BANGKOK'S URBAN SPRAWL: LAND FRAGMENTATION AND CHANGES OF PERI-URBAN VEGETABLE PRODUCTION AREAS IN THAWI WATTHANA DISTRICT

Agricultural lands are heavily affected by urban sprawl. Urbanization therefore plays a significant role in changing megacities' agricultural fringes such as in Bangkok's peri-urban vegetable production areas. This study focuses on the prime vegetable production areas in Bangkok and aims to: 1) understand and determine the land use changes to these areas, 2) clarify the landscape configurations of these areas to assess landscape fragmentation, 3) discuss and recommend land use planning policies and measures to conserve the existing peri-urban agricultural landscape. We use a geographic information system (GIS) database and three thematic map layers (land use, waterways, and roads) to analyze and clarify land use proportions, changes in the vegetable production areas, and the land configurations during different periods from 1976 to 2015. The fragmentation of the vegetable production matrix increased due to the immediate effect of the expanded road network construction and due to a later consequence of the contiguous roadside urban development. The remaining vegetable production areas were mostly away from the primary road leading to the Bangkok centre city. The monitoring system on the fragmentation of agricultural lands is essential as a database to find suitable measures to control urban sprawl in various cities.