عنوان مقاله [English]
Sustainable land management depends on preparing a multi-time land cover map, it is necessary to determine the process of destruction or improvement of the natural covers for these areas by identifying the type of land cover / land use at different times. One of the most important and serious issues that endanger the sustainable development is land degradation. Man-made destructive activities in nature, including deforestation, overgrazing and pasture conversion, unprincipled construction, and increased agricultural cultivation, which may also have important socio-political consequences, are increasingly destructive. Land degradation and destruction of natural resources in developing countries is much more than other countries, so that natural resources and the environment are the most vulnerable parts of these countries, and usually the first part of poor and developing countries that are destroyed and occupied in line with economic growth and development, is their natural resources. Population and urbanization growth is one of the most important factors in the destruction of natural resources in developing countries. In fact, the most important ecological impact of urbanization and distribution urban areas is the destruction of natural resources and encroachment on the natural environment. Iran's natural resources have also been severely disrupted over the past five decades, and in many cases, irreparable effects have been inflicted on it. So that, according to the reports published by the Forests, Rangelands and Watershed Management Organization (FRWO), the level of the country's rangelands since the nationalization of forests and rangelands has increased from about 100 million hectares to less than 85 million hectares. On the other hand, Sustainable land management depends on the preparation of land use maps at different times. In fact, land classification results are the basis of many environmental and socio-economic programs. The study of changes in natural areas provides valuable information for better management of natural resources in order to protect, rehabilitate, develop and even utility them. Therefore, it is necessary to identify and monitor the process of destruction or improvement of the natural cover of these areas by classifying the type of land cover / land use of the target areas during different times and determining the amount of possible changes. This study aims to determine the tenure and conversion of natural areas using coverage / land use maps of the city of Sisakht and its surroundings and also to analyze the extent of its changes during the years 1988 to 2020 with the use of remote sensing.
Detection of change, the process of determining and / or describing changes in land cover / land use characteristics are performed on the basis of rearranging multi-time remote sensing data and satellite data. On the other hand, the appropriate spatial resolution of satellite data is determined by the user needs and the scale of the study area. Therefore, Landsat satellite data with moderate spatial resolution and appropriate time coverage is the most widely used data on a regional scale that is widely used in different parts of the world to classify land use to determine land use. Is placed. In order to prepare the land use map in this research, appropriate quality data in terms of cloudiness and dust of Landsat 5 and 8 satellites related to July 1988, 2000, 2011 and 2020 were used. For this purpose, the necessary radiometric, atmospheric and geometric corrections were applied to the satellite data. Then, to increase the accuracy of classification and increase the accuracy of land use map, a data set layer was created by combining different spectral and spatial bands. In order to increase the accuracy of detecting land cover types with a wide range of spectral characteristics, the thermal band of satellite data was also included in the data set. Finally, in order to classify as accurately as possible and prepare a map corresponding to the reality of land cover / land use in the study area, two powerful monitored base pixel methods including maximum likelihood and support vector machine were used to compare their accuracy.
All corrections, data preparation, data collection, classification and analysis, and extraction of maps were performed using ENVI® 5.3, ArcGIS® 10.7, Google Earth Pro 9, Excel 2016 software.
The results of this study showed that the level of natural areas of forests and ranges in the study area has decreased by at least 24% during the 32-year period. In contrast, the gardens, construction and human intervention, and occupation has increased. So that the natural covers of the region, including the forest and range, has decreased from 4678 hectares in 1988 to 3327 hectares in 2020. While, the area of orchards has increased from 583 hectares in 1988 to 1331 hectares in 2020. In general, the destruction of natural resources or their conversion to other land uses is affected by economic and social issues. The results also show that while the effect of increasing the population of Sisakht city on the destruction and tenure of natural areas, the factor of turning forests and ranges into gardens and orchards plays a more prominent role in the destruction and tenure of natural resources. In other words, according to demographic statistics published by the Management and Planning Organization of Kohgiluyeh and Boyer-Ahmad Province, although the city of Sisakht, unlike many other cities in the country, is not considered a major city in accepting immigrants and its population growth relative to many cities have not been many (7856 people in 2016 compared to 6814 people in 2006), the level of destruction of natural resources is significant. The main factor can be considered in the attractiveness of gardening and increasing the garden areas by utilizers. Undoubtedly, the process of destruction and tenure of forests and ranges, and natural resources will not stop as long as profiteers and opportunists hope for the transfer of natural areas. Considering the economic costs and environmental considerations, the change of national land use and natural areas will have serious consequences on the path of sustainable development. Therefore, any humanizing change in the environment of the natural areas of each region and its conversion to other land uses should be based on the land use plan of that region.