Analysis of mangrove forest changes as a natural beach protection in Surabaya, East Java Indonesia

Surabaya is the most populous city in East Java with high human activities and needs. These human needs include opening new land for residential areas so that some mangrove areas began to be converted into residential areas. This activity can directly cause ecological impacts and threaten the sustainability of the coastal environment. On the other hand, mangrove areas in Surabaya are also developed for conservation and tourism areas. The purpose of this study is to determine the changes in mangrove area in the Surabaya area during the period 2015 to 2019 based on GIS. This study is using maximum likelihood classification method then the area calculation is done by calculate geometric method. The results were obtained from 2015 to 2019 shows an area change every year. So far the exact cause is unknown, but the condition of area changes can occur due to several things, for example from the conversion of mangrove forests to residential areas, drainage needs in rivers or estuaries and stand growth.