QUANTITATIVE GEOMORPHOLOGICAL RESEARCHES
Year:2017 | Volume:5 | Issue:3 |Papers Count:11

Introduction Sand ramps are a kind of sedimentary accumulation found at the foot of the slopes of some desert and semi- desert region in the world. Sand banked up against mountain fronts or other topographical obstacle, forming a ramp (Bertram, 2003). For this reason they called sand ramps. The land form among the people of central of Iran is called Kuh-e-Rig, means a mountain of sands. Until the early 90s, sand ramps they was considered as sand dune. But more exactly studying showed despite more materials of sand ramps are sands, but there are huge differences between sand ramps and sand dune in terms of form, materials, and processes. Despite researches in the past, Sand ramps not form just only by Aeolian processes, but another geomorphological processes such as fluvial and colluvium processes. In fact, sands mound up against mountain slopes. Thus they may be seen as a falling or climbing deposits. Therefore, they are actually very complex landform and different of another sand dunes. Sand ramps contain a "variety of sediments formed in different environment including Aeolian, fluvial and talus deposits" (Bertram, 2003). The aim of this research is studying of sand ramps of Tange-Chenar Catchment located in the south of Mehriz city in the Yazd province. The study region is located in the west slopes of Shirkuh mountain with more than 4000 meters high between 31° 18’ to 31° 26’ of northern latitudes and 54° 18’ to 54° 29’ of eastern longitudes...

Introduction: Flow of water is one of the major transformative landforms of small scale (such as a river beach) to large (planet Earth).So in each basin management we need a comprehensive view about basins and identify the major problems to solve them with a planning application. The problems of the region to else show different level but transformation landforms affected drainage network is the most important. Gheshlagh basin is located in the central part of Kurdistan Province and and Like this Provincehas an abundance of water power. Basin located in Esfandaghe- Marivan zone that is the most tectonic active zone in iran. Geological Survey, climatology, soil, land coverage, physiography and hydrology, and particularly field studies defining the role of streams and rivers of the area in the form of the act of creation well water hazards on humans and his work also highlights.so the main objective of this research is Zoning landform evolutions potential affects the drainage network…

Introduction: Karst aquifers act as large natural reservoirs of rainfall, and spring discharges reflect periods of poor or abundant rainfall, as well as long term climate change. The annual discharge of karst springs depends on climate, geology and karst. The karst springs Discharge in a 42-year period in China shows that the discharge of Shentou Springs responds remarkably to precipitation change (Ma & et al.; 2004, 274). The determinations of large karst systems discharge have been analysis by the investigation of precipitation and supplement reduction periods. Data show that hydrologic year depended to last year precipitation. In Mediterranean climate and regional condition the annual peak hydrograph occurs during spring season. Also, Insufficient recharge due to poor annual rainfall affected the peak discharge in hydrograph; this hydrograph reveal drought which effected by reduction in discharge during the following year as well (Fiorillo; 2009, 290)…

Introduction: According to the physicochemical characteristics and high rate of erodibility, Marl is one of the most important sedimentary units are in Iran. These properties caused large environmental and civil damages and so, the study of erosion and erodibility of the marl units is essential. One of the most important points about marls is grain size nature and elements in them and their effects on amount of erosion. The physical and chemical proprieties of soil are very important in the development of badlands. This study deals with the physicochemical characteristics of the marl units and their effect on various forms of erosion in Nowbaran Saveh region. Badlands are a typical landform of greatly dissected fine-grained materials in arid or semi-arid environments like Nowbaran, although they are also found in different climatic conditions. Badlands typically have steep, unvegetated slopes, high drainage densities, high erosion rates and a tendency to form a regolith profile with dried cracks, making the surface puffy. Climate and geology are several factors determining the tendency to badland formation. Runoff, rain splash, marl and loose formations together with massive wasting processes such as creep, sliding and flow, become the dominant factors determining landform genesis, resulting in the formation of badlands in Clayey- silt slopes…

Introduction: Management of natural disasters needful local information set able for perils and decrease of process them. At this contex the indication of the potential landslides in the area which due to geographical condition and the construction of human is prone to landslides is necessary. Ghalae chai dam is one of these areas. Therefor, the purporse that is followed in this study is that, the Motions and instabilities hillside and affective factors in it be known to deleterious effect of that be prevented in the field of the natural resources and in the other parts of construction of development and economic and areas with high potential risk is identification and be zonied. Therefore the main purpose of this research, is to assessment of Analytic Network Process and Logistic Regression methodi n determine the landslide prone areas in the range Axis and Reservoir of Ghalea Chai Ajabshir…

Introduction: Erosion and sedimentation are highly important in geomorphological studies. Accelerated soil erosion causes adverse agronomic, ecologic, environmental, and economic effects both on-site and off-site. The main on-site consequences involve the reduction in soil productivity, while the off-site consequences are mostly due to the sediment and sediment-associated chemicals transported from the source into surface waters. Nowadays most researchers investigate the sediment particle size distribution in river systems from different standpoints in order to understand the hydrodynamic behavior of suspended sediments and to calibrate transfer models and sedimentation in flood plains and channels. Water spreading system is a mechanical method to control flood in the plain in order to recharge of aquifer and increase the groundwater level. Suspended materials in floods can be changed the sediment and soil texture and structure and increase the depth and fertility of soils on which these floods flow. Hence, it is necessary to investigate these changes and their process so that an appropriate method for increasing the efficiency of these plans can be presented. Despite the importance of sediment particle size distribution, no studies on this subject have been done in Iran. Therefore, the main objective of this study was to investigate the effect of water spreading system on sediment particle size distribution watershed, alluvial fan, and water spreading system of Zahab Plain…

In this study, the quality of Urmia plain groundwater in 1380 and 1393 are discussed and analyzed. The main purpose of this study is to investigate the temporal and spatial changes in groundwater quality, mapping elements for the study time period and comparison of the elements in the waters with the region and international standards. Statistics of meteorological data as well as Urmia plain groundwater quality data, (20 sample wells), (1380-1393), are the most important data in this study.1: 25000 topographic maps and 1: 100000 geological maps and GIS software are important used tools in this paper. The methods of study analysis are based on geostatistical methods and analysis of Wilcox, Piper and Schoeller graph. The results show that in 1380 the maximum of chloride is in the center of plains, but in 1393 the maximum amount of it, is pasted to east of plain (west margin of Urmia lake)…

Introduction: About 36 percent of Earth's land surface covered arid and semi-arid lands.19 percent of these levels is dry completely and without plant life. In Iran, One- third to one- quarter of surfaces is covered with running sands (Ekhtesasi, 1375, 97).So far, there has been a lot of discussion for identification of appropriate indicators for rapid assessment of Intensity and the extent of degradation in arid lands. Using of geomorphologic Indices Due to the It was possible to measure as a quantity and also it has a direct relationship to processes of erosion and sedimentation, is very important. Ripple mark Are waves that formed by the wind blowing on sandy areas. When wind blows on the sandy ground, Makes the movement of sand And therefore are formed Ripple marks (Montagne and Thomas, 2002, 806). Whatever Particle diameter is larger represents the region's severe winds, so larger particles is, more their resistance against wind erosion (welfare, 1388, 16)…

In recent years due to excess exploitation of ground water in fertile plains, land subsidence has become one of the main natural disasters. Neglecting such a phenomenon can cause severe irreparable damages. Accordingly, it is indispensible to assess the potential of fertile lands for subsidence. This study evaluates the potential of land subsidence and effective factors in Farough - Seydan fertile land in Marvdasht. First, the 11 piezometers of 14 available piezometers in statistical period of 1374- 1378 are evaluated. And the empirical relationship of Lamb- Whitman is used to have the map of land subsidence risk. Hence, after Thiessen networking some parameters are prepared such as primary osteoporosis, the coefficient of compression capacity, the initial thickness of intended layers, effective stress the primary and secondary, Raster layers of thickness of saturated area between raw water table and hypothetical layer, initial pore water pressure, changes in effective stress, probable subsidence and its risk. The data show that there are two zones with extra high risk (5.57 percent of the plain) and high risk (19.76 percent of the plain) in which two factors are the most effective ones; the density of the clay layers and excessive water withdrawals…

Introduction: Gullies are an important part of the soil erosion process and their occurrence and development may cause serious problems to a region s economy. They erode agricultural lands and act as potentially important sediment sources for rivers and reservoirs. Gully processes have been studied from a range of viewpoints (e.g. hydraulics, agricultural and forest engineering, hydrology and geomorphology) but despite a wealth of information collected, particularly in the last 20-30 years, many problems of morphology remain poorly known. Attempts to define gullies and their typology reflecta discouraging diversity of opinions. As far as gully spreading is concerned some authors believe that because of the scarcity of data there is an insufficient knowledge of gully development. Recent studies indicate that (1) gully erosion represents an important sediment source in a range of environments and (2) gullies are effective links for transferring runoff and sediment from uplands to valley bottoms and permanent channels where they aggravate off site effects of water erosion. In other words, once gullies develop, they increase the connectivity in the landscape. Many cases of damage (sediment and chemical) to watercourses and properties by runoff from agricultural land relate to (ephemeral) gullying. Consequently, there is a need for monitoring, experimental and modelling studies of gully erosion as a basis for predicting the effects of environmental change (climatic and land use changes) on gully erosion rates. In this respect, various research questions can be identified…

Rivers of the most important factors affecting geomorphological processes and cycles of erosion, till now studies extensively on morphological changes in rivers and the factors affecting them are taken. The aim of this study was to study morphological changes Khorramabad River - Doab Veysian and factors contributing to the change geometry and create relationships between them. In order Estimated Discharge with different return periods from Discharge Chamanjir station and Doab Veysian statistical period (1335-1334) and (1392-1391) was used. After completing the Statistics by software SMADA statistics maximum discharge Chamanjir station and Doab Veysian were fitted with different statistical distributions and Statistics for the Log Pearson Type III distribution was the best fit…