What is Map Projection?
Mahdi
Modiri
Associate Professor of Urban planning, Malek-Ashtar University of Technolog
author
text
article
2003
per
The earth is spherical, or in a better estimation, spheroid (pseudo-sphere) or elliptical. A map should represent the 3D land on a two-dimensional surface as accurate as possible.In producing maps, it is important that we achieve a clear and distinguished relationship between realities on the Earth and corresponding points on the map. Therefore, making any map must start with a map projection system. There are dozens of map projection systems that one can choose from among.
The systematic and orderly process of transferring points from spherical surface of the earth to a flat surface (map) in a way that spatial relationships are preserved is called a map projection system. The process of map projection system is implemented through application of geometry and mathematical relations. In terms of geometric concepts, the earth is a spheroid (pseudo-spheroid) which is slightly compressed.According to another definition, the mapping of the meridian and the earth's orbits as a network called the Geographic Coordinate Network on a flat surface is called the map projection system.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
2
8
https://www.sepehr.org/article_28311_bbe256396a9fab5c7293e564dd50268e.pdf
An Introduction to Military Geography (Part XIII)
Seyyed Yahya
Safavi
Assistant Professor, Imam Hosein University
author
text
article
2003
per
Places and StructuresUrban spots or areas refer to parts of the earth with a population density equal to or more than 300 inhabitants per square kilometer and the average number of buildings of at least one per hectare. This definition covers all small towns and suburbs as well as small and large cities with different shapes, whether adjacent to each other or at distances from one another, which are based on smooth or rough ground.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
9
11
https://www.sepehr.org/article_28312_25cdcdce2838a2e855db9ef857dca0d0.pdf
Virtual Analysis of the Form and Process in Topographical Maps on the Scale of 1:50000
M.H.
Ramesht
Associate Professor, University of Isfahan
author
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Nojavan
Instructor at the Islamic Azad University
author
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Enteshari
Instructor at the Islamic Azad University
author
text
article
2003
per
In geographic studies, one of the main concerns of geomorphologists is the achievement of analyses that can be explained within the framework of landform and geomorphic processes. This issue is not possible without field surveys and direct observations, especially for small-scale phenomena, and although visual remote sensing is able to help solve the problem to a degree, availability of images and their utilization are not as easy as access to 1: 50000 topographic maps.This paper, which is the result of a research project at the Islamic Azad University, describes a method that studies and analyzes the form of contour lines in topographic maps in order to explain the geomorphic forms and processes that create them, and to determine the principles and basics that are based on formic assessment of contour lines in topographic maps.
To achieve such principles, the assessment of thirty regions in terms of field surveys, analysis, recognition and classification of landforms and contour lines and the relationship between landform and the type of contour lines have been carried out in the framework of an experimental comparative method. The most important result obtained in these studies is that the form of contour lines in topographic maps indicates the spatial content, which means that it is possible to recognize the form and process as well as the forming material of sediments of a region without possession of geological information by relying on certain theorems and analyzing the morphology of contour lines in topographic maps.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
12
21
https://www.sepehr.org/article_28313_f60046628509d0d2e59c101001ffa799.pdf
Application of the GPS Technology in Measurement of High Structures' Displacement Due to Weak Winds
Roghiyyeh
Golvari (Translator)
author
text
article
2003
per
The global positioning system (GPS) has been developed for military purposes, such as single-point position determination and navigation. The first civilian GPS applications were for geodetic purposes including baseline measurement using differential methods.When tall structural systems are controlled, we can introduce GPS technology as a method of measuring displacements.In this paper, two experiments were performed to evaluate the accuracy of measurements using GPS. In addition, an assessment of the GPS capability to measure the smallest movements of the Stuttgart television tower and the high industrial chimney of the Opole power plant due to weak winds has been presented.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
22
24
https://www.sepehr.org/article_28314_9aa04dffd9ae56ec6b8927430a408e3d.pdf
Short-Distance Photogrammetry in Industrial Environments
Khosrou
Khajeh (Translator)
author
text
article
2003
per
Application of photogrammetry in industrial environments requires full automation capable of functioning without human supervision. The main elements in such systems are the high resolution of cameras, the strength and durability of cameras in terms of their geometric shape and structure and the frequency of their response. In this regard, a series of modern cameras have been designed that provide both 2000 × 3000 and 70000 × 40000 sensors and so remove the usual obstacles that preclude the acquisition of precision and show great potential for high precision metrological 3D images.
The high efficiency and features of the 3D metrology system have made it possible for the few but highly skilled producers to find a place in the global market. Most of these systems can be characterized by the following features: Specific objectives (reflective targets, light emitting diodes (LEDs), high contrast object characteristics, points and patterns image, etc. that are used to produce signals representing the desired points in order to achieve optimal contrast.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
25
27
https://www.sepehr.org/article_28315_e9267e632d937eecf41e0fc9e1eb0500.pdf
Geographic Data in Computers
Seyyed Ali
Ebadinejad
Member of Faculty, Police University
author
text
article
2003
per
Geographic Information System (GIS) was introduced for the first time in Canada in the early 1960s, and since then its users increased day by day until it became global in the 1980s.Large institutions, and even small companies whose number of staff do not exceed the number of the two hands’ fingers, have established national or global geographic information systems to be able to provide valuable information and data to public and private departments and companies. In this way, they prevent unnecessary repeat of work during collecting data and digitizing maps.Today, most of the papers in this science reflect the results of field experiments and pay less attention to the principles of this science. As a result, it's often observed that experts are very capable at the advanced stage of science but weak at its fundamental stage.
Unlike most data types that are commonly used in new information systems, geographic data is of particular complexity, since these data should include information about location, probable topological connections and recorded characteristics of certain matters. The topological and spatial aspects of the GIS used in design and mapping, and the means of distinguishing between these systems and a new system are among the information that have applications in various fields such as banking, secondary research, booking of airplane tickets and recording medical cases.
Geographic data are connected to certain points of the earth’s surface based on standard coordinate systems. If the subject under study relates only to a limited area, the coordinate system can be purely local, otherwise it may be a visual network at the national or international level, such as the Mercator Coordinate System, which is confirmed by everyone in the field. Geographic data are often recognized as a geographical example of "topics" and phenomena. All geographic studies use phenomenological concepts such as city, river, flood plain, limits of classes of plant species and soil continuity as the main components of the analysis and synthesis of complex information.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
28
31
https://www.sepehr.org/article_28316_07cd61ef1ca5de4ba7e191eff9afacf3.pdf
An Analysis of Livestock Grazing and Watershed Management in the Nemieh Territory of Asalam Tabesh Nomads
Nasrallah
Mowla'ei Hashjin
Assistant Professor, Department of Geography, Islamic Azad University
author
text
article
2003
per
The nomadic animal husbandry system of Iran is one of the oldest and most important methods of animal husbandry breeding in the country. The basic features of this system include its main reliance on natural pastures, so that livestock is fed naturally in the territory of the Ile (tribe) using summer and winter ranges.Change of rangeland ecosystem as a result of the grazing of various types of animal husbandry is inevitable, and if this change is not supervised and controlled, it will lead to soil erosion, a steady decline in the vegetation surface cover of rangelands and risk to the natural environment and life of nomads.Grazing management has been seeking to interfere in the changes through control of intensity and time of grazing in order to maximize the production yield by achieving quantity and plant composition, minimizing environmental degradation and profitability for livestock breeders.Considering the importance of natural grazing of animal husbandry in rangelands on the one hand and the necessity of preserving the natural environment and watershed management on the other, and with the aim of paying due attention to livestock grazing management in watersheds, in this paper, based on descriptive research method and using documentary and secondary methods as well as field studies in the form of observation and analysis of questionnaires, analytical survey of livestock grazing and watershed management have been conducted.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
32
40
https://www.sepehr.org/article_28328_021a781a27daf0870564d7bcd0a4fcc5.pdf
Interpretation of Aerial and Satellite Images (Part X)
Hamid
Malmirian (Translator)
author
text
article
2003
per
Archeology deals with historical and prehistoric study of people by analyzing their remnants, especially the remains discovered through excavation. Archeological exploration studies the evident historical monuments of early societies. The existence of these places is often known through historical documents. Particularly important is the interpretation of aerial photograph in determining places not mentioned in history. Surface and subterranean features significant for archeology are identified by using aerial photo interpretation. Surface features including ruins, gates, stone columns and other surface signs can be directly seen. Examples of visible ruins are:
Rocky buildings such as Stonehenge (England), castles (across Europe), and Indian residences in the southwest of America; gates including bird-shaped and snake-shapes; circular wheels such as the Big Horn Drug Wheel in Wyoming, and other superficial signs including Indians’ pictures in Peru. The image (2-31) shows the Nazca lines. It is estimated that they were formed at least 1500 years ago and have a region of approximately 500 square kilometers. Many geometric shapes, along with narrow straight lines that are 8 km long have been found. Apparently they have been built up through removal of millions of stones to show the lighter earth tones of the ground below. Stones removed, the lines were piled up around the outer boundaries.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
41
44
https://www.sepehr.org/article_28330_c8ae6bbb7c5f6d2babee8835bceb665f.pdf
A Review of Iran's Population Indexes at the Outset of the 21st Century
Hosein
Hataminejad
Member of Faculty, Shahid Chamran University of Ahwaz
author
text
article
2003
per
Population geographic analyses dealing with relationships and interactions between human groups and geographic spheres are mainly based on statistical data. The existence of such analyses will be the prerequisite of any land allocation planning and organization of living space. There is no doubt that due to socioeconomic changes and especially changes in world political systems, it is not possible to accurately predict demographic indicators for the countries of the world.For example, Afghanistan's political transformations over the past quarter of century and possible future developments in Iraq have, and will have, significant effects on the structure and composition of population and its spatial movements across the country. In any case, the tables of the Index show the status of the indicators of Iranian population and their prediction up to 2015.
Table (1) shows the demographic changes of Iran from 1881 to 1996. As the figures in this table show, from 1881 to 1921, the population growth rate of Iran was very low and equal to 0.6%.Low levels of nutrition and health and higher mortality rates were major factors in this low population growth rate. From the years 1921 to 1941 (World War II), a steady growth in population is observable.In these two decades, the growth rate was about 1.5 percent. The current figure (2002) also applies to Iranian population.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
45
46
https://www.sepehr.org/article_28331_2c976ba8007f55abf281b6f7e223a6a9.pdf
Landslide of Bayanloo Village in Bijar Province
Bahram
Azadbakht
Member of Faculty, Islamic Azad University of Shahr-e-Ray
author
text
article
2003
per
The district of Bijar is located in Central Iran. This area is located on the urumiyyeh-dokhtar volcanic strip along the northwest-southeast direction. For a brief survey of the geological situation, the district of Bijar is subdivided as follows.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
47
48
https://www.sepehr.org/article_28333_4ea033ee9fc0908ba1212a06f82cffc5.pdf
An Analysis of Socio-Economic Structure of Fisheries Society of Bushehr Province
Ali
Haj Agha Mohammadi
Member of Faculty, Islamic Azad University of Najaf Abad
author
text
article
2003
per
The Bushehr province, geographically located along the vast sea shores with a population of more than 700,000 people, contains tremendous natural wealth and resources. This province holds the second place amongst the country’s provinces in terms of the number of fishing and floating boats. In this research, the socioeconomic and cultural characteristics of this province and it’s quality of productive performance is studied in relation to major factors such as individual and familial characteristics of fishermen, coordinates of the vessels and fishing centers and the technology of fishing at micro level, and then the performance of fishing in this province and its role in providing a significant portion of the livelihood of inhabitants of this province and creating employment in the area and the existing obstacles on the way of increasing the quantity and quality of fishery are investigated. Based on the findings on several fishing areas in Bushehr, the conclusion was made that if the distribution of fishing sites, the type of fishing, the cost of fishing equipment, the relationships within fishing groups, the atmosphere governing the life of fishery and the relationship of these groups with the Fisheries Organization are not paid due attention, there will be some problems, and it is not unlikely that the Fisheries Organization miss its goals in the long run.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
49
53
https://www.sepehr.org/article_28334_486d6e68daea7b1596c97b82cc9c8cc2.pdf
The Effects of Tang-Baragh Areas' Geomorphology on Locating and Implementation of Mollasadra Dam And Power Plant Project (Constructed on Fars Branch of Kor River)
Shahab
Ghahramani
Member of Faculty, Police University
author
text
article
2003
per
In this paper, we investigate the role of geomorphology in locating and implementing Mullah Sadra dam and power plant in the Tang-e-Baragh area on the Kor River. Determination of the final location of the implementation of this design and construction of the main body of the dam has been directly influenced by geomorphological study of the area. The upstream strait has been selected as the location of the project due to appropriate morphology of its floor and side banks compared to the main strait, which has an inappropriate morphology with faults, seams and gaps.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
54
57
https://www.sepehr.org/article_28337_04e532839768b105e7f9232198356720.pdf
Geology of Aligudarz City
Fereshteh
Tavakkoli
author
text
article
2003
per
The purpose of geological studies is to identify water-containing layers and basin reservoirs, as well as to determine the tectonic and geological structure of the area. In general, the Aligudarz plain and its southern highlands are located at the site of the major geological structural unit of Iran, so that it is bounded on the north to Sanandaj and Sirjan and on the southwest to Oshtorankooh, which is part of the High Zagros. Considering the geologically and structurally special location of the site, two examples are briefly described.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
58
61
https://www.sepehr.org/article_28341_af486db667aea42af5a985d477188258.pdf
Applications of IRS1C/1D Satellite Images - Part II
Mahmud
Mohebbi
author
text
article
2003
per
The advantage of repetitive Wifs data with poor spatial resolution is to estimate products. The analysis of Wifs data at different times indicates the phenological changes that cause the product to be isolated and can be used to identify the products and changes due to different stages of growth.The results of the Wifs data at different times show that different products are separated according to temporal and spectral characteristics. However, they show similar shapes like forest, city and deep water with their little or no changes. These shapes can be used to normalize atmospheric effects on temporal data needed for spectral profiles.
Scientific- Research Quarterly of Geographical Data (SEPEHR)
National Geographical Organization
2588-3860
12
v.
45
no.
2003
62
64
https://www.sepehr.org/article_28342_020ca7a6f9ef925b61c82e1138609963.pdf