neural network model
در نشریات گروه جغرافیا-
نشریه جغرافیای طبیعی، پیاپی 48 (تابستان 1399)، صص 105 -127
در این پژوهش ابتدا از طریق مطالعه پژوهش اقدام به شناسایی معیارها و زیرمعیارهای که در جهت پایداری زیست محیطی موثر است شد. پس از پایان مراحل دلفی ، معیارهای منابع و خدمات محیط ، سلامت محیط و انرژی به عنوان مهمترین معیارهای ارزیابی پایداری زیست محیطی در شهر بابک انتخاب گردیدند سپس با استفاده از مدل شبکه عصبی به تحلیل و ارزیابی پایداری زیست محیطی شهر بابک پرداخته شد. در این مطالعه خشکسالی در شهر بابک را طی یک دوره آماری سی و دو ساله 1361 - 1392 با شاخص SPI خشکسالی مورد تجزیه و تحلیل قرار گرفت. این شاخص به طور خاص برای سری های زمانی شش؛ دوازده و چهل و هشت ماهه محاسبه شد. که شهر بابک طی دوره آماری سی و دوساله و بویژه هفت ساله اخیر مواجه با خشکسالی بوده که در مقیاس سالانه شش ماهه بیشتر خشکسالی های آن از نوع خشکسالی های ضعیف تا متوسط است.
کلید واژگان: پایداری زیست محیطی، مدل شبکه عصبی، خشکسالی، شاخص SPI، شهر بابکIn this study, first, by studying the research, criteria and sub-criteria were identified that are effective in terms of environmental sustainability. After the Delphi stages, the criteria of environmental resources and services, environmental health and energy were selected as the most important criteria for assessing environmental sustainability in Babak, then using the neural network model to analyze and evaluate the environmental sustainability of Babak. In this study, drought in Babak city was analyzed with a SPI index of drought during a statistical period of 32 years 1361-1392. This index is specifically for time series six; Twelve and forty-eight months were calculated. The city of Babak has been facing drought during the statistical period of thirty-two years, especially the last seven years, and on an annual scale of six months, most of its droughts are mild to moderate droughts. But in the long-term Myas 48 months, 75% of the droughts were severe and very severe, which shows a high relationship with the quantitative and qualitative decline of groundwater in this area.
Keywords: environmental sustainability, neural network model, drought, SPI index, Babak city -
امروزه با توجه به روند رو به رشد جمعیت در شهرها و روستاها و تمایل به زندگی شهری بیشترین تغییرات کاربری اراضی در نواحی شهری به وقوع می پیوندد. توسعه سریع شهری در دهه های اخیر موجب تغییرات وسیعی در الگوی کاربری زمین پیرامون شهرها شده و تاثیرات زیست محیطی و اجتماعی-اقتصادی زیادی را به همراه داشته است. در این پژوهش با استفاده از تصاویر ماهواره ای تغییرات کاربری اراضی و شبیه سازی رشد و توسعه شهر رشت به کمک مدل شبکه عصبی و سلول های خودکار زنجیره مارکوف انجام گرفت. برای این منظور از تصاویر سال های 2000، 2008 و 2017 ماهواره لندست استفاده گردید. پس از پیش پردازش تصویر و انتخاب بهترین ترکیب باندی، تصاویر با روش شبکه عصبی طبقه بندی شد. سپس تصاویر طبقه بندی شده در مدل ساز تغییرات زمین وارد گردید و نقشه های خروجی مدل ساز با روش CA-MARCOVE برای سال 2027 پیش بینی شد. نتایج بدست آمده در فاصله زمانی 2000 تا 2017 نشان می دهد که تغییرات مساحت در اراضی شهری، شالیزار و جنگل به ترتیب به میزان 87/9041، 03/7841 و 78/55 هکتار بوده که میزان آن در شهر رشت مثبت و در شالیزار و جنگل منفی می باشد و نقشه پیش بینی سال 2027 با روش CA-MARCOVE نیز موید افزایش قابل توجه کاربری شهری به مقدار 04/14105 هکتار در سال های آتی است. نتایج این پژوهش نشان می دهند که ادامه روند فعلی تغییرات کاربری اراضی به نتایج مضر زیست محیطی و به تبع آن آسیب های اقتصادی- اجتماعی جبران ناپذیر می انجامد. بنابراین ضروری است دستگاه برنامه ریزی و مدیریت منطقه، رویکردی جامع برای جلوگیری از مشکلات زیست محیطی آتی و مهار توسعه افقی سکونتگاه ها در این منطقه در پیش گیرد.
کلید واژگان: کاربری اراضی، تصاویر ماهواره ای، مدل شبکه عصبی، سلول های خودکار زنجیره مارکوف، شهر رشتNowadays, most land use changes occur in urban areas, due to the growing population in cities and villages and the desire to live in urban areas. Urban rapid development in recent decades has led to large changes in the cities around and has had many environmental impacts. In this research, we evaluated land use changes and urban development simulation using satellite imagery and with neural network model and Markov chain auto-cells in Rasht city. For this purpose, Landsat satellite imageries were used from 2000, 2008 and 2017. After preprocessing the image and selecting the best band combination, the images were classified using the neural network method. Then the classified images were entered into the land changes model and predicted modeling output maps using the CA-MARCOVE method for 2027. The results obtained between 2000 and 2017 indicate that the area changes in urban lands, rice fields and forests were 9041.88, 7841.33 and 55.78 hectares, respectively, which were positive in Rasht city and negative in rice fields and forest and the projection map for 2027 with the CA-MARCOVE method also indicated a significant increase in urban use of 14105.04 hectares in the coming years. The results of this study indicate that the current trend of land use changes will lead to adverse environmental impacts and, consequently, irreversible socio-economic damage. Therefore, it is essential for the region planning and management unit to adopt a comprehensive approach to conduct future environmental problems and to curb the horizontal development of settlements in the area.
IntroductionThe importance of land use as a key component in natural resource management, environmental change and a dynamic and affecting biological condition requires accurate quantitative and qualitative information to be provided and varied in the short term. (Triantakonstantis & Stathakis, 2015: 194; Akbari and Rezaei, 1397: 94). In the meantime, remote sensing data provide valuable multi-temporal data on the processes and patterns of land cover change and land use, and help to develop an understanding of the impact of human activities on natural resources. (Esfahanzadeh, 2016: 34). Urban development is a global phenomenon and one of the most important phenomena that has a great impact on both nature and human environment due to its many ecological and socio-economic aspects. The city of Rasht, like other urban areas, has undergone numerous changes in agricultural and horticultural uses and residential uses over many years. In this study, satellite imagery is used to evaluate land use changes and simulate urban development in the period 2000 to 2017, so that the results of the research can be of great help in micro planning. And provided the experts with a great deal to prevent environmental degradation.
MethodologyIn this study, using satellite imagery of land use changes and simulation of growth and development of Rasht city using neural network model and Markov chain automated cells. Landsat 2000, 2008 and 2017 images were used for this purpose. After image preprocessing and selecting the best band composition, the images were classified by neural network method. Selected classes include 7 classes, forest, man-made areas, paddy fields, sand, sea, ponds and vacant lots. The digital layers used to classify and apply Markov auto cells include: GPS capture points for image classification and accuracy assessment, proximity to main roads, river avoidance, distance from surrounding villages, slope And height. Then, the classified images were entered into the land change modeler and the model outputs were predicted by CA-MARCOVE for 2027.
Results and discussionThe results show that out of the total area of man-made area increased, 3612 hectares were converted to paddy fields and 1 hectare to water use, 2138 hectares were made to man-made areas, 1646 hectares to the sea and 24 hectares to the Bayer area. In the present study, Markov chains and automated cell fusion methods were used to predict land use changes in Rasht. To do this using IDRISI software, three series of land use maps were prepared for the years 2000 to 2017. Finally, based on the factors involved in urban land use changes in the study area, the inputs of the automated cell model were selected as Table (1). The prediction is a function of the model inputs. Table 1: Input variables in the automated cell simulation model Row Variables affecting land use 1 near the main ways 2 distance from the river 3 elevation 4 slopes 5 distance from surrounding villages Source: Authors' Studies, 2018 Then, by calculating the Kramer coefficient in the model, one can obtain an estimate of the correlation of each variable with the existing land uses and hence its ability to predict land use changes. By repeating 10,000 times of trial and error in the multilayer neural network, calibration and conversion potential maps were generated in the images from 2000 to 2008 and 2008 to 2017. Following the acceptable accuracy of the model for prediction, using the CA-Markov model, the 2027 User Prediction Map was prepared for the study area shown in Figure (1). Figure 1: Land use forecasting map of Rasht city using CA-Markov for 2027, Source: Research Findings, 2018. Table 2. Land use area of 2027 using CA-Markov User class 2027 forecast area (ha) Jungle 0/13 Sands 0/9639 Water 974/26 rice field 4797/82 Man-made areas 14105/04 Wasteland 1599/03 Sea 6/39 As can be seen from Table 2, the area of most land uses, except for man-made areas and the sea, declined as forest land use from 1031/95, sandy land from 15/42, water from 22/333, paddy fields from 88/12/85 and wasteland from / 66. 3629 hectares decreased in 2000 to 0.13, 0.96, 97.26, 47.72 and 15.03 ha in 2027, respectively. In contrast, the land use area of the man-made areas increased sharply to 14105.04 hectares, while sea use increased by 6.39 hectares.
ConclusionThe use of Landsat satellite imagery is useful in terms of availability, duplicate coverage and lower cost of source data, as well as determining the extent of land cover changes and land use prediction using the models used in Research can be a good alternative to costly methods of discovering change in the shortest time possible. Other objectives of this study were to use satellite imagery and LCM tools to detect changes occurring in the region during the study years 2000–2008 and 2008–2017. Therefore, multi-layer neural network method was used to detect the changes. Examination of changes from 2000 to 2008 showed an increase in urban class area, with the city area increasing from 6793.91 hectares in 2000 to 8940.41 hectares in 2008. The highest increase in urban area was observed from 2008 to 2017 after image classification. During the study periods, paddy, forest and wilderness land use has been steadily declining, and vegetation use has had a protective role as urban land use. In this study, the prediction of physical growth in the city of Rasht in the coming years (2027) was investigated. This is how the 2017 forecast map was first derived using the CA-MARKOV model. Comparison of the results of the prediction map with that of the image classification showed high accuracy. The 2027 forecast map also shows a significant increase in urban land use by 14105.04 hectares in the coming years. Considering the results, it is possible to study changes in vegetation cover and to prevent its unnecessary changes and transformations. Because vegetation plays an important role in reducing environmental issues in urban areas. In contrast, the disappearance of vegetation causes severe environmental crises in relation to the rapid growth of urbanization and the formation of the thermal island of the city. As a result, vegetation is considered as an indicator of environmental sustainability in urban communities. Therefore, proper vegetation management is considered as an integral part of any sustainable urban development. Since degradation of vegetation and rising surface temperature can have adverse effects on the environment, identifying environmental sensitivities (crises) caused by this factor is essential as it can play an important role in urban development management.
Keywords: Land Use, Satellite image, Neural network model, Markov chain auto-cells, Rasht city -
بررسی نقش سرمایه اجتماعی بر توسعه نواحی روستایی هدف اصلی این تحقیق بوده است. منطقه مورد مطالعه تحقیق دهستان چهاردانگه جزء استان البرز و از توابع شهرستان ساوجبلاغ بوده است. جامعه نمونه از طریق مدل کوکران و برابر 38 خانوار معین شده است. داده های مورد نیاز تحقیق بر اساس مطالعه میدانی و برخی اسناد جمع آوری شده است. برای تعیین پایایی پرسشنامه از روش آلفای کرونباخ (0/75) و برای تعیین روایی از نظرات کارشناسان استفاده گردیده است. داده های جمع آوری شده از طریق آزمون های آماری نظیر آزمون تی، رگرسیون و مدل شبکه عصبی مورد تجزیه و تحلیل قرار گرفته است. نتایج تحقیق نشان می دهد که رابطه معناداری بین سطح سرمایه اجتماعی و توسعه روستایی وجود دارد که در آن مولفه های مشارکت، آگاهی و اعتماد عوامل تعیین کننده هستند. نتایج مدل شبکه عصبی نشان دهنده این است که متغیرهای مشارکت، اعتماد و آگاهی بیشترین تاثیر را در روند توسعه دارند، در حالی که نقش انسجام اجتماعی و شبکه اجتماعی محدودتر می باشد.
کلید واژگان: سرمایه اجتماعی، توسعه، مدل شبکه عصبی، انسجام اجتماعی، دهستان چهاردانگهThe main aim of this paper is analysing the role of social capital on rural development. Research study area is Chahar Dangeh district in Savejbolagh County of Alborz province. Research sample is determined through Cochran's model as 380 households. Required data has been collected based on field study and some documents. Research questionnaire validity is calculated through Cranach's alpha (0/75) and its reliability is measured through viewpoints of experts. Collected data are analyzed through statistical test including T-test, Regression and neural network model. Result shows that there is meaningful relationship between level of social capital and rural development, in which, components of participation, Knowledge and trust are more determinants factor. Results of neural network model depicted those variables such as participation, trust and knowledge has the most important role on the development process, while the role of social coherence and social network is more limited.Keywords: Social Capital, Development, neural network model, Chahar Dangeh district
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