Judul: Pengaruh Perubahan Tutupan Lahan DAS Cisadane Hilir terhadap Kualitas Air Sungai Cisadane Hilir Kabupaten Tangerang, Banten
Abstrak: The land usage pattern surround the Cisadane watershed has changed year to year on Cisadane watershed especially at down segment. The change of land usage has effected the quality of water physically, chemically and biologically. The decrement of water quality has relation to the utilization of water resource at Cisadane Watershed especially at down stream. The water resource utilization might be for industrial, husbandry, agriculture land and setlement purposes. Those utilizations duct the wastes to the stream. It could disturb the utilization of clean water. The evaluation to the types of land cover change and water quality of down stream of Cisadane for several years, is needed in order to determine the effect of land cover and water resource utilization to the quality of water. This study is aimed to analyze the impact of land cover to Cisadane watershed especially at the down stream during 2005-2008, examaine the water resource utilization at Cisadane down stream and account the pollution load which is approviate to the sources of contaminants and the carriying capacity. Therefore this study is expected that it can be input of information and give contribution to the management of Cisadane watershed for the some years a head. The condition of Cisadane stream at the transition area of middle part to the stream down is included as the moderate up to worse criteria with the score of WQI 60, 09 – 34,45 while the mouth area of stream is included as worse up to strongly worse with the WQI 57, 56 – 17, 72. The condition is worse nearer to the mouth part. It is caused by the accumulation of pollutant from the downstream and middle stream. The 100% of respondences (180 people) agree that the quality of Cisadane stream water nowadays is in bad condition. They state that Cisadane water is not proper to be used directly for daily purpose, such as for cooking, drinking, bathing and washing. But some of them (56, 67%) still use the water for washing the clothes and bathing. Based on classification result, there are eight land use on Cisadane Watershed area. Land use changing happened in forest, mixed garden, recident area, rice field, fisheries area, bare land, and fields. Land use change on Cisadane watershed area connected to water quality on this area. Some parameters that can used to know the water quality are water temperatures, TDS, BOD, COD, DO, nitrate, ammonia dan nitrite. Based on Classification result on assesment of sources of air, water and land pollution, residencial and industry area were the major producer of liquid wastes on this area. It can be seen from increasing of water pH, COD and BOD parameters. Based on calculation result, the highest pollutant load is mostly predicted coming from some sources (people and husbandry). The TTS is 187.809,23 ton/year, BOD is 36.767,65 ton/year, COD is 18.302,23 ton/year, TN is 1.372,7 ton/year and TP is 166, 39 ton/year. Pollutant load from people and husbandry on Cisadane watershed area for COD,TN parameter still on minimum capability and over capability for BOD, TP and TSS parameter.
Keyword: