نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 50 (تابستان 1383)

The conversion of satellite data into vector formats requires classification and interpretation of low-level information while maintaining accuracy of measurement and spatial detail; on the other hand rasterizing a map (which is consistent with satellite data) means decomposition and degradation of high-level cartographic information. Therefore, in combining and integrating image and cartographic data in a data structure, such exchanges should be considered.

River terraces are important components of natural landscape, and among the key elements in the study of geomorphic features of river phenomena in regional and local scale as well as trend of river power changes in relation to different factors in the course of time. These phenomena, as river forms, represent the level of flowing waters in the past and river performance in response to changes in the characteristics of several factors. Regarding the activity of processes. and influenced by changes and disturbances in conditions, the river sometimes has to cut its bed and create benches parallel with its longitudinal profile. The river terraces, which provide successive changes in beds of river flows, are in fact considered the best means for surveying the past history of regions in terms of the type of changes and rivers’ reaction to such changes in different times. Considering such an important feature, these phenomena are among the topics discussed in different sciences of the earth, especially geomorphology and soil science. For soil sciences, the terraces are: smooth surfaces with mild slopes formed by heterogeneous pebbles whose presence along the rivers provides a relatively stable place for soil formation. For geomorphology, river terraces, as the most important geomorphologic forms, are results of the operation of water flows which have been formed by fluctuations and changes in various factors, such as changes in the energy of morphodynamic factors. River terraces formed and developed by alternation of the processes of destruction and sequestration in the rivers are usually seen as slope cuts on either side of the rivers’ banks or only on one side of them. Generally, it can be said that the formation of terraces around the bed of rivers suggests adjustments and changes in longitudinal profile of rivers in response to changes in the type and amount of exchanges related to the location, special time and evolution of longitudinal profile of river in order to adapt to the new conditions. Despite the importance and major influence of tectonic activities on river alluvia and formation of terraces, research in this area has been very trivial. The difference in the shape of channels and variation in the response of rivers to such activities (due to difference in flow rate, type and amount of bed load) have possibly been the main reasons for complexity of the subject and, as a result, a decrease in the number of studies in this field

In the last four decades, almost all of the Qanats of Borkhar in northern Isfahan have dried up. Agriculture-oriented surface water wells are converted into semi-deep and deep wells. Currently, due to the water deficit of these wells, the agricultural water supply of this plain is confronting a crisis. The type of agricultural water resource management in Borkhar has affected its development. Lack of water resources and absence of proper management of these resources have, along with other factors, changed the use of agricultural lands. This paper has utilized national and international scientific documents and reports, field study, interviews and results of questionnaires. The results of research and data analysis show that due to water deficit and lack of proper management of water resources in the production, transportation, distribution and consumption processes, agriculture in Borkhar has become unstable and is heading for destruction. Close cooperation is needed between the local people and the Water Organization regarding problems of water resource management. Land use changes in the future must also be carried out by study and research and a specific plan, and combination of traditional and modern techniques must be utilized in Borkhar.

Most countries need maps of 1: 50,000 or smaller scales, such as 1: 100,000 and 1: 250,000: 1, for use in civilian constructions and military activities. In design of ground military operations, most of the maps used are of 1: 50,000: scale, and for this reason, these maps should be accurate, up-to-date, reliable and timely (prepared instantly). Throughout the world, the main source of data for preparation of 1: 50,000 topographic maps are up-to-date photographs. Due to a number of technical problems and other issues described in the paper, the production of linear analogue or digital maps of 1: 50,000 directly and by using aerial photographs in appropriate scales is not practiced in Turkey. Instead, first analogue or digital linear maps are produced on a scale of 1:25,000 using aerial photographs, and then topographic maps of scale 1: 50,000 are derived from 1: 25,000 maps using the generalization technique. It is also possible to produce topographic maps of 1: 50,000 scale directly using Mono or Stereo photographs with good resolution available in the market. In this research, the methods of production of topographic maps of 1:50,000 scale from aerial photographs in appropriate scale and Spot Satellite’s panchromatic stereo images have been compared and examined in terms of time and speed of production, the main components related to cost, the ability to discover and interpret 330 different features existing in the standard for preparation of 1: 25000: 1 and 1: 50,000 maps the results’ accuracy, comprehensiveness and interpretability and the need for ground completion of the results obtained from the two methods.

What is known today in our country as handicrafts is a strong tree deeply rooted in history, and many of its branches are as old as human existence on this planet, gradually formed through centuries according to the needs, utilization of human intelligence and abilities as well as application of facilities around him. The production of handicrafts is not limited to the Third World, poor or crowded countries. The nature of these arts is such that each society considers them from its own point of view. In poor and densely populated countries with a great number of workforce, these products are considered as workforce-demanding and cost-effective industries that can be a solution for many economic, social and political problems, and in advanced countries, along with the ultra-modern industries, the handicrafts industries and arts, and even their consumption, are known to be the treatment of many psychological illnesses, and because of the connection these arts have with the nature of human beings, they are used as relievers of human mental pains. Our country, due to the breadth of lands, diversity of climates, glorious history, culture and civilization and intelligent people, enjoys all the necessary factors and relative advantages, so that it is regarded as one of the three focal points of handicrafts in the world along with China and India, and considered by experts and practitioners in the field as the first country in the world in the field of handicrafts in terms of diversity and variety of products. (Tolu’e Behboud, 1996) Traditional Iranian arts are genuine “people's arts” that arise from the pure nature of people. These arts have long penetrated in all aspects of people's lives and have become inseparable.

GPS has become an important geomatic instrument today. Due to multiple applications of GPS in various areas such as surveying, map preparation, earthquake control and navigation, GPS has gained millions of users around the world. In the international arena, a great number of extensive GPS plans have been implemented. In this paper, the author provides a summary of the major aspects of GPS operations and earthquake control in India, and concludes with determination of the general lines of important issues to be addressed.

The era of paper maps is gradually coming to an end, and these maps are replaced by integrated databases that enable cartographs to store and update data. The result of this transformation will be the availability of less expensive and more up-to-date maps, both in paper and in digital form. Since the beginning of the new era, art, like science, has received considerable attention in production of maps. Obviously, maps record the discovered features of the surface of the earth accurately and comprehensively. However, preservation of the beauty of the map as well as recording of cultural heritage are not forgotten, because the thoughts of each community are involved in most methods of mapping. This fact still holds; but just as any society is undergoing change, cartography is also experiencing transformation. We are in the middle of a revolution in map production methods.

The inner layers of the earth are the same as the inner parts of a peach. The deeper layers are denser and are often separated from each other by sharp sections. There are three types of large divisions. 1) Shell 2) Coating 3) Dense core, which is likely to be of iron or nickel (Figure 3-5). As we have expressed before, there is a shell, brain and holes on the surface of the earth.

The purpose of this research is to model the tidal phenomenon globally for all free waters of the world. In order to model this phenomenon, harmonic analysis method has been used. For the formation of the model for elevation of instantaneous level of water, nine main tidal components (Ssa, Mm, Mf, MO1, P1, K1, N2, M2, S2) have been taken into account in calculations. In order to form the cosine and sine coefficients of the mathematical model, a series of orthogonal and unit functions have been used in the study area. We used all the raw and main data of the TOPE × / POSEIDON altimeter satellite to estimate the unknowns. The information gathered by this satellite has been sent to us by the US Space Agency in a period of 10 years in the format of 117 CDs. The accuracy of the data collected by the TOPE × and POSEIDON altimeter is reported to be 2 cm and 3 cm respectively. In order to estimate the accuracy of the models derived from modeling calculations, the following tests are performed. 1 - Comparison of the results of the instantaneous water level elevation model with satellite observations in a period that has not been considered in modeling calculations. 2. Comparison of the model of mean water elevation with the models calculated by R.H.Rapp, 1994, and M.C.Kim, 1998. 3 - Comparison of the model of domains of tide major components of O1, K1, M2, S2 with the calculated values for the domain of these components in the position of 215 tidal stations selected throughout the world. The average accuracy of the instantaneous water level elevation is estimated to be 1.677 mm. The mean differences from comparison of the instantaneous water level elevation model with satellite observations in a period that did not participate in modeling is calculated to be 13.25 cm. The average difference between the model of mean water level and the model by R.H.Rapp, 1994, is 13.01 cm. Furthermore, the mean differences obtained from comparison of the model of domains of components O1, K1, M2, S2 with the values provided for the domains of these components in tidal stations were 05.26cm, 05.76cm, 07.08cm, 11.48cm, respectively.

Shahrestanak, with an area of about 135.15 km2 is amongst the sub-basins of Karaj basin, located at the southern part of the central Alborz, 55 km northeast of Karaj city. Hydrological and geomorphologic studies and identification of potentials in the region can make the desirable and rational exploitation of natural potentials in developmental plans possible.
Since the beginning of the year 1993, the region was examined several times, and after initial acquaintances, specialist and local surveys in terms of physiography, geology, soil science, land potentials (mountainous land types), meteorology, hydrology, erosion, sedimentation and vegetation were carried out, as well as a brief overview of Chalous – Tehran Highway and the watershed management operations of the past and its outcomes. Proposals were raised for construction of “Bandarsars”, Fountain-Water storage in soil and traditional Reservoirs, plan of drinking water transfer from Shahrestanak to Tehran, protection and sanitation of springs, creation of recreational bases (with regard to construction of the Tehran - Chalous highway), and modification and change of the roads’ course because of the slip and break and the consequent dangers along the roads. There are views on how to prioritize the implementation of projects that vary according to the conditions and obstacles in the area, financial resources and administrative possibilities and constraints. Plans that are more comprehensive and more inclusive in terms of providing and increasing security and revenue are of greater priority. The inclusive quality of plans is suggested considering people’s participation in terms of building, maintaining and exploitation of the benefits of plans.

Since immemorial past, drought has been one of the dangerous natural disasters for human life. As it is seen in historical texts, this phenomenon has always caused many social-economic changes, such as wars, famine and immigration. In this research, the wet and dry periods of some of meteorological stations of Lake Urmia Basin, located in the northwest of Iran, have been analyzed. For this purpose, first the stations of Urmia, Tabriz, Saqez and Miandoab have been normalized using yearly methods. In other words, the precipitation was turned into a standard score (Z-Score). Then, the intensity of either of dry and wet periods was defined in two classes: weak to average dry (-1.5 <z <-0.5), severe dry (z<-1.5), weak to average wet (+0.5 <z <+1.5) and extreme wet (z> +1.5). In addition, the roughly normal period (-0.5 <z <+ 0.5) was considered as a period neither significantly wet nor suffering from drought. In the next step, a Run Test was performed on monthly precipitation data and their homogeneity was confirmed. Subsequently, using time series method (SARIMA), the monthly precipitation of these stations was modeled and predicted for the future (based on the most appropriate model) until 2002. Finally, according to the predicted values, the degree of severity of the year’s wet-or-dryness has been determined. The results of the study show that the annual precipitation of this basin in the years 2001 and 2002 is almost normal and will be accompanied by an upward trend and exit the state of drought.

The Earth's climate is not constant; the range of changes is vast and includes from warm and humid periods to the glacial. Rocks and sediments carry many signs of the past climatic changes with them. Salt deposits, red soils, kaolin, lime sediments and corals are evidences of hot climes, and glacial sediments and deposits and river terraces are evidences of cold climates. The dating of such evidence suggests that some of these changes have occurred in long-term and some others in short-term. Mesozoic heat lasted for millions of years, while glacial and interglacial periods of the Pleistocene have lasted only thousands of years. Why and how do such vast changes occur? With a systematic approach to the Earth, it would be easier to answer this question. Earth is a system in which a set of interconnected processes act on a large spatial and temporal scale, so there is not a single cause, and necessarily a set of causes are effective. In general, climatic conditions are the result of a mutual and complex interaction of two important sources of energy, namely solar energy and the Earth’s energy. Radiation from the Sun is the first source of the Earth’s energy that drives the Earth's fluids (water and atmosphere). The internal energy of the Earth is the cause of movement of plates; this movement causes continental displacement, formation of volcanoes, rise of mountains, and large changes on the scale of the sea level. So far, several views have been laid down in explaining the causes of climate change, but none of them has definitely answered the questions; each has described a part of the phenomenon. With the emergence of the theory of tectonic plate, this theory found a special place in explaining the causes of long-term climate changes.