PENGARUH PERBEDAAN TATA GUNA LAHAN TERHADAP BEBAN CEMARAN BOD (BIOCHEMICAL OXYGEN DEMAND) SUNGAI (STUDI KASUS SUNGAI SERANG - JAWA TENGAH)

Abstract

ABSTRACT DAS Serang is one DAS in Central Java that flow across 4 regencies. According to BPS’s statistic data there are several kinds of land use in the regencies passed by Serang river. Each of the land use has different effect on the value of river’s BOD. Beside that, there is also change, either area’s increase or decrease of each form of land use. After compare three types of land uses of research area : domestic activity, wet field agriculture, and dry field agriculture, domestic activity contributing the greatest load of contaminant. The difference between wet field agriculture and dry field agriculture are type of land and rate of contaminant flow. Agriculture activity affect during rainy season only. The largest domestic BOD load of contaminant occurs in segment 3 with an average increase value 0,86 percent in 2031. The largest wet field agriculture BOD load occurs in segment 3 with an average increase value 0.71 percent in 2031. The largest dry field agriculture BOD load occurs in segment 2 with an average decrease value to -2.49 percent. Data from the District Health Office and District Boyolali Grobogan note house with a latrine ownership in less than 50% exist in the data Puskesmas Karangrayung and Puskesmas Geyer. Therefore, it consider to build latrines with septic tanks in these areas. Avoiding excessive use of fertilizers on wet field agriculture is important for the reduction of organic contaminants flow into the river, because wet field agriculture require regular fertilization. Improvements in the DAS should be done on the upstream side because it will be more influential in affecting water quality downstream than improvement on the downstream. Key Words : Serang River, Land Use, contaminant load, BOD