Geography and Environmental Planning
Year:2018 | Volume:29 | Issue:2 (70) |Papers Count:12

Today, soil infiltration decreased due to rainfall decreasing, high grazing of rangeland, and land use change. Consequently, the majority of rainfalls convert to unusable runoff. In this area, also rainfall patterns are unpredictable, both in terms of amount and time, but, rainfall could be sufficient to make rainwater recharging/harvesting as a reliable and economical source of water via integrated watershed management. Integrated watershed management requires a lot of inter-related information to be generated and studied in relation to each other. Remote sensing, geographical information system, and AHP techniques provide valuable and up-to-date spatial information on natural resources and physical terrain parameters. In this study, the potential rainwater harvesting site was identified using remote sensing, GIS and AHP techniques. To implement the decision rules, information layers were prepared by overlaying runoff coefficient, slope, drainage network, land use permeability, lithology and soil maps. Suitable sites for each rainwater harvesting/ recharge method are determined using Iranian reports standard for rainwater harvesting structure and international researches. According to results, suitable area for check dam construction, Faroe meter, combined Bankt and Pitting was 627, 253, 247 and 81 hectare (9. 8%, 3. 9%, 3. 85, and 1. 2%) respectively. As a result, the methods used in this study show the highest accuracy, preciseness, and ability in the larger basins than other methods.

The spread of urbanism, cities spatial and physical development and their role in economic, political, cultural arenas have caused different players to try to control urban spaces and also to increase their sphere of influence which creates special landscapes and specific forms in cities. The spread and variety of issues and the apparent role of politics and power in cities both at national and international level have attracted the attention of political geographers and geopolitician and resulted in the formation of the new branch of geopolitics entitled “ urban geopolitics” . Urban geopolitics studies mutual relations between geography, power and politics in urban spaces and places that the consequence of the relations is competition between urban elements and its spatial reflection. The purpose of this article, using the descriptive-analytic method and library resources, is to explain the concept of "rivalry" in urban geopolitics and its spatial reflections in the cities considering theories of political economy and urban political ecology. The research argues that "rivalry" is a key concept in urban geopolitics that spatial reflections of which in urban elements can be discussed within the framework of peaceful and violent actions in different scales from local to global levels such as rivalries of cities at international level for hosting the Mega-Events, creating landscapes and symbols, and urban conflicts.

Explanation of one concept in different cognitive schools has very great importance. In this field, in the geographical sciences; space concept as a very important paradigm in the geography could be taken different meaning in different cognitive schools. Space consists of a bilateral relation between human and the environment. Geographical science analyses this space and its issues with human and physical dimension. So, in this paper, the main question is ‘ what is the definition of space in Positivism and Hermeneutics schools? ’ . This research has fundamental approaches in the philosophy of geography and has referred to valid documents and bibliographies for the compilation of information. This research deals with descriptive and analytical approaches, the space definition has been given according to the characteristics of the two important schools. Findings of the research reveal that in the Positivism school, space was considered as a perceptual concept. In other words, researchers should make use of their sense and their experience for detecting things in space. In Positivism school, a researcher should not involve his ideology or his culture for discovering the truth. So, Positivism geographical research has been integrated with quantitative tools such as statistics, mathematics and positive models. In Hermeneutics school, meanings, ideas, theories, together obtain their objectivity and importance by a dominant power and ideology. In this school, geographical spaces also are derived from dominant ideological and power. Consequently, the ruling discourses are constantly creating meaning and landscape, and recognizing these symbols and perspectives requires a kind of interpretation to identify the forces and non-visible discourses that make these symbols.

Considering the importance of erosion and the lack of erosion and sedimentation stations in the region, using a model that has the ability to estimate erosion and sedimentation at certain times and places seems to be necessary. So, in this study, the experimental models of SLEMSA and GIS have been used to investigate the efficacy of these models, to simulate and estimate soil losses, and to identify areas susceptible to erosion in the northern part of Mahidasht basin of Kermanshah and its effective factors with an area of 81400 hectares. For this purpose, maps and values of the main parameters needed for the SLEMSA model, including topographic data, rainfall erosion and soil erosion, as well as atmospheric temperature, rainfall, vegetation, and geology maps were prepared. The results show that the topographic factor (slope and slope length) has the most effect on the erosion of the Mahidasht basin. The total amount of erosion in the studied area is estimated at 2494910 tons per year and the erosion value per hectare is estimated at 30. 65 tons per year.

The beautiful city of Isfahan is among the cities with transportation, traffic and parking problems resulting in an increase in environmental pollutants which can be considered among the most important problems of this city. Development of public transport and infrastructure equipment can be mentioned as one of the ways to reduce the city's problems. In this regard, developing BRT lines with its numerous advantages might have a very significant role. Currently, the first line of Isfahan BRT is implemented in two phases and it gives service to many citizens daily. Though the system has many benefits to urban transport systems and plays a very significant role in reducing the environmental pollution of the city, if you do not set up the system in accordance with the appropriate standards and criteria, it would cause several problems. The current attempt is an applied one and the method applied is based on documents, with inductive data collection. Data used in this study were collected from statistical sources, questionnaires, library and etc. The study used international standard questionnaire in comparison format. The mentioned questionnaire which was completed by 40 experts, professionals and bus drivers was developed by Institute for Transportation and Development Policy (ITDP) and was released in 2014 for the first time in international level. The results obtained from this study pointed to the fact that Isfahan’ s BRT lines would get the bronze medal and inappropriate condition based on the international standards. The score for Isfahan BRT system would be 45 and since based on the classification of this institute the gold line needs a score of more than 85, the silver line needs a score of 70-84 and the bronze line needs a score of 50-69, unfortunately, the city of Isfahan with the score of 45, from the sum of negative and positive indices, even would have a place lower than the bronze line.

In recent years, Phenomena such as population growth, the expansion of large cities, the human activities and climate change, caused of a reduction in wetland’ s water, which causes temporary or permanent drying in some of them including Gavkhouni wetland. For investigation of the effects of drying on the Gavkhouni, Playa micro-forms situation was evaluated. By using fractal model perimeter-area, micro-landforms were evaluated in 2 consecutive years. The DAP values obtained, in 2013 showed a quantity of 1/27 to 1/40 and in 2014, values 1/27 to 1/44. For evaluating of the area’ s climate, monthly total precipitation and minimum and maximum monthly air temperature climate charts were drawn, related to the years 2013 and 2014-Using data from the Varzaneh meteorological station. The climate charts indicated a decrease in rainfall from 120. 6 in 2013 to 87. 8 mm in 2014, an increase in the monthly minimum temperature from 3. 23 in 2013 to 3. 52 ° C in 2014, and an increase in the maximum monthly temperature from 29. 93 in 2013 to 30. 47 ° C in 2014. The obtained values from the fractal model showed that micro-landforms tend to increasing of chaos with the over of time. This chaos might have occurred because of the drying it. The results show that with the continuation of the Gavkhouni current trend, the desertification may be intensified and the increase of sedimentation of salt minerals on sedimentary deposits, also the expansion of the salt zone causes the conversion of the wetland to the desert.

Karst masses have great importance in water supply of settlements and agricultural lands in arid and semi-dry areas. The most the mountains in Kermanshah province consist of carbonate formations, that Parâ w-Bisetoon mountain masses in Zagros structural zone (thrust) are one of the most important karst masses. Karst landforms such as dolines, uvulas, and karst caves in this mountain mass are created due to affecting factors in the karst development such as the carbonate formations, tectonic, climatic and geomorphological conditions. The purpose of the present study is to zonate the development of surface karst in Parâ w-Bisetoon mountain mass using Entropy model. This study used seven factors of geology, elevation, slope, aspect, rainfall, temperature and distance from the fault as independent variables and sinkholes factor as the dependent variable. The results of this study indicate that 39% of this area is categorized as the high and very high karst development. The accuracy of the model using the sinkholes layer indicates that 98% the sinkholes of region are in these two areas. Also there are a large number of karst springs (Saraw) around the mountain that shows the development of karst in the area.

Soil erosion is one of environmental problems in northern Khorasan province and Badranloo basin. Surveys show that about 461574 tons of soil are eroded from the loess fertile lands of the Badranloo basin annually which has led to a decrease in soil fertility and accumulation of sediment. The sediment resulting from erosion reduces the useful life of dams and water structures in the low stream of basin. The aim of this study was quantitative evaluation of water erosion in the Badranloo basin and the Experimental erosion Potential Method (EPM) has been used in this regard. In this study, within evaluating the water erosion, the specific sediment value for sub-basins and the whole of Badranloo watershed is calculated by ILWIS 3. 3 software and specific sediment yield map (GSp) was prepared. ANOVA method was used in SPSS software for analyzing the geological and escalation erosion, along with for statistical analysis of the role of topographic factors in the severity of soil erosion. The results indicate the alarming state of ecological instability in the basin area. So, the annual average water erosion of soil in the basin is about 23. 73 ton / ha. Among sub-basins, the sub-basin No. 4 located in the center of the basin with an annual concentration of about 63. 89 ton / ha has the highest soil erosion. Groove and mass erosion are common water erosions at the basin level. In addition to lithology conditions and land-use change, among topographic factors, slope and direction of gradient have the greatest effect on the severity of the soil erosion of the basin due to the high correlation.

There is an undeniable relationship between local identity and history of mankind. During historical periods, the effect of climate on human society, centers of civilization and way of living and thinking was so intense that caused a lot of studies done in this area. Thus, it can be stated that climate change and its occurrence during the Quaternary are considered as important environmental factors in the formation of settlement associations of Iran. The results show that the distribution of these centers follow a special arrangement. The establishment of settlement nuclei confirms the fact that the early settlement of the civil association and settlement nuclei have been formed on the margins of lakes. Among the most important civic associations on the terrace of the Hamon alluvial lake in the past and present, two cities of Soukhteh and Zabul can be pointed out to. Soukhteh city, as the oldest settlement in Hamon, is considered on the highest terrace of the lake. Also, Zabul city, as one of the biggest city in the eastern of Iran, is situated on the second terrace of the lake.