عنوان مقاله [English]
Exploring the concept of scale and it’s explaining in geomorphology
There are several fundamental issues in geomorphology. These include scale. There are a special relationship between landscapes and the components of their forms, which indicates a kind of scale continuity. These rules and scale relations prevail not only at the level of perspectives but also at the level of land forms, and due to the complexities of this concept in geomorphic studies, have received less attention. However, the accuracy of many geomorphic concepts is related to such concepts. Usually in scale geographic literature, a simple ratio is defined that is often used to represent the extent to which a phenomenon is reduced to its actual ratio in the maps but the reality is that scale in geomorphology involves a broad concept and any subject that expresses a ratio is in the conceptual realm of scale, and few geomorphologists have pointed to this important issue.The scale plays a vital role in geomorphology, both in the realm of performance and in the field of epistemology. For example, in the field of soil geology, the chemical processes of particles change with the reduction of dimensions to two microns, and the properties of their elements generally change and so in the geography of clays, which can only express the size of each substance (not their sex), chemical performance is doubly important many of the vital and mineral reactions in the soil depend only on the size of the elements, not the elements themselves. So in statistical analysis, relationship measurement, that is, correlation techniques, is one of the concepts of scale, because when you write a linear formula or other form of correlation, the ratio between the two variables is actually defined. Therefore, scale is one of the fundamental issues that, from a theoretical point of view, leads to the design of other concepts such as universality, fractal, river networks, geoallometry specific scale, and so on.
Materials and methods
To achieve the advanced concept of scale in geomorphology, after a relatively extensive search of books and articles in this field, several geomorphological pioneers who used this concept in the field of scale in their work with a special theoretical innovation were selected . These seven were:
John .Charles Doornkamp ، Geographer from the University of Nottingham, England
John Tilton Hack , American geologist and geomorphologist
Evans, a geomermologist from Durham University in the UK and a graduate of York University in Canada
Donald Lawson Turcotte , Geologist , Cornell university,USA
Benot Mendelobert, a French-American mathematician from Yale University
Dave Rosgon , hydrologist and geomorphologist from the Universities of Nevada, Montana and Colorado
Leila Goli Mokhtari Geomorphologist from Sabzevar University, Iran
Then, by selecting the books and writings of these researchers in this field , began to study, separate and classify their opinions then repetitive content, sometimes shared by them, was removed. In the final stage, began to extract new found writings that were specific to each of them, and their content was summarized and analyzed as an opinion.
Results and discussion
In the first step of the research, the most important result that has been achieved in terms of time is the way of developments and the volume of work that has been done in this field. Review of the researchers' scientific papers shows that studies of the scale of the trend have increased in the last 30 years and theoretical innovation in the application of this concept has become increasingly complex. In
The second step in the importance of thematic classification of the opinions of the seven researchers was a semantic difference with the subject of the scale. Although all the writings can be called scales, but the novelty of the work of these seven researchers were that they presented completely different and original interpretations and concepts. For example, the specific scale of Evans' innovation , Invariance scale of turcotte or geoallometry of Golemokhtari's theoretical innovations. With these initial achievements, the views of these seven researchers are now described and analyzed.
Scale in general is called the actual size of a phenomenon in geography which is usually shown as a deduction or as a line. Fraction in numerical scales can be expressed with a fixed face and multiple denominators Such as maps 1:50000, 1:250000 and so on. Another pattern of scale display is expressed by showing a fraction with a different face and a fixed denominator, which is called gradient, such as two in a thousand or five in a thousand …. , the ratio in geometry is expressed as an angle and is called a tangent.
In the last three decades, geomorphologists and related sciences have been able to apply some of the complex concepts of scale in their work that named with specific titles. These concepts include Universality scaling, which is due to hacking, and the concept of "specific" which is due to Evans' work. Turcotte defines the concept of Invariance scale (meta-scale) and Mendelobert's fractional scale, Rosgon, the thematic scale and Goli Mokhtari , can be considered the creators and determinants of scale in geoallometry.
Finally, it can be said that each researcher has presented different concepts in the discussion of scale but the common matter between these researchers is the deeper understanding of the importance of the earth and the phenomena of geomorpholog and it must be confessed that the depth of their understanding of geomorphology has played a leading role in their theoretical inovation.
Finally, it can be said that each researcher has presented different concepts in the discussion of scale but the common matter between these researchers is the deeper understanding of the importance of the earth and the phenomena of geomorpholog and it must be confessed that the depth of their understanding of geomorphology has played a leading role in their theoretical inovation.Finally, it can be said that each researcher has presented different concepts in the discussion of scale but the common matter between these researchers is the deeper understanding of the importance of the earth and the phenomena of geomorpholog and it must be confessed that the depth of their understanding of geomorphology has played a leading role in their theoretical inovation.