فصلنامه جغرافیا و پایداری محیط
پیاپی 24 (پاییز 1396)

Sedimentation in reservoir of dams, especially in sediment transport susceptible areas, leads to the reduction of reservoir capacity, disruption in flood control and spillway performance, reduction of hydropower generation and reservoir water quality. The area reduction method is one of the most common methods to estimate sediment distribution in reservoirs. The parameters of this method are based on the data of a limited number of dams in America. The results of applying these parameters to estimate the distribution of reservoirs sediment in the other dams, will not be correct. Therefore, the present study aims to extract the optimal parameters of the area reduction method using imperialist competitive algorithm to achieve the accurate prediction of sediment distribution and compare it with the results of reservoir hydrography. First, combining this algorithm with the area reduction method in MATLAB, the optimal values of the three parameters m, n, and c were obtained in the general equation of the reservoir type. Finally, the model was updated based on the optimal parameters of the surface area reduction method. Then, by introducing new reservoir hydrography data in the optimal model, the sedimentation trend was predicted in the feature years (1410 and 1420). The results showed that this method was more consistent with the actual volume of the reservoir at different levels of the dams rather than the methods of Borland and Miller and Lara. According to the results, in the years mentioned, about 26 and 36 percent of the active capacity of the reservoir will be reduced respectively. Based on the satisfactory results of this research, regarding the combination of optimization method with area reduction method, it is suggested to use this model as a useful method in other important and strategic dams in the country in which the reservoir hydrography carried out. In this case, by understanding distribution and prediction of sediment amount, it is possible to utilize the reservoir operation policies to decide with higher reliability on the problems caused by sediments.

Public spaces are the main element of urban structure, in which the stage and backdrop to the drama of public life is shaped. Comfort is a prerequisite for a successful urban space, and an important integrative dimension of the urban experience. In this regard, climate comfort, as the most influential factor, is applicable when the balance is maintained between the temperature released and the temperature absorbed by the skin in the environment. This balance is affected by the environmental elements of temperature, relative humidity, wind flow, and appropriate orientation of urban physical structure. The last element can be recognized as the lowest cost effective factor in climatic comfort of the citizens in public open spaces. In this research, the correlation method is used to determine the appropriate orientation for the public open spaces in Bandar Abbas. Accordingly, at first, a comparison between eight cardinal directions was calculated in terms of the extent of exposure to the sun using analysis of variance method (ANOVA) in R software based on a fixed rectangle form corresponding with these direction during a year. Then, by removing the disruptive winds of comfort, these directions were prioritized using the extent of climate comfort. Based on the results, the north-south orientation is significantly more important than others and the east-west is the most undesirable orientation for public spaces physical orientation in Bandar Abbas. This can be a guideline for future development of the city concern public open spaces. However, other climatic factors, including cover, materials, etc. have been neglected in this study. Other factors and variables must be considered in future researches to study the climatic comfort of citizens comprehensively with the intervention of all variables.

Evaluation and selection of the most appropriate methods for bed-load estimation is necessary because of the sampling difficulties and inaccurate estimations of the empirical equations. The present study aims to compare the efficacy of ANN and SRC statistical models to estimate the bed-load sediments. Collecting bed-load measurement data and their respective discharges, 5 stations with the highest number of samples were selected. Then, SRC and ANN models were developed. Finally, the estimations of two models were compared with observed values using correlation coefficient and RMSE indices. The results showed that bed-load has been increased by increasing the amount of flow rate in all hydrometric stations. Significant level of difference between observed and estimated values ​​of the ANN model (0.592) is greater than the SRC model (0.144). This means that observed and estimated values ​​of the ANN model are closer together than SRC model, so estimations of ANN model are more accurate. The Root Mean Square Error index (RMSE) for ANN model is also smaller than the SRC model in all stations, so that the sum of five stations RMSE for ANN and SRC models were 2505.7 and 5195.3 respectively. The correlation coefficients of the ANN model are greater than SRC model in all stations. The greater average of correlation coefficients of five stations using ANN model (0.765) than the SRC model (0.503) indicate that ANN model has more accurate estimations. Finally, ANN model was selected as more appropriate model to estimate bed-load sediments. Regarding the measurement problems of bed-load, our results can lead to making more accurate estimations of bed-load and total sediment load.

During the recent decades, a lot of attention has been paid to approaches such as organic farming as a way to deal with issues and maintain environmental equilibrium in terms of sustainability. However, on the other hand, given the nature of organic farming with emphasis on no use of chemicals in the production process, it is a bit difficult to reach, so one of the recent approaches that has been considered to protect the environment, especially in the field of agriculture, is the production of healthier goods with low usages of external inputs. Thus, the aim of this study was to investigate the feasibility of producing low-input pistachio in Dasht-e-Rabat region of Shahr-e-Babak County. Research population included pistachio growers of the supposed region (N=2500) whom about 189 of them were selected as the research sample using Bartlet Table and quotas random sampling technique. Research tool was a questionnaire whose validity was verified using face validity procedure. Moreover, its reliability was also verified calculating Cronbach's Alpha reliability coefficient in a pilot study (from 0.70 to 0.89). Descriptive and also one-sample t-test results showed that out of different necessary factors for low-input pistachio production, economic, legal and social factors are in an unfavorable situation, while technical and attitude factors have favorite conditions. Also, the results of logistic regression showed that the factors such as attitude, technical factors and acquaintance of necessary time to take orchards organic are the main variables affecting the production of organic/ lowinput products.

Performance evaluation is crucial for land cover change modeling. The main objective of this study is performance evaluation of GEOMOD using landscape metrics and spatial processes in landscape transformation for modeling change patterns of forest cover in Neka River Basin, north of Iran. Therefore, the land cover maps for the years 1984, 2001, and 2010 were used as the observed land cover maps. Suitability map from forest to non-forest was produced using weighted linear combination algorithm. Fuzzy membership functions and analytical hierarchy process were used to standardization and weight of criteria, respectively. We calculated the indices including class area, patch density, edge density, mean fractal dimension index, interspersion and juxtaposition index, effective mesh size, and mean related circumscribing circle using Fragstats and spatial processes using decision tree algorithm in Land Change Modeler. The relative error obtained by comparison of observed map versus simulated map for patch density, related circumscribing circle, and for effective mesh size metrics was the highest. The model was able to predict shape complexity, fragmentation, compactness and spatial heterogeneity, and area of forest class with high consistency. Landscape transformation analysis determined attrition according to the decrease in patch density and area of forest. Besides, the model predicted the same spatial process. The results of this research showed that this method can produce comprehensive information with high performance from uncertainty of result accuracy.

Natural resources are expected to be the basis for development due to the economic, export value as well as the ability to become the raw materials of different industries. Therefore, the present study aims to study the effects of natural resources on the development of 12 countries that have different levels of development and various degrees of natural resource utilization in a comparative approach using several indicators. The final goals of this article is to reach theoretical conclusion about the impact of natural resources on the development of the countries. In the present study, qualitative comparative analysis method has been used as a means of quantitative and qualitative research and a powerful tool to analyze the causal complexities. Therefore, four phases of data fuzzy, formation of values table, a method to analyze the variables using complex causality and validation of the results of the research were considered. From the viewpoint of the horizons, the research is of a longitudinal nature, since, unlike a cross sectional study that is unique to a specific time period, in this research, the main themes have been considered over 150 years. Overall research results show that many countries, while having natural resources, have not achieved development due to the low level of other indicators. Few countries such as the United States have reached a higher level of development, using natural resources and benefiting from other indicators, such as literacy and democracy. Oil as one of the natural resources in the second study period has had a significant impact on development, but in the third period, the role of industrialization and import of energy resources in combination with efficient and effective government management justifies the development model of countries through the level of literacy and democracy. In sum, natural resources, if aligned with the level of technology, provide a higher level of development, otherwise it will reduce developmental dependence and economic rent.

Local people always play a very important role in rural tourism development decisions. So that it is always known as one of the principles of sustainable tourism development. Therefore, local perception towards rural tourism development help tourism managers and policy makers to make better decisions. So, the current study aims to assess the relationship between rural sustainability and rural tourism development by modifier role of local people perception. The statistical population is Local people in Qalat region of Shiraz. According to Morgan table, 385 were selected by available sampling method. Data were collected using a questionnaire. The reliability of the questionnaire was measured using Cronbach's Alpha and composite reliability. Its validity was measured using convergent and divergent validity. To examine hypothesis, the Partial Least Squares and Structural Equation Modeling were used. The results showed that without considering local perception as a modifier role, there is a positive relationship between general sustainability and rural tourism development in Qalat region, confirming all relationships between sustainability aspects and rural tourism development. However, considering modifier role, from the economic points of view, local people have not had positive opinions about rural tourism development. The positive economic aspects of economic have not been significant among local people and negative environmental impacts of Qalat area have increased with the arrival of the tourist.