Simulasi Komputer Pengaruh Relokasi Keramba Jaring Apung Terhadap Kandungan Nitrat Di Dalam Air Waduk Jatiluhur

Abstract

Fish cages to breed fish for food had grown uncontrollable in Jatiluhur long-shaped reservoir. As the number of fish cages is pretty high and some additional nutrient from the overland water enters the reservoir, they can raise Nitrogen concentration in the reservoir water. Nitrogen is one of nutrient that is used by aquatic weeds to grow so it triggers eutrophication in the reservoir. Then it can give nuisance to the machinery of the electric generators and the agriculture lands. The research used computer model to prove the reduction of nitrogen concentrations through relocations of fish cages to upstream sides. The basic idea of reduction is by taking advantage of the biochemical processes in the flowing water to the outlet gate. The source of nitrogen is the overland water and the residue of pallet. Then computations on concentrations of Nitrate based on horizontal scheme that divides the reservoir into some segments along the water flow from inlet to outlet. In a segment, a homogeneous condition is applied, and the waters move from one segment to the adjacent downstream segment. Preceding those, scenarios on the percentage of relocated fish cages were developed as it is a way to obtain amount of reduction of Nitrate concentrations at the outlet zone. It is found that the amounts of Nitrogen reductions at the outlet zone depend on the number of relocated fish cages and the distance of the relocated zones.