Integrated water quality modelling for spatial planning

The main objectives of spatial planning is to ensure that the utilization of land resources is planned and implemented in an organized manner to meet the needs of present and future generation. The aim of this study is to develop an integrated water quality modelling for spatial planning. Study area is Ciliwung watershed, in the middle of Jakarta Coastal watershed. This area is ideal for such a study. Jakarta is the capital city of the Republic of Indonesia, the most-populous national capital, incorporating one of the world's largest coastal cities. The environmental condition of Ciliwung River is very poor. In this area exist a spatial distribution of socio-economic activities and related land uses such as urban area, industry, mining, agriculture, forestry, aquaculture and fisheries, commerce, transportation, and all the human activities that generate the associated manmade pollution and other environmental issues. Water quality modelling of Ciliwung River has been used to analyse the correlation of water quality in the river body with the land use in that area. Water quality modelling was performed using the QUAL2K public domain free software. Eutrophication models were used to determine the fate and transport of organic pollutants. Correlation analysis was carried out in term of to design the optimal land use planning. Optimizing land use was intended to obtain maximum economic benefits without causing environmental pollution. Several scenario analysis was applied in this area. Based on the water quality modelling, it is can be identified, the main pollution problem in Ciliwung system is in the downstream area, due to the high load of non-point source pollutants in the area. Pollution control in the downstream of Ciliwung is very crucial in term of the sustainability of Ciliwung water resources. Ciliwung pollutant load control can be done by land use planning and build a waste treatment plant. Spatial planning is needed in this areas to get the area with minimal pollutant loads.