Document Type : Research Paper

Authors

• Maryam Soleimani parapari azad ¹
• Masoud Kherkhah zarkesh ²
• Mohammad Jafar Soltani ³
• Alireza Majidi ³

¹ MSc, Islamic Azad University, Science and Research Branch, Tehran

² Associate Professor, Water and Soil Conservation Engineering Department, Soil Conservation and Watershed Management Research Institute (SCWMRI), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

³ Assistant Professor, Soil Conservation and Watershed Management Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

Abstract

 Introduction
The rapid growth of cities and the process of industrialization have created numerous environmental problems across many parts of the world. It is essential for planners and managers to be aware of changes in land cover and land use over extended periods to evaluate and predict the impacts caused by these changes. Remote sensing is an effective tool for monitoring land use changes in urban areas and their surroundings. Tehran has expanded significantly over the last few decades due to population growth and migration, leaving substantial effects on the surrounding environment. Consequently, this study presents a model based on the decision tree algorithm to classify and monitor land use changes using images from TM and MSS sensors in the western region of Tehran between 1975 and 2011.
 
Materials and methods
In this study, one MSS sensor image and three TM sensor images from the Landsat satellite, all taken in June, were used along with ancillary data, specifically a digital elevation model extracted from the 1:25000 topographic map of the Mapping Organization. After pre-processing, land cover indices, including vegetation index, DT method, and its combination with the maximum likelihood classification method, were used to extract land use classes. The accuracy of the classified images obtained from the DT was evaluated using the kappa coefficient and overall accuracy, and finally, the changes in different land use classes over time were calculated using the image comparison method.
 
Results and discussion
According to this study's findings, the overall classification accuracy for 2011 is 82%. The results of change monitoring indicate a positive and increasing trend in the density of built-up land over the 36-year period, while other land types have decreased. The density of the built-up land class in 1975, with an area of 2166 hectares (equivalent to 8%), increased to 8125 hectares (29%) by 2011. In total, the percentage of relative change is 21%, equivalent to 5959 hectares. By examining the land use changes in the west of Tehran from 1975 to 2011, shown in the maps, it is evident that urban development and increased demand for various services, coupled with a lack of adequate space, have led to the destruction of green spaces in the western part of Tehran, replaced by other land uses.
 
Conclusion
This research aimed to monitor land use/cover in the west of Tehran with high classification accuracy using a model based on the DT algorithm combined with the maximum likelihood classification method. Multi-temporal satellite images from the Landsat satellite’s TM and MSS sensors, along with ancillary data, were used to conduct the research. After preparing a land use map for each period, a map depicting land cover and land use changes was extracted. The results of this research indicate that remote sensing data combined with classification techniques have a high capability to extract various types of land use maps and evaluate land use changes. Moreover, Landsat’s MSS and TM sensor data prove to be suitable and cost-effective tools for depicting and analyzing land use/cover changes over time. Additionally, the findings highlight that using a branching or multi-stage method for classifying satellite images offers advantages such as reduced processing time, improved accuracy in small classes, and the ability to use different data sources, feature sets, and algorithms at each decision-making stage.
 

Keywords

• Maximum likelihood classification
• MSS sensor
• Remote sensing
• TM sensor
• Vegetation index