per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
1
14
822
Research Paper
کاربرد الگوریتم رقابت استعماری در تعیین پارامترهای بهینة روش تجربی کاهش سطح برای پیشبینی روند رسوبگذاری در مخزن سدّ دز
• The Application of Imperialist Competitive Algorithm in Determining the Optimal Parameters of Empirical Area Reduction Method to Predict the Sedimentation Process in Dez Dam
آرش آذری
arashazari.ir@gmail.com
1
صادق سوری
soori.sadegh@gmail.com
2
حسین بنکداری
bonakdari@yahoo.com
3
استادیار مهندسی آب، دانشگاه رازی، کرمانشاه، ایران
دانشجوی کارشناسی ارشد مدیریت منابع آب، دانشگاه رازی، کرمانشاه، ایران
استاد مهندسی عمران، دانشگاه رازی، کرمانشاه، ایران
رسوبگذاری در مخازن سدها بهویژه در نواحی مستعدّ حمل رسوب، باعث کاهش ظرفیت مفید مخزن، اختلال در کنترل سیلاب و عملکرد سرریز سد، کاهش توان تولیدی نیروگاه و تأثیر بر کیفیّت آب مخزن میگردد. روش کاهش سطح یکی از مرسومترین روشها برای تخمین توزیع رسوب در مخازن است. پارامترهای این روش، بر پایة اطّلاعات تعداد محدودی از سدهای آمریکا تهیّه و تدوین شده است. استفاده از این پارامترها، برای تخمین توزیع رسوب مخازن سدهای دیگر نتایج درستی به دنبال نخواهد داشت؛ لذا هدف از این پژوهش، استخراج پارامترهای بهینة روش کاهش سطح با استفاده از الگوریتم رقابت استعماری برای پیشبینی دقیق توزیع رسوب و مقایسة آن با نتایج حاصل از هیدروگرافی مخزن است. ابتدا با ترکیب این الگوریتم با روش کاهش سطح در محیط متلب، مقادیر بهینة سه پارامتر m، n و c در رابطة کلّی تیپ مخزن به دست آمد. در نهایت مدل بر اساس پارامترهای بهینة روش کاهش سطح به روزرسانی شد؛ سپس با وارد کردن اطّلاعات جدید هیدروگرافی مخزن در مدل بهینه، روند رسوبگذاری در سالهای آتی (1410 و 1420) پیشبینی شد. نتایج بیانگر تطابق بیشتر این روش با مقادیر واقعی حجم مخزن در ترازهای مختلف سد دز نسبت به روشهای برلند و میلر و لارا بود. بر اساس نتایج به دست آمده، در سالهای مذکور به ترتیب حدود 26 و 36% از ظرفیت مفید مخزن کم خواهد شد. با توجّه به نتایج رضایتبخش این پژوهش در خصوص ترکیب روش بهینهسازی با روش کاهش سطح، استفاده از این مدل به عنوان روشی سودمند در سایر سدهای مهم و استراتژیک کشور که در آنها هیدروگرافی مخزن انجام شده است، پیشنهاد میشود. در این صورت، با شناخت نحوة توزیع و پیشبینی میزان رسوبات، میتوان سیاستهای بهرهبرداری از مخزن و تصمیمگیری در مورد مشکلات ناشی از رسوبات را با ضریب اطمینان بالاتری انجام داد.
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.
Extended Abstract
1-Introduction
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 the sediment distribution and correction of the height–area–volume curves of reservoirs. The parameters of this method have a direct impact on the sediment distribution over time which should be corrected based on the physical and hydraulic properties of each dam. Therefore, the present study aims to investigate the efficiency of imperialist competitive algorithm in extracting optimal parameters of area reduction method and prediction of sedimentation process using this method. So that, it minimizes the difference between the amount of reservoir sedimentation in the area reduction method and the results of reservoir hydrograph at the end of period.
2-Materials and Methods
The research area of this study is Dez Dam reservoir. Dez dam is located on the Dez River at 23 km northeast of Andimeshk. Area reduction empirical method was used to predict the sedimentation process in the reservoir. This mathematical method is based on observational principles using reservoir type equations and a dynamic solving method to extract height–area–volume curves whose parameters need to be estimated accurately. As a result, combining the imperialist competitive algorithm with the area reduction method in MATLAB, optimal values of the three parameters m, n, and c were obtained in general relation of the reservoir type. Then, the results of this method and the methods of Borland and Miller (1958) and Lara (1962) were compared with the reservoir hydrography data. 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).
3-Results and Discussion
The results showed that the application of imperialist competitive algorithm for the extraction of optimal parameters of the area reduction method would lead to a greater correlation between estimated and actual volumes of the reservoir (reservoir hydrography in 2010) at different levels compared with methods of the Borland, Miller and Lara. So that the total calculation errors in estimating of reservoir volume at different levels in these methods was 0.25, 14.7 and 17 (percent) respectively. Finally, by applying the optimal parameters of imperialist competitive algorithm in the area reduction method, the height–area–volume curves of the reservoir were predicted for the years of 1410 and 1420 that showed a reduction of the reservoir active capacity about 709 and 972 million cubic meters in these years. Given the need of water supply for 125,000 hectare downstream dam lands in these years, this situation will create a major challenge for water resource specialists in the region.
4-Conclusion
With passing of time and sediment accumulation behind the reservoir, the useful volume and useful life of the reservoir are reduced and the volume-level-height curves need to be corrected. Common methods for correcting these curves after reservoir sedimentation have been developed based on the conditions and statistics and information recorded in reservoirs abroad. The use of the same methods for country interior dams without optimizing the coefficients have problems and sometimes full of errors. Therefore, calibration of area reduction method and extracting optimal parameters of this method have a special importance in predicting the sedimentation process in reservoirs, which greatly reduces the predictive error. In this regard, the use of imperialist competitive algorithm for optimization has dramatic results. So, considering the satisfactory results of this study regarding the combination of the optimization method with area reduction method, it is recommended this model be used in other important and strategic dams of the country where the reservoir hydrography is carried out.
https://ges.razi.ac.ir/article_822_5a0dbe43c13ecaf332cb4b4bc8e10f7c.pdf
الگوریتم رقابت استعماری
بهینهسازی
روش کاهش سطح
توزیع رسوب
سدّ دز
mperialist Competitive Algorithm
Optimization
Area Reduction Method
Sediment Distribution
Dez Dam
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
15
31
823
Research Paper
نقش جهتگیری کالبد فضاهای شهری در میزان آسایش اقلیمی شهروندان (مطالعة موردی: شهر بندرعبّاس)
The Role of Urban Spaces Physical Orientation on the Extent of Climate Comfort of Citizens: Case study of Bandar Abbas
فواد خیرآبادی
kheirabadi.usk@gmail.com
1
حسین نورمحمد زاد
2
هوشمند علیزاده
3
کارشناس ارشد طرّاحی شهری، عضو باشگاه پژوهشگران جوان و نخبگان دانشگاه آزاد اسلامی، سنندج، ایران
استادیار شهرسازی، دانشگاه یزد، یزد، ایران
دانشیار طرّاحی شهری، دانشگاه کردستان، سنندج، ایران
فضاهای شهری، عناصر اصلی ساخت شهر هستند که به قلب و کانون راهبردی اجتماعی مربوط میشوند. راحتی و آسایش، پیشنیاز یک فضای شهری موفّق هستند، از این میان، آسایش اقلیمی به عنوان تأثیرگذارترین فاکتور آسایش، زمانی برقرار میشود که بین دمای دفعشده و جذبشده توسّط پوست بدن در محیط، تعادل ایجاد شود. این تعادل، تحت تأثیر عواملی مانند درجة حرارت، رطوبت نسبی و جریان هواست و جهتگیری مناسب کالبد به عنوان کمهزینهترین و تأثیرگذارترین عامل به منظور کنترل این عناصر محیطی تأثیرگذار بر آسایش اقلیمی شهروندان در فضاهای باز مطرح است. در این پژوهش، از روش همبستگی با هدف دستیابی به مناسبترین جهتگیری برای فضاهای باز شهر بندرعبّاس از نظر اقلیمی استفاده شد؛ از این رو، ابتدا اختلاف بین جهتهای مختلف از نظر میزان آفتابگیری در یک مستطیل ثابت در هشت جهت اصلی و فرعی در طول سال به کمک روش آنالیز واریانس با استفاده از نرمافزار آماری آر. روی دادههای 44 سالة هواشناسی تجزیهوتحلیل و مقایسه شدند؛ سپس با حذف جهت بادهای مخلّ آسایش از روی گلبادهای برگرفته از دادههای ذکرشده، جهات یادشده، از نظر میزان آسایش اقلیمی، اولویّتبندی شدند. از این میان، طبق نتایج پژوهش حاضر، جهت شمالی - جنوبی با اختلافی معنیدار نسبت به دیگر جهتهای اصلی، مطلوبترین و جهت شرقی - غربی نامطلوبترین جهتگیری کالبد فضاهای باز شهر بندرعبّاس است که میتواند در طرّاحیهای آینده مدّ نظر قرار گیرد. به هرحال، در پژوهش حاضر به دیگر عوامل تأثیرگذار بر آسایش اقلیمی از جمله پوشش، مصالح و... توجّهی نشده است. این عوامل و متغیّرها، باید در پژوهشهای بعدی موردمطالعه قرار گیرند تا آسایش اقلیمی شهروندان را بتوان به طور همهجانبه با مداخلة همة متغیّرها پیگیری کرد.
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. Extended Abstract 1-Introduction People have five basic needs in urban space: comfort, convenience, effective communication with the surroundings, active relationship. Feeling of comfort includes bioclimatic comfort, physical comfort, and social and psychological comfort (Carr et al., 1992). Climatic comfort is generated when there is a balance between disposed and absorbed temperatures of the skin. Bandar Abbas is located in a warm and humid climate whose climatic characteristics are a long and warm season and a short and cool season (Zabul Abbasi et al., 2006). Due to intense sunlight and high humidity, in most days of the year its open spaces are distant with favorable climate conditions. Lack of attention to the orientation of urban spaces has made urban spaces not have suitable climatic conditions for being used by citizens and lose their position in the city. The aim of this study was to find the most appropriate orientation of physic for open space in Bandar Abbas with an emphasis on increasing climatic comfort. 2-Materials and Methods The determination of the climate comfort zone in this study has been done on a psychometric chart or clay climate. The data used in this study are hourly data for the analysis of total 44 years (1961-2004) of Bandar Abbas. To get the proper orientation of the urban spaces, the first rectangular space with a golden ratio (length * 1.63 width) and closeness ratio of 1/2 (width * 2height of the wall) is first simulated. Then this rectangular space is considered to have eight different orientations (north-south, 22.5, 45, 67.5, east-west, 112.5, 135, 157.5). This calibration is started as clockwise from the north and 22.5 is added exponentially. In each of these orientations, the solar radiation rate is calculated every 30 min throughout the year and the results are compared. To determine the importance of their differences in different months, at first the significance of these differences should be approved by R software. Thus the analysis of variance (ANOVA) test was used. Also, in the second part (i.e., wind factor) the rate, feature and direction of the winds were obtained on the basis of the monthly wind rose during a 44-year periods in the city. Eliminating undesirable directions and disrupting the climatic comfort, the most desirable and undesirable direction was determined by matching these directions with eight directions. 3-Results and Discussion Out of eight studied orientations, the range of 45° (NS to 22.5° and NS to 157.5°), is the most favorable range for orientations of the physic of open spaces in Bandar Abbas in terms of the importance of sunlight to increase climatic comfort. In contrast, the most unfavorable range is the range of 45° (EW to 112.5° and EW to 67.5°). We found that NS and EW, respectively are the most favorable and unfavorable orientation. Of these two orientations, 45° and 135° are the most moderate orientations; a range between favorable and unfavorable ranges. In terms of the wind, a certain range cannot be determined, but the best one is NS because it is driven the most flow into space throughout the year. Moreover, conductive flows in this direction has a desirable quality in order to improve the climate comfort and reduce humidity. The results of this section prove the simultaneous effect of these factors on the level of climate comfort of the citizens in open spaces and the role of the orientation of these spaces in controlling these climatic factors. Accordingly, determining the most suitable orientation of the open spaces of the urban spaces requires the attention of all the affected climatic factors and otherwise the actual results may not be obtained. 4-Conclusion According to the results, the north-south direction is the most suitable orientation for the open spaces of Bandar Abbas, due to the level of climate comfort of the city citizens. Besides, if we use this for open spaces, we will see the highest level of climate comfort in them. It should be noted that in this study, sunshine radiation and flow wind were used as the main factor affecting physical orientations of urban open spaces in order to increase climatic comfort of citizens. 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.
https://ges.razi.ac.ir/article_823_99250a6182139ae688914b03690626eb.pdf
جهتگیری کالبد فضاهای شهری
آسایش اقلیمی
باد
تابش
اقلیم گرم و مرطوب
بندرعبّاس
Orientation of the Physic of Open Space
Climatic Comfort
Wind
Warm and Wet Climate Bandar Abbas
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
33
44
815
Research Paper
مقایسه کارآیی مدل سنجه رسوب و شبکه عصبی مصنوعی در برآورد بار کف رودخانهها
Comparing the Efficiency of Sediment Rating Curve and ANN Models in Estimating River Bed-load
جمال مصفایی
jamalmosaffaie@gmail.com
1
امین صالح پورجم
aminpourjam@yahoo.com
2
محمودرضا طباطبائی
taba1345@hotmail.com
3
استادیار آبخیزداری، پژوهشکدة حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
استادیار آبخیزداری، پژوهشکدة حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
استادیار آبخیزداری، پژوهشکدة حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
به دلیل مشکلات نمونهبرداری و عدم دقّت کافی معادلات تجربی، سنجش و گزینش مناسبترین روشهای برآورد رسوبات بار کف، اهمّیّت زیادی دارد.هدف پژوهش حاضر، مقایسة کارآیی مدلهای آماری شبکة عصبی مصنوعی و منحنی سنجة رسوب در برآورد رسوبات بار کف است؛ بدین منظور، ابتدا 5 ایستگاه هیدرومتری دارای بیشترین تعداد نمونه انتخاب شدند؛ سپس منحنی سنجة رسوب و مدل شبکة عصبی مصنوعی با 70% دادههای آنها ساخته و ارزیابی دقّت برآورد دو مدل با 30% باقیماندة نمونهها انجام شد. نتایج نشان داد که در تمامی ایستگاهها، با افزایش مقادیر دبی جریان، رسوبات بار کف نیز افزایش مییابد. میانگین سطح معنیداری تفاوت بین مقادیر مشاهداتی و برآوردی مدل شبکة عصبی مصنوعی (59/0) بالاتر از مدل منحنی سنجة رسوب (14/0) است که نشاندهندة تفاوت کمتر مقادیر مشاهداتی و برآوردی مدل شبکة عصبی مصنوعی نسبت به مدل منحنی سنجة رسوب و صحّت بیشتر برآوردهای مدل شبکة عصبی مصنوعی است؛ همچنین در تمام ایستگاهها، شاخص مجذور میانگین مربعات خطا برای مدل شبکة عصبی مصنوعی کمتر از مدل منحنی سنجة رسوب است، به طوری که مجموع مجذور میانگین مربعات خطای پنج ایستگاه برای مدل شبکة عصبی مصنوعی و منحنی سنجة رسوب به ترتیب برابر 7/2505 و 3/5195 محاسبه شد. بالاتر بودن ضریب همبستگی بین مقادیر مشاهداتی و برآوردی در هر پنج ایستگاه، با استفاده از مدل شبکة عصبی مصنوعی (765/0) نسبت به مدل منحنی سنجة رسوب (5038/0)، نشان از تخمینهای دقیقتر مدل شبکة عصبی مصنوعی دارد. در نهایت، مدل شبکة عصبی مصنوعی که از دقّت بالاتری نسبت به مدل سنجة بار کف برخوردار است، به عنوان مدل برتر انتخاب شد. با توجّه به مشکلات اندازهگیری رسوبات بار کف و اریب زیاد ناشی از محاسبة بار بستر به عنوان درصدی از بار معلّق، نتایج این پژوهش میتواند کمک شایانی به برآورد دقیقتر بار بستر و نیز بار کلّ رسوبی نماید.
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. Extended Abstract 1-Introduction The sustainable development approach is possible by maintaining and managing triple sources of water, soil and vegetation in the watersheds. The existence of natural factors causing erosion in Iran has made Iran have a high potential for soil erosion and sedimentations. The sediment load of the rivers can be divided into two categories, including suspended load and bed-load. Sediment load can be calculated either by direct measurements of sediments or indirectly by sediment transport formulas. Although direct measurements of sediments are more reliable, this is not cost-effective for all rivers. In fact, it is particularly more costly and more complex for bed-load sediments. On the other hand, estimating the bed-load of rivers is very important, because this part of sediment load has a large contribution in total sediment load and also plays a significant role in filling the reservoirs of dams. Due to the complexity of the bed-loads transport phenomenon, the relatively precise estimation of bed-load sediments is problematic in many rivers, and requires case studies. Therefore, evaluation and selection of the most appropriate methods for bed-load estimation are necessary. The present study aims to compare the efficacy of ANN (Artificial Neural Network) and SRC (Sediment Rating Curve) statistical models in five rivers of Iran to estimate the bed-load sediments. 2- Materials and Methods Collecting bed-load measurements data and their respective flow discharges, 5 hydrometric stations with the highest number of samples were selected. Then, SRC and ANN models were developed using 70% of samples. In order to evaluate the accuracy of the estimations of the two models, the estimated bed-load values of the two models for the remaining 30 percent of the flow discharge samples were compared with the corresponding observed values using correlation coefficient (R) and root mean square error (RMSE) indices. Independent t-test was also used to test the significance of the differences between the observed and estimated values of the two models. 3-Results and Discussion Although based on the independent T-test, estimated values of both models are satisfactory, the results of Root Mean Square Error (RMSE) index indicates that there are lower differences between the observed and estimated bed-load values for the ANN model in all hydrometric stations. The correlation coefficients between the observed and estimated values of the SRC model are the only significant for Armand station, while correlation coefficients between observed and estimated values of the ANN model are significant (at 5% confidence level) for all stations. These results show that the estimations of ANN model are more accurate than those of SRC model. The result also showed that in all hydrometric stations, bed-load has been increased by increasing the amount of flow discharge. Because of the complex relationship between the bed-load sediment and flow discharge, it is recommended that Artificial Neural Network model which is well adapted to cope with these complex relationships be used for more accurate bed-load estimations. It should be noted that in this research, flow discharge was used as the only input of ANN model to estimate the bed-load sediments, while these models are capable of using various parameters affecting bed-load discharges as model inputs. 4- Conclusion The purpose of this study was to determine the suitable model to estimate bed-load sediments in 5 hydrometric stations located on different rivers of Iran. The results showed that in all hydrometric stations, there is a direct relation between flow discharge and bed-load sediments. In other words, bed-load discharge has been increased by increasing the amount of flow rate. This study also indicated that bed-load estimations of ANN model are more accurate than those of SRC model. Of course, due to the complex relations between the flow and bed-load sediment discharges, the suitable model must be determined at each hydrometric station for more accurate estimations of this variable. However, regarding higher accuracy of the Artificial Neural Network estimates, it is recommended that this model be used to estimate bed-load sediments in lack of bed-load data.
https://ges.razi.ac.ir/article_815_c787386bc2637e497e1d6df91b7c4403.pdf
بار رسوبی
نسبت بار کف
بار معلّق
انتقال رسوب
دقّت برآورد
Sediment Load
The Ratio of Bed-Load
Suspended Load
Sediment Transport
Estimation Accuracy
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
45
62
824
Research Paper
امکان سنجی تولید پسته کمنهاده (مطالعه موردی: منطقه دشت رباط شهربابک)
Feasibility Study of Low- input Pistachio Production: Case Study of Dasht-e-Rabat Region- Shahr-e-Babak County
فرنگیس سادات حسینی دانا
dohouie.farangis@gmail.com
1
مهدی نوری پور
mnooripoor@yu.ac.ir
2
دانشجوی کارشناسی ارشد ترویج کشاورزی، دانشگاه یاسوج، یاسوج، ایران
دانشیار ترویج کشاورزی و توسعة روستایی، دانشگاه یاسوج، یاسوج، ایران
طی دهههای اخیر، توجّه به رویکردهایی نظیر کشاورزی ارگانیک به عنوان راهکاری برای حلّ مشکلات و حفظ تعادل زیستمحیطی به منظور پایداری مطرح شده است؛ امّا از طرف دیگر، با توجّه به ماهیت کشاورزی ارگانیک که عدم استفادة کامل از موادّ شیمیایی در فرایند تولید است و عملا ًاجرای آن اندکی مشکل است. یکی از راهکارهایی که در راستای همین رویکرد طی سالهای اخیر برای حفظ محیطزیست بهویژه در بخش کشاورزی موردتوجّه قرار گرفته است، تولید محصول سالمتر با استفادة کمتر از نهادهها است؛ لذا، با توجّه به اهمّیّت این موضوع، هدف از پژوهش حاضر، امکانسنجی تولید پستة کمنهاده در منطقة دشت رباط شهرستان شهربابک بوده است. جامعة آماری پژوهش حاضر، شامل باغداران پستة منطقة دشت رباط شهرستان شهربابک بودند (2500 نفر)که با توجّه به جدول بارتلت، 189 نفر با استفاده از نمونهگیری تصادفی سهمیهای انتخاب و دادهها از طریق پرسشنامه جمعآوری شدند. روایی محتوایی ابزار پژوهش توسّط متخصّصان توسعة روستایی تأیید و پایایی ابزار سنجش نیز با استفاده از ضریب آلفای کرونباخ که مقدار آن برای گویههای مختلف بین 70/0 تا 89/0 به دست آمد، مورد تأیید قرار گرفت. نتایج حاصل از یافتههای توصیفی و تی تست تکنمونهای نشان داد میانگین موجود هر یک از عوامل زمینهای، اقتصادی، قانونی - نهادی و عوامل اجتماعی پایینتر از وضعیّت مطلوب است. در حالی که عوامل فنّی و فردی (نگرشی) در وضعیّت مطلوبی قرار دارند؛ بنابراین، به طور کلّی، تولید محصول پستة کمنهاده در منطقة مورد مطالعه، در حال حاضر چندان امکانپذیر نیست؛ همچنین، نتایج تحلیل رگرسیون لجستیک نشان داد که مؤلّفههای عوامل نگرشی، عوامل فنّی، آگاهی از مدّتزمان لازم برای کمنهاده کردن باغات، از مهمترین عوامل تأثیرگذار بر تولید محصول کمنهاده است.
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.
Extended Abstract
1-Introduction
A look at the development of different countries shows that one of the most important sectors that influence the development process, is always the agricultural sector. On the other hand, there are many concerns around the world about the effects and consequences of some agricultural activities on the environment and society. The human struggles with the nature which has been intensified after industrial revolution with the advent of chemicals having devastative effects on nature. The use of chemical pesticides and planting of high yielding crops and grasses increased agricultural production, but this increasing trend was associated with environmental problems. The emergence of these problems has caused the world's people to move in with a global approach to organic or at least low input agriculture. The organic farming system is a comprehensive production management system, whose implementation involves the results such as product health, biodiversity, life cycle preservation and biological soil management. Generally, the purpose of organic farming is to increase the productivity of crop production, while maintaining the soil fertility, increasing the production of the product with the least reliance on the use of chemicals. Garden products in Iran are of special importance because most of the agricultural exports in Iran belong to them. Pistachio is one of the most important export products of the agricultural sector in Iran, which annually, despite the fact that the area under cultivation of pistachio gardens in the country was 450 thousand hectares and the production of these gardens was about 187 thousand tons dry pistachios, but only a very small percentage of these products are produced without using fertilizers and poisons, or organically with minimal use of pesticides and chemicals. Therefore, considering the problems facing pistachio production of Iran, including environmental pollution and human health, in one hand, and market demands on the other hand, the production of organic or at least, low-input pistachios has its own importance. Thus, the aim of this study was to study the feasibility of low input pistachio production in Dasht-e-Rabat region of Shahr-e-BabakCounty.
2- Material and Methods
This study was an applied research based on goal and quantitative in terms of approach and survey in collecting data. Research population of the study consisted of pistachio producers in Dasht-e-Rabat area of Shahr-e-Babakthat about 189 ones of them were selected as the research sample using statistical sampling tables. Since the area of Dasht-e-Rabat consists of two villages of Rabat and Mansel Abad, the sample was distributed in proportion to their populations. Thus, the sampling technique was quota random sampling. The required data in this study were compiled using a six-part questionnaire (contextual, economic, legal-institutional, technical, social, and attitudinal) based on the five-part Likert scale. Face validity of the questionnaire was verified by related specialists. Also, the reliability of the supposed questionnaire was verified calculating Cronbach’s Alpha coefficient in a pilot study. The collected data were analyzed using SPSS software. Data analysis techniques were descriptive (i.e. coefficient of variations, mean score and standard deviation) and also inferential including one sample t-test and logistic regression.
3-Results and Discussion
The findings of descriptive analysis of the factors affecting the possibility of low input pistachio production and one-sample t-test showed that among factors (contextual, economic, legal-institutional, technical, social and attitudinal) affecting the possibility of low-input pistachio production, the average status of the contextual, economic, legal-institutional and social factors were lower than the desired situation, but the technical factors and attitudes were in a favorable situations. On the other hand, the results of the logistic regression analysis showed that the attitudinal factors, technical factors and knowledge about the time required to minimize inputs, were as important factors in predicting the production of low input pistachios.
4-Conclusion
Generally, the research results indicate that the factors affecting the possibility of low input production in Robat district of Share Babak region are lower than their optimal level. Therefore, it can be concluded that low-input pistachio production is not feasible at this time, but it is expected that by adopting appropriate policies and programs, a better situation will be established in future.
https://ges.razi.ac.ir/article_824_19568a41a7b39069822912536e2378de.pdf
امکان سنجی
کشاورزی کمنهاده
کشاورزی ارگانیک
پسته
شهربابک
Feasibility Study
Low-Input Agriculture
Organic Agriculture
Pistachio
Shahr-e-Babak
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
63
80
825
Research Paper
نقش سنجههای سیمای سرزمین و فرایندهای مکانی تغییر در ارزیابی کارایی مدل ژئومد (مطالعه موردی: حوضه آبخیز نکارود)
The Role of Landscape Metrics and Spatial Processes in Performance Evaluation of GEOMOD (Case Study: Neka River Basin)
شریف جورابیان شوشتری
sharif_shooshtari@yahoo.com
1
کامران شایسته
ka_shayesteh@yahoo.com
2
مهدی غلامعلی فرد
m.gholamalifard@modares.ac.ir
3
محمود آذری
azarimahmood@yahoo.com
4
خوان ایگناسیو لوپز مورنو
nlopez@ipe.csic.es
5
دانشجوی دکتری محیطزیست، دانشگاه ملایر، ملایر، ایران
استادیار ارزیابی محیطزیست، دانشگاه ملایر، ملایر، ایران
استادیار ارزیابی محیطزیست، دانشگاه تربیت مدرس، نور، ایران
استادیار آبخیزداری، دانشگاه فردوسی مشهد، مشهد، ایران
محقّق هیدرولوژی، مؤسّسة تحقیقات ملّی، ساراگوسا، اسپانیا
ارزیابی کارایی مدل پیشبینی تغییرات پوشش سرزمین، بخش مهمّی جهت اطمینان از صحّت نتایج حاصل است. هدف پژوهش حاضر، ارزیابی کارایی مدل ژئومد با استفاده از سنجههای سیمای سرزمین و فرایندهای مکانی تغییر جهت پیشبینی تغییرات جنگل در حوضة آبخیز نکارود، شمال ایران است. جهت انجام این کار، از نقشههای پوشش سرزمین سالهای 1363، 1380 و 1389 به عنوان نقشههای واقعیّت زمینی استفاده شد. نقشة شایستگی انتقال از جنگل به غیرجنگل با استفاده از ترکیب خطّی وزن داده شده، تولید شد. از توابع عضویت فازی برای استانداردسازی و از تحلیل سلسلهمراتبی نیز به منظور وزندهی معیارها استفاده شد. سنجههای سیمای سرزمین شامل مساحت کل، تراکم لکّه، تراکم حاشیه، چینخوردگی ابعاد، دایرة محدودکننده، سوراخشدگی (مشبّکشدگی)، پراکندگی و مجاورت با استفاده از نرمافزار کمّیکردن الگوی سیمای سرزمین (فرگستتس) و فرایندهای مکانی تغییر با استفاده از درخت تصمیمگیری در محیط مدلساز تغییر سرزمین محاسبه شدند. بیشترین میزان خطای نسبی حاصل از مقایسة نقشة واقعیّت زمینی با نقشة پیشبینیشده برای سنجههای تراکم لکّه، دایرة محدودکننده و سوراخشدگی به دست آمد؛ در صورتی که مدل توانست با دقّت بالایی مساحت، پیچیدگی اشکال، تکّهتکّهشدگی، فشردگی و ناهمگنی مکانی لکّههای جنگلی را پیشبینی کند؛ همچنین فرایند مکانی تغییر حذف طی سالهای مورد مطالعه با توجّه به کاهش مساحت و تعداد لکّهها اتّفاق افتاد که مدل نیز به درستی همین فرایند را پیشبینی کرد. نتایج مطالعة حاضر نشان داد این روش با کارایی بالایی میتواند درک جامع و کاملی از عدم قطعیّت صحّت نتایج تولیدشده ارائه دهد.
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.
Extended Abstract
1-Introduction
Land cover changes are recognized as a major driver of global ecosystem changes as well as key factor in global climate change (Tian et al., 2011). In order to analyze and predict these changes, researchers have designed different types of models. There are several sources of uncertainty in simulation models that can be categorized into three categories including data, model, and process of future change (Pontius & Neeti, 2010). Several models have been developed to predict land cover changes such as CLUE-S (Verburg et al., 1999), DINAMICA (Soares-Filho et al., 2002), Land Change Modeler (Eastman, 2006), CA-Markov (Eastman, 2006), and GEOMOD (Pontius et al., 2001). GEOMOD is a model based on Geographic information system that can simulate the location of deforestation zone using bio-geographical and socio-economic characteristics as well as spatial data of forest in different periods (Echeverria et al., 2007). As an advantage of GEOMOD, compared with complex models, it does not require large amounts of data for calibration and validation (Echeverria et al., 2007). Landscape metrics can lead to an increase in interpretation and better evaluation of the results of land cover change models. The main objectives of this study are (1) simulation of Hyrcanian Forest changes in Neka River Basin using GEOMOD; (2) performance evaluation of the GEOMOD model using landscape metrics and spatial processes in landscape transformation.
2-Materials and Methods
Neka River Basin is located in the east of Mazandaran province, north of Iran. The district lies between 53° 17′ 30″ to 54° 44′ 22″ E and 36° 27′ 46″ to 36° 41′ 8″ N. GEOMOD is used to predict dynamics of Hyrcanian Forest for the years 2001, 2010 and 2022 (because the observed land cover maps for the years 2001 and 2010 were available to compare with simulated land cover maps). In this study, a multi-criteria evaluation procedure was used to generate the transition suitability map from forest to non-forest. Multi-criteria evaluation consists of three main procedures: Boolean intersection, Weighted Linear Combination (WLC), and Ordered Weighted Average (OWA). In the present study, WLC was employed to combine factors and constraints. Factors were standardized in spatial information system using fuzzy membership functions. Six factors including distance from residential area, distance from agricultural land, distance from rangeland, distance from road, elevation and slope were employed. Analytical Hierarchy Process was used to weight the criteria using pairwise comparison (Moeinaddini et al., 2010). Seven landscape metrics were selected for accuracy assessment of model using Fragstats software (McGarigal et al., 2002). The relative error was calculated to quantify the difference between landscape metrics derived from the observed and the simulated layers (Sakieh and Salmanmahiny, 2016). Analysis of spatial processes was also calculated to evaluate the model performance using decision tree algorithm in Land Change Modeler (Bogaert et al., 2004).
3-Results and Discussion
Forest showed a decrease of 3000 ha (4.1 % of forest area, and 1.6 % study area) from 1984 to 2001. This class decreased from 69169 ha to 67198 ha (2.8 % of forest area, and 1.1 % study area) between 2001–2010 period. According to the modeling results, a decrease 4225 ha was revealed in this class of land cover.
The area under forest showed a decreasing trend from 2001 to 2010, and the model showed a good consistency between the forest areas of reference and simulated maps with a relative error value of zero. Observed maps depicted a decreasing trend for patch density during 1984–2010 (from 1.5 to 1.3). GEOMOD could also predict a decreasing trend for this index. Difference between the real data and modeling effort in 2010 was more than 2001, and the model was not able to simulate the patch density with high accuracy. Model was not able to predict the values of patches per unit area, but it is well predicted area and distribution of largest patches according to good agreement of the forest area for 2001 and 2010. Edge density decreased in ground truth layer during 1984–2010 (from 14.7 to 12.9 m/ha). The model results also demonstrated a decreasing trend with relative error values of < 1 in both years for this index. Decrease in edge density of simulated and reference maps suggest the reduction of spatial heterogeneity and conversion of forest patch to non-forest class (Munsi et al., 2010). Mean fractal dimension index indicates the complexity of the patch shape. According to the results of this metric, forest in the study area showed simpler in shape during 23 years. GEOMOD also predicts less complexity in shape but the difference between ground truth data and simulation in 2001 (relative error of 0.4 %) was more than 2010 (relative error of 0.1 %). Reference data for mean related circumscribing circle index showed decreasing trend (from 0.33 to 0.30) during 1984–2010. In terms of this index, the model generates good agreement between reference and observed maps in 2001, and 2010 with relative error values of 5 %, and 0.4 %. Spatial process was attrition in the ground truth data due to the reduction in area, and number of patch per unit area during 1984–2001, and 2001–2010. Similarly, the simulation outputs represent attrition for two periods.
4-Conclusion
Landscape metrics lead to increase and improve performance evaluation of land cover models. Type and number of indices used in various studies are different and various metrics are recognized effective and useful in assessing the characteristics of models. In the present study, seven metrics were used to evaluate the model performance in simulating of forest pattern. These metrics indicated high potential for evaluating simulation success based on description of shape, density, aggregation, interspersion and juxtaposition, and proximity of patches. Besides, the results of this study showed that spatial change processes are also useful tools for evaluating the performance model.
https://ges.razi.ac.ir/article_825_a7ee87a9dea264343bbf8c7c4c101dc8.pdf
مدلسازی تغییرات پوشش سرزمین
ژئومد
ارزیابی صحّت
سنجههای سیمای سرزمین
فرایندهای مکانی تغییر
Land Cover Change Modeling
GEOMOD
Accuracy Assessment
Landscape Metrics
Spatial Process in Landscape Transformation
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
81
96
826
Research Paper
تأثیر منابع طبیعی بر توسعه کشورها
The Impact of Natural Resources on the Development of Countries
محمدجواد بربری
barbari1394@gmail.com
1
عبدالحسین کلانتری
2
حسین راغفر
h.raghefar@alzahra.ac.ir
3
غلامرضا غفاری
4
دانشجوی دکتری جامعهشناسی توسعه و اقتصاد، دانشگاه تهران، تهران، ایران
دانشیار جامعهشناسی، دانشگاه تهران، تهران، ایران
دانشیار اقتصاد، دانشگاه الزهرا، تهران، ایران
دانشیار جامعهشناسی، دانشگاه تهران، تهران، ایران
با وجودی که فراوانی منابع طبیعی میتواند با آمادهسازی نهادههای تولید و تأمین مالی زمینهساز توسعه باشد، تأثیر آن بر رشد و توسعه مورد بحث است و برخی صاحبنظران معتقدند که فراوانی منابع طبیعی، بر توسعه اثر منفی بر توسعه دارد و کشورهای دارای منابع طبیعی بسیار، با نفرین منابع مواجه میشوند. هدف پژوهش حاضر، بررسی تأثیر منابع طبیعی بر توسعة کشورهاست. به همین منظور، مجموعهای از 12 کشور منتخب (درحالتوسعه، توسعهیافته و تازهصنعتیشده) با درجات متفاوت برخورداری از منابع طبیعی، طی سه دورة زمانی انتخاب شده است. این تحقیق، با استفاده روش تحلیل تطبیقی که مبتنی بر جبر بولی است، صورت گرفت. کشورهای منتخب عبارتند از: انگلستان، ایالات متّحده، ایران، برزیل، ترکیه، چین، روسیه، ژاپن، کرة جنوبی، مالزی، مصر و هند. شاخص توسعة انسانی به عنوان متغیّر وابسته و شاخصهای مردمسالاری، سرانة تولید ناخالص ملّی در ابتدای دوره، سطح سواد، استعداد کشاورزی، سرانة جنگل، منابع انرژی فسیلی و رانت منابع طبیعی به عنوان متغیّرهای مستقل انتخاب شدهاند. نتایج پژوهش نشان میدهد که فراوانی منابع طبیعی در صورتی که با توانمندی نیروی انسانی، ساختار مناسب سیاسی و مدیریت صحیح همراه باشد، شرایط مناسبی برای توسعه ایجاد میکند. فقر منابع طبیعی در صورتی که با ساختار نامناسب سیاسی و توانمندی پایین منابع انسانی همراه باشد، نمیتواند منجر به توسعه شود؛ در این صورت، در مورد اثرات وفور منابع طبیعی بر توسعه باید با احتیاط اظهار نظر کرد. توضیح روشنتر آنکه نمیتوان استنباط کرد که اگر فراوانی منابع طبیعی در کشوری وجود نداشت، از لحاظ توسعه در وضعیّت بهتری قرار میگرفت؛ زیرا کشورهای زیادی وجود دارند که دارای سطوح پایین منابع طبیعی بوده، امّا در وضعیّت مناسبی از نظر توسعه قرار نگرفتهاند. به بیان دیگر، تأثیر مثبت فراوانی منابع طبیعی بر توسعه، قابل اثبات است؛ امّا نمیتوان اثر معکوس را نتیجه گرفت.
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.
Extended Abstract
1-Introduction
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. However, resource review shows that the abundance of natural resources does not always lead to economic growth and there is a controversy among the researchers. Opponents will argue for reasons such as job mitigation, the ineffectiveness of the national government through government enlargement, economic rents, and the struggle of political groups and supporters of supplying production and financial needs.
Therefore, the present study aims to study the effects of natural resources on the development of 12 countries (Iran, Brazil, Russia, China, Egypt, South Korea, Japan, United Kingdom, United States, Malaysia, India, Turkey) that have different levels of development and various degrees of natural resource utilization in a comparative approach using several indicators. In addition this comparison has been done over three periods to examine the role of time and technology.
2-Materials and Methods
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. As a result, four phases of data fuzzy, formation of values table, a method for analyzing 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. Indicators used include forest per capita, agricultural land per capita, renewable water per capita, farmers' talent, democracy, literacy rate, GDP per capita, energy resources and natural resources rents. Part of the required data was extracted from the Food and Agriculture Organization of the United Nations (FAO) site and some others by historical studies. The data were selected for the 12 targeted countries, with the distribution of the appropriate size and area of the planet, as well as cultural, political and economic varieties.
3-Results and Discussion
The results of the first period (1900-1850) show that a combination of democracy, GDP per capita, literacy, high agricultural potential, forest per capita (low), renewable water per capita (low) and agricultural land per capita (low), the basis for development The United States and the United Kingdom.
In this period, due to the fact that oil had no effect on the economies of the countries, it was not used in modeling. In the second period (1900-1950), although the developed model is the same for both countries, the level of development of the United States is higher than the United Kingdom due to the higher level of natural resources and the availability of oil resources. The UK has also increased its development through looting other countries' natural resources. In the course of this period, Japan has begun the development and has reached the level of development at the end of the period, but its development model is unlike the other two countries. In the third period (1950-2000) by the end of colonialism and independence, the process of industrialization of societies began by importing of energy resources. The development model is included democracy (high), literacy (high), energy resources (low) and natural resources rents (low). Unlike other countries, the Russian development model is not included, but it is not analyzed as the model coverage is less than 0.7.
4-Conclusion
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 (1900-1950), 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.
https://ges.razi.ac.ir/article_826_ff952bb047324bfa42e85ded74fe7b0b.pdf
منابع طبیعی
توسعه
تحلیل تطبیقی
نفرین منابع
رانت منابع طبیعی
Natural Resources
Development
Comparative-Qualitative Analysis
Resource Curse
Rent of Natural Resources
per
دانشگاه رازی
جغرافیا و پایداری محیط
2322-3197
2676-5683
2017-09-23
7
3
97
115
827
Research Paper
ارزیابی رابطه بین پایداری مناطق روستایی و توسعه گردشگری روستایی با تعدیلگری درک مردم بومی در روستای قلات شیراز
Assessment the Relationship between Rural Sustainability and Tourism Development by Modifier Role of Local People Perception
محمد نجاررزاده
mnajjarzadeh@semnan.ac.ir
1
مجید نعمت الهی
mnematolahi@live.com
2
حسین بلوچی
hossinbalochi@alumni.ut.ac.ir
3
استادیار جامعهشناسی، دانشگاه سمنان، سمنان، ایران
کارشناس ارشد مدیریت گردشگری گرایش بازاریابی، دانشگاه سمنان، سمنان، ایران
دانشجوی دکتری مدیریت بازاریابی بینالملل، دانشگاه سمنان، سمنان، ایران
همواره مردم بومی مناطق روستایی، نقش بسیار مهمّی در تصمیمگیریهای توسعة گردشگری روستایی دارند؛ به گونهای که به عنوان یکی از اصول توسعة پایدار گردشگری شناخته میشوند؛ بنابراین، درک مردم بومی نسبت به توسعة گردشگری روستایی به مدیران و سیاستگذاران گردشگری در تصمیمگیری بهتر کمک میکند. در این راستا، هدف پژوهش حاضر بررسی رابطة بین پایداری مناطق روستایی و توسعة گردشگری روستایی با تعدیلگری درک مردم بومی است. جامعة آماری پژوهش، مردم محلّی منطقة قلات شیراز است. بدین منظور، نمونهای برابر با 385 نفر بر اساس جدول مورگان و با روش نمونهگیری در دسترس انتخاب شد. دادهها با استفاده از پرسشنامه گردآوری شد. پایایی پرسشنامه با استفاده از آلفای کرونباخ و پایایی مرکب و روایی آن با استفاده از روایی همگرا و واگرا مورد سنجش قرار گرفت. به منظور دستیابی به اهداف پژوهش، از رویکرد کمترین مربعات جزئی و مدل معادلات ساختاری استفاده شد. نتایج نشان داد بدون در نظر گرفتن درک مردم بومی به عنوان متغیّر تعدیلگر، پایداری عمومی منطقه رابطة مثبت و معنیداری با توسعة گردشگری روستایی دارد و رابطة معنیدار همة ابعاد پایداری با توسعة گردشگری روستایی تأیید شده است؛ ولی با ورود متغیّر درک مردم بومی به مدل ساختاری، از لحاظ اقتصادی دیدگاه مردم محلّی نسبت به توسعة گردشگری مثبت نبوده است. از نگاه مردم بومی، جنبههای مثبت اقتصادی گردشگری قابل توجّه نبوده و آثار منفی محیطی منطقة قلات با ورود گردشگر بیشتر شده است.
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
Extended Abstract
1-Introduction
Local people have always played an important role in decision-making of rural tourism development. They have known as an important principal of sustainable tourism development. Therefore, local people perception towards rural tourism development helps tourism managers and policy makers to make a better decision in rural destinations. In addition, by the role of local people perception in tourism decisions and by the importance role of previous studies, undoubtedly the process of rural tourism development will be depended on local people. Rural district of Qalat in Shiraz has natural and historical potential for tourists and rural tourism development as well. But there is no study about rural development in this region. Moreover, the role of local people and different aspect of sustainability (economic, social and environmental) has not been investigated in this region. Given the assessment of tourism sustainability and the role of local people, this study aims not only to investigate the modifier role of local people perception towards rural tourism development in Qalat Region but also to consider all aspects of sustainability in the way of rural tourism development.
2-Materials and Methods
In this research the most important aspects of sustainability have been considered in the village of Qalat located in Shiraz. The sample population was the local people of Qalat village. According to Morgan table, 385 people were selected. Questionnaire was used to collect data. In this research, which is an applied one, a descriptive-survey method is used. Data were analyzed by Structural Equation Modeling (LISREL) and Warp Partial Least Squares (Warp PLS) method. Questionnaire's validity was measured by internal consistency whose validity was measured by convergent and divergent validity. Convergent validity was measured by Average Variance Extracted and divergent validity measured by Fornell- Larcker criterion.
3-Results and Discussion
Ignoring the modifier role of local people perception, economic sustainability has a significant relationship with rural tourism development. The impact level of economic sustainability was (0/22), with due attention to significant level (3/14), it can be said this relationship was significant. This impact also confirmed in PLS software, based on impact factor (0/22) and the level of significant (<0/01). Social sustainability has significant relationship with rural tourism development considering impact factor (0/34) and significant value (5/97). Among the sustainability aspects, social sustainability has the most effect on the rural tourism development. This impact also confirmed in PLS software based on its impact factor (0/3) and significant value (<0/01). The impact level of environmental sustainability was (0/13), with due attention to significant level (2/11), it can be said this relationship was significant. This impact also is confirmed in PLS software based on impact factor (0/13) and the level of significant (<0/01). By the role of modifier local people perception, the impact level of economic sustainability on rural development has not changed proving that modifier hypothesis of local people modifier has not been confirmed in this relationship. However, local people perception has a significant impact on the relationship between social sustainability and rural tourism development which could modify this relationship. Finally, local people perception could not modify the relationship between environmental sustainability and rural tourism development.
4-Conclusion
Structural modeling of this research, ignoring and considering role of modifier show that the level of rural tourism development extremely depends on general sustainability. In present study, the environmental dimension has a significant impact on the development of rural tourism. It should be noted that rural tourism can cause environmental problems which is considered as a motivation for environmental conservation at the same time. In fact, it can act like a double- edged sword. Tourism planner has paid attention to both perspectives. Except for of environmental problems, paying attention to economic revenues and increasing local businesses has affected rural tourism development process. The best sustainable rural development model is to pay attention to all three dimensions of sustainability. Despite the success of social sustainability in Qalat region, it can be said that general sustainability has faced the challenge, due to the local people perception towards tourism development process and lack of economic and environmental sustainability. The results show that the impact level of overall sustainability is higher than each dimension, so this structure should be considered as a general perspective. It means that addressing just one dimension of this variable will cause disorder in the region and retard growth rate and development in the long term. Therefore it is recommended to achieve rural growth and development, pay attention to each economic, social and environmental dimensions in the same time and the same level, in order to provide growth and development opportunities for rural people.
https://ges.razi.ac.ir/article_827_66c3032f15219c4c4e0a03e51d62268a.pdf
تعدیلگری
پایداری
کمترین مربعات جزئی
Modifier
Sustainability
Partial Least Squares