Sutami Reservoir Research Articles

Examining Water Quality Indices Method in Varied Climatic Regions – Sutami Reservoir Case Study

Examining Water Quality Indices Method in Varied Climatic Regions – Sutami Reservoir Case Study

Reservoir water budget estimation using satellite and ground measurement data

Rising air temperatures, increased rainy runoff, reduced dry season runoff, and severe weather conditions have intensified floods and droughts, significantly affecting the reservoir water supply. The accuracy of reservoir water balance is crucial for meeting water needs. The study compares satellite data and ground measurements to analyze the water budget of Sutami Reservoir in Indonesia. Satellite data collected included precipitation (Tropical Rainfall Measuring Mission-TRMM) and evaporation (Global Land Data Assimilation System-GLDAS). The water balance approach was utilized to analyze the water budget. The suitability tests used were Root Mean Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), Correlation Coefficient (CC), and Relative Error (RE). The study revealed that the data from TRMM and GLDAS satellites closely resembled ground measurements. The reservoir water balance analysis revealed that satellite data aligns with ground measurements, indicating water shortages in the dry season and excess water in the rainy season. Satellite data is particularly beneficial for watershed management in areas lacking ground measurement equipment, as it can be analyzed for various purposes.

Akurasi Data Curah Hujan Satelit Terhadap Data Pengukuran di Daerah Tangkapan Air (DTA) Waduk Sutami

Sutami Reservoir that located in the Brantas River Basin is a multi-purpose reservoir, it’s used to provide of raw water, irrigation, flood control, and power plants, fish farm, and tourism. Rainfall data information is very important in hydrological analysis as the basis for determining operating patterns, water balances, and calculating sediment rates. Rainfall data that is recorded in a row can show us trends or the nature of rain, but in reality it is very difficult to obtain representative rainfall observation data, both in terms of quality and length of observation data, which is quite in accordance with what is required in several locations, it is very difficult due to the absence of rain stations or broken gauges. Therefore, by taking advantage of technological advances, it is necessary to analyze the accuracy of rainfall data via satellite (GPM V6 and TRMM 3B43 V7) as an alternative to using rainfall data to fill data shortages at certain locations. The results of the analysis of the two satellite rainfall data (GPM V6 and TRMM 3B43 V7) are based on the Nash Sutcliffe Efficiency (NSE) parameters, Root Mean Square Errror (RMSE), Real Error (KR), Correlation Coefficient (R) can be used as an alternative to rainfall data, with satellite rainfall data GPM V6 has better accuracy and performance with average value of NSE 0,8, RMSE 66,46, KR 21,63%, R 0,92.

Identifikasi Kekeringan Meteorologi menggunakan SPI 3 Bulanan dan 6 Bulanan di DAS Brantas Hulu

Drought is a state of water availability that is far below the need for water for survival, agriculture, economic activity, and the environment. Drought in the Brantas Hulu watershed has been recorded as hampering the function of the Sutami Reservoir. This study used the Standardized Precipitation Index (SPI) method of 3 monthly and 6 monthly to determine the distribution of drought in the form of duration, severity, and maximum intensity of the Brantas Hulu watershed. This study also analyzed the relationship between the 3-monthly and 6-monthly SPI index to the sutami reservoir inflow discharge in the Brantas Hulu watershed using the Pearson Correlation method including correlations without lag, lag 1, and lag 2. The data used are monthly rainfall data for 30 years for the period 1991 - 2020 from 10 Rain Posts in Malang City, Batu City, and Malang Regency as well as monthly inflow debit data for 10 years for the period 2011 - 2020 from Perum Jasa Tirta 1. In general, the distribution of the maximum drought duration occurs for 15 – 17 months, while the SPI of 6 months occurs for 25 – 29 months. The maximum drought severity occurs for 5 - 6 months, while the 6-month SPI occurs for 9 – 11 months. The maximum drought intensity of SPI is 3 months and 6 months is categorized as Dry. Otherwise, the correlation of 3 monthly SPI and sutami reservoir inflow discharge without lag and lag 1 is worth 0,2 to 0,3, while for lag 2 it is worth 0,1 to 0,2. The correlation value of the 6 -month SPI index and the inflow discharge of Sutami Reservoir without lag is worth 0,3 to 0,4, while the correlation of lag 1 and lag 2 is worth 0,2 to 0,3.

Discharging Sediment Downstream: The Opportunities and Challenges of Sediment Management in Sutami Reservoir, Indonesia

Discharging Sediment Downstream: The Opportunities and Challenges of Sediment Management in Sutami Reservoir, Indonesia

Mathematical model distribution of some water quality parameters in the reservoir

Sutami Reservoir is one of the largest reservoirs in East Java Province and is very useful in the life of people in Malang. However, the water quality of Sutami reservoir currently degrades due to waste. This study aims to determine water quality using the pollution index method and mathematical modeling. Polynomial regression is the most suitable mathematical model. It was obtained by statistical testing and adjusted based on population index data. Sutami Reservoir is classified as a reservoir with a eutrophic trophic status. The load capacity in eutrophic conditions at the monitoring station revealed that the levels exceeded the maximum pollution load limit. The relevant authorities need to take action to overcome the waste problems which contribute to the degradation of water quality in Sutami reservoir

Interpretative Structural Modeling Dalam Analisis Kelembagaan Pengendalian Kualitas Air Waduk Sutami

The Sutami Reservoir, located in Malang Regency, East Java, has moderate to severe levels of pollution. This pollution problem can reduce the water quality of the Sutami Reservoir, so it requires coordination from the agencies concerned to formulate water pollution control policies. The management agency for the Sutami Reservoir is the ‘Perum Jasa Tirta 1’ (PJT 1). The institutional analysis applied is the Interpretative Structural Modeling (ISM) method, to find out which agencies are key elements/factors. There are eleven agencies analyzed. Agencies that are included in the ‘Dependent’ sector are the Water Resources Public Works Office, the Tourism and Culture Office, the Livestock and Animal Health Office, the Population Control and Family Planning Office, and the rice farmer groups. Institutions in the ‘Linkage’ sector are the Food Crops, Horticulture, and Plantations Office and the Industry and Trade Office. Institutions in the ‘Independent’ sector that play a key role are the Environment Office, the Fisheries Office, Balai Besar Wilayah Sungai Brantas, and the floating net cage fish farmer group. These four agencies are the key elements that have a big driving power so that more in-depth coordination needs to be carried out for the formulation of policies and regulations for water quality control.

The effect of horizontal drainage on sediment water content in the spoilbanks of Sengguruh reservoir, Brantas river, Indonesia

In the Brantas River System, Sengguruh is the first reservoir in the direction of the river flow. This reservoir functions to protect Sutami Reservoir from severe sedimentation. The effective storage capacity was about 24% of its initial storage. In order to restore the storage, dredging work at Sengguruh Reservoir must be carried out over the course of the year. To support the dredging, it is necessary to carry out technical work so that sediments in the temporary spoilbanks can be immediately hauled to another place and then are ready to be refilled. Hauling can be done optimally if the sediment condition in the spoilbanks is quite dry. Therefore, it is necessary to know how horizontal drainage can affect the sediment water content in the spoilbanks.

Daya Dukung dan Laju Pertumbuhan Microcystis Hasil Isolasi dari Waduk Sutami pada Berbagai Variasi Konsentrasi Nitrat dan Fosfat dalam Medium Selektif B-12

The main objective of this research was to calculate the carrying capacity and growth rate ofisolated Microcystis result in Sutami reservoir on a variety of nitrate and phosphateconcentrations in the B-12 selective medium. Research was conducted in the laboratory withpure experiments using completely randomized factorial design with factors of nitrateconcentration variation (8, 16, 32, and 64 ppm) and phosphate (0.2, 0.4, 0.8 and 1.6 ppm) in B-12medium. Repetition of the study was conducted three times at the same time. Microcystispopulation abundance which was counted every day until the stationary phase (day +30) wasused to calculate the rate of growth (β) and maximum abundance of Microcystis can besupported by each medium treatment (γ). The results showed that the growth rate of Microcystiswas not significantly influenced by levels of phosphate in the medium but significantly positivelycorrelated with increasing nitrate concentration in the medium. Carrying capacity or themaximum abundance (γ) of Microcystis was influenced by the combination of nitrate andphosphate in the B12 medium. Concentration of phosphate 0.4 ppm in medium combined withnitrate 8−64 ppm could support the highest abundance of Microcystis.

The decision making analysis of increasing storage capacity of sutami reservoir with Analytical Hierarchy Process (AHP) approach

Sutami Reservoir is located in Malang, East Java, Indonesia, is a multi-use reservoir to supply water for hydropower plant, agricultural irrigation, industry, communities and flood control. The functional of Sutami reservoir is decreasing over time caused by the reduced of reservoir capacity as a result of increasing in sedimentation rate every year. If this problem is not handled properly, it can be causing the failure of reservoir function. Various efforts have been done to overcome the causes of sedimentation in the upstream part of the reservoir intensively and sustainably. An innovative step is needed to increase the storage volume of Sutami reservoir. This step is to extend the lifespan of the reservoir. There are several alternative actions which can be taken, but this is still a polemic among experts and stakeholders. This is because many conflicts in criteria which are taken into consideration. This study aims to determine the priority order of proposed alternative actions through the multi-criteria decision making process using the Analytical Hierarchy Process (AHP) method. AHP allows uniting the subjective qualitative assessments of individuals through importance-level pairwise comparisons into an assessment of group decision making. Weighting result of the pairwise comparisons using Social, Environmental, Technical, and Economic aspects as a criterias are as follows: the alternative of heightening the dam body by 5m is the top priority with the weight of 36.2%. The alternatives heightening the spillway by 0.5m is the second priority with a weight of 25.7%, the alternative of dredging sediments as much as sediment inflow in the third priority with a weight of 20.5% and the last priority is the status quo a weight of 17.7%. Keywords: Decision Support System, Water Resources Management, Sutami Reservoir Dam, AHP

Performance of Bayesian quantile regression and its application to eutrophication modelling in Sutami Reservoir, East Java, Indonesia

Phytoplankton has an important role in aquatic ecosystem as the primary natural feed for another aquatic biota. However, the density of phytoplankton must be controlled at desirable level in order to prevent eutrophication. Because eutrophication can damage the ecosystem and as the consequence will led to mass mortalities of fish. There are several factors that affecting phytoplankton density such as light availability, temperature, pH, and nutrient content. Nutrient content is composed by nitrate and phosphate. The relationship between nutrient content and phytoplankton density commonly performed by using simple linear regression. But, this method cannot give an overall description of the data since it is worked at conditional mean. Moreover, simple linear regression has several limitation like highly influence by outlier and need the fulfillment of classical assumption. Thus, the aim of this research are to offer an alternative method namely Bayesian quantile regression and provide its performance compared to simple linear regression under various data condition. Also to apply such model to the relationship between nutrients content and phytoplankton density in Sutami Reservoir. The results indicate that Bayesian quantile regression performs better that simple linear regression when the outlier exists. Unfortunately, the data of phytoplankton density and nutrients content in Sutami Reservoir contains outlier according to Cook’s distance criteria. It means that Bayesian quantile regression should be used. The obtained model showed that the parameter values of regression model between nutrients content and phytoplankton density vary, which are depended on the analyzed quantile

The application of Bayesian quantile regression to analyse the relationship between nutrients content and phytoplankton abundance in Sutami reservoir

Phytoplankton plays a significant role in aquatic ecosystem as the main feed for another aquatic biota. However, the abundance of phytoplankton must be controlled. This is due to the exaggeration of phytoplankton abundance can lead to eutrophication and the mass mortalities of fish. One of the dependent factors for phytoplankton abundance is the nutrients (nitrate and phosphate) in the relevant aquatic ecosystem. This study aims to analyze the relationship between nutrients and phytoplankton abundance, also to determine the maximum limit of the nutrient content in order to prevent eutrophication in Sutami Reservoir. The relationship usually analyzed by simple linear regression. Unfortunately, the data of phytoplankton abundance and nutrients content in Sutami Reservoir contains outlier according to Cook’s distance criteria. It means that simple linear regression cannot be used. Thus, the alternative method which is Bayesian quantile regression considered. The result of analysis indicates that the parameter value of regression model between nutrients content and phytoplankton abundance is varying, which are depended on the analyzed quantile.

Exploration of Physics-Chemical Quality Lahor Reservoir of Malang District, Indonesia

Lahor Reservoir was built and functioned as a water provider for agricultural activities, flood control, electricity generation, tourism activities and inland fisheries. This reservoir is one of the inflows of the Sutami reservoir which is the largest reservoir in East Java. This Lahor Reservoir is drained by three rivers, namely the Lahor River, Leso River and the Dewi River, which flows through housing and paddy fields, allowing the entry of organic and inorganic materials from various activities around the rivers and reservoirs. The aim of the study was to assess the physico-chemical parameters of the Lahor reservoir during the dry season. This research was conducted between March and April 2018. Water quality analysis was carried out in the Laboratory of Environmental Engineering Department of ITN Malang. The study was conducted by survey method and sampling method. Measurement of physical and chemical parameters of the waters was determined at 4 stations and each station consisted of 5 sampling points with different depths. Data analysis using descriptive statistics (mean, graph). The assessment of the temperature in the waters of the Lahor Dam ranged from a value of 24-28o C, turbidity with a value of 0.4 NTU, DO values from surface to base increased significantly with values of 29.1 mg / L, 33.9 mg / L and 34.3 mg / L and still meet the minimum water requirements for aquaculture. The high BOD value at the Lahor reservoir outlet is influenced by the accumulation of organic substances from several inlets and dam waters. Phosphate values are higher along with water depth and Fecal Coli ranges from 1-2 MPN / 100 mL at all sampling points. In general, the Lahor reservoir water still meets the quality standards for class I waters.

The comparison study for the models of reservoir release rule for irrigation. Case study: Sutami Reservoir

AbstractThree models of release rule for operating a large reservoir for irrigation water supply are discussed in this paper. The models are a 50-grid storage continuous line restricted release rule, a single rule curve release rule, and a multi 4 rule curves release rule. These three models are to be optimized by stochastic simulation using 30 year inflow data with the maximization of the average monetary annual production in the irrigation area as the objective function. The purpose of this study is to look for the proper release rule for operating the Sutami Reservoir. The optimization is done first by the random search stochastic simulation model to generate a number of alternative solutions. Using these solutions as a generation of solutions, the genetic algorithm model is the applied to improve the solution. Afterward the best of solutions are checked by the Add-Ins Solver of MS-Excel 2010 to see if they can still be improved further. The results show that the 4 rule curves model gives the best solution with the average monetary annual production in the irrigation area of USD 72.248 million.

Evaluation of synthetic rainfall application with respect to the flow volume at upstream Brantas watershed, East Java Province of Indonesia

Abstract Indonesian Technical Implementation Unit (UPT) of Synthetic Rainfall has modified climate by generating synthetic rainfall from 9th May until 4th June 2013. This unit has cooperated with the Department of Technological Study and Application (BPPT) of Indonesia and Perum Jasa Tirta I and TNI AU Lanud Abdulrachman Saleh. This study intended to increase reservoirs water level in upstream Brantas watershed, one of them is Sutami reservoir. Successive grade evaluation of synthetic rainfall used the method of Double Ratio and Flow Discharge. The target area is upstream Brantas watershed that is represented by 12 rainfall stations and the control area is in the distance of ±30 km from the boundary of upstream Brantas watershed and is represented by 5 rainfall stations. Results show rainfall increasing by 152.05% according to the Double Ratio method and the increase of flow discharge from Sutami reservoir by 74.19% according to the Flow Discharge method.

Reservoir Inflow Prediction under GCM Scenario Downscaled by Wavelet Transform and Support Vector Machine Hybrid Models

Climate change has significant impacts on changing precipitation patterns causing the variation of the reservoir inflow. Nowadays, Indonesian hydrologist performs reservoir inflow prediction according to the technical guideline of Pd-T-25-2004-A. This technical guideline does not consider the climate variables directly, resulting in significant deviation to the observation results. This research intends to predict the reservoir inflow using the statistical downscaling (SD) of General Circulation Model (GCM) outputs. The GCM outputs are obtained from the National Center for Environmental Prediction/National Center for Atmospheric Research Reanalysis (NCEP/NCAR Reanalysis). A new proposed hybrid SD model named Wavelet Support Vector Machine (WSVM) was utilized. It is a combination of the Multiscale Principal Components Analysis (MSPCA) and nonlinear Support Vector Machine regression. The model was validated at Sutami Reservoir, Indonesia. Training and testing were carried out using data of 1991–2008 and 2008–2012, respectively. The results showed that MSPCA produced better extracting data than PCA. The WSVM generated better reservoir inflow prediction than the one of technical guideline. Moreover, this research also applied WSVM for future reservoir inflow prediction based on GCM ECHAM5 and scenario SRES A1B.

Control of Microcystis spp . Bloom By Combination of Indigenous Denitrifying Bacteria From Sutami Reservoir With Fimbristylis globulosa and Vetiveria zizanoides

The purpose of this research were to know the ability of polyculture macrophyte (Fimbristylis globulosa and Vetiveria zizanoides) and combination of both with consortium of indigenous denitrifying bacteria from Sutami reservoir that added by Microcystis spp. or not to reduce the concentration of nitrate, dissolved phosphate and the carrying capacity of Microcystis spp. Experiment was done in medium of Sutami reservoir water enriched with 16 ppm of nitrate and 0,4 ppm of phosphate. Denitrifying bacteria were used in this research were DR-14, DU-27-1, DU-30-1, DU-30-2, TA-8 and DU-27-4 isolated from Sutami reservoir. The treatments were incubated during 15 days. Microcystis spp. abundance was calculated every day, but measurement of the the concentration of nitrate and dissolved phosphate were done every six days. The results showed that both treatment and a combination of both macrophytes with a consortium of denitrifying indigenous bacteria were added or not either Microcystis able to reduce nitrate at 99% and 93-99% orthophosphoric. Combination of macrophytes with denitrifying indigenous bacterial consortium from Sutami reservoir was able to inhibit the carrying capacity of Microcystis spp. highest until 47.87%. They can also significantly reduce the abundance of Microcystis from 10 7 cells/mL in early of treatment to become 0.35x10 4 cells/mL after fifteen days incubation.

The Effectivity of Scirpus Grossus and Limnocharis Flava As Fitoremediation Agents of Nitrate-Phosphate To Prevent Microcystis Blooming In Fresh Water Ecosystem

The aim of this study was to reduce the concentration of dissolved nitrate-phosphate, because it can prevent the occurrence and inhibit the growth of Microcystis bloom waters. The study was conducted experimentally in the laboratory. The Microcystis isolation was carried out in Sutami Reservoir. Then, remediation treatment with hydromacrophyte (Scirpus grossus, Limnocharis flava and combination of both hydromicrophyte) were done during the 15 day incubation period. Abiotic factors were measured on day 0, 6, 12 and 15, but the abundance of Microcystis cells was counted daily. The productivity of hydromacrophyte was measured at the end of the research. The research results showed that hydromacrophytes were effective to reduce nitrate and phosphate concentrations. The combination of S. grossus and Microcystis reduced nitrate concentration up to 99.89 %, while the highest reduction of dissolved phosphate (98.22 %) was resulted from the combination of L. flava and Microcystis. The combination treatment of L. flava and S. grossus was capable to prevent Microcystis growth rate and produced the carying capacity of 65 cells.L-1.day-1 and 6.93 x 10 4 cells/mL.

The Capability of Equisetum ramosissium and Typha angustifolia as Phytoremediation Agents to Reduce Nitrate-Phosphate Pollutants and Prevent Microcystis Blooming in Fresh Water Ecosystem

The aim of this study is to find out the kind of hydromacrophyte composition having the highest capability to reduce nitrate-phosphate pollutant and Microcystis growth in phytoremediation media using Equisetum ramosissium, Typha angustifolia and the combination of both. Microcystis were obtained from Sutami reservoir, then being inoculated in a media grown by hydromacrophytes (E. ramosissium, T. angustifolia and both of the hydromacrophytes) in the batch culture system. The number of Microcystis was counted every day within fifteen days. Abiotic factors were observe, including the concentration of nitrate using brucine-colorimetry method and orthophosphate (dissolved phosphate) using stannous chloride-colorimetry method on day 0, 6th, 12th and 15th. The growth rate of Microcystis carrying capacity and orthophosphate-nitrate levels among treatments were analysed by ANOVA test. The results showed that E. ramosissium and T. angustifolia in mono and polyculture techniques had similar potentiality to reduce the nitrate and ortophosphate. The concentrations of nitrate and orthophosphate decreased over 70 % in the 6th day after incubation. All of the treatments were able to reduce the carrying capacity of Microcystis up to 46 % , but the growth rates were similar in all media, that is, around 97-170 cells/L/day. Keywords: Equisetum ramosissium, Microcystis, nitrate, phosphate, Typha angustifolia

Blooming Stimulation of Microcystis in Sutami Reservoir Using Nutrients Nitrate and Phosphate in Different ratio

Microalgae Cyanobacteria from the genus Microcystis has the potential to bloom in Sutami reservoirs that located in Malang, Indonesia at a particular time. Microcystis is a notorious species because it can produce toxins that are dangerous to other organisms. The objective of this research is to determine the influence of different ratios of Nitrate and Phosphate on the growth of Microcystis in Sutami reservoir. The study was conducted from April to November 2009 and was carried out in situ in the reservoir Sutami with quasi experiment using a completely randomized design. Sutami reservoir water which already contained plankton community therein, including Microcystis were treated with five variations ratio of Nitrate and Phosphate (10, 20, 40, 80, and 160) and untreated water as control. Experiments carried out by using a transparent plastic bag diameter 1 m and 1.5 m long, inserted into the water and be immersed in the water by using bamboo. Calculation of Microcystis abundance and physic-chemical quality of water is done every three days for a month. The results showed that the higher concentration of orthophosphate in the media water of Sutami reservoir have the maximum abundance of Microcystis. Abundance of Microcystis grown in Sutami reservoirs have positively correlated with actual levels of nitrate, nitrite, total phosphate, conductivity, pH, temperature, ratio of Nitrate to Phosphate treatment and water KMnO4 value.Keywords: Blooming Microcystis, the ratio of nutrients Nitrate to Phosphate, Sutami reservoir