| During the last three decades, Jeddah City in Saudi Arabia has witnessed rapid growth in urban population from less than 1 million to 3.4 million. The essential goal of this research was to detect the land use land cover (LULC) changes in Jeddah City. Supervised classification, post-classification comparison, and Normalized Differences Vegetation Index (NDVI) differencing was used to detect the changes between 1984, 2000 and 2013. The data were acquired by Landsat Thematic Mapper (TM) on June 22nd 1984 and May 1st 2000 and Landsat-8Operational Land Imager (OLI)on May 21st 2013. Four classes were mapped: build-up area, barren lands, vegetation and water. Because of the difficulty to distinguish urban area from barren desert areas using spectral information alone, texture was produced using the red band and incorporated into image classification. The spectral-textural datasets produced more accurate LULC maps for change detection. The results show significant increase in build-up areas from the middle to the east, north and south, while barren lands shrank. The vegetation increased and was found to be related to urban areas. The water class shows slight change in the coastal areas, specifically around the international port and some recreation areas in the north. The NDVI was applied in this research to measure the vegetation vigor, and the results of NDVI differencing show increasing vigorousness of vegetation in newly established recreational and resort areas, around urban development and along the streams. Moreover, watershed-based analysis is unique to this study for Jeddah City and it was useful to analyze the urban growth and NDVI change patterns. |
