M. Widyastuti
Fakultas Geografi Universitas Gadjah Mada

Published : 7 Documents
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Journal : Indonesian Journal of Geography

WATER QUALITY MODELING FOR POLLUTANT CARRYING CAPACITY ASSESSMENT USING QUAL2KW IN BEDOG RIVER Setiawan, Akhmad Darajati; Widyastuti, M.; Hadi, M. Pramono
Indonesian Journal of Geography Vol 50, No 1 (2018): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (586.558 KB) | DOI: 10.22146/ijg.16429

Abstract

Considering the abundance of potential pollutant sources along Bedog River, i.e. highly dense residential areas, agricultural lands, and industrial areas, this study aimed to quantitatively assess the Pollutant Load (PL) and Pollutant Carrying Capacity (PCC) of the river based on Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD)parameters. The assessment employed a water quality modeling using Qual2Kw that provided not only the comprehensive values of PL and PCC but also the amount of PL that should be reduced to meet the PCC of every river segment. Water sampling and primary parameter measurement were conducted purposively in seven observation points, which included one point source and six non-point sources (river segments). River segments were determined according to the characteristics of land use and drainage system. Descriptive, graphic, and spatial analyses on water quality modeling show that the COD and BOD of Bedog River (2.24 km) indicates a small presence of PL compared to the river?s PCC. The PCC allows additional pollutant loads of 566.95 kg/day or 0.024 ton/hour BOD and 22,965.12 kg/day or 0.96 ton/hour COD. However, a high BOD in segments 3, 5, and 6 and a high COD in segment 5 imply the needs for PL reduction.
WATER QUALITY CHARACTERISTICS OF JONGE TELAGA (DOLINE POND) AS WATER RESOURCES FOR THE PEOPLE OF SEMANU DISTRICT GUNUNGKIDUL REGENCY Widyastuti, M.; Haryono, Eko
Indonesian Journal of Geography Vol 48, No 2 (2016): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1676.469 KB) | DOI: 10.22146/ijg.17595

Abstract

Abstract Doline ponds (telaga) have an important role as one of water resources in karst areas, especially during dry seasons in Gunungkidul. Recently, the doline ponds are facing various environmental problems, i.e. steadily decreasing water storage, water loss, and degrading water quality. The research aims to determine the characteristics of Jonge Telaga which include the continuity of flow, utilization, pollution sources, physical water quality (temperature, EC,TDS, TSS, and turbidity), chemical water quality (pH , NO2, NO3, NH4, PO4, BOD , COD, and detergent), and biological water quality (total coliform). In order to determine the characteristics of Jonge Telaga, the research was conducted using a survey method, i.e., observing the continuity of flow and measuring physical, chemical, and biological water quality. Initially, the water was sampled purposively based on the area and the depth of this doline pond. The qualitative description of the results shows that Jonge Telaga is a closed perennial doline pond, whose main pollution source comes from domestic activities, such as bathing and washing. According to the Governor Regulation of the Special Region of Yogyakarta Number 20 Year 2008 on Water Quality Standards, Jonge Telaga meets all of the water quality criteria, except the temperature and detergent, for a Class II water.Abstrak Telaga mempunyai peran penting sebagai salah satu sumberdaya air di daerah karst, khususnya pada musim kemarau di Kabupaten Gunungkidul. Pada saat ini telaga menghadapi berbagai permasalahan lingkungan yaitu simpanan air yang terus berkurang, air yang cepat hilang, dan penurunan kualitas air. Tujuan penelitian adalah untuk mengetahui karakteristik telaga yang meliputi kontiyuitas aliran, pemanfaatan, sumber pencemar, kualitas fisik air telaga (TDS, TSS, suhu, kekeruhan, DHL), kimia air (pH, NH4, PO4, NO2, NO3, BOD, COD, deterjen) dan biologi air (coliform total).  Penelitian ini dilaksanakan berdasarkan metode survei. Untuk mengetahui karakteristik telaga dilakukan pengamatan kontinyuitas aliran, pengukuran kualitas air secara fisik, kimia dan biologi. Pengambilan sampel air dilakukan secara purposive mendasarkan pada luasan dan kedalaman telaga. Analisis hasil dilakukan secara deskriptif kualitatif. Hasil penelitian menunjukkan bahwa Telaga Jonge merupakan telaga yang tertutup dengan ketersediaan air menerus sepanjang tahun. Sumber pencemar utama telaga adalah kegiatan domestik (mandi dan cuci). Kualitas air Telaga Jonge menurut baku mutu air kelas II PERGUB DIY Nomor 20 Tahun 2008 masih di bawah ambang batas kecuali suhu dan deterjen.