Geography and Environmental Sustainability
Year:2012 | Volume:2 | Issue:3|Papers Count:7

In karst regions, the main goal of geophysical method is to study carbonate stone, which are not directly visible. By geophysical method, it is possible to gain some valuable information about amount of stone and describe horizons containing inconsistencies which are of great interests in karst studies. The region under study located in zagros producing zone have been built out of carbonate constitutes. Karst springs of kermanshah play an important role in providing the water for kermanshah province, because of this importance, geophysical operations have been done to recognize the role of earth structure (fractions) in making karset springs. GPR is one of important methods in recognizing the surface structure of earth. In this study, using GPR geophysical deeds have been done in two springs of sarab yavari (zone according to zagros) and sarab niloofar (unfair zone of zagros). Using 100 MHz antenna, the some related information was obtained, and The surface fraction and in consistent zones have been studied, these studies show that sarab yavari spring which is located in zagros fraction has more solution phenomena, but sarab niloofar spring which is located in inconsistent zagros zone has less solution phenomena. The results of this study show that GPR is able to recognize karst springs closely and the obtained results are more acceptable and reliable.

The soil erosion and sediment yield are mainly due to marl formations in the Talkherood watershed. This study was conducted to evaluate relationship between physicochemical properties of Talkhe_rood watershed marl samples and rill, gully, mass and badland erosion types. For this purpose, marl samples were taken from marl sediment of homogenous work units. Twenty four samples were selected, and some of main physicochemical properties of these marls were determined in lab. These properties were: pH, EC, CEC, Lime, gypsum and OC contents, SAR, Na, K, Cl and Ca + Mg and clay, silt and sand percentages. These data were interpreted by ANOVA and mean comparisons analyze (SPSS software Ver. 11.5) methods. Results showed that pH, gypsum content and sand percentage had statistically significant differences between four erosion types. Mean comparison showed that significant difference of pH, was between mass and badland erosions, sand between badland and gully ones, and gypsum, rill and gully, also badland and gully ones.

The purpose of this study is to evaluate the coordination of population and urban service distribution in Anzali city, and try to provide a planned strategy to balance the distributtion os services in the whole city, so that all the citizens could benefit from these facilities. The research method is descriptive and analytical method where we use coefficient entropy and Gini method to analyze the population distribution and the TOPSIS model for analyzing urban service distribution. The Research Population is 9Anzali's urban areas specified based on the city's comprehensive plan which have been evaluated by 8 utilities Indexes. Results of the study show that the distribution of population in urban areas is balanced, but only 13 percent of the total population of the city utilize balanced urban service and 40% of the population located in semi-balanced situation and 47 percent located in unbalanced terms of urban services. Applying Pearson’s correlation between the demographics and distribution of urban services in urban areas, indicates a lack of correlation between the two mrntioned variables. Thus, in addition to a need for increasing the quality of urban service parameters, establishing an effective communication and coordination between the population and urban service distribution in the areas of Bandar Anzali is necessary.

Estimating the water requirement is among the most important factors in the design of irrigation and water resources management. To determine the water requirement, the evaporation-transpiration point of the reference crop should be estimated. Given that a variety of methods have been recommended in this regards, selecting the appropriate method is a hard and complex task. In this study, five selected stations in Kermanshah province during the period between 17 and 54 years were used. Five methods including FAO - Penman - Monteith, Thornthwaite, Modified Blaney-Criddle, modified Hargreaves and Penman have been used to do the needed calculations which are done based on monthly and annual data. The calculated values of the potential evaporation - transpiration and the recommendations of the World Meteorological Organization indicated that of the five methods mentioned above FAO - Penman - Monteith provides a more accurate estimate. The results showed that the monthly and annual maximum ET0 were 8.5 and 48.9 millimeters which was for Ravansar station and the minimum order of 5.8 and 38.4 mm which was experienced in Kangavar station, and finally it showed that the maximum annual water requirement for Ravansar station is 923.3 mm.

Ravansar with diverse natural and human tourist attractions is one of the main tourist destinations of the western Iran and Kermanshah province which attracts many tourists annually. Due to the high tourism potential and diversity of attractions, prioritizing and identifying potential areas for tourism development in this region for specifying the strengths and weaknesses is very important and seems inevitable. This article from the viewpoint of its purpose is an applied one and according to its method is a descriptive - analytical study and survey. to achieve the goal of the article, 9 parameters including altitude, situation of infrastructure, number of tourists, facilities and services, accessibility, potentials of attraction surroundings, the ability to attract tourists in different seasons, economic impacts and the absence of natural hazards in seven most important tourist sites were selected and prioritized using TOPSIS techniques. For determining the weight of indices, views of 30 experts concerned with the tourism were analyzed using AHP method. The TOPSIS model results prioritized Ravansar tourist attraction sites as following: Ghori Ghaleh Cave with 0.766 score in first rank, Sarab Ravansar with 0.716 score in second rank, Kavat cave with 0.589 score in third rank, Oveys-e Gharani shrine, Sarab-e Javari, Tape Mousayi and Tagh-e Farhad with respectively 0.569, 0.65, 0.249 and 0.224 score were located in the next priorities. Finally, to enhance strengths and reduce obstacles and problems in seven different tourist attraction sites of Ravansar, some solutions were offered.

Drought is a creeping phenomenon which occurs because of insufficient environmental moisture as a consequence of precipitation shortage. To analyze Tehran’s Droughts, we used monthly precipitation data of 14 stations for the period of 1976 – 2007 and Standardized Precipitation Index (SPI) in 1, 6 and 12 month time scales. Severity and duration of dry periods were estimated for each of these three scales. Result of this research shows that when duration increases, the number of drought occurrences and the highest frequency of drought events happen in 1 till 6 month durations. In addition to it, it was found that the severest drought of Tehran province has been in 1995 with SPI coefficient of more than -3 and the greatest precipitation in 1982 with SPI coefficient above +2. Markov chain model was used to calculate the balance of probabilities of wet, dry and normal courses in annual SPI. The results showed that the equilibrium probability of dry, wet and normal periods in the stations of this province is 29, 30 and 41 percent respectively. This means that the climate conditions in the region often are normal. Furthermore the probabilities of dry and wet conditions are very close to each other.

To do the synoptic analysis of extreme and widespread precipitations in Caspian western coasts, daily precipitation data from 1340/1/1 to 1 on the 14×1383/11/10 (15992 days) interpolated by Kriging method. These data provide to calculate maximum precipitation and area percent under precipitation for each day including precipitation. On this basis, were identified the most extreme and the most widespread regional precipitations and were selected severe precipitation by 99th percentile base index. Using environment- circulation approach and agglomerative hierarchical cluster analysis by “Ward” method, we could identify three circulation patterns of atmosphere thickness between 500-1000 hpa levels which were effective for creating the extreme and widespread precipitations of Caspian western coasts. However these patterns have many similarities, but, they are considered as different patterns for these regions. Then, to analyze the precipitations in every atmosphere thickness pattern, the representative day was defined on the basis of correlation coefficient with 95% threshold and in these days, sea level pressure maps, atmosphere thickness in 500-1000 hpa levels, functions of frontgenesis and humidity convergence flux were mapped and analyzed for 500, 600, 700, 850, 925 and 1000 hpa levels. The results show that the relatively deep trough on the north and northwest sections of Caspian Sea between Caspian Sea and Black sea can make background for occurring the extreme and widespread precipitations in studied region. The analysis of frontgenesis function maps in the Caspian western coasts confirms the existence of front core on the Caspian Sea and around it too. The analysis of humidity convergence flux indicate that Caspian sea is the most important source of providing the humidity of western coasts precipitations of this sea, and Black sea and Aral lake are in the next importance rankings.