1. Department of Environmental Science, The Graduate School, Universitas Gadjah Mada, Yogyakarta 55284, Indonesia
2. Department of Environmental Geography, Faculty of Geography, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
3. Department of Geographic Information Sciences, Faculty of Geography, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia