Physical Geography Research
Year:2015 | Volume:47 | Issue:2|Papers Count:10

Introduction: More and better production of food is one of the necessities of today's world. Since production of agricultural products of one region depends on the air and climatic factors, it is important to examine the role of climate in agriculture (Mohammadi et al., 2004: 123). In relation to agroclimatology, numerous studies by different scientists and agricultural climatologists have been carried out in Iran and the world. Tobaybsir (2004) in a research says that in most regions of the Iran, especially in Lorestan Province like the other arid regions in Asia and North Africa, chickpea is usually planted in the spring and, thus, inadequate soil and water is the main limitation for this crop production. Chalakyan (2011) using data of annual precipitation, growing season precipitation, temperature, growing season relative humidity, elevation, slope, aspect, soil depth and wind speed made a zonation of the agroclimatic cultivated chickpea via AHP method for Ardabil Province. The results of the study indicated that the temperature and height of Ardabil Province are the main effective factors in cultivation of chickpea. Up to 120,000 to 150,000 hectares of land in Kermanshah Province is allocated to planting chickpea and the average yield is 450 kg per hectare (Haghparast, 2012: 13). A summary review of the literature shows that all the studies are conducted on this specific product and exclusively in agricultural areas. This research was employed spatial analysis functions of GIS, AHP and TOPSIS model to identify the areas suitable for cultivation of chickpea in Kermanshah province to put at the center of their attention.

Introduction: Simulations of river flow and understanding different components of hydrologic cycle are important for programming of the conservation aspects of water resources. Since the study area is located in the site of dam construction, the estimation of rainfall runoff and sediment yield are very important for better management of water resources. Therefore, in this study, the SWAT model was applied. SWAT model is one of the multipurpose simulation models for management of watershed. The main objective of hydrologic models is simulation and prediction of the behavior of the catchment basin. Hydrologic models can simulate land surface hydrological processes to improve water resources management. Today, GIS tools are commonly used in natural resource management; especially in watersheds with several banks. They have linked information such as digital maps. GIS is designed and developed to predict the results of spatial management activities. For situation awareness systems, we need to add the elements of system dynamics. SWAT model is an advanced communication window possible to combine a set of models and GIS data in groundwater and surface water flows and floods.

Introduction: Water-vapor is an essential climate element. Through latent heat exchanges, the water vapor is considered as the principal way of energy transport through the global atmosphere and it is also a dominant greenhouse gas (Held and Soden, 2000). Over the oceans, warmer surface temperatures may lead to increased evaporation and, therefore, greater specific humidity, but an approximately constant relative humidity (RH); the greater concentration of water vapor will, in turn, warm the surface further, since water vapor is a potent greenhouse gas (GHG) OPCC, 2007; Dessler and Sherwood, 2009). As temperature rises, the atmosphere's capacity to hold water vapor is also increased. As the water vapor can be transported vertically through convection and subsidence, and horizontally by atmospheric circulation, changes in surface absolute moisture can cause changes in moisture aloft (McCarthy and Toumi, 2004). The Clausius-Clapeyron relation represents exponential increases in the atmosphere's water holding capacity with increasing T at approximately 7% K-1 (Manabe and Wetherald, 1967; Allen and Ingram, 2002; Trenberth et al., 2005). Knowledge about changes in water vapor in the upper troposphere and lower stratosphere is important because it can result in strong alterations in radiative forcing, hydrological cycle, precipitation intensity, human activities and biosphere. The aim of this study is to analyze spatiotemporal variation of atmospheric humidity of Iran during 1979-2013.

Introduction: The coastal zone is one of the greatest environmental and economic assets of each nation. In coastal regions the natural forces that cause shoreline changes are embodied in waves, currents, wind and other factors. Gorganroud River Delta is located in 53o 57 to 54 o I E and 36 o 56 to 37 o N in Southeast part of Caspian Sea. In this study, gibbosity of Gorgan River delta has been studied at the river mouth. The Gorganroud River basin from the Caspian Sea catchment basin is covering a large part of it in Golestan Province. The total flow rate of Gorgan Bay River Catchment is about 500 cubic meters and total of their discharge is 3.5 million tons per year. With average slope less than 0.1 percent, the study area is very low slope.

Introduction: Management principles predominated on the development and evolution stages of the geomorphic landscapes are different. This is because of variability in landscape evolution, its relationship with other system components and its response to environmental changes and feedback. One of the most important methods of management of geomorphic landscape is the study and evaluation of morphometric parameters and allometric measurements. Allometric measurement is the investigation of relative changes between system components. It also represents the development of a system component compared with that of the entire system or other components. Therefore, the study and evaluation of barchan morphometric parameters and allometric relations between them will help managers and environmental planners achieve the unified and accurate recognition from landscape, in one hand. On the other hand, it may be effective in the determination of stability, equilibrium and thresholds of barchan system. One of the most important problems of management in arid and semi-arid regions is the identification and application of environmental principles governing on the behavior of Barchan dunes. Barchans are one of the aerial depositional features formed in regions by sand and prevailing uni-directional wind. The aims of this study are to determine the most important morphometric parameters of Barchan dunes in the southeast part of Haj Ali Gholi Playa and also to recognize relationships, the ratio and allometric properties between them. These are conducted to identify the management principles governing on the Barchan dunes.

Introduction: Urmia Lake in the northwestern corner of Iran is one of the largest permanent hyper saline lakes in the world and the largest lake in the Middle East. It is extended as much as 140 km from north to south and is as wide as 85 km east to west during high water periods. Qualitative and quantitative degradation of water resources is one of the major challenges in the way of sustainable development. The features and phenomena in the earth surface have been changed over time; the lakes as one of these features and due to a closed environment are not considered as an exception. Due to climatic changes such as reduced rainfall, increased temperature and also uncontrolled use of surface water resources in watershed areas, distinguished changes are exposed on the earth surface. Monitoring such changes should be considered as an important issue in the national and regional development and natural resource management. Monitoring the coastal areas and extraction of water at different intervals is currently regarded as an infrastructural research interest due to the significance of coastal zone management and dynamic nature of such sensitive ecological environments. Urmia lake is the twentieth largest lake of the world and at the same time one of the most unique and invaluable global water ecosystems. The lake surface area was estimated to have an area as large as 5620 km2 but since 1989 it has generally been declining and was estimated from satellite data to be only 2032 km2 in August 2011. The decline is generally resulted from a combination of drought, increased water diversion for irrigated agriculture within the lake's watershed and also mismanagement.

Introduction: In recent decades, a large variety of science experts, including geology and mine scientists, have considered remote sensing technology as one of the most important instruments to receive information. Access to hyper spectral data is one of the main evolutions in the remote sensing technology. The main feature of the technology is its application in identification of minerals and detection of the minerals. Existing narrow and spectral bands of hyper spectral images provide the possible for geologic and mineralogy examination of an area. Paying attention to existing maps of the mineral distribution has been provided by classic method. Therefore, new sensor such as Hyperion has provided new capabilities in planning of biophysical and biochemistry features.

Introduction: The major threat to habitability of a region may be degradation of arid lands, particularly in developing countries where many people depend upon restricted resources for their livelihood, Although land degradation process in arid regions (desertification) is not new or site specific, the environmental awareness in a world board scale has extended and generated a wider public interest, extensive to the scientific circles and governments, Desertification affects the livelihoods of millions of people, including a considerable proportion of the poor in arid lands which occupies about 41 % of the Earth's land and are home to more than two billion people. The persistence of unresolved stabilization of these fragile environments and a substantial decrease in ecosystem services as a result of intensive use of resources, incapacity of wide spread suitable technologies for providing increased supply of food, forage and fuel, water scarcity, and climate change all made desertification as one of the main environmental challenges today and a major limitation to meet human needs. Recently, arid regions and desert ecosystems with several potential and various resources such as unconventional water became remarkable areas for economic projects. With desert condition and in order to guarantee both rich and sustainability and prevent undesirable consequences of these economic projects, it is essential to address suitable areas for aquaculture in any aquaculture activities. In the case of suitable site selection research, the researchers apply MultiCriteria Evaluation (MCE) in Geographical Information Systems (GIS) to determine suitable sites for aquaculture in Iran.

Introduction: Tourism is a process which has been existed with all its special forms from the ancient times so that the mental, cultural, social and economic demands of the human beings can be met. One of the growing branches of this industry is named as ecotourism. Nowadays, tourism has become one of the main levers of economic and social development in many regions of the world. Tourism in the regions should be based on sustainable development to preserve the nature as well as conserve historical and cultural heritage of that region and the intellectual application of the natural resources. Ecotourism development aligned with ceo-environmental potential of the land as an effective tool and approach plays a major role in sustainable development, promoting the life standards of human society and maintaining the natural equilibrium. Assessment of ecological potential is an effective step and suitable tool in order to direct the present activities and functions performed for the land toward a sustainable development. One of the ways for identifying and evaluating the ecological capacity of each region is application of the Multi Attribute Decision Making method (MADM) and comparison of other indices. This method has identified the sites with ecotourism potential in the city of Roudan and, ultimately, suggests the appropriate locations for ecotourism development in the city.