Modeling of built-up land expansion to agricultural land using simweight algorithm and cellular Automata-Markov in the Yogyakarta Urban Area

The Special Region of Yogyakarta has the fourth-highest urban population ratio in Indonesia, 70,5 - projected to increase to 86,9 in 2045. The Yogyakarta Urban Area is a center of urban activities in the Special Region that grows rapidly. This urban sprawl is a real threat to crop farmland in urban fringes, which has been functionally preserved to maintain regional food availability. This research aimed to (1) characterize the profile of built-up land growth in the Yogyakarta Urban Area and (2) estimate rice field areas at risk of conversion to built-up lands in 2040. Remote Sensing technology and Geographical Information Systems (GIS) were used to examine the relationship between the built-up land growth and seven driving factors. The results showed that the leading driving factor was the distance to existing settlements. In 2015-2020, the urban features spread to the southeast, and this spatial trend was projected to shift northeastward until 2040. The land development projection for 2040 also showed that the northeast side of the city center had the highest probability of agricultural land conversion, including in parts of Depok and Ngemplak Districts. The model revealed that 770 hectares of rice fields would have been converted to built-up land by 2040. © 2023 Author(s).