Abstract:
Yedy Buluk basin is located on the east of Sabalan volcanic massive. Yedy Buluk River, drains this basin from west to east. This area is regardedas part of Caspian major system. In this study we have estimated rate of erosion sediment yield using PSIAC and Janson- Gembhart methods. In order to estimate erosion and sediment yield, we studied characteristics of geology, geomorphology, soil, climate, topography, runoff, land cover, land use, erosion condition and stream erosion in four sub-basins using aerial photographs, topographic maps, geological maps and field activities. Study of these factors in PSIAC method indicates that a total of four sub-basins have located in three erosion classes (with mean sediment discharge degree). Specific erosion in Yedy buluk basin was estimated at 319 m3/km2/year. To be confident with the results, we used Janson and Gembhart method for estimation of erosion.1- Associate Professor, Department of Physical Geography, University of Mohaghegh Ardebili. On the basis of this model the whole area of Yedy Buluk sub-basins was classified within two erosion classes (with low sediment discharge degree) reaching at 159.5 m3/km2/year. Factors of low or mean erosion rate and sediment yield in Yedy Buluk basin show high resistance of rocks (volcanic rocks), thickness of land cover, adhesiveness and permeability of soils, the nonexistence of accelerated land use (for example extensive plantation), low rates of erosion types (rill erosion, gully erosion, sheet erosion and stream erosion) and a gentle topographic gradient in most parts of basin. But if accelerated grazing intensifies, it will testify accelerated erosion.Azay-tapa is a small and single hill (65 m hight) in Jolfa township in Azerbaijan of Iran. In southern footslope of this hill, harvester ants, have most important role in formation of mosaic of surface features on slope in addition to effects on slope pedogeomorphic conditions in their nest replacing. This paper is based on this hypothesis that there is a relationship between ants and/or their nests and geomorphologic conditions of slope. Therefore, investigation on this relationship is an essential goal in this paper. Biogeomorphological methodologies, pedogeomorphic indices of slope and characteristics of harvester ant nests have been analyzed. The results showed: 1) Greater ant biomass occurred along two geomoephologic unit edges at the contact between slope and alluvial fan, 2) Out of biogeomorphological processes, this slope at present was affected from bioerosion and bioconstruction, and 1- Assistant Professor, Geography Research Group, University of Tabriz.The degree of correlation between discharge and precipitation parameters was not the same in all seasons. In autumn the highest and in winter the lowest degree of correlation was observed between discharge and precipitation parameters. There is also a difference of the degree of relationship between discharge and precipitation regimes, In such a way that simultanous graph in Ghaleroudkhan and Polroud basins show a higher stability compared to Navroud basin especially in the middle of period.As a whole by looking at the graph it is clear that there is a close correlation between trend of discharge and precipitation parameters in research stations which indicate the high correlation of changes in discharge parameter to the changes in precipitation parameter and the role of precipitation regime is proved to be one of the most important factors in the fluctuation and changes in the discharge changes of Guilan rivers.In this research, Navroud, Ghaleroudkhan and Polroud rivers were chosen as case study and authors tried to determine the type and time of changes in discharge regime in relation to the precipitation applying Mann-Kendall statistics. Results show that during 38-year period of 1345-82, the parameters of discharge and precipitation have been subjected to abrupt changes and trends. The research on two parameters is characterized. we found that during the early period there was closer relationship between "U(ti)" of parameters discharge and precipitation but at the end of the time period they got away from each other such that discharge parameter in all stations and seasons showed a descending trend in relation to precipitation variable. 1-Associate Professor, Department of Physical Geography, Tehran University.2- Ph.D student of the Science and Research Branch University Science Department: Islamic Azad University of Chaloos.Dr. Mohammad Hossein Saraei 1Esmaeil Pourhammed 2The Analysis of Spatial Organization of East Azerbaijan in Urban and Regional Levels Using Entropy Model (Chaos Index)Date received: 23 November 2007 Date accepted: 3 May 2008AbstractDeep and narrow valley of Shirvan that is similar to a canyon, and it’s reaches have been affected by active faults being indicators of disequilibrium. Examining the river terraces and valleys is one of the most important subjects concerning fluvial geomorphology. At northern Sabalan massif the remnants of volcanic ash as erosional terraces are seen higher than 210-220 m above the present bed of Shirvan valley. The flow of stream has dissected very deep valley in ignimbrite approximately 100 m deep similar to canyon shape. In this article the formation of both geomorphic phenomena of Shirvan valley and terraces along it have been examined. In order to attain this purpose the arithmetic and semi-logarithmic longitudinal profile by the use of topographic maps with a 1:50000 scale is plotted and then the value of gradient index of any reach of river has been calculated.Results of this study indicate that the semi-logarithmic longitudinal profile of river is made of three parts. It’s middle part conditions corresponds to disequilibrium. 1-Assistant Professor, Azad Islamic University, Ahar Branch.However, these results explained that the extreme temperatures of Esfahan have been influenced by the commencement of the cold season and the trend has changed since 1990. The clarification results of the trend of changes in maximum extreme temperatures of Esfahan proved to be positive, and the minimum extreme temperatures were negative, mainly influenced by the commencement of the cold season. This is an indication of the reduction of intensity of cold season and it’s approaching toward a temperate situation. Inversely, the meaningful and significant changes of extreme temperatures in Esfahan are an indicator of the gradual increment of maximum temperatures and the intensification of summer warming.In this study the data relating to the absolute minimum and maximum daily temperatures of Esfahan synoptic stations during the statistical period of 1951-2005 (55 years) have been used. For studying the correlation between minimum and maximum temperatures with global heating, we have used the mean global temperature anomaly data for the time period 1991-2005.The Regression models (including simple linear, S-shaped curve, and polynomial) along with Mann-Kendal statistic were employed for finding the significance of trends. The changes of temperature time series are among the methods used in this study. Results of this study indicate the lack of meaningful and significant changes in extreme values of long term temperatures of Esfahan.1-Assistants Professor in Climatology, University of Esfahan.2-PhD Student in Climatology, University of Esfahan. Research methods are descriptive. In order to gather required information we have used questionnaires, interviews and field research. The analysis of data was carried out through SPSS software. Finally we have proposed strategies about planning and tourism management including establishing settlements and entertainment centers, roads, air lines, tourism experts, and propagandas on culture and tourism, etc.The Boundary of any country is usually very deprived due to the lack of sufficient equipment and budgeting, illegal imports, unemployment and poverty of native people. Lower attention of the government at the boundary region has led Sistan and Baluchestan Province to face with reduced tourism development.Changing the tourism rules due to the existence of ancient and historic places in this region shows positive effects. Despite the existence of suitable tourism opportunities for native people, the tourism industry has not developed appropriately. In this research problems of tourism in the area have been determined and important strategies proposed.1-Assistant Professor, Geography Department, University of Zabol.2-M.Sc. in Geography and Rural Planning, University of Zabol.
Machine summary:
"Dr. Aghil Madadi 1 Estimating Rate of Sediment Yield in Yedy Buluk basin in Ardebil Province Using PSIAC and Janson- Gembhart Methods Date received: 23 July 2007 Date accepted: 22 April 2008 Abstract: Keywords: for protection of the landscape, the import of biostabilization and bioprotection is necessary, and 3) Biogeomorphological relations show that some of the behavioral indices of ants and characteristics of Dr. Davood Mokhtari 1 Biogeomorphology of Southern Slope of Azay-Tapah in Northwest Iran: with an Emphasis on the Role of Harvester Ants Date received: 24 December 2007 Date accepted: 14 April 2008 Abstract Keywords: Guilan, Precipitation Regime, Discharge Regime, Mann-Kendall Statistics, Trend.
Dr. Ghasem Azizi 1 Mehrdad Ramezanipour 2 Precipitation Changes and it’s Influences on the Discharge Regime of Guilan Rivers Date received: 24 November 2007 Date accepted: 3 May 2008 Abstract : The Aim of this Article is the use of a mathematical model for explaining the existing population settlement in East Azerbaijan."