Physical Geography Research
Year:2016 | Volume:47 | Issue:4|Papers Count:11

IntroductionLinking resolution global climate models to local scale as a micro climatic process is a significant issue. Recently, attempts have been made by the climatology scientists to develop dynamics and statistical downscaling methods to express climate change at a local and regional scale. Two general techniques are been used for downscaling of the output of general circulation models (GCM). The further is by statistical methods in which the output of a statistical model (MOS) and a planned approach to weather short-term numerical prediction is presented. The later is regional climate model (RCM), same as limited GCM model in a subnet of network global model by dynamic method that uses climatic conditions temporal changes according to GCM model. Both methods play an important role to determine the potential effects of the climate change caused by increased greenhouse gas emissions. Much work is done to use this method for downscaling of the global model output in different areas in which the performance of the model is assessed. Uncertainty analysis has been done on these methods or compared by other statistical methods.

IntroductionIn several perspectives including geographical determinism, possibilism, exceptionalism, ecological and other views, it is discussed about understanding how human and the environment interact. Human in dealing with different environments, depending on the capabilities of environment and existing tools and techniques, adopt themselves with the nature or interfere in it. Karst landscapes are one of the most sensitive and fragile environments that any interference by habitants could led to irreversible conditions. These environments are one of the most valuable resources of fresh water. Nearly 25% of the world population lives in karst areas- landscapes that are characterized by sinkholes, caves, and underground drainage (Veni, 2001). The interaction of human and karst has been regarded in the many studies mostly about the impacts of human activities on karst. In general, there are few studies concentrated on the various effects of karst on the human societies. Andrejchuk (2005) and Lovász and Gyenizse (2012) have regarded karst landscapes as a settling factor. These studies show that comparing with non-karstic areas because of the specific hydrology and geomorphology of karstlands the population mostly has concentrated around karst springs and in the other parts settlements are highly sparse. In fact, the history of human settlement dates back far into the past in karst environments. A significant number of protected areas as the world heritage belong to karst areas (UNESCO, 2008). Many of them, such as Yunnan, Guizhou and Chongqing in south western China, Cradle of Humankind World Heritage Site in South Africa, Lascaux cave in France and Shanidar cave in Zagros Mounts in Iraqi kurdistan have been protected for their archeological and historical values.

IntroductionTodays, the application of new methods for monitoring and online management of agricultural farms is necessary to increase quality and quantity of agricultural products. Remote sensing is one of the technologies that can be used to monitor agricultural farms and natural resources. This technology is capable of detection and prediction of farm changes by application of satellite and aerial images. Satellite images have some limitations for application in agriculture, namely, high cost, low revisit time and low spatial and spectral resolutions.

IntroductionFrost as a harmful climatologic phenomenon affects various human activities and biological processes. Due to mountainous nature of Kurdistan Province as the study area of this research in one hand and type and diversity of effective air masses on the other, the frequency, severity and duration of this phenomenon in the province are outstanding. Confronting frost could be one of the major programs of the province authorities especially in the agricultural sector. Satellite images can be a good way to study the frost because of the continuity and repeatability of the relevant data. With the previous studies and the lack of researches related to the frost and estimation of land surface temperature by satellite images in the country, this study aims at determining the optimal algorithm in order to study and extract the earth’s surface frost zones in the spring and autumn in the region using night-time images of the AVHRR sensor.

IntroductionToday, with the increasing population and the need for strategic and industrial crops the farmers are simulated to grow these kinds of crops. Thus, this subject has now been caused the inappropriate use of land and natural resources. On the other hand, the natural environment resources have limited the ability to use its resources and the climate change intensifies this limit ability. Agriculture is one of the most sensitive parts of human activities to changes in climate parameters. The slightest shift in climatological factors of plant growth, the growth of plant processes affected these changes in the performance and quality of crops. In climate change condition, some natural environments with the most appropriate conditions and resources are provided for the development and optimal use of human and with the least appropriate condition the human manipulation can lead to damages to natural environment. Therefore, to any manipulate and development in environment, before planning to use it, we need to evaluate the potential of the environment. In addition to the potential of environments for the future, due to climate change, it is required to consider any planning. The aim of current study is to provide a land suitability assessment in the condition of climate change. Given the sensitivity of crops to climate change, one of the agricultural products as a sample product has been selected to implement the procedure.

IntroductionThe study of climate change and its trend have usually been complicated as problems for specific scientists in these subjects. Obviously, climate has been changed during the history of earth many times, and their evidence are landforms in many regions of the world, where we can readily observe now. The landforms could not be justified with the present climate. In fact, any climate creates specific geomorphic systems. Therefore, the existence of different geomorphic systems in different regions of the world shows that climate has changed frequently over time. In the KhezrAbad basin of Yazd Province we can observe landforms that have been created in different periods of climate of different temperature and precipitation conditions. Thus, with studying of present landforms in the basin, it has been tried to reconstruct past climate. The climate could justify such landforms reasonably. KhezrAbad Basin is located in the south-west Yazd city in the slope of Shirkuh Mountain along 31° 48´ 7" to 32° of northern latitudes and 53° 49´ 42" to 54° of eastern longitudes.

IntroductionThe knowledge about spatial variability of precipitation is a key issue for regionalization in hydro-climatic studies. Measurements of meteorological parameters by the traditional methods require a dense rain gauge network. But, due to the topography and cost problems, it is not possible to create such a network in practice. In these cases the spatial distribution pattern of precipitation can be produced using different methods of interpolation. Interpolation could be done only based on the data of the main variable (i.e. through univariate methods) or on the information obtained from both the main and one or more auxiliary variables (i.e. through multivariate methods). The classical interpolation methods such as arithmetic mean and linear regression (LR) methods are independent of the spatial relationship between observations, while geostatistical methods (such as kriging) use the spatial correlation between observations in the estimation processes (Isaaks and Srivastava, 1989).

IntroductionThe consequence of cooperation between environmental factors and circulation patterns in a long time can determine the arrangement of type and manner in humidity in geographical area. The knowledge about space dispersion in geographical areas assists preparing sound programming and proper environmental decision making. Relative Humidity is the most commonly used measurements of moisture content in the air. The key to understand relative humidity is to understand that it is a measure of the ‘actual humidity’, relative to the maximum possible humidity at a given temperature. Let’s explain it a bit further. In this context a number of studies have been conducted to refer this. Some of these studies are Diffenbaugh and et al. (2008), Ohayon (2011), Jia and et al. (2011), Homar and et al. (2010), Chao-bing and et al. (2011), Allard and Soubeyrand (2012), Ageena and et al. (2013), Del Río and et al. (2013), Kim and et al (2014) and Bajat and et al. (2014). This research is fulfilled to detect the temporal and place spatial autocorrelation of humidity in Iran.

IntroductionPrecipitation is one of the most important meteorological variables in comparison with other climatic parameters. It varies extremely over time and space. The occurrence of this climate phenomenon requires specific circumstances in environment. Its accurate measurement is important to a wide range of decision makers including hydrologists, agriculturalists, industrialists and etc. The density of rain gauges and meteorological radars is often too poor to satisfactorily capture rainfall characteristics at fine spatial resolutions. To overcome this problem gridded precipitation data base was developed based on interpolation of the daily precipitation data. ERA-Interim is the latest gridded global atmospheric reanalysis produced by the European Center for Medium-Range Weather Forecasts (ECMWF). This data covers the period from 1 January 1979 to the present. The precipitation analysis and estimation is based on obtained precipitation data from rain gauge stations, meteorological radars and satellite sensors. The forecasted precipitation is available at 3-hourly based on applying different models.