فهرست مطالب

علوم جغرافیایی - پیاپی 31 (پاییز و زمستان 1398)
  • پیاپی 31 (پاییز و زمستان 1398)
  • تاریخ انتشار: 1398/11/05
  • تعداد عناوین: 8
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  • Pages 1-15

    Drought is considered as one of the vital natural disasters that can be occurred in any climate. Given that drought incidence is inevitable, so its recognition is of important in order to efficient management of water. In this article drought forecasts in Tehran and Mashhad are considered. To this Markov models have been applied. At first stage after preprocessing of data, according to precipitation features, lowest temperature, highest temperature and wind Markov chains were created and the possibility of its incidence for next year was calculated, then at second stage precipitation level, lowest and highest temperature were forecasted by Markov hidden models so that based on them necessary decisions for water source management can be taken. Suggested method was compared based on error rate and accuracy by standard hidden Markov models and Bayesian network. The results show that suggested method on Mashhad collection data had 14% and 31% and on Tehran collection data 10% and 15% better accuracy compared to HMM and Bayesian network, respectively.

    Keywords: Drought, water source management, Markov chain, hidden Markov model
  • Pages 16-34

    Water resources shortage is the most important issue discussed regarding the future because the world population will have been over than 9.4 billion as of 2050. As a result, the states will concern mainly the water supply, food and protection of the environment. This research was practiced to identify the factors affecting acceptance of modern irrigation systems used in Yaroogh district in Miandoab. This research is quantitative regarding its nature and applied regarding its goal. Data was collected using a standard-made questionnaire for identifying affecting factors. The reliability of questionnaire was assessed through Cronbach's alpha which was >0.78 for all sections of the questionnaire. To assess the validity of the questionnaire, the board of experts was used considering the goal of research. The research population includes utilizers of water in Baroogh district. The statistical society including 125 subjects that have been studied using survey method. The data was analyzed using SPSS and AMOS software. Results obtained from correlation analysis and structural equations showed that there is a significant relationship among 4 affective factors including attitude, education, socioeconomic factors and acceptance of the modern irrigation systems. Based on the results obtained from this research, it is suggested the public and private sectors focusing on the economic and technical training to predispose the utilizers' knowledge promotion through holding training courses for having them to get familiarized with technology use in modern irrigation systems.

    Keywords: Modern irrigation systems, farmers' acceptance, Miandoab
  • Pages 35-50
    Background and Objectives

    Determining and mapping the soil colour are important to identify the important chemical, biological, and physical properties of the soil, especially through the areas where their measurement is difficult or not precisely practical. Several researchers in different parts of the world have used remote sensing to study soil temperature and humidity and its relation with different uses in environmental sciences. However, using of satellite imagery and remote sensing technology to determine the soil colour have been not observed worldwide in the literature. Therefore, such research can be useful in the field of environmental sciences, especially soil science and geomorphology. Hence, in the present study to study of soil colour through four different classes of calcareous, salty, coarse, and sandy soil samples, with the most colour variation, were used based on two methods of field operation and remote sensing approaches in Harat Plain, Yazd province.

    Materials and Methods

    The study area of Harat Plain is located in the geographical coordination of northern latitude range from 29° 54' 27" to 30° 27' 12" and eastern longitude range from 54° 07' 11" to 54° 36' 16". It covers a surface area of 1220 square kilometers, including a large part of saline land and bare ground and marginal cities of Harat and Marvast. This arid region with typical geomorphology of Central Iranian playas has a mean annual rainfall of 110 mm and an average annual temperature of 20 degrees Celsius.

    Results

    Firstly validation and verification of data revealed total accuracy and Kappa coefficient of 82% and 0.792, respectively indicating comprehensible levels. Then to obtain the soil colour in the field operation, Munsell’s colour system was used and to measure remote sensing data, Landsat 8 imagery was used. Also, with the aim of using remote sensing technology and satellite imagery data for soil science studies, evaluation of different bands in ENVI software and preparation of soil colour map have been done in ArcGIS software. The results revealed that in the calcareous, salty, coarse, and sandy soils, the best band showing the Hue parameter is 5, 10, 7, and 10, respectively. Therefore, in the calcareous, salty, coarse, and sandy soils, the best band showing the Chroma parameter is 7, 7, 1, and 11, respectively. Finally, in the calcareous, salty, coarse, and sandy soils, the best band showing the Value parameter is 6, 11, 11, and 10, respectively. According to the linear equations between soil colour parameters and various bands, the spectrum band, which have the most correlations, were selected for each soil component. Then by combining all produced multi band images, one image was generated that represents the soil colour in respecting regions.

    Conclusion

    In conclusion, for the study area, which is a desert plain in central Iran, Landsat 8 satellite imagery can be used to map the soil colour map for different types of soil units.

    Keywords: Soil Colour, Remote Sensing, Landsat Satellite Imagery, Harat Plain, Yazd Province
  • Pages 51-71

    Landslide Susceptibility Mapping, a background on factors affecting the landslide, its occurrence, risk management and risk prevention. The aim of this study is to prioritize the factors affecting landslide susceptibility mapping and basin load it using the Shannon entropy index. To achieve this goal were taken into account 12 factors affecting the landslide was prepared to study and map the factors mentioned in the GIS. Prioritize the factors identified by the use of Shannon entropy index layer, which had a role in the occurrence of landslides. The landslide susceptibility zoning map was prepared using Shannon Entropy Index and evaluated with ROC And obtained accuracy of the model as well (24/81%) with a standard deviation of 0389/0.

    Keywords: Modeling, Landslide, Zoning, Entropy, basin once Nishapu
  • Pages 91-112

    Climate is one of the main determinant factors in agricultural production. This study aimed to investigate the relationship between climate variables with yield and duration of corn and wheat growth stages. For this purpose, the data related to, the number of days of growth stages, together with climate variables including minimum, average and maximum temperatures, minimum ground temperature, sunshine hours, evaporation, minimum, average and maximum relative humidity, relative humidity at 09 and 15 GMT, the total precipitation, the number of rainy days with 0.1, 1 and 5 mm and more for a 19-year period between 1995-96 and 2013-14 were collected from agrometeorological research station in Darab, Fars Province. Statistical analyses were performed using Pearson correlation coefficient and regression equations. According to the results of this study, evaporation and maximum relative humidity had the highest correlation with the length of the entire corn growth season (correlation coefficient of 0.807). For wheat, the results showed that the highest correlation was observed between the minimum and maximum relative humidity and the length of the growth period at the heading stage (correlation coefficient of 0.867). In addition, the results revealed that the highest impact of climate variables on corn yield occurred at the three leaf stage, so that at this growth stage, the minimum and average of  relative humidity had the highest significant correlation at the 1% probability level with yield (correlation coefficient of 0.890). For wheat, the highest correlation was observed between yield and relative humidity at 09 GMT at the ripening stage. In conclusion, the results showed a good accuracy of the statistical models in estimating the growth period and yield of corn and wheat.

    Keywords: Agricultural Climatology, Crop Yield Estimation, Corn, Wheat, Statistical Model
  • Pages 113-132

    Given the importance of tourism it is composed of a wide range of options; This is only part of a country's industry and Many countries have prompted a major investment in this sector pay. As a result of what this industry is of great importance to the stability, Because the tourism industry without careful planning and attention to the potential ecological, climatic and environmental problems for each region and tourists will follow. Research and development approach - a combination of operational and research methods (athletics, library, descriptive and analytical) To determine the potential climate comfortable tourism Yazd province is the issue. Which refer to the statistical data of meteorological years 1981 - 2011, including temperature, precipitation, sunshine, humidity and wind speed has been prepared. To analyze the necessary software such as ArcGIS, SPSS, EXCEL, Convert and Grapher is applied; The results show that in addition to achieving the objectives of the study, Yazd province a lot of diversity in all climatic conditions and the balance of performance and comfortable the various influences on tourism. So that only two months during the year had the best comfortable Only three of the 10 city Abarkooh, Khatam and Taft a year than any other city in terms more appropriate to have the tourist reception.

    Keywords: Geographical environment, potential climate, comfort tourism, TCI, THI, Yazd province
  • Page 133

    High spoilage and vulnerability, seasonal and being a non- permanent agricultural products, low operation in unit of level and also population growth, hidden and seasonal unemployment, income reduction and consequently increasing of rural- urban migrations are from most important challengs that agricultural section and rural community confronted with them. A most advantages connections between tow agricultural and industrial section is to establishing conversion and complementary industries that in addition to removal of above- mention problems, it leads to regional inequalities reduction The considering to this industries will be causes a blooming in large part in rural economy. Through scientific and accurate establishing of conversion and complementary industries, a modern relatively era is added to rural communities construction that will transform the socioeconomic texture of the rurals and creates new fields in this areas. In present research is investigated The locating of conversion and complementary industries of agricultural products to achieving economic development in Zarin Dasht county. The method of research is based on the purpose applied and based on nature the descriptiveanalytical. To Evaluation of Indicators and locate of conversion and complementary industries in the case study area were used from Geographic Information System and Hierarchical Analytic Multi-Attribute Technique AHP. The required data were collected by designing a coupled comparison questionnaire and interview with Agricultural Jihad Experts in Rural Industries of the City of Dara Shahr. The results of this research shows establishing conversion and complementary industries in the area which is identified in terms of 9 indicators of optimal areas can be appropriate solution for preventing from waste and increasing the addittional value of agricultural products, and through employment will be cause increasing income of rural low paid groups and reduction of rural- urban migrations.

    Keywords: conversion, complementary industries, economic development, AHP model, rural areas, Zarin Dasht County