STUDI PENGARUH TATA GUNA LAHAN TERHADAP KUALITAS AIR DENGAN METODE NATIONAL SANITATION FOUNDATION’S- INDEKS KUALITAS AIR (NSF-IKA) (Studi Kasus Sungai Plumbon – Kota Semarang)

Plumbon River is one of the rivers flow in semrang city. River with a length of 18.45 km is the main river in the Watershed Plumbon. Based on the land use data semarang city, Plumbon river flow through pattern of land use forests, agriculture, settlement, and fisheries These condition could potentially contaminate the river result of the impact land use, so that can affect level water quality Plumbon river. Research to know how much water quality in the River Plumbon, this study using the National Sanitation Foundatio’s – Water Quality Indeks (NSF-WQI) method. NSF-IKA methode Consists of 9 parameters : temperature, turbidity, total solid, pH, DO, BOD, Nitrate, Total Phosphate, and Fecal Coliform. The result monitoring water quality using NSF-IKA metode showed water quality in each river segment is middle category.  Highest values water quality indeks in the point upstream with score 66.06 and the lowest water values water quality indeks in segmen 9 (downstream plumbon river) with score 51.82. The dominant source of pollutants in the River Plumbon sourced from land use is BOD, Nitrate, Phosphate and Fecal Coliform.