GEOGRAPHICAL RESEARCH
Year:2012 | Volume:27 | Issue:1 (104)|Papers Count:10

In this study, frequency and location of frontogenesis related to heavy rainfall have been analyzed using environmental to circulation approach. Based on the threshold of upper 99 percent, we selected 125 days of the super and overall heavy rainfall from IRIMO data base (included 1437 synoptic, climatic and rain gage stations from 21/3/1961 up to 31/12/2004). Frontogenesis frequency and their locations have been detected from 0o to 120o E and 0o to 80o N in five levels (1000, 925, 850, 700, 600 and 500 hPa level) at 00:00, 06:00 and 12:00 UTC. The results of this study showed that frontogenesis at 500, 600 and 700 hPa levels and its subsequent instability do not affect Iran very much (with an exception of 18:00 UTC in 500 hPa Level). Frequency analysis of frontogenesis at 850 hPa level indicated that in comparison to surrounding areas, Iran is more active. Generally, frequency of frontogenesis is highest at 925 and 1000 hPa levels over Iran.

Iran is a country which has experienced the Nomadism because of its own geographic position; in particular from north and eastern north it has been faced with the entrance of nomadic tribes and has accepted the first social, cultural and political effects. The nomads have played an important role in keeping an eye on Iran's boundaries in the past. The most of governments which have governed on Iran have had a nomadic source, meanwhile, their relationships with central government is very important. These tribes have been always considered as a danger for the government because of their farness from center. In such a way that the government's influence in it has been so little in most eras and they have been self-governing particularly, so that they only gave a hand in the times of war to dispatching military force. In the past periods, the existence of these nomadic tribes in Iran's boundary regions had caused a lot of troubles for Iran's governments. Their seasonal moving and easy change of the allegiance would cause the frontiers more and more impermanent and unclear. The purpose of this research is to investigate the effect of nomadism on Iran's western boundaries. The hypothesis of this research is that the lifestyle of nomadism in Iran's western regions has made postpone in the process of political boundaries genesis in that part of country. The methodology used in this research is an analytic descriptive one.

Flow river forecasting plays an important role in designing, management, and utilization of water resources. The main object of the research is to study the possibility of forecasting and monitoring the Northern Karon rivers (Armand and Bazfat) discharge by using modern simulation methods. In this research, Armand and Bazoft discharge variations was investigated. In this regard, Monthly data of SOI, NAO, and ENSO in the regions of NINO3, NINO3.4, NiNO4, and NINO1+2 for the period of 1968 to 2007 were collected from the National Center Environmental Prediction (NCEP). Daily discharge data of Armand and Morgak hydrometric stations were prepared from Niro ministry data center. In order to have the optimal designing of artificial neural network architecture, for Discharge River forecasting on the basis of climatic signals, genetic algorithm method was used. The results show that ENSO signals in NINO1+2 and NINO3 regions are the most effective signals on Armand and Bazfat discharge variations. Thus, ENSO signals can be used for forecasting the Northern Karon rivers discharge.

Sustainable tourism development is a process that interacts with host life quality, visitor′ demands and preservation of natural and human environment. In the sustainable tourism approach, with an emphasis on the key function of hosts and guests'' perception to understand and constantly evaluate their beliefs and imaginations toward tourism development in destination, subjective indicators are used and there is an attempt to extend this kind of indictors. The objective of this research is to evaluate tourism development in Tamashkel County in Tonkabon within sustainable tourism development framework. The research method applied was giving questionnaires to three key groups of local inhabitants, visitors and officials. The findings of research indicate that the process of tourism development in Tamshkel County results in degrading resources, dissatisfaction of visitors and negative perception of host and that it has a great distance from rural sustainable tourism development indicators. Therefore, it follows an unsustainable pattern.

Nesar anticline is located in west of country and in north of Kermanshah province. Pattern of drainage network at each district is under the effect of various factors which has intensive anomaly in Nesar anticline in spite of its low area and this in turn reflects different lithology, tectonic effects and slope changes in anticline. The goal of this research is the recognition of influential factors and degree effect of each factor in anomaly of drainage network pattern of Nesar anticline. In this research, at first in respect to the kind of drainage pattern, the anticline is divided into 6 parts, then lithology, tectonic and topography slope were evaluated and analyzed as main variable. Results show that lithology is the main factor of anomaly of drainage pattern in Nesar anticline. The parallel pattern in hard constructions (lime) and areas of full of slope has taken shape and dendrite pattern has evolved in weak constructions (Gourpi-Pabdeh) and areas with lower slope. Morphometric figures of drainage network are influenced by constructions material and slope level. Age of constructions has no effect in shaping pattern of drainage. Landslide and tectonic interferences are other influential factors in anticline drainage pattern. Tectonic by omitting Asmari and outcrop of Gourpi construction and Pabdeh play main role in shaping dendrite pattern in parts 4 and 5, but in other parts has little effect as displacement and interrupting drainage network by cracks.

The present paper that was based on the documentation method and secondary analysis of data from censuses Population and Housing Statistics Center of Iran, intended to thoroughly analyze the effects of these factors in rural migration on rural aging population; in addition, the increase in aging of Iranian employees in agriculture sector and its consequences were examined. Results have shown that migration from the village to city is one of the most important reasons for aging of rural population in Iran. Moreover, during the years 1345 to1385, the agricultural sector employees have become about 5.7 years older, while the total employees have become only 2.2 years older. The results of this review consider migration of human resources from rural areas as one of the most challenges of rural development from the viewpoint of sustainable development in Iran that weakens the rural economy and culture and makes agricultural employees older and have caused the instability of the situation in rural areas.

In the current attempt, the relation between precipitation change in Southern coasts of Iran and sea level pressure data of NCEP / NCAR database were investigated through correlation method using environment to circulation approach in the period of 1960-2004. After calculating the correlation matrix between the percipitation amount and pressure, the precipitation-pressure correlation map for each station was plotted. Comparison and analysis of the resulting maps revealed that regardless of minor differences, this area has a two-modeled nature. Results showed that precipitation in southern coasts of Iran is more affected by two precipitation- pressure patterns of Asian monsoon and Sudanese, which is coincided with the location of installation India monsoon circulation and Sudanese monsoon regime. On the other hand, the results of this research showed that precipitation change and its occurrence at southern coasts of Iran in sea level is affected by predominance of the monsoon regime on Southern of Asia and Sudanese circulation pattern. Hence, precipitation change in Southern coasts of Iran is more related to the decrease and increase of pressure rate in action field of this pattern.

Quantifying urban landscape is fundamental for monitoring and assessing ecological and socioeconomic consequences of urbanization. Expansion of roads is a significant factor driving urban landscape change. The aim of this research is quantifying impacts of roads on Isfahan city landscape. To achieve this aim, land use map of Isfahan was created in 6 classes: urban, green spaces, agricultural, bare land, road and water. Combining gradient analysis with landscape metrics were used for analyzing landscape pattern. Landscape metrics were computed along a 15×3 km2 east-west transect cutting across city center with a moving window technique. In this study, we used 3 metrics: percentage of landscape (PLAND), Patch Density (PD), Largest patch index (LPI). To assess road impacts, urban class was merged with road, and then comparing these two transects, road impacts were assessed. The results showed that the urban landscape pattern of Isfahan was greatly changed when road corridors were merged with urban patches. Merging road and urban patches resulted in a sharp reduction in patch density and a rise in largest Patch index. Landscape patch density is significantly correlated with road percent coverage and the most important effect of road corridors on urban landscape is increased habitat fragmentation.

In spite of considerable increase in the resolution of general circulation and regional models, none of these models are capable to predict and downscale the meteorological outputs in the scale of meteorological station. In this regard, different dynamical and statistical models have been developed for downscaling outputs of GCMs. In this paper, grided meteorological outputs of General Circulation Models (ECHAM4 and HadCM2) and 18 IPCC scenarios have been downscaled over Iran for future periods by MAGICC-SCENGEN model. Each period is a 30-years period centered on a year. The range of periods is from 2000 (i.e., 1986-2015) to 2100 (i.e., 2086-2115). Result of HadCM2 model shows a % 2.5 decrease in precipitation until 2100 but ECHAM4 shows a %19.8 increase for this period. Another difference between results of these 2 models is that HadCM2 predicts an increase in precipitation in next decades for Mazandaran, Golestan, Khorasan Shomali, Khorasan Razavi, Semnan, Tehran and some parts of Guilan and Ghazvin provinces, while ECHAM4 predicts a decrease for those regions. HadCM2 predicts precipitation decrease for southeast of country (Hormozgan, Kerman, Bushehr, south of Fars and some parts of Sistan and Baloochestan), but in ECHAM4 those regions will have precipitation increase in similar period. About temperature, both HadCM2 and ECHAM4 agree in temperature increase in next decades for all provinces. These 2 models predict, on the average, 3 to 3.6oc increases in temperature until decade 2100. Maximum increase in decadal temperature in ECHAM4 and in 2100 decad is about 1oc more than HadCM2 and both of them are in conformity with each other in spatial distribution of decadal temperature.

In recent century, sustainability has been the most important feature especially in economic, social and environmental issues. So that it has always been the main concern of regional, national and even international planners; as the consequent challenges were the main threat to achieving sustainable development of human society. In this study, all aspects of sustainability including environmental, cultural, economic and social aspects were considered so that in this way we can better explain the sustainability condition of Zabol city and determine the best stable neighborhood and unstable challenges. Acoording to research findings, some districts of Zabol are far from the real sustainability, and some districts have been able to have a step toward sustainability by creating appropriate infrastructures. Among which one can point to Nasional district of Zabol that has many of the qualitative and quantitative indicators of sustainability and certainly in a near future, it can be named as a real sustaintable residential district in Zabol.