جستجوی مقالات مرتبط با کلیدواژه "geomorphology" در نشریات گروه "عمران"

The alteration in the landform pattern leads to changes in other landscape parameters such as soil, geology, and vegetation. Hence, the study of landforms and the investigation of factors that influence their formation and evolution are significant scientific disciplines in the fields of geomorphology and pedology. Climatic conditions with influencing on the geological processes, in conjunction with topographic features and the characteristics of parent materials, play an important role in forming and transformation of landforms.

In this research, the landforms of the study area were delineated using a digital elevation model with a resolution of 10 meters and the SAGA software based on the topographic position index. Subsequently, in two landforms, namely the plain and the open slope, which exhibited the highest degree of repeatability in the region, excavation and sampling were conducted, and the physicochemical properties and parameters such as parent material, elevation, and slope percentage were examined for each profile.

The studies indicated that in the plain landform the variation of slope is low and its maximum is three percent. This subject proves the transportation of parent materials from higher geomorphic surfaces accumulated in lower areas, resulting in the formation of this specific type of landform which is suitable for agriculture. Moreover, in the open slope landform with relatively high slope variations, erodible marl parent materials underwent alterations and transformations over time, leading to the development of distinct geomorphic surfaces. In this landform, the percentage of clay is reduced with depth, except for the profiles that have irregular patterns. Because of almost high slope, the soil depth of this landform is low. The reason for this low depth of soil is that the position of slope has the most important effect on the soil depth. Therefore, the positions on the top of the slope have low depth soils than the position on the bottom of the slope.

Topography has been known as a major factor in evolution and development of soils. The studied landform of this research showed that not only topography has a direct role in pedogenic processes but also parent materials are very importance in change of the processes and in landform construction. In this research, the landforms of the study area were separated based on topographic position index. In topographic position index, height and slope are used as the basic parameters for analyzing and classification of the landforms. Surveying the physical and chemical characteristics as well as assessing the parent material, height and slope percentage of the dug-up profiles in the more consequential landforms of the study area revealed that parent materials and slope have effective roles in creation of the landform. However, in the study area because of the arid and semi-arid conditions of the region and reduction of aeration and washing, the role of slope in creation of landforms was stronger than the role of parent materials. Thus, simultaneous study of the role of slope and parent materials in the regions with high aeration and active processes in geomorphic surface changes may create a broad context of research on creation of landforms.

Environmental hazards are the result of improper human activity and exploitation of the environment. Identification and analysis of these hazards in field of geography could we studied from two different point of views.. Kharrazi Highway is an important highway in Tehran, the construction of which began three decades ago and is now in use. This highway is one of the routes whose identification of hazards according to the geomorphological features of the surrounding environment, is one of the main objectives of this study.This research is based on Analytic Hierarchy Process (AHP) and scenario writing model as well as statistical forecasting method. In these methods, EXCEL and ARC GIS soft wares have been used to predict the damages and to select the appropriate location for the construction of the road network, respectively. This regarding to environmental factors and geomorphology when selecting and constructing this communication highway can provide a probability high percentage of environmental hazards. In this study, the amount of risk and hazard was measured and it was found that according to the effective parameters, Base on the effective parameters and amount of risk and hazard measurement of study, the eastern part is in a high-risk area. in terms of human statistics, in 7years the death toll has increased from 19 to 509 person, which indicates an increase risk rate for future periods.