Papers by hidayat pawitan
Sungai Bekasi adalah sungai utama yang mengalir di Kota Bekasi dengan luasan sekitar 21.049 ha. P... more Sungai Bekasi adalah sungai utama yang mengalir di Kota Bekasi dengan luasan sekitar 21.049 ha. Pada tahWl2002 dengan hujan sebesar 250 mm selama 8 jam, elevasi muka air naik +18,75 m dan menyebabkan banjif 138 ha di pennukiman selama 2-3 hari, lebih jauh lagi pada tahun 2005 dengan hujan hanya 127l.nm selama 6 jam, elevasi muka air naik + 18,90 m dan menyebabkan banjir sebesar 164 ha dipennukirnan selama 3 hari. Kejadian ini menWljukkan bahwa masalah banjir di Kota Bekasi s~makin memburuk dikemudian hari. Qleh karena ito, tujuan dan peneIitian ini adalah (1) menganalisis kapasitas alir ®n kecepatan izin maksimum dari sungai bekasi; (2)merancang penanggulangan banjir disebabkan keterbatasan kapasitas alir. Untuk mencapai tujuan dari penelitian ini, metoda analisis dibagi dalam 3. bagian yaitu (1) kapasitas alir dengan HEC-RAS; (2) kecepatan izin maksimum sungai dan (3) peniugkatan kapasitas alir. Berdasarkah hasil penelitian, kapasitas alir dievalauasi dengan model hldraulik dan didapat kapasitas alir terbesar 764 m 3 /dt dan terkecil462 m 3 /dt. Untuk menaikkan kapasitas dan melindungi daerah banjir, maka dibangun tanggul di bantaran sungai, tetapi harus memperhatikan gaya tarik yang disebabkan kecepatan aliran. •. .. .-. .. .
Degradasi tanah merupakan isu penting karena terkait dengan pengelolaan lahan dan kualitas lingku... more Degradasi tanah merupakan isu penting karena terkait dengan pengelolaan lahan dan kualitas lingkungan berkelanjutan. Pemulihan tanah degradasi lebih tepat dilakukan, jika diketahui karakteristik atau resiliensinya. Tujuan utama penelitian ini adalah karakterisasi dan klasifikasi tanah terdegradasi di lahan kering di Kalimantan Tengah berdasarkan kualitas lahan (LQ) yang menentukan kelas kesesuaian lahan pada tipe penggunaaan lahan (LUT). Kualitas lahan yang digunakan terdiri atas ketersediaan air (w), ketersediaan hara (n), toksisitas Al (t), ketahanan tanah terhadap erosi (e), dan deteriorasi tanah antropogenik (d). Tipe penggunaan lahan yang digunakan antara lain padi lokal, padipadi-kedelai, karet, dan kelapa sawit pada tiga pola A, B, dan C. Tujuan lainnya adalah karakterisasi dan klasifikasi degradasi dan resiliensi tanah berdasarkan indeks lahan dan kelas kesesuaian lahan. Pengkelasan kesesuaian lahan secara parametrik didasarkan indeks lahan yang berasal dari pendugaan produksi komoditas masing-masing LUT berdasarkan kualitas lahan. Hasil penelitian menunjukkan bahwa Alfisols memiliki daya dukung tertinggi ditunjukkan dengan indeks lahan yang lebih tinggi dari tanah lainnya pada LUT kelapa sawit. Indikator utama degradasi dan resiliensi tanah adalah LQ ketersediaan hara, ketersediaan air, dan toksisitas Al. Potensi tanah yang tinggi tidak menunjukkan kemampuan resiliensi, begitu pula sebaliknya bahwa potensi tanah yang rendah tidak menjamin rentan degradasi. Resistensi tanah di lokasi penelitian relatif tinggi. Lahan pertanian yang terdegradasi umumnya sulit untuk pulih kembali melalui masa revegetasi alami yang dikenal sebagai lahan tidur. Resiliensi alami maupun resiliensi antropogenik tidak banyak berbeda di tanahtanah lahan kering Kalimantan Tengah. Taksa tanah tidak mampu menunjukkan perbedaan terjadinya degradasi dan resiliensi di lahan kering Kalimantan Tengah.
Reformulation of Crop and Management Factor in ANSWERS Model (Y. Hidayat, N. Sinukaban, H. Pawita... more Reformulation of Crop and Management Factor in ANSWERS Model (Y. Hidayat, N. Sinukaban, H. Pawitan and K. Murtilaksono): Crop and management factor value is significantly corelated with outputs of ANSWERS model especially on soil erosion. Using daily crop and management factors (daily C factors), the ANSWERS model performs well in predicting soil erosion which is showed by determination coeffient (R 2 0.89), model efficiency (0.86), and average of percentage model deviations (24.1 %). Whereas using USLE C factor (2 cropping systems), predicted is much higher than measured soil erosion (over estimate). Output of the model is not statisfY; it is represented by model coefficient (0.40) and average of percentage model deviations (63.6%).
Available quantity and quality of water resources in catchments area has been deteriorated, yet t... more Available quantity and quality of water resources in catchments area has been deteriorated, yet the management pertaining water resources has not been done in a proper way. Water harvesting techniques are alternative by which the water resources can be maintained to cope with the sustainable use of water resources in catchments area. We reviewed experiences of Indonesia in managing water resources in some of catchments area to come up with the recommendation of best practices of water resources management in general and particularly water harvesting techniques. Despite the available fresh water (15,500 m 3 capita-1 year-1) is more than double of the world available fresh water (600 m 3 capita-1 year-1), but its distribution is varies. In Java Island for example, where the population reaches to a number of 65% of the total population of Indonesia, but the water only available for 4.5% of the total national water availability. The fact that the available water of about 30,569.2 million m 3 year-1 in Java are not enough to cover the need and will be a deficit water in this island at least till 2015. The available water is also fluctuated during wet and dry seasons. For instance, the flow of Cimanuk River (West Java) is recorded as much as 600 m 3 second-1 during the wet season, but only 20 m 3 second-1 in the dry season. How to manage water in the area with water surplus and deficit is a crucial question to be answer. Water harvesting is becoming very important to cope with sustainable management of water resources. There are different techniques of water harvesting that have been successfully applied as part of water resources management in catchments area in Indonesia. Channel reservoir, on-farm reservoir or "Embung", infiltration ditches, infiltration well, water harvesting dikes, etc. Channel reservoir with cascade system is one of many rainfall and runoff harvesting techniques, which has been proven to be an effective method to reduce peak runoff, extend the time response to runoff generation and to some extend to increase available water for irrigation during the dry season. In Cibogo micro catchment in West Java for example, river flow can be reduced as much as 63% after construction of 2 channel reservoirs with cashcade system and also delay response time of the river flow up to 1 hour. This two important points are very significant to reduce the risk of flood in the down stream areas where the cities are generally situated. On-farm reservoir has also been applied by farmers for supporting their farming to extend cropping. Other water harvesting techniques such as infiltration ditches, infiltration wells, dams, water harvestinmg dikes are also discussed in this paper.
Jurnal Agromet Indonesia, Dec 1, 1998
TEKNIK, 2008
One of the big rivers flowing in center of Semarang city is Garang river with watershed area abou... more One of the big rivers flowing in center of Semarang city is Garang river with watershed area about 220 km 2 and having characteristic such as big flood discharge and flash flood. Where flash flood on January 25 th 1990, caused more than 45 people died and goods losses until 8.5 billion rupiahs. One of some models to pedict water level is used black box model. Artificial Neural Network one's of the black bock model. In this research, Artificial Neural Network (ANN) with back propagation method is used to predict water level in Garang river where as input are rainfall in upstream of Garang river during two days, while as output is water level in downstream of Garang river for two hour later. Result of optimum predicting have MSE 0.0037 and average of error 1.18 %.
The possibility of ANSWERS model application for predicting runoff and sediment yield is discusse... more 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. PENDAHULUAN Latar Belakang Untuk mengatasi kendala air di Pulau Lombok (curah hujan rt 1500 mm/th selama 2-2,5 bulan) pemerintah menganjurkan untuk menerapkan sistem gogo rancah, membangun embung-embung dan Waduk Batujai. Pembangunan Waduk Batujai selesai pada tahun 1982 dan setelah itu m d a h air sudah teratasi.
IOP conference series, Nov 26, 2018
Global climate change has been recognized as a challenging isue in the past decades and with sign... more Global climate change has been recognized as a challenging isue in the past decades and with significant impacts on many aspects of human life, especially on the availability and vulnerability on water resources. Food production requires a large portion of water demands and directly related to population that is still increasing in Indonesia. Therefore food production will have direct impacts on land and water resources with great implications on environmental degradation. Water resources development and management in Indonesia under stress in changing climate is considered still in low risk of water scarcity nationally with space-time variation, such as for Java Island and many developing urban areas already at high water stress level. Sustainability of water resources in such areas could be achieved only through trade-off and balancing the competing water demands and available supply, satisfying the law of mass conservation as a sufficiency condition. These high-risk water stress areas would need development of water storage and irrigation infrastructures and adoption of crop-water productivity strategy to improve water use efficiency for food and agricultural production and ensure water and food security of the country.
IOP conference series, Nov 19, 2018
The simulation of the mesoscale convection system (MCS) during the 13-19 January 2014 was conduct... more The simulation of the mesoscale convection system (MCS) during the 13-19 January 2014 was conducted for Greater Jakarta (GJ) using the Weather Research and Forecasting (WRF) model. In this study, WRF simulations were carried out for different sizes of urban and built-up area, which in the experiment (SCE) wider than the standard (CTL) simulations. The results of the two WRF simulations are evaluated against the surface observations. The comparison of the measured wind speed and direction in the GJ area shows a reasonable result between observed and simulated data. The results showed a consistent significant contribution of urban and built-up development to wind speed. The significantly increasing wind speed was up to 3 ms-1. There is no persistent variation in the wind speed and direction of each station. Simulations suggest that the new urban developments caused an intensification and expansion of MCS propagation. The SCE simulation provided a stronger convective cloud system that spreads from south to north.
IOP conference series, Sep 19, 2019
The development of land-use in the upper Ciliwung watershed can be converted every year, which ha... more The development of land-use in the upper Ciliwung watershed can be converted every year, which has an impact on surface flow, peak discharge and runoff volume. This study aims to look at projections of changes in land-use and their impact on changes in peak discharge and volume of river flows in the Ciliwung Hulu watershed. The tool used in this study consisted of a tool for analyzing land-use changes and projections, namely the CLUES model, while for hydrological responses using the HEC-GeoHMS tool combined with a GIS tool. The results of the analysis of land-use change found a pattern of changes in land-use in the Upper Ciliwung watershed in the period 1996-2013 there were 5 patterns of changes in land-use. Projected land-use change in 2030 with two scenarios. Scenario 2 which is able to hold the rate of change of forest to more than 30%. Scenario 1 HEC-HMS produces peak discharge 114.1 m 3 /second and runoff volume reaches 5.85 x 10 6 m 3 while in scenario 2 with peak discharge 107.0 m 3 /second and runoff volume 5.70 x 10 6 m 3 .
The possibility of ANSWERS model application for predicting runoff and sediment yield is discusse... more 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. PENDAHULUAN Latar Belakang Untuk mengatasi kendala air di Pulau Lombok (curah hujan rt 1500 mm/th selama 2-2,5 bulan) pemerintah menganjurkan untuk menerapkan sistem gogo rancah, membangun embung-embung dan Waduk Batujai. Pembangunan Waduk Batujai selesai pada tahun 1982 dan setelah itu m d a h air sudah teratasi.
The possibility of ANSWERS model application for predicting runoff and sediment yield is discusse... more 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. PENDAHULUAN Latar Belakang Untuk mengatasi kendala air di Pulau Lombok (curah hujan rt 1500 mm/th selama 2-2,5 bulan) pemerintah menganjurkan untuk menerapkan sistem gogo rancah, membangun embung-embung dan Waduk Batujai. Pembangunan Waduk Batujai selesai pada tahun 1982 dan setelah itu m d a h air sudah teratasi.
Jurnal pengelolaan sumberdaya alam dan lingkungan, Aug 1, 2017
Hydrological drought is water deficit from normal conditions on the hydrological system. Hydrolog... more Hydrological drought is water deficit from normal conditions on the hydrological system. Hydrological drought occurs through a complex process preceded by a rainfall deficit. The series of processes that show a change of drought signals through the hydrological cycle is expressed as drought propagation. This study aims to identify the characteristics of hydrological and meteorological drought and to identify meteorological drought propagation to hydrological drought through Larona Watershade. Standardized Precipitation Index (SPI) is used as indicator to identify meteorological drought while hydrological drought is characterised by Standardised Streamflow Index (SSI) with 1, 3, 6 and 12 months accumulation periods. Propagation meteorological drought to hydrological drought was analyzed using Pearson correlation. The results showed that duration and severity escalate by the increase in the accumulation period SPI and SSI. While the number of drought events is inversely proportional to the accumulation period SPI and SSI. Althought the number of hydrological drought events was fewer, but they occurred over longer duration and much severe than the meterological one. Severe hydrological drought (SSI 1 =-14.8) in 1997-1998 has declined water storage of Lake Towuti by 90% leading to reduction in Larona hydropower production. Furthermore, our findings provide promising approach to detect hydrological drought that may occur in the near future.
Jurnal Agromet Indonesia, Dec 18, 2002
Uploads
Papers by hidayat pawitan