Simulating saltwater intrusion in the vicinity of Segara Anakan Estuary and its potential impact to the lowland agriculture

Abstract

Segara Anakan is the largest estuary ecosystem in the south coast of Java Island. There are three major rivers, and at least seven creeks, discharge their flow to the estuary. Lands in the vicinity of the estuary are fertile, and utilize by community as agriculture land. Nowadays, community must face saltwater intrusion problem into the rivers. The aim of this study is to investigate the saltwater intrusion length into the river in the vicinity of estuary, focused on three main rivers, Citanduy, Cibeureum, and Cikonde. The saltwater intrusion is simulated using Surfacewater Modelling System (SMS), with freshwater discharge and the seawater level as main parameter. Simulation result shows that the rivers are highly risk to saltwater intrusion, especially during the dry season. The rivers become mostly brackish environment along the year. The lowland agricultures are highly risk to crop yield failure, especially for the paddy field which located between Citanduy and Cibeureum River. The adaptation scheme should be applied to overcome the problem.