نوع مقاله : مقاله پژوهشی
1 استادیار، گروه جغرافیا، دانشکده اقتصاد، مدیریت و علوم اجتماعی، دانشگاه شیراز، شیراز، ایران
2 دانشجوی دکتری، گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران، ایران
3 دانشجوی دکتری، گروه جغرافیای طبیعی، دانشکده جغرافیا و برنامه ریزی، دانشگاه تبریز، تبریز، ایران
4 دانشآموخته کارشناسی ارشد، گروه جغرافیای طبیعی، دانشکده جغرافیا، دانشگاه تهران، تهران، ایران
عنوان مقاله [English]
Considering the ever-increasing changes in land uses and the need for managers and experts to know how changes have taken place in policy and options for solving the existing problems. Detection of changes to determine the trend over time seems necessary. On the other hand, modeling future changes is important for understanding the quality of future changes. Therefore, the full recognition of land use, its past changes and the prediction of future changes plays an important role in the sustainable management of resources. Modeling land use processes is an important tool in optimizing land use and land use planning. One of the models used to predict landslide changes is the model of artificial neural networks and Markov chain analysis. The features of the artificial neural network include the ability to learn and generalize and process information in parallel.
Considering the goal of urban development during the years 2000 to 2012, satellite imagery of the years 2000 and 2012 in June has been used. After the preparation of satellite imagery and pre-processing of images, the landuse in the study area for the years 2000 and 2012 has been prepared. Then useing the LCM model landuse change patterns of changes were analyzed. Then, based on the Markov chain model, the potential for changing each use to residential use is measured. This means that each pixel was capable of showing change the image from one land use to another. Then, based on the major changes in the region in the survey, three sub-models of shifting change were identified as transforming pastures into habitat areas, converting agricultural production into settlements, and transforming dryland farming into settlements. After calculating the potential for the transfer of any land use to a settlement using descriptive data, a plan for predicting the use of land for 2025 and 2040 was then provided.
Given that the purpose of the present study was to assess the development of residential areas, the extent of changes in these areas were assessed during the years 2000 to 2012. The results indicate that the residential areas increased from 8.3 square kilometers in 2000 to 12.6 square kilometers in 2012, according to the land use map, and mostly changes in the urban area of Songhor area have been made. The results of the assessment of changes indicate that the land use change from irrigated agricultural to residential use during the 12 year period was 1.9 km2, which for dryland agriculture it was 0.6 kilometers, Also 1.8 km2 of rangelands has become residential. The results of this study indicate that the irrigated agricultural lands of the city of Sangar, especially the southern regions and pastures near the urban area, have had most changes. Among the changes in other uses, about 11.5 km2 of the rangeland has been converted into rainfed farming, and about 12.3 km2 of land has also become rangelands and also, about 4.7 km2 of irrigated agricultural has become arable land or Bayer land and about 1.5 km2 of rangelands has become irrigated agricultural land.
The growing population has led to an increase in the number of habitat areas and, as a result, agricultural lands and pastures have undergone changes. The growing trend of settlement development varies from region to region, and in the urban area of Songhor more are moving toward the southern regions of the urban area. Considering the geomorphologic status of the study area, a large part of the range is covered by rangelands. Irrigated agricultural lands which have a significant share, are located on the outskirts of the city of Songhor, which are undergoing further changes. According to the main objective of the research, based on descriptive data such as distance from communication, distance from urban boundaries, elevation and slope, the amount of development of residential areas for 2025 and 2040 is also projected. The results of the forecast indicate that in the case of the growing trend, the development of the settlements will reach about 18.2 km2 in 2025, and will reach 24.2 km2 in 2040, due to the high potential of the southern regions of the city of Songhor, the highest rate of development of settlements will be towards these areas. The results indicate that the increasing number of settlements in the city of Songhor will lead to the degradation of high-quality agricultural lands and pastures. If the trend is continued, the irrigated agricultural around of the city of Songhor will reach the lowest level by 2040. Also most of the pastures will also be degraded. Hence, it is necessary to identify areas suitable for the development of a settlement before increasing of rate the destruction occur, so that less prone areas for agriculture and pastures can be degraded.