Code River Research Articles

Artikel Review: “Kondisi Terkini Kualitas Air Sungai Di Daerah Istimewa Yogyakarta”

Domestic waste and heavy metals are common problems found in river water. Household activities around the river contribute domestic waste to the river. Also, due to industrial activities in the last few centuries caused heavy metal pollution. This article discusses the quality of Bogowonto, Winongo, Code, Gajah Wong, Opak, Belik and Bedog rivers for the analysis of domestic waste parameter values, while the heavy metal content for Bogowonto and Code river was excluded. The analysis method is purposive sampling and composite sample. The rescent research result on the observation of various parameters showed a fairly high waste content for domestic waste with BOD (Biochemical Oxygen Demand) parameters,while the highest pollution content for heavy metal waste is lead and iron.

Disaster evacuation challenges in high-density urban neighborhood Kampung Code, Yogyakarta

The article discusses the challenges of disaster evacuation in the high-density urban neighborhood of Kampung Code in Yogyakarta, Indonesia. The rapid urbanization along riverbanks in the area has led to increased vulnerability to flooding and other environmental hazards. The study aims to identify the characteristics and challenges of circulation routes for supporting disaster evacuation in riverbank settlements like the Kampung Code. The research uses a mixed-methods approach, including surveys, interviews, and observations, to gather data using a town-watching approach. The article emphasizes the importance of understanding the specific characteristics of space in these areas to enhance community resilience and disaster recovery. The study occurred in Kampung Jogoyudan, one of the most populated areas along the Code River, and serves as a model for understanding and addressing evacuation challenges in other high-density urban environments.

The Impact of Local Wisdom "Merti Code" on SDG's Goals in Protecting the River Environment in Yogyakarta

This paper examines the impact of the local wisdom "Merti Code" which has become the culture of communities around the banks of the Code River on maintaining the river environment, which is a sustainable development goals (SDG's.) This report analyzes comprehensively from empirical and policy approaches regarding government regulations regarding the river environment. The main aim is to emphasize the importance of maintaining the river environment through the community's communal cultural approach "Merti Code" even though river environmental maintenance has been regulated by several government regulations, both central and regional. From the analysis of the results of this research, it was found that the effectiveness of implementing the Local Wisdom "Merti Code" was found in order to maintain the sustainability of river environmental maintenance. Because this local wisdom is known to have an impact on a clean river environment with a good water ecosystem balance and can also provide economic benefits for the surrounding community and even the Yogyakarta City government, with the emergence of "Merti Code" cultural tourism which is an annual routine agenda of the Yogyakarta City Government, since 2000. The results found, there is a correlation between the implementation of the 'Merti Code' community culture originating from the communities along the Code river and the belief in maintaining the cleanliness and environment of the river. The trust that grows in society (Local Wisdom) is more effective than the river environmental protection regulations implemented by the government so far.

Hydrological Potential Mapping to Generate Micro-Hydro Power in Code River

Fossil fuel energy utilization in Indonesia is consider high consisting of 65% coal sources and 20% fuel, while only 15% are generate from new and renewable energy sources. This number is critical due to the commitment to reduce greenhouse gases by 29% or 41% as declared Glasgow in 2021. Alternatives source of energy could be obtained from solar, wind, and water. The energy generate from those sources are consider intermittent, however, water utilization can be optimized by construct several weirs (small-scale reservoirs) to accumulate the rain water as a kinetic energy source to generate electricity. Only some part of the world, especially tropical Indonesia archipelago, has enough rain to generate energy. This research intends to measure the potency of Code River, representing small river in generating micro-hydro power. The Code River is representing a small river on the island of Java as part of the archipelago in Indonesia which has the characteristics of a river, a small water catchment area, and has high discharge input from rainfall because it is in the tropics. The weir is equipped with a penstock pipe, as water intake to the generator. The pipe inner diameter made of high-density polyethylene material can be 200, 300, 400, 500, 700, 800, 1,000 and 1,600 mm. Each pipe size can produce discharges of 0.42, 0.75, 1.62, 2.1, 3.1, 3.5, 6.0 and 24.0 m3/s respectively. The combination of discharge and head height will produce electrical energy (in watts). Based on hydrological modelling consisting of 52 sub-watersheds, the highest electricity production in 2021 is 8,359,218.3 kWh with 800 mm pipe size (3.5 m3/sec discharge). The electricity production is based on reliable discharge between 7-96% which is different for each weir location. In conclusion, the electricity supply for the whole year (100%) is inadequate

Statistical Evaluation on Water Pollution Level of Code River, Yogyakarta Based on Heavy Metals Concentrations and Sampling Locations

Statistical Evaluation on Water Pollution Level of Code River, Yogyakarta Based on Heavy Metals Concentrations and Sampling Locations

Pemberdayaan Ekonomi Masyarakat Melalui Pelatihan Produksi Detergen Ramah Lingkungan dan Pemasaran Digital

The Kamulyan Garbage Bank is located in the Brontokusuman Village RW 20-22, Mergangsan District, Yogyakarta City which is around the Code River. Not a few people throw away the water for washing clothes in the river, thereby disrupting the aquatic ecosystem. This is the reason and objective of this community service program, which is to reduce the impact of river pollution and empower the people around Kali Code. The implementation method is carried out through seminar and practice of using environmentally friendly detergent production equipment, seminar and practice of standard operating procedures (SOP) using production tools, seminar and practice of calculating the cost of production (HPP), as well as seminar and advanced digital marketing practices. This program is in accordance with the UAD Community Service Program roadmap for 2020-2045 which refers to the realization of accelerated marginal areas towards smart, healthy, environmentally friendly areas with socio-entrepreneurship characteristics, universal values and Islam in 2020-2045. Based on the results of the questionnaire, as many as 90% of participants experienced an increase in knowledge after seminar and practicing.

Monitoring the Diversity of Amphibian and Reptiles In the Upstream part of Code River Using e-DNA Method

Research on the diversity of amphibians and reptiles on the upstream part of Code River had been done in 2012 and 2017. Result on two previous results were found anurans, snakes and lizards but we did not find any freshwater turtles. Method used on the 2012 and 2017 research was conventional using Visual Encounter Survey (VES). Conventional methods such as VES have limitations, which was the inability to detect difficult-to-find animals such as freshwater turtles. Therefore, a new approach was taken to monitor the diversity of amphibians and reptiles especially to detect freshwater turtles in the Code River, namely the environmental DNA (eDNA) method. The purpose of this research were to monitor the diversity of amphibians and reptiles, and to reveals eDNA sampling efficiency compared to VES. An e-DNA metabarcoding process is conducted with universal CO1 primer on the water sample taken from upstream part of Code River. The results obtained were compared to the data from conventional studies held in 2012 and 2017. The results in 2021 found 12 species of amphibians but all of these species did not naturally distribute in Yogyakarta and even in Indonesia. Furthermore, 5 species of snakes were found, with only 1 species of snake naturally occur in Yogyakarta. Subsequently, we found 6 species of lizards whose natural distribution does not exist in Yogyakarta and even in Indonesia. Finally, we obtained 1 species of tortoise whose natural distribution does not exist in Yogyakarta and even in Indonesia. By far, in Indonesia the identification of amphibian and reptile species in rivers using the e-DNA method has shown less accurate results. The inaccuracy may be due to the lack of specificity of the sequence targets and primers for monitoring reptiles and amphibians in rivers. The target sequences used in this study did not have significant differences between species in reptiles and amphibians, so that the herpetofauna that had been recorded in the Code River were not identified using the e-DNA method. Based on this research, conventional sampling is recommended for monitoring herpetofauna in river areas.
 Keywords: Monitoring, Amphibians; Reptiles; Code River, e-DNA

Transformation of River Restoration Movement Network

A study on social network transformation of river restoration movement is very important as it is related to the network’s ability of adapting to various changes and a movement’s sustainability. This research aims to reveal the history of movement emergence, tactic, and strategy, process and procedure of social network establishment and social network transformation. An ethnographic approach was chosen by involving Komunitas Pemerti Kali Code (Code River Observer Community) as the main subject of current research. Data collection was conducted through live-in-society process for 2 months to conduct participant observation, in-depth interview and Focus Group Discussion. Data analysis was constructed using Mario Diani’s theory about social movement as a network. The result of research shows that the first factor is the emergence of problem and grievance about river contamination by rubbish and waste due to people’s poor literacy about river. The second one is movement strategy and tactic used in the form of structural and cultural approach to restore the river. The third is the process of creating social network based on shared idea, value, norm, collective identity, and interest related to the river. The fourth is social network experiencing transformation from spontaneity, institutionalization to autonomy phase as the attempt of adapting to and reconciling with the form of change to maintain the movement sustainability.
 Keywords: River Restoration Movement, Movement Strategy, Social Network Establishment, and Social Network Transformation

THE ESTIMATION OF FLOOD-AFFECTED AREA IN THE DOWNSTREAM OF CODE RIVER, YOGYAKARTA, INDONESIA

The rapid development of settlements and sediment deposition has increasingly narrowed the drainage in the Code River. This condition causes floods and wider distribution of the affected areas. This research aims to estimate the maximum amount of rain, predict the probability of flood, and predict flood-prone areas in the Code River. Data were collected by observation, remote sensing image interpretations, literature studies, and documentation. Data analysis was performed using Log Pearson Type III for design rainfall analysis, Weibull formula for flood probability analysis, and rational method for planning maximum discharge analysis. Flood modeling is carried out by the iteration method. The results show: (1) the maximum amount of rain based on the calculated design rainfall with a return period of 5 to 40 years is R5 = 106.83 mm, R10 = 116.67 mm, R20 = 127.30 mm, R40 = 134.25 mm, (2) the probability of flood that is predicted from the maximum discharge caused by the design rainfall at each return period is Q5 = 82.45 m3/sec, Q10 = 89.42 m3/sec, Q20 = 96.95 m3/sec, Q40 = 101.86 m3/sec. (3) Inundation of the flood target area in the 5-year return period covers an area of 0.4456 km2, the 10-year return period covers 0.5209 km2, the 20-year return period covers 0.6023 km2, the 40-year return period covers 0.6555 km2. This paper presents information on the potential for a flood at various return periods to increase preparedness and reduce risks due to flood disasters.Keywords: Disaster, Floods, Estimated Flood-Affected Areas, Code River, Yogyakarta

Urban settlements quality in Kotabaru Village, Gondokusuman Subdistrict, Yogyakarta City

This research was conducted around the Code River, especially in Kotabaru village, Gondokusuman Subdistrict, Yogyakarta City. The purpose of this study is to examine the characteristics of urban settlements and analyze their quality. The data collection method was carried out by using the multistage random sampling method. This sampling technique was carried out in two stages, namely classifying and selecting samples randomly. Data processing was done by scoring method using Sturges’ rules. Quantitative data analysis was carried out using descriptive statistics, while qualitative data analysis was carried out by explaining the results of data processing in depth. The results showed that most of the houses had poor accessibility, poor physical building conditions, good environmental sanitation, and residential environment characteristics with moderate conditions. This study also found that the quality of settlements in the study area with poor, moderate, and good classes was 30.43%, 50%, 19.57%, respectively. Indicators that lead to poor quality of settlements include accessibility, number of health facilities, land area per person, distance of clean water sources from fecal dumps, road width, and tree cover.

Antibiotic Resistomes and Microbiomes in the Surface Water along the Code River in Indonesia Reflect Drainage Basin Anthropogenic Activities.

Water and sanitation are important factors in the emergence of antimicrobial resistance in low- and middle-income countries. Drug residues, metals, and various wastes foster the spread of antibiotic resistance genes (ARGs) with the help of mobile genetic elements (MGEs), and therefore, rivers receiving contaminants and effluents from multiple sources are of special interest. We followed both the microbiome and resistome of the Code River in Indonesia from its pristine origin at the Merapi volcano through rural and then city areas to the coast of the Indian Ocean. We used a SmartChip quantitative PCR with 382 primer pairs for profiling the resistome and MGEs and 16S rRNA gene amplicon sequencing to analyze the bacterial communities. The community structure explained the resistome composition in rural areas, while the city sampling sites had lower bacterial diversity and more ARGs, which correlated with MGEs, suggesting increased mobility potential in response to pressures from human activities. Importantly, the vast majority of ARGs and MGEs were no longer detectable in marine waters at the ocean entrance. Our work provides information on the impact of different influents on river health as well as sheds light on how land use contributes to the river resistome and microbiome.

Structure and Distribution of Macrobenthos Community in Code River, Yogyakarta, Indonesia

This research aimed to explore the community structure of macrobenthos in Code River, Yogyakarta. This research was conducted during December 2019-January 2020 in Code River, Yogyakarta. Data was taken 4 times in 6 stations. Macrobenthos was taken using a Surber net with a size of 30 x 30 cm and sampling at 5 spots in each station. Data analysis consisted of density, diversity index, dominance index, and evenness index. Water quality data consisted of water temperature, flow velocity, water depth, water pH, dissolved oxygen, and organic matter. The results showed that the density of macrobenthos ranged from 54-172 ind/m2. Our results showed that Code River has moderate diversity based on the Shannon-Wiener diversity index. Sulcospira testudinaria is the most dominant species in Code River. The evenness index showed high except at station 2 which was categorized as moderate. Code River has pretty good water quality, but stations 3, 4, and 5 which are located in the city area, it has a high organic matter content.

Initial investigation of microplastic pollution in river sediments at Yogyakarta City Indonesia

Microplastics of less than 5 mm have been widely found in the river sediments that cross the city. Sources of microplastic pollutants can be seen in rivers crossing Yogyakarta City studies on microplastic have never been carried out. This study analyzed the abundance and characteristics of microplastics in river sediments of Yogyakarta City. Data collection was carried out in December 2019 in Winongo River, Code River, and Gadjahwong River. Each sample of the three sediments was taken at each point of the three inlets and outlets in Yogyakarta City. The sediment sample was separated to obtain supernatant-containing microplastics. The abundance of microplastics was quantified and grouped based on the shape, size, and color. Data were analyzed using descriptive and inferential statistics to compare the concentration of microplastic in the three rivers. The results showed that the abundance of microplastics ranged from 279.31 to 1,026.93 particles kg-1, with a higher abundance in the inlet than the outlet. The Code River sediment has the highest microplastic abundance, followed by the Gadjahwong River, and Winongo River. The sediment samples in the rivers crossing Yogyakarta City have been contaminated mainly by the fragment-shaped, transparent, and 1-100 µm microplastics.

Organic Removal Treatment Using Microbubble Generator (MBG) in Eutrophic Disorder Condition

The Techno Park basin, built as an extension of a small tributary of the Code River primarily acts as a retention basin for runoff during the rainy season. It improves the quality of water that has been degraded by domestic wastewater discharge from the surrounding community. Therefore, this study aims to assess the extent to which water quality of the basin can be improved with aeration technology. The aeration technology is a Microbubble Generator (MBG) built using a 100 Watts submersible pump with three horizontal nozzles at a depth of 40 cm from the water surface. Furthermore, the profiles of dissolved oxygen (DO) concentration were measured at the basin’s inlet and outlet, as well as the depths of 1 m below surface water and the bottom of the basin. Diurnal DO was measured to investigate the causes of supersaturation. The aeration performance was also determined from the COD parameters at the inlet and outlet. Discharge measurements were then conducted on the tributary/drainage channel to the inlet basin. The result showed that the DO supersaturation concentration has been attributed to the contribution of photosynthesis from phytoplankton such as algae. Furthermore, no change in DO concentration was observed in a range of 1 m depth from the surface of the water to the bottom (0.3 - 0.14 mg-DO/l). In this eutrophic state, DO increased exponentially during the daytime hours and then decreased during the night. The daily measurement showed an increase in the average DO of 2.31 mg/l (standard deviation of 1.56 mg/l), with average CODinlet fluctuations of 18.79 mg/l (standard deviation of 13.56 mg/l) and average CODoutlet of 14.38 mg/l (standard deviation 2.94 mg/l). Due to additional DO concentration coming from eutrophication during daylight, it was not possible to make a precise assessment of the effectiveness of the MBG aerator.

Application of a hydrological method for determining monthly environmental flow in Code River, Indonesia

The declining groundwater in Yogyakarta could potentially affect the Code River baseflow, thus lowering the river streamflow. Consequently, the riverine ecosystem would suffer from a low quantity of streamflow. The quantity standard of streamflow can be determined by calculating the environmental flow. In this study, the environmental flow requirement (EFR) for the Code River is determined by applying an enhanced version of the most-used hydrological method, namely the Modified Tennant Method based on Multilevel Habitat Conditions III (MTMMHC-III). The EFR in the Code River could be calculated successfully by the MTMMHC-III with a satisfactory temporal variability. The EFRs are the lowest during July to October in the normal years, July to September in the wet years, and July to December in the dry years. The EFRs are highest during January to April in the normal and dry years and January to May in the wet years. However, the EFR might become too low in the dry years, especially from the beginning of the dry season (May) until the early wet season (December), with only 4-11% of the average annual flow. Ultimately, the MTMMHC-III method is a better hydrological method than the original Tennant Method and Q95 method.

IDENTIFIKASI EFEKTIVITAS REAERASI MENGGUNAKAN MICROBUBBLE GENERATOR (MBG) PADA AIR EMBUNG

The retention basin at the Faculty of Engineering Gadjah Mada University was built as a flooding control into the Code river and improving the water quality. The water entering the basin, especially in the dry season, is characterized as greywater due to the dense settlements around the university. The purpose of this study was to determine the effectiveness of reaeration process using a Microbubble Generator (MBG) to increase DO, with the aim of this leading to an improved water quality. The MBG aerator with submersible pumps was installed at a depth of 40 cm from the water surface and placed in the middle of the pond. The aerator was permanently turned on. In situ monitoring of DO was carried out using a seri Lutron WA-2017SD DO meter. The increasing DO correlated with the changes of the surrounding weather which impact on water and air temperature. At the time of DO data collection, the water temperature ranged from 24.5oC - 27oC and the change in DO measured at the inlet and outlet of the reservoir was in the range 0.3 - 1.1 mg/l, with the DO directly surrounding the aerator reaching up to 2.4 mg/l from the inlet. With the DO increased, the concentration of pollutant organic loads can be reduced and the nitritation and nitratation processes has taken place properly so that it has reduced the pollutant load before the water enters the Code river.

Fast and selective colorimetric detection of Fe3+ based on gold nanoparticles capped with ortho-hydroxybenzoic acid

A fast and selective colorimetric sensor for detecting Fe3+ was developed using gold nanoparticles capped with ortho-hydroxybenzoic acid (o-HBA AuNPs). This sensor was characterized using UV-Vis spectroscopy, FTIR spectroscopy, XRD, and TEM. The absorbance of surface plasmon resonance (SPR) at 534 nm increased after the addition of Fe3+. It was confirmed by FTIR, XRD, and TEM data indicating that Fe3+ acted as a bridge among the capping agents of AuNPs. The bridges blocked AuNPs from aggregation and caused an increase in the uniformity distribution of o-HBA AuNPs. Under the optimized condition, this sensor had a good calibration curve linearity at 534 nm. The value of R2 obtained was 0.9994 with LoD of 9.19 μM and LoQ of 30.57 μM. This sensor exhibited good precision and accuracy for Fe3+ detection in rice field, river, and sea waters and has been successfully used to detect Fe3+ in the real water samples collected from various locations of Code River, Yogyakarta, Indonesia.

Analysis of river water quality in the upstream of the Code River, Indonesia

The Code River is one of the main rivers of the Opak watershed that crosses the center of Yogyakarta City, Indonesia. Commercial buildings and densely populated areas dominate the basin of the Code River. This condition affects the decline of water quality because people throw their waste into the river. Therefore, it is necessary to know the status of water quality and the class of the river. This research was conducted to find out the water quality and its designation on the upstream of the Code River. The methods used in determining water quality are the pollutant index of the Ministry of Environment Decree No.15 of 2003 and National Sanitation Foundation-Water Quality Index (NSF-WQI). The parameters used in this study are turbidity, DO, BOD, pH, TDS, Total Phosphate, Nitrate, and Fecal Coliform. The result of water quality in the upstream of the Code River, according to the pollutant index method, revealed that the value obtained was 5 - 16, with the status of water quality, was medium polluted and heavily polluted. Whereas according to NSF WQI, the value was at the range of 48 - 56 with the status of water quality was medium to bad.

The Relationship between River Flow Regimes and Climate Indices of ENSO and IOD on Code River, Southern Indonesia

Predicting the streamflow regimes using climate dynamics is important in water resource management. However, in Indonesia, there are few studies targeting climate indices and streamflow. A previous study found difficulty in developing a statistical prediction model for this relationship due to its non-linear nature. This study attempted to address that gap by applying multiple regression (MR) models using second- and third-order polynomial functions to show the non-linear relationship between climate and flow regime indices. First, a correlation analysis was performed to check the variable relationships. There was a good and significant correlation of El Niño Southern Oscillation (ENSO) with the flow regime indices. Secondly, MR models were developed with the same-time variables. The developed model showed that the Indian Ocean Dipole (IOD) had the effect of strongly increasing the high flow in La Niña phases. Finally, time-lagged MRs were developed aiming at forecasting. Lagged MR models with six-month leading climate indices demonstrated a relatively good correlation with the observed data (mostly R > 0.700) with moderate accuracy (root mean square error = 44–51%). It suggests that the forecasting of flow regime may be possible using ENSO and IOD indices.

ANALISIS NERACA AIR PADA SUB DAERAH ALIRAN SUNGAI CODE YOGYAKARTA

Abstract Water is one of the sources of human life. Population growth continues to increase and results in higher utilization of water sources. This will certainly affect the availability of water in the city of Yogyakarta. Water balance is a comparison between the water availability potential and the water demand of a place in a certain period. Water balance analysis is useful for knowing the amount of excess water (surplus) or lack of water (deficit) so that water use can be managed as well as possible. The calculation was done by analyzing the 10-year rainfall data using the Thiessen Polygon method to obtain the mean rainfall value. The available debit was calculated using the F.J. Mock method. The dependable discharge was calculated with 80% reliability from the 10-year debit data. The debit data was sorted from the largest to the smallest value, so that a probability value of 80% was obtained from the interpolation of the data sequence. Water demand was calculated based on the irrigation planning standard (KP-01). The results of the study show that the average water availability in the sub-watershed of Code River Yogyakarta was 527.92lt/sec. Based on the results of the analysis, the highest water deficit occurred in the first October at 278.40 l/sec and the lowest deficit was in the second July at 73.01 l/sec. However, the availability of water in certain months was quite abundant. Therefore, it is necessary to do a special study so that water is not wasted and can be used to cover water shortages in dry months. Keywords: Water balance, Water availability, Water demand, Code river, Thiessen polygon, FJ mock