of the floodplain from geomorphologic, pedologic, hydrologic and geoecologic point of view. It also describes the basic geomorphological forms and natural processes, constituting the floodplain system and participating in its formation.

The Ore Mountains belong among thoroughly investigated parts of the Bohemian massif. The survey of geomorphological research is related to the Kateřinohorská k1enba Dome. Some geomorphologically relevant information are to be found in geological literature, too.

The main focus of the article is the significance of the geomorphological method for the reconstruction of paleogeographic events that took place in the Late Pleistocene and Holocene. The specific data obtained as a result of applying this method are given. A reasonable curve of the Caspian Sea level fluctuations in the Holocene was compiled. A risk zone has been defined, within which the level of the Caspian Sea will fluctuate in the future, under modern physics-geographical conditions, which is fundamental importance when planning any economic measures in the coastal zone. Predictions were made and later justified of the Caspian Sea level fluctuations in the 20thearly 21st centuries. The climatic nature of the Caspian transgressions was confirmed. Obtained were new data on the evolution of the shores of the Caspian Sea under rising level conditions, which can be used when forecasting the development of the shores of other seas in the conditions of the present-day rise of the World Ocean level.

The article presents a methodological approach to assessing the geomorphological safety of sea coasts based on the close interdependence between geomorphological conditions and active coastal recreational activities. One of the key stages of the proposed assessment is recreational-geomorphological zoning, which results in separation of regions, districts and local areas in relation to relief homogeneity and recreational situation. The suggested approach is based on the quantitative indicators of the environment — conditions of relief formation and the geomorphological properties of the territory. Group of criteria for the situation of relief formation includes lithological, hydrometeorological, human and social factors. Among the group of geomorphological criteria are: morphometric characteristics of the coast, the dynamics of the coast and the activity of slope processes. Resultant geomorphological safety was classified into three classes: the most suitable areas for recreation; territories subject to further refinement; and inconvenience territories that cannot be used at all. The results of the geomorphological safety assessment are designed to increase the effectiveness of recreational environmental planning. The suggested principles of geomorphological assessment can be used not only for the Baltic region, but almost for any coastal region, which may require some correction of criteria.