2026. EVALUATING THE IMPLEMENTATION OF JEMBER REGENCY SPATIAL PLANNING REGULATION NO. 1 OF 2015 IN GEOMORPHOLOGICAL CONSERVATION OF HUMMOCKS (GUMUK). Indonesian Journal of Environment and Disaster. 5, 1 (Apr. 2026), 139–153. DOI:https://doi.org/10.20961/ijed.v5i1.3001.