Understanding a shallow lake ecology: Water quality and trophic status analysis

The quality of rivers and coastal is gradually deteriorating along with rapid population and socio-economic growth in the watershed to the estuary. Sampling was conducted in Semarang city rivers and Demak district rivers, Central Java Province, Indonesia, at four different stations according to geography and designation: river basins, estuaries, and rivers affected by industrial and domestic waste. Research time is August - October 2023 during the dry season. The research method uses descriptive analysis to determine the variables to be studied based on the research results in the field. River and coastal pollution levels are measured using the Heavy Metal Pollution Index method, with several water quality parameters measured, such as BOD, COD, Ammonia, TDS, TSS, and Total Coliform. In contrast, the heavy metal parameters measured are Cd, Ni, Zn, Cu, and Pb. The heavy metals and water quality parameters analyzed guided by Government Regulation of the Republic of Indonesia Number 22 of 2021 class 2. Water quality and heavy metal analysis use the Heavy Metals Pollution Index (HPI). HPI is an assessment method that shows the influence of individual heavy metal compounds on overall water quality. The results show that the status of non-metal water quality in terms of HPI analysis shows that Sampling Station (SS) 1 is 224.30 (unsuitable for drinking), SS 2 is 645.98 (unsuitable for drinking), SS 3 is 320.09 (unsuitable for drinking), SS 4 is 252.09 (unsuitable for drinking), and metal parameters in terms of HPI analysis show that SS1 is 26.43 (good), SS2 is 2345.84 (unsuitable for drinking), SS3 is 26.43 (good), and SS4 is 12.64 (excellent). The conclusions from these four research areas indicate that the status of water quality, according to the HPI is unsuitable for drinking, however, indications of heavy metals in 2 areas are still tolerable, namely good and excellent. The decline in water quality in the research area is caused by domestic and industrial waste polluting the waters. In conclusion, this river area requires further management from the collaboration of various stakeholders.Keywords:Water QualityHeavy MetalCoastalWatershed

Irrigation water quality analysis and monitoring is tricky task in semiarid tropics (SAT characterized) experiencing water scarcity. Conjunctive use of water in SAT have emphasizes on surface and ground water quality analysis for increase in agricultural production. Surface water quality analysis is carried out for reservoir water, canal flow, return flow and streams for a Devarabelakere, Village in Harihara Taluk in Davangere District of Karnataka State, India. It is located 12 Km towards west from Davanagere and 9 Km from Harihara. Devarabelakere pickup is constructed at downstreamof the Bhadra Reservoir at a distance of 136.00 Km. The total catchment area of this sub-project is 2106.90sq. Km. of which 1338.90 sq.Km SAT. Average Water quality index in the pre and post monsoon season for surface water was found between in the range of 51 to 75 and falls in the poor water quality status and suitable for irrigation and industrial purpose. Ground water sampling is also carried out at Deverabelekere command area and water quality index in pre and post monsoon seasons was found between the range 26 to 50 and falls in good water quality status and used for drinking, irrigation and industrial purpose. Although WQI shows many of the water samples were suitable or fit for irrigation, calculated other indices such Kelly’s Ratio (KR), Permeability Index (PI), Magnesium Absorption Ratio (MAR) with higher values covering all factors makes the water unsuitable which influences the irrigation water quality. In the study area the crops grown like Sugar cane in area of 28 ha, Plantation crop in area of 34 ha and Semi dry plant grow in 1152 ha and efficiency was found 37.03 % in post monsoon season for canal water and 44.38 % in pre monsoon due to temporal variations in season implicating the yield which is addressed by this paper.

River Water with good quality status is the primary needs for the Indonesian people who live along the river. Indonesia has more or less 303 rivers with varied status of water quality. On the other side, the government is obliged to conduct the current situation mapping and to spread the status of river water quality to the surrounding society. It is certainly not an easy job considering the amount and width of the monitoring area. Therefore, this research has proposed a new concept to map the status of river water quality using the STORET method by involving the active participation of the local river community. The locations of research are: Kambaniru river, Brantas river, dan Gajah Wong river. There are seven parameters used to determine the status of river water quality those are: temperature, EC/DHL, TDS, PH, DO, BOD and Caliform. The river community can report the data of analysis result into a system in accordance with the sampling location by enclosing the spatial data. The system will present the status of water quality starting from each point of location to the status of water quality of certain river. The testing result functionally indicates that the system is able to give perfect accuration value. While from its usability, the respondents’ responses are as follows: very agree 60.40%, agree 37.95%, and disagree 1.65%.

Water quality and trophic status of waters play an important role in aquaculture activities because they will affect the growth process of cultivated fish, if the water quality and trophic status are low then they can support aquaculture activities in the waters of Laguna Lake, South Ternate City. The purpose of this study was to determine the water quality and trophic status in the waters of Laguna Lake in supporting and supporting freshwater aquaculture activities. The research method used in this research is descriptive qualitative, the results of air analysis are described based on Class and Water Quality Standards, while the trophic status is estimated based on Carlson, 1977. The results of the analysis show that the water quality in Laguna Lake is still in accordance with Class II Quality Standards. PP No. 22 of 2021, while the trophic level status in Laguna Lake is also classified in the oligotrophic category, namely TSI <40, TSI in Laguna Lake waters ranges from 20.69-23.28. Based on the results of the analysis of water quality and trophic status, it was found that the waters of Laguna Lake are still good and can support freshwater fish farming activities

Batang Asam River as a source of raw water for Drinking Water Supply Systems (SPAM) and daily needs. On May 19, 2015 there was pollution in the Batang Asam River due to the spillage of palm oil wastewater from one of the palm oil companies around the Batang Asam River. The water river becomes smelly and black and many fish die. The initial testing showed that BOD parameter = 10 mg / l), COD = 50 mg / l, TSS = 16 mg / l, N-Total = 3.86 mg / l, pH = 6.02, Oil and fat = 2.8 mg / l, where almost all parameters above the quality standard. The purpose of this study was to analyze status of water and water quality of Batang Asam River Using Pollution Index Method as a result of spilling palm oil wastewater. Water sampling of the Batang Asam River was carried out in 4 (four) locations, namely the upstream area of Lubuk Bernai Village, the Central area of Lubuk Lawas Village and Tanjung Bojo Village and the downstream of Kampung Baru Village (Pengabuan River Estuary). Parameters tested were pH, TSS, TDS, BOD, COD, DO, Fe, Oil and fat based on Government Regulation Number 82 of 2001 concerning Water Pollution Control and Water Quality Management For Class II. Analysis of water quality status using the Pollution Index method based on the Minister of Environment Regulation Number 115 of 2003 concerning Guidelines for Determining the Status of Water Quality. The results showed that the analysis of the average waterquality of Batang Asam River from four locations tested were parameters pH 6,8, TDS parameters 79,5 mg / l, TSS parameters 15,25 mg / l, DO parameters 3,025 mg / l, BOD parameters 2,935 mg/l, COD parameters 14,5 mg / l, Fe 0,645 mg / l and parameters of oil and fat 1 mg /l satisfy the class II water quality standard (PP No. 82 of 2001). The status of Batang Asam River shows that the status of water quality is mildly polluted with a pollution index value of 1,0 ≤ IP ≤ 5,0 which is 1,96.

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 Cimahi City has experienced a decrease in the quality of raw water caused by flooding in several places, especially during the rainy season, therefore it is necessary to anticipate this by constructing infiltration wells, ponds, or lakes. Cimahi City has 5 lakes, one of which is the Ciseupan Lake. This lake can be one of the options for raw water sources in Cimahi City. Based on this, it is necessary to identify the water quality and trophic status of the lake so that it can be utilized optimally by local residents. This research aims to describe the status of water quality and trophic status of the Ciseupan Lake by analyzing the parameters of pollutant sources. The method for determining the status of water quality is the Pollution Index based on Decree of the Ministry of Environment Number 115 of 2002 concerning “Pedoman Penentuan Status Mutu Air”. Quality status can be determined according to the pollutant index classification, the greater the value, then the worse the water quality. The method for determining trophic status uses the UNEP-ILEC method. Based on the results of calculating the water quality status, the pollutant index value at the Ciseupan Embung in 2021 is 9.5 while in 2022 it is 8.9 which according to Minister of Environment Decree Number 115 of 2003, in both years the water quality status of the lake was included in the moderately polluted category. The trophic status of the Ciseupan Lake is classified as hypertrophic, this indicates that the lake water has been heavily polluted by nutrients.

Mahakam Ulu Regency is a regency located in the upper reaches of the Mahakam River. The Mahakam River in Mahakam Ulu Regency consists of several tributaries, one of which is the Sebenaq River, located in the capital city of Mahakam Ulu Regency. The Sebenaq River is used by the local community to meet the need for clean water because PDAM is not yet available and is also used as a means of transportation. The Sebenaq River flows through the central office area of the Mahakam Ulu Regency Government, main roads, and residential areas. Along with the development of Ujoh Bilang Village as the center of the capital city of Mahakam Ulu Regency and the use of Sebenaq River water by the surrounding community, it is deemed necessary to conduct research related to the water quality and quality status of the Sebenaq River. This study aims to provide data on water quality and quality status of the Sebenaq River to be used by related parties in the management and utilization of the Sebenaq River in the future. The locations for water sampling, river cross-section profile data collection, and in-situ parameter testing are Station I (Upstream of Sebenaq River), Station II (Tributary of Sebenaq River), Station III (Sebenaq River Crossing Road 1), Station IV (Sebenaq River Crossing Road 2), and Station V (Downstream of Sebenaq River). Based on the results of the calculation of the determination of water quality status using the Pollutant Index method with class I quality standards according to Government Regulation No. 22 of 2021, the water quality status of the Sebenaq River is classified as lightly polluted, with details of Station I (Upstream of the Sebenaq River) having a score of 3.795 indicating lightly polluted conditions, Station II (Sebenaq River Tributary) with a score of 2.781 indicating lightly polluted conditions, Station III (Sebenaq River Crossing Road 1) with a score of 2.361 indicating lightly polluted conditions, Station IV (Sebenaq River Crossing Road 2) with a score of 2.878 indicating lightly polluted conditions, and Station V (Downstream of the Sebenaq River) with a score of 2.327 indicating lightly polluted conditions.

Tempe Lake is one of 15 lakes as national priority to be saved. Today, the Tempe Lake has been blooming of aquatic weeds. The aims of research are i). to know the vegetation succesion, ii). To know the condition of water quality in lake and input river to lake, iii). To identify the main pollution sources of the nitrogen (N) and fosfor (P). The research carried out in dry season on June and August 2015. Analysis of succesion vegetation using the theory of vegetation succession in shallow lakes. Analysis of water quality using the criteria for fisheries and trophic status. Identification of N and P pollutant sources using secondary data namely agriculture area, type of fertilizer, total population, livestock. Based on the research, that in Tempe Lake has been processing the succession of vegetation, at least about four group of vegetation dominantly, namely phytoplankton, floating plant, emergent plant, and fringing plant. The lake water quality and the input river to lake still meets the criteria for fisheries. However, according to the status trophic of lake based on N dan P were hypertrophic with the average concentration N-total 0,697 mg/L and P-total 0,224 mg/L. The status trophic for the input river to lake based on N was oligotrophic with the average concentration of N-total 0,362 mg/L and based on P was eutrophic with the average concentration of P-total 0,291 mg/L.

Effects of water replenishment on lake water quality and trophic status: An 11-year study in cold and arid regions

Water quality is a crucial aspect of environmental sustainability, particularly for rivers that serve as primary sources for domestic, industrial, and agricultural activities. This study evaluates the water quality and pollution status of the Belayan River in Kenohan District, Kutai Kartanegara Regency. The study employs physical, chemical, and biological parameters to assess water quality, using the STORET method for pollution classification. The sampling locations consist of 4 stations: Station 1 (Mouth of the Belayan River), Station 2 (Muhuran Village River), Station 3 (Sebelimbing Village River), and Station 4 (Upper Belayan River in Kenohan Village). The parameters observed in this study are pH, Total Suspended Solids (TSS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Nitrate, Phosphate, and Fecal Coliform. The water quality status of the Belayan River based on the STORET method is classified as moderately polluted, and using the Pollution Index, it is lightly polluted. The highest TSS pollution load is 3859.5 tons/day. This pollution is caused by various residential, agricultural, and water transportation activities that produce waste and potentially pollute the Belayan River.

Urban river, as an important component of urban ecological system, has many roles in urban ecological construction. Statistical and trend analysis of surface water quality from Xi'an moat river have been performed to provide a framework for sustainable water resources management. The trend analysis was performed using the non-parametric Spearman correlation and tested for statistical significance using the Student's t-test. Weekly surface water quality data from 28 stations on Xi'an Moat River have been analyzed. Apart from the statistical and trend analyses, the quality of the Xi'an moat river was assessed for other urban uses, according to the national, Environmental quality standards for surface water (GB 3838–2002). The important information has been gained from this analysis, especially on the identification of significant temporal and spatial trends of water quality parameters and the status of river water quality according to the water quality standards. The analysis indicated that the quality of the river water is, on average fair, and the river water could be used with caution for water quality standard for landscape and recreation area purposes.

Surface water quantity and quality assessment in Pinios River, Thessaly, Greece

This Final research was conducted in Ciujung River where this research was conducted in Serang Regency with its head in Nagara Village, Serang Regency, and downstream in Tirtayasa Village, Serang Regency. The research was conducted for 3 months from October – December 2022 starting from 09.00 – 12.00 and continuing from 12.00 – 13.45. The purpose of the study is to identify and determine the sources of pollution that have the potential to pollute the Ciujung River, analyze water quality, water quality status, and pollutant levels in the Ciujung River, and analyze the carrying capacity of polluter loads in the Ciujung River. And analyze the burden of pollutants in the Ciujung River. The length of the Ciujung River studied is 31.3 km. The parameters used for this study are pH, Temperature, DO, BOD, COD, Nitrate, Phosphate, and Total Coliform. The method used in identifying the source of pollution contained in the Ciujung River is carried out by conducting field observations and taking samples of Ciujung River water. Sampling in the Ciujung River was carried out by the grab sampling method. which is done at 6 sampling points. Analysis of river water quality was carried out at the Trisakti University Laboratory. The results of the analysis are then compared with the quality standards of PP No. 22 of 2021 in Attachment VI. Water Quality Status is calculated by the Polluter Index method. Nonpoint sources of pollution are dominated by residential areas, stalls, garbage, shops, mosques/prayer rooms, schools, and markets. Point sources of pollution are obtained from industrial areas. Measurement of river characteristics is carried out in October, November, and December by measuring distance, width, depth, cross-sectional area of the river, river speed, and river discharge. The results of the analysis of water quality in the river stated that for phosphate parameters almost all exceeded quality standards due to domestic waste from the environment, the runoff of agricultural fertilizers, livestock waste, and very high industrial activities. The BOD parameters at point 2 and point 5 exceed the quality standards due to the content of organic waste. The load capacity of BOD pollutants is 3.64 kg/day – 20.20 kg/day, COD is 42.63 kg/day – 144.22 kg/day, Nitrate is 1.67 kg/day – 3.47 kg/day, Phosphate 0.79 kg/day – 3.11 kg/day, Total Coliform is 8694.19 kg/day – 33042.56 kg/day. BOD Pollution Load of 314.26 kg/day- 1744.99 kg/day COD of 2365.46 kg/day - 12460.37 kg/day Nitrate of 144.55 kg/day- 423.16 kg/day Phosphate of Total Coliform of 454133.37 kg/day – 2854876.86 kg/day.

Reservoir is a vital tool for human utilization of water resources, and the deterioration of its water quality can seriously threaten the water cycle and sustainable urban development. However, there are relatively few studies in academia that analyse and evaluate the water quality of multiple reservoirs at the same time. To address this knowledge deficit, we collected 108 water samples from three different reservoirs in Chuzhou City for 36 months (from 2019 to 2021), explored the drivers of changes in water quality parameters over time and the extent of eutrophication. Our results indicated that the water quality of the reservoirs was deteriorating during the study period, among which Huanglishu Reservoir and Shahe Reservoir reached mild eutrophic status, and both had higher eutrophication levels than Chengxi Reservoir. Secchi depth, total nitrogen and total phosphorus were the principal factors inducing eutrophication. The biassed utilization of reservoir functions was the major contributor to the discrepancy in the degree of eutrophication. Furthermore, Pearson correlation analysis revealed that there are significant correlations between many water quality parameters. Cluster analysis grouped the 12 months of each year into three clusters (stable water level period, rainy season high flow period and winter low flow period). Based on this, analysis of variance showed that most water quality parameters varied considerably between the clusters. Collectively, this study identified the actual water quality conditions of three reservoirs in Chuzhou City and provided guidance for local water quality management and environmental protection.