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Prediction of runoff, sediment yield and their quality using ANSWERS model at Batujai reservoir area, West Nusa Tenggara Gatot Irianto; Hidayat Pawitan; . Soedarsono; H. Soewardjo
Forum Pasca Sarjana Vol. 16 No. 1 (1993): Forum Pascasarjana
Publisher : Forum Pasca Sarjana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (796.108 KB)

Abstract

The possibility of ANSWERS model application for predicting runoff and sediment yield is discussed in this paper. Three types of rainfall duration (e.i. 6; 8 and 10 hours) with three amount of total rainfall of 100; 200 and 300 mm and two different systems consistink of four kinds of land use were used for simulating runoff and sediment yield. The result showed that the runoff initiation was identified at 189 minutes from the start of rainfall when the amount of rainfall total was 200 mm with 8 hour duration (about 0.0001 inch/hour). The initial sediment yield was shown to be about 0.45 kg at 188 minutes from the begining of rainfall when rainfall total w+ 300 mm with 6 hour duration. Actual runoff and maximum sediment yield were recorded about 0.0017 inchlhour and 12.000 kg respectively. The land use which were considered as potential for erosion protection were mixed gardpn and wet rice. The considered land use would reduce runoff and sediment yield about 50% than traditional land use. The type of output indicates that ANSWERS model is promising for predicting runoff and sediment yield.
PANEN HUJAN DAN ALIRAN PERMUKAAN UNTUK PENINGKATAN PRODUKTIVITAS PERTANIAN LAHAN KERING, PENANGGULANGAN BANJIR DAN KEKERINGAN Gatot Irianto
BERITA BIOLOGI Vol 5, No 1 (2000)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/beritabiologi.v5i1.1096

Abstract

Rainfall and runoff harvesting study at the Kali Garang basin, Semarang under the cooperation program between Centre for Soil and Agroclimate,Agency of Agriculture Research and Development (CIRAD) France and Government of Central Jawa for improving soil productivity,controlling flood and drought are presented in this paper.The results show that through water harvesting it is possible to increase diversity, improving added value and decreasing agriculture risks of agriculture commodity. Moreover rehabilitation of degraded land and soil conservation practices can be promoted.
PENGEMBANGAN TEKNOLOGI PANEN HUJAN DAN ALIRAN PERMUKAAN UNTUK MENEKAN RESIKO KEKERINGAN DAN MENINGKATKAN PRODUKTIVITAS LAHAN (Studi kasus di Sub DAS Bunder, Kabupaten Gunungkidul, Provinsi DIY) Gatot Irianto; Nurwindah Pujilestari
BERITA BIOLOGI Vol 6, No 3 (2002)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/beritabiologi.v6i3.1228

Abstract

Limited water supply on dry season at dry terrain,cause plantation index and plant productivity low. Mean while yearly water volume are potentially enough for twice plant even more if they manage well. Because of that reason using and developing water resource by rainfall and run off harvesting technology, increasing productivity and maintain dry terrain farm operations system at watershed system are approximation strategy needed to put into practice. That strategy can put into practice through hydrologist characteristic modification at river flow area with escalating capacity and capability watershed distribution to minimalist inundation risk and dried out at dry season. Research result at sub watershed Bunder, Wonosari, DIY by way of building two level dam at river bed (hydrology network) can producing 11.6% (channel reservoir 1) and 18.4% (channel reservoir 2) surface flow from existing river-bed and this result can supply water irrigation at least 3 times in planting season rice-secondary crop- secondary crop). If cropping pattern change to rice-rice-secondary crop then run off harvest need to increase become 100% at upper subwatershed (channel reservoir 1) and 19% at lower subwatershed, with condition at MK 1.irrigation area that can be plant with rice only 0.19 ha and the rest of it can be plant with peanut. Rice productivity at rice field are 2.4 ton/ha.
KAJIAN EVALUASI LAHAN UNTUK PENGEMBANGAN CENDANA DINUSA TENGGARA TIMUR Marwan Hendrisman; Hendri Sosiawan; Gatot Irianto
BERITA BIOLOGI Vol 5, No 5 (2001)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/beritabiologi.v5i5.1468

Abstract

Komoditas kayu cendana menyumbangkan Pendapatan Asli Daerah (PAD) sampai 40% untuk Propinsi Nusa Tenggara Timur (NTT),sehingga dapat dijadikan komoditas andalan bagi Propinsi ini. Pulau Sumba dan Pulau Timor diduga merupakan tempat asal tumbuh cendana, sehingga untuk pengembangan budidaya cendana dapat dicari daerah yang mempunyai ekosistem yang mirip dengan daerah asalnya.Teknologi budidaya tepatguna bagi cendana perlu dikembangkan untuk memperluas areal tanam komoditas tersebut.Untuk itu perlu dibentuk suatu dewan riset cendana secara lintas sektoral dari berbagai disiplin ilmu.
Alternative Method for Calculating Runoff Coefficient Based on Discharge Simulation Model by Applying Unit Hydrograph Concept (Kali Kripik Sub Watershed Case Study) BUDI KARTIWA; GATOT IRIANTO
Jurnal Tanah dan Iklim (Indonesian Soil and Climate Journal) No 19 (2001): Desember 2001
Publisher : Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21082/jti.v0n19.2001.%p

Abstract

Comparison of two method on calculating runoff coefficient (Cr), is discussed in this paper i.e. classical method and alternative method. The first one calculates Cr based on the hydrograph separation analyses, and the second one based on the discharge model simulation by applying unit hydrograph concept. The classical Cr values is calculated using simple method and the alternative Cr values is calculated using H2U (Hydrogramme Unitaire Universel) transfer rainfall-discharge model, for 47 rainfall and discharge events from September 1998 to March 1999 on Kripik sub Watershed. The H2U model calculates discharge based on convolution product between excess rainfall and hydrological network density that was represented by probability density function. The Cr value according to this model is determined when the Cr is resulting the best discharge simulation. During the period of September 1998 to March 1999, the classical Cr value varied between 2,8 to 69,1%, while alternative Cr between 1,0 to 48,8%. The smallest and the biggest differences between classical and alternative Cr values were 0,3% and 26,5%, respectively. According to regression analyses and Nash-Sutcliffe criterion, the coefficient of determination (R2) and the coefficient of efficiency (F) were 0,9312 and 0,6829, respectively. Statistically, these values indicate that the alternative Cr value was similar to classical one.