Analisis Dampak Tanggul Terhadap Elevasi Banjir Sungai Nagara Kalimantan Selatan

Nagara River is a river in South Kalimantan province with extensive swamp area which formsseasonal flood plain and protects downstream area from flooding and salt water intrusion. Theplan for land use change from the swamp area to plantation area involves building dyke on thesides of Nagara River. This research aims to analyze the elevation of Nagara River duringflooding when the swamp area is occupied as an extension of flood plain, compared that resultedfrom the scenario when this area is converted into plantation area which needs dyke on the sidesof the river for flood protection. There are two kinds of scenarios, first only one side of the riverwhich will be build dyke, and second both sides of the river will be built dykes. The analysisinvolved rainfall data analysis using daily module rainfall, design discharge analysis usingRational Method and hydraulic analysis using HEC-RAS software with one-dimensional steadyflow. The result shows that using dyke at elevation +11.00 m, the increase of water level is notsignificant while one side of the river is protected by dyke. An increase of 30 cm of water elevationis obtained using scenario of both sides are protected by dykes. The increase of water level maycause flooding in the area located at the upstream and downstream of the plantation area

Geospatial Analysis of Land Use Change in Way Kuripan Watershed, Bandar Lampung City

The purpose of the study is to analyze land use and land cover change impact on Way Kuripan discharge. Six scenarios of land use and land cover changes at Way Kuripan watershed area of 53.54 km² was developed based on geospatial analysis with Geographic Information System. Peak discharge is calculated by using rational method. From the six scenarios simulation, scenarios 1, 2, 3, and 4 maintained the protected areas of 80.15%. Land use and land cover changes done by changing areas from vacant land and agricultural areas to be residential, industrial and government office areas. From the analysis, peak discharge of scenarios 1, 2, 3, and 4 change slightly which are between 11.19% and 23.46%. These results are in contrast to scenarios 5 and 6, in which scenario 5 keep the protected areas about 53.35% while in scenario 6 left the protected areas around 30%. Those protected areas changed into residential areas. The result showed that in scenario 5, the peak discharge changed about 66.29%. While in scenario 6, it changed about 107.19%. It can be concluded that the existence of protected areas in Way Kuripan Watershed was very important role to reduce the peak discharge values

Estimasi Potensi PLTMH Dengan Metode Regionalisasi Pada Ungauged Catchments Di Kecamatan Suoh

. Electricity is the major problem in Suoh sub-district because there is no electricity distributed by National Electricity Company (PLN). Suoh is located in the upstream of Way Semaka and water is available in river tributaries throughout the year which can be utilized for micro hydro power. This research aims to analyse the potency of the rivers including Way Hantatai, Way Sekandak and Way Gunung Lanang. The three rivers are categorised as ungauged catchments. Research method includes analysis of hydrologic similarity berween Way Semaka and Way Besai catchments, application of regionalization method where FDC for Way Semaka was developed from discharge data from Way Besai located close to Way Semaka. Measurement of flow variables in the rivers are used to verify dependable discharge calculated by regionalization method. The potency of electricity power is calculated based on dependable discharge Q50 and head. The result shows that hydrologic similarity exists between Way Semaka and Way Besai catchments. Calculated discharges based on river measurements comparable to dependable discharges between 80%-93% from the FDCs for the three rivers. The maximum electricity power which can be generated are 15.26 KW, 4.12 KW and 2.71 KW for Way Hantatai, Way Sekandak and Way Gunung Lanang respectively

Angka Keamanan Lereng Timbunan di Atas Tanah Lunak pada Proyek Jalan Tol

Pekerjaan konstruksi timbunan yang digunakan pada infrastruktur jalan maupun jembatan tidak lepas dari berbagai permasalahan terutama ketika timbunan tersebut berada di atas tanah lunak. Untuk mengatasi permasalahan tersebut dapat dilakukan dengan perbaikan tanah dasar dengan stabilisasi, pemadatan maupun dengan penambahan material lain. Perbaikan tanah dengan penambahan material lain dapat diterapkan atau diaplikasikan secara horisontal dengan bahan sintesis seperti geogrid atau geosintesis maupun vertikal dengan menggunakan PVD atau stone column. Perbaikan atau peningkatan karakteristik tanah dasar dibawah timbunan dapat diindikasikan dengan angka keamanan timbunan yang memenuhi persyaratan SNI yaitu minimal 1.5. Pada penelitian ini akan dianalisis besarnya angka keamanan timbunan berlereng diatas tanah lunak dengan menggunakan aplikasi komputer. Tanah lunak akan mendapatkan perkuatan dengan penambahan geotekstil dan minipile yang akan diaplikasikan dibawah timbunan. Berdasarkan hasil simulasi dengan aplikasi komputer didapatkan angka keamanan dengan perkuatan geotekstil belum memenuhi tingkat keamanan lereng karena angka keamanan yang didapatkan < 1.5 baik dengan penggunaan geotekstil tipe 15 maupun tipe 25. Sedangkan perkuatan dengan minipile, angka keamanan yang diperoleh dapat memenuhi angka minimum keamanan lereng yaitu pada tinggi timbunan 5 m dengan penggunaan 5 minipile didapat 1.56, tinggi timbunan 7 m dengan penggunaan 8 minipile didapat 1.54 dan tinggi timbunan 9 m dengan penggunaan 9 minipile didapat angka keamanan 1.5. Semakin tinggi timbunan yang diterapkan pada tanah dasar dengan kosistensi lunak maka beban yang diterima tanah dasar semakin besar sehingga jumlah minipile yang diperlukan untuk mendapatkan keamanan lereng juga semakin banyak

Sediment Analysis in the Way Besai Hydroelectric Watershed Using the USLE Method (United Soil Loss Equation)

Way Besai hydropower station is located in Way Besai river basin (watershed) with most watersheds surrounded by mountains that cause erosion resulting in sediment buildup. The purpose of this research is to know the degree of erosion hazard and to know the sediment by the Universal Soil Loss Equation (USLE) method in Way Besai Watershed. The location of this research was conducted at Way Besai Sub River Watershed, Tulang Bawang Watershed, West Lampung Regency with Way Petai as the control point. The data needed in this research is the limitation of Way Besai Watershed catchment, land use data and land type at Way Besai Watershed catchment area. From the result of sedimentation analysis with USLE method, it can be known that the erosion rate of Way Besai Watershed catchment area is 305.03 ton/ha/year which is classified as Class IV Hazard Erosion or heavy and sedimentation of Way Besai Watershed catchment area is 165.079,13 ton/year

Storage Capacity Analysis on the Construction of Reservoir C Faculty of Medicine University of Lampung

Reservoir is a basin that can be utilized to contain excess rain water which will be used during dry season and it is also an act of effort to nurture the existence and sustainability of the environment, nature and the ground water, so that the water can always be available in an adequate quantity and quality to fulfill the needs for the living. reservoir is also utilized to maintain the quality of the water ground and as an ecotourism object as well. In University of Lampung, there are several reservoirs that can be found, one of which is reservoir C which is located at the faculty of medicine, University of Lampung. The main purpose of this research is to find out the capacity storage of the reservoir by using several supporting softwares to simplify the calculation. the supporting softwares which are used in this research are AutoCAD 2017, Microsoft Excel 2017, and Google Earth Pro. The outputs of this research are (1) The estimation of flood discharge at reservoir C faculty of medicine, University of Lampung (2) The storage capacity of the reservoir C faculty of medicine, University of Lampung based on this research, it can be concluded that reservoir is qualified as a conservation reservoir which has 6594.9909 m 3 storage capacity

Analisa Hidrologi dan Hidrolika Saluran Drainase Box Culvert di Jalan Antasari Bandar Lampung Menggunakan Program HEC-RAS

This research was conducted to know the Rainfall Intensity in Antasari area using Intensity Duration Frequency curve (IDF) knowing at what time of year again when the maximum discharge channel in Antasari will be exeeted and to know drainage channels capacity in Antasari based on hydrology analysis and hydraulic using HEC-RAS.The calculations performed by using minutely rainfall data obtained from BKMG Panjang, Bandar Lampung from 2000 until 2011. After checked based on statistical parameters, using Log Pearson III methods to find rain plan based on 2 years, 5 years and 10 years return period. The results were made in IDF curve by connecting consentration time to IDF curve obtained rainfall intensity for each return period. This intensity value will be inserted into the rational formula to obtained the discharge plan value for each return period. The discharge value will be inserted to channels modelling made on HEC-RAS program. it can be obtained for what return period the discharge will be exceeded. The hydrology analysis and hydraulic performed again by using trial and error model. it can obtained the channel capacity.Based on these results, it can conclude that the rainfall intensity is 58 mm/hour for 2 years return period, 76 mm/hour for 5 years return period and 115 mm/hour for 10 years return period of time. The channels capacity exceeded for 10 years period of time and channels capacity is 1,09 m3/hour

Analysis of Rainfall Characteristicsfor Flood Estimation in Way Awi Watershed

This study investigates rainfall intensity distribution in Way Awi watershed located in Bandar Lampung, and how their impacts on flood peak and flood hydrographs. Hourly rainfall data is examined to obtain design rainfall intensity and rainfall intensity distribution at rainfall duration from three to eight hours. Rainfall-runoff model, i.e. Rational method is used to calculate flood peak while unit hydrograph method is used to develop flood hydrograph. This study shows that in Way Awi watershed 88.3% to 96.4% of 24-hour rain occurs in three to eight hour durations. In addition, rainfall with three hour duration generates the highest flood peak, followed by four hour duration rainfall. When rainfall duration and design rainfall intensity are the same but rainfall intensity distribution is different, generated flood hydrograph may have different flood peak magnitude and timing. Result of this study is useful for flood analysis and mitigation in Way Awi watershed

Analisis Kedalaman Gerusan Lokal (Local Scouring) di Hilir Bangunan Pelimpah (Stepped Modified Spillway) dengan Model Fisik 2D

Spillway is a hydraulic structure whose existence is very important because it is built to release excess water or flood discharge that cannot be accommodated in the dam. The hydraulics analysis of this study used a spillway design (Stepped modified Spillway) with a 2-D physical model and the sediment used was sand with a uniform diameter of 1.8 mm or passed sieve no. 16. This research was carried out 5 times for every 25 minutes of upstream water level observations.In the Stepped spillway spillway the maximum scour (dsmax) occurs at an upstream height (H0) of 3 cm of 0.125 m with an Lds of 0.09 m from the downstream of the spillway. Meanwhile, for the Stepped Modified Spillway spillway, the maximum scour (dsmax) occurs at an upstream height ( H0) 3 cm is 0.076 m with Lds of 0.221 m. This shows that the greater the flow rate, the greater the depth of scour that occurs. So it can be concluded that the Lacey method is the closest to the laboratory results. This is because a balance has been achieved. The deeper the local scour that occurs, the more volume of sediment carried downstream of the weir