JOURNAL OF GEOGRAPHICAL SCIENCES
Year:2005 | Volume:4 | Issue:5|Papers Count:9

Coast is a unique environment in which atmosphere, hydrosphere and lithosphere contact each other. Coastline is one of the most important linear features on the earth’s surface, which display a dynamic nature. Coastal zone, and its environmental management requires the information about coastlines and their changes. This paper examines the current methods of coastline change detection using satellite images. Based on the advantages and drawbacks of the methods, a new procedure has been developed. The proposed procedure is based on a combination of histogram thresholding and band ratio techniques. The study area of the project is Urmia Lake; the 20th largest, and the second hyper saline lake in the world. In order to assess the accuracy of the results, they have been compared with ground truth observations. The accuracy of the extracted coastline has been estimated as 1.3 pixels (pixel size=30 meters).  Based on this investigation, the area of the lake has been decreased approximately 1040 square kilometers from Aug-1998 to Aug-2001. This result has been verified through TOPEX/Posidon satellite information that indicates a height variation of three meters.

In this article, an attempt was made to study the Iran’s trend of temperature in recent decades, dealing with the relationship between this trend and increase in the amount of co2 in the atmosphere. First, stations with long-term data (since 1958: because data about co2 was available since 1958) were selected, then those which missed data in two successive years, were deleted from the dataset and all the study was conducted just with 12 stations. In this research, in order to determine the authenticity of the data, autocorrelation test and run test were carried out and nonparametric Mann Kendall test was performed to determine its amount, direction and significance. According to the results obtained, in the most stations under consideration (synoptic stations) the increasing of temperature with different rates was observed, for example Abadan and Shahrood were not observed trend, Esfahan, Tabriz and Kerman slight positive trend, Babolsar and Zanjan moderate positive trend, Yazd, Kermanshah and Mashhad some high deal trend, Tehran and Boushehr high trend and Anzali moderate negative trend observed. It was supposed that there is a same relationship between the trend of increasing temperature in Iran and the growth in the amount of co2 in the atmosphere.

Throughout the cold war the Caspian Sea was part of the Soviet Union’s overall security zone. Moscow attached so much importance to this zone that it totally ignored its southern Caspian neighbor, Iran, when it came to dividing and using the landlocked sea’s surface and bed. The central Soviet government strictly supervised the oil exploration and decided on the share of each of the three remaining states that made up its political and security sovereignty zone. The collapse of the Soviet Union in 1991 and the end of the cold war, however, re-defined power’s sole in international relations replacing geostrategic factors with geo-economic ones. That is why the world powers have now shifted their focus on getting access to energy resources. Lying between the Persian gulf and the Caspian Sea where 75 percent of the earth’s energy resources lie Iran enjoys a sensitive strategic and geopolitical situation which has tied its security to that of the region and the rest of the world. It therefore feels relatively immune from the superpowers’ security harassment knowing that its stability cannot be threatened seriously by others. At present the main hurdle for the exploration of the Caspian oil and gas resources is the lack of consensus among the now five states rimming the disputed body of water and the absence of a legal regime. This research attempts to clarify the geo-political situation of the Caspian Sea and how its new geopolitics play a role in the establishment of a legal regime. The global developments in the 21 st century are rapidly replacing the geo-strategic concepts and applications by their geo-economic counterparts prompting us to expound on the Caspian Sea region’s geo-strategic and geo-political features in the first place and then its legal regime.

By occurrence of climate change phenomenon and increasing of human’ s interference on global climate, two natural disasters mamely drought and flood have effected on different parts of the earth. In the recent years, our country was alternatively witness in occurring of floods and sever droughts in most of places, specially twice occurring of these natural disasters, improve each other as because of severe droughts, vegetative coverage and humidity of soil are spoiled that is facilitation agent for flowing destructive floods. On the other hand, occuring of severe floods have destroyed agricultural lands and lynching fertile soils and has amplified the effective of drought in these places. In a watershed which has high submergible potential, with an alternative and correct management, we can reduce the effects and damages of flood and use of it for increasing of water potential in this place, for example increasing of soil moisture and discharging of aquifer and increasing of water resources of lake of dams. For succession in these actions, an alternative and optimum flood risk management in that watershed is necessary. Kardeh watershed is located near Mashhad, and is considered as a case study. The risk of flown floods in this basin is modulated with three flowing types of statistical models: 1) probability Distribution Function, 2) Linear Regressive Model, 3) Auto Regressive Independent moving Average (ARIMA) Models. According the results of models testing, Probability Distribution Function couldn’t be able to model the floods risk in basin. Regressive Model doesn’t offer acceptable responses because it obeys from one general trend. ARIMA Time Series Models are tested in difference stages and finally, ARIMA (1, 2, 3) Model offer the best statistical fitness. According the conclusion from this research, by using of three statistical models, we can get a fit model for flood risk management for (Kardeh) basin, that It is usable into practical and conclusion of this research is expansible and usable for the other similar watershed basin.

This essay is a study on effects of tourism on change of land use in urban and rural hinterland areas of Lahijan. Urban quarters are divided into different groups regarding their locationconcerning tourist regions or their being located in communication cousrses. Effects of tourism on change of land use in thes regions are investigated withrespect to land price quality and its kind of use, and also quantitative and qualitative study of its residents. In rural region, role of tourism on change of land use is studiedregariding the location of villages and popilation movement. In this respect citydevelopment and its tourist regions in rural and also the amount that regions in rural suburbs and also the amount that villages asccept or send immigrantsis of special concern.

Sistan and Baluchestan province has experienced severe drought during last decade. This, in turn, has had an important impacts on rural life of the area. The impacts of drought have been more perceptible on the livelihood of area for two reasons: first, they have been dependent on natural pasture, and second, government have not had any specific program to support the livestock raising  against drought. The south and eastern slops of Taftan in Baluchestan had been the home of people in the past times, whom their livelihood were based on exploitation of natural pastures. They have changed their livelihood to Semi Nomadism since 1310, when the nomads disarmed and agricultural activities started. Changing the livelihood from Nomadism to Semi Nnomadism and sedentarization is a common phenomenon, but it should be gradual and indigenous. It should embody "socialized" stage, otherwise it may result in undesirable consequents The objective of this study is to investigate the livelihood's trends and changes of mentioned group. Following this, this paper studied the drought indicator of the area based on statistical data, and then analyses the collected data (based on field study) by using “spear man correlation". The result shows that, Semi Nomadism livelihood has changed as a result of drought as follows: groups that have some agricultural lands in "Sangan", have changed their agricultural activities and productions, and have maintained some livestock raising. Because the government have supported farmers against drought in some ways. Another small groups have changed their livelihood from Semi Nomadism to Transhumance, and are settled in "Shondeh" in the mountain area of Taftan. This two groups can continue their past livelihood based on exploitation of natural pasture by using recent rainfall and end of drought. Finally, the considerable number of population have lost their livelihood and have emigrated to urban centers. They did not have sufficient capital and skills for living in the urban centers and may encounter the urban problems.

South and South Western of Qom Areas are elevated and their altitude reach to around 3000m. Annual precipitation of these areas vary between 100 to 300 mm. Our studied areas face deficit in terms of its under groud water resources. The pastural areas cover about 771465 hectars, are mainly poor and become of overgrazing, they are over shadowed by rapid negative trend. The dominat species seen in the plains are halophyts. There are also a great variety at different plant species. Pedology, hydrobgy and climatology of Qom all are observed and it is notable that the plant covers in east of Qom are affeceted by soil and climate factors. But plants in southwest and west of areas are under influence of climatological elements.