spatial analysis of aeolian landforms by fractal theory (case study: ardestan rig)

spatial analysis of aeolian landforms by fractal theory (case study: ardestan rig) abstract natural sciences face to a great revolution, nowadays. now, scientists think the world as a collection of complex systems which prediction of consequences of this complex systems is so difficult. in this situation the systems have rotational act so irregularly lead to regular and regularly lead to irregular. in the meantime, geomorphic landforms have special shapes, sizes and special aspects, and the spatial arrangement of these shapes to each other can be determined by many influence factors in their formation. since the landforms behavior are nonlinear in nature, it can be analyzed using statistical methods which fractal geometric is is one of them. the theory, attempts to use its equations to represent the complexity by mathematical way. the purpose of this study is fractal analysis of aeolian landforms of ardestan rig. for this purpose, we used cartosat images of 2008 and 2011, and for fractal analysis, we divided typical aeolian landforms of study area into four categories ; longitudinal sand dunes, cross sand dunes, barkhans and planted sand dunes. to determine the fractal dimension, we used box counting method. results show that the geometric patterns of landforms have fractal characteristics so it can be analyzed for different years. the dimension of fractal as a main index, show that planted sand dunes that have a most extent, have a great dimension because it don’t changed during the study period, and indicating the stabilization of sand dunes. the maximum rate of change belongs to longitudinal and cross sand dunes that their extent is decreasing and this has been shown to reduce the fractal dimension and its implementation. in general, the result of fractal analysis matches with realities of aeolian landforms. keywords: fractal theory, geomorphic landforms, aeolian landforms, ardestan rig introduction today, mathematics is a strong way for explain process and the complexity of nature so this turmoils have to be made in the form of mathematical and quantitative relationships and to some extent predict their effects. for this purpose to illustrate the complexity, use of fractal geometry and its dimension for understanding the heterogeneity in natural environments is common agency of this study is the morphological behavior of each wind geomorphic forms in the environment. it should be noted that the behavior of landforms are nonlinear in nature, so they can be analyzed with statistical methods and fractal geometry is one of the approaches that attempt to use their theories and formulas can represent the complexity and quantity in the form of mathematics. the term nonlinear is unequal relations between influential forces or stress and geomorphic response to states. this paper aims to explain the behavior of fractal geometry and morphological landforms by using geometry and use mathematics for determine the rate of changes. so, focus on wind landform because of having more variability than other landforms due to faster to better results may be achieved in a shorter timeframe. special analysis are the major challenges facing researchers. also evaluated in terms of the fractal dimension is other goal of this study. methodology the study area is between 33 30- 33 45 north longitude and 52 15- 53 east latitude and the divisions in the zvareh- ardestan-isfahan. the height of the southwestern region to the north in 1410 to 910 and an average gradient is 0.5 percent. in this study aims to identify 5 index landforms and detemine the limit of the development extracted carefully. the data used for this purpose are: - cartosat1 image 2008 - cartosat1 image 2011 - geological map 1: 100,000 geological box counting is one of the most widely used method in fractal studies snd in this research has been implemented. the different between the fractal dimension that obtained in different periods show that they will be more changes occurred in the phenomenon. in addition, this study show the ability of fractal geometry to identify the changes that happened in landforms. result the results showed that natural sciences, such as geomorphology are face to inherent variable that are not very repeatable or predictable and have highly sensitive to initial conditions. since geomorphologic landforms have a special sizes and dimension, the spatial arrangement of these shapes to each other can determined many effective factors in their formation that we cand identify these effective factor accurately. behavior of landforms in nature is non-linear and can be analyzed by statistical methods. wind landforms set of complex systems, which sometimes act in a rotational manner and at a time when the irregularities leading to the order. this complex behavior is contrasts with the simple laws of physics and is nonlinear and dynamic. in this study it was observed that mathematics is a powerful tool to describe landforms and processes of in nature. because of the size and dimensions of the special landforms they could analysis by mathematics and statistics and the following factors in their changing were studied. in this study, the fractal theory in geomorphology and particularly in landforms analyzed exactly and were used and it could give us satisfactory results by mathematic and statics. the fractal dimension of landforms was studied. in addition, this study showed the ability of fractal teory to identify the changes that happened in landforms.