Change detection in land use using remote sensing data and GIS (Case study: Ardabil county)

Population growth، urban development and the need of new residential regions and resources for human food، enhanced land use changes all over the world. The aim of this study was detection of land use changes in the last 25 years in the county of Ardabil. In this research، changes in land use were investigated based on LandSat imagery interpretation in three time periods between، 1987، 1998 and 2010 using GIS and remote sensing techniques and statistical methods. The map of study region was then georeferenced using DGN after geometric and atmospheric correction. Sample points in each land use class were taken in sufficient number and of suitable distribution among the study area. Using supervised classification (maximum likelihood algorithm)، the best band combination and the land use maps for the years 1987، 1998، and 2010 were produced. The accuracy of the produced land use maps using overall accuracy and Kappa statistic was approved. The results indicated that some irrigated farming، gardens، residential and industrial areas and degraded lands have increased between 1987 and 2010; and the area of some land uses have decreased such as forests، rangelands and dry farming areas during this period. According to the findings from this research on the period of 1987-1998، rangelands and forests decreased 10. 20% and 0. 5% respectively، but dry farming lands، irrigated farming lands، and the barrier lanes have increased 5. 62%، 1. 8%، and 1. 8% respectively. In the period of 1998-2010 rangelands، dry farming lands and forests have decreased 7. 9%، 11. 52% and 3. 69% respectively، but irrigated farming lands have increased 1. 2% and the barrier lands have also increased 17. 7%. The kappa coefficient of land use maps was calculated 0. 81، 0. 87 and 0، 89 for the years 1987، 1998 and 2010 respectively.