Physical Geography Research
Year:2016 | Volume:48 | Issue:2|Papers Count:12

Introduction: The city population, in particular at the industrialized cities and centers of provinces, has increased dramatically in Iran during recent decades. Arak city as center of Markazi Province is among those industrialized cities which has experienced a fast increase in population. These changes in population numbers tend to increase consuming water resources as well as increasing in energy resources demand. This situation is accompanied with global warming and caused an increase in temperature values during recent decades....

Introduction: In spite of its short time period compared with the earth long evolution history, quaternary has had a significant effect on the final formation of the landforms and vital resources. It is the final analysis of these levels and fully dependent on the earth genetic diseases and, above all, significant climate changes that have happened during this period. Gavkhouni basin morphological perspectives demonstrate several climate changes in quaternary. The effects of these changes are a completely known phenomenon on the lake. Indeed, the lake can be viewed as an archive within which quaternary climate changes evidence has been maintained....

Introduction: Nowadays, the exploitation of the renewable energy sources such as wind plays a key role in human life. Although, Iran has a high potential for wind power generation, there is not an efficient energy planning yet. Environmental variables such as wind speed have variations according to spatial points. It seems reasonable to consider that there exists a spatial correlation between wind speed data at different locations. In geostatistics the spatial autocorrelation of data could be investigated by calculating the experimental semivariogram. The parameters of the fitted semivariogram model may be used to estimate the wind speed at unknown locations through kriging algorithms....

Introduction: In general, loess sediments are one of the most widespread forms of aeolian sediments. During the past few decades, loess stratigraphy studies played key role in the investigation about global climate changes. These sediments are usually yellowish in color and silt makes 70 to 90 percent of its volume. In Iran, loesses outcrop are often in northeast part of south Caspian Sea. The previous studies revealed that loess/paleosol sequences correspond to cold/ warm period of climate, especially during quaternary period. Therefore, loess deposits are the most important natural archive of climate changes and are ideal for reconstruction of paleoclimate and geomorphological change in Quaternary. The thick loess/paleosol sequences of northeast Iran provide unique opportunity to reconstruct the terrestrial paleoclimate changes recorded in these sediments....

Introduction: Today, mathematics is a strong way to explain process and the complexity of nature so this turmoil has to be made in the form of mathematical and quantitative relationships and to some extent predict their effects. For this purpose, to illustrate the complexity, we used fractal geometry and its dimension to understand the heterogeneity in natural environments. The purpose of this study is to examine the morphological behavior of each wind geomorphic forms in the environment....

Introduction: Water vapor can spread in molecular, unstable and erratic phase and can also transfer by convection and advection process. This transfer happens from the earth and ocean surfaces to the atmosphere in hot air. This type of transfer is considered as the main pattern. In the studies of the atmosphere, one of the prominent factors to be considered is the complexity of water vapor and its cycle. Water structure is different above the surface of the earth and the oceans. The study on water structure was initially conducted in 1960, in which a great deal of information gathered by the meteoric satellites and many researches were carried out about this phenomenon. One of the water structures is the atmospheric river, which is recently considered as a separate factor. The definition of the atmospheric river as the Tropospheric River was initially introduced by Riginald Newell in 1992. Given the fact that Middle East, especially Iran, is facing an overwhelming trend of drought, it is necessary to provide programs and plans to prevent this phenomenon. Moreover, the vast and small water sources and the moisture entries have to be identified....

Introduction: Rainfall prediction at regional and global scales is mostly the principle component of hydro-meteorological studies in un-gauged regions. Ground-based measurements of precipitation are available with high accuracy in synoptic stations. Spatial distribution of operational stations is now as one of the biggest problems in the developing countries such as Iran, which the spatial distribution of the stations is not enough. In recent decades, remote sensing data have widely been used by many researchers in the world for drought monitoring and management of water resources. The satellites data can be used as compensation for temporal and spatial distribution of rainfall. The satellite-based rainfall estimates provided by the Tropical Rainfall Measuring Mission (TRMM) satellite at global scale, are now available freely as the only data source in the regions without in-situ measurements. Most regions of Iran have arid and semi-arid climates. The evaluation and calibration of TRMM data in different regions of Iran at daily and monthly time scales is very important before those data are used by researchers, experts, climate scientist, hydrologist, and etc. Therefore, a comprehensive evaluation and calibration of the TRMM 3B43 and 3B42 dataset at 87 synoptic stations in Iran including six climatic zones, is the main objective of this present research....

Introduction: In the recent decades, mismanagement, human activities and climatic conditions developed a new view of Iran ecosystems, called desertification. Life cycle assessment (LCA) is a method to construct environmental profile of production systems. That was developed by industrial instruments, but in recent years it is applied by agricultural production process as well. Today, it is acknowledged that land use should be assessed by LCA, but there is still no consensus on the parameters for assessment. In order to assess such land use impact, it is initially necessary to define the variables in the LCI. Once the inventory data is gathered, the LCI results have to be characterized in the impact assessment phase. The main framework of LCA is based on the "from cradle to grave" where we are able to evaluate environmental impacts truly from start point to the end. In this way, we can use the theory of LCA to assess desertification indicators and estimation of ecosystem resistance to this phenomenon. Thus, in this research an LCA approach was applied for estimate ecosystem susceptibility to desertification.....

Introduction Daily weather informationis currently available for about 40000 stations across the world. But, distribution of these stations is relatively uneven in some parts of the world. Moreover, there are often large amounts of missing values (Schuol and Abbaspour, 2007: 301). Using generated data can help fill missing or even to correct erroneously measured data (Fodor et al., 2010: 91). LARS-WG is a stochastic weather generator which can simulate weather data under both current and future climate conditions at a single site (Semenov and Barrow, 2002: 3).