Spatial analysis and geomorphic characteristics of coral reefs on the Eastern part of Lombok, Indonesia

Abstract

The eastern part of Lombok Island is a highly dynamic environment with many physical processes as well as very complex landuse. In addition to the anthropogenic origin, sedimentation in this area also occurs due to natural origins, such as volcanic processes. Due to hydrological processes since the 1257 CE eruption of Samalas volcano, almost half of the materials were transported and deposited to the coastal area. These deposits can affect the state of the aquatic environment, so they, directly and indirectly, affect the coral reef conditions. However, the spatial information of coral reefs in this area is rarely known. Therefore, the spatial distributions of coral reefs in this area should be investigated to distinguish and determine the factors that regulate its patterns. The multidisciplinary approach, including geomorphological survey, remote sensing and geographic information system (GIS), as well as geostatistical analysis, has been used to gain a deep understanding of the spatial distribution and geomorphic features of coral reefs in the eastern part of Lombok. Our results show that coral reefs on the eastern part of Lombok are mostly fringing reefs and developed on shallow continental shelves in depth between 0-20 m and located close to the main island. In addition, coast typology in the eastern part of Lombok divided into river deposition coast and wave erosion coast. Finally, the absence of coral reefs in some areas in the eastern part of Lombok can be caused by sedimentation and pollution from the river as well as the extraction of remnant coral reefs.