Water Quality Sampling Research Articles

Water Quality Sampling Provides Insight into Nutrient Sources and Pathways in an Agricultural Watershed in the Midwestern USA

HighlightsHysteresis and flushing indices were calculated for 23 storm events.Wetter conditions led to a dilution effect for nitrate during storm events.Travel times were faster for all nutrients during the winter, likely due to lack of vegetative cover.Results can be used to choose practices that effectively target specific nutrient sources and pathways.Abstract. Understanding where agricultural nutrients originate in the landscape can help mitigate downstream transport by selecting and installing best management practices that target nutrient sources. We collected flow and water quality data from 2017–2021 at two similar HUC-12 watersheds in northeastern Indiana, which provided an opportunity to link nutrient sources with transport processes in intensively managed agricultural watersheds. We calculated metrics to represent changes in nutrients during a storm event, including hysteresis (the change in concentration on the rising limb of the hydrograph compared to the recession limb) and the flushing index (the difference between concentrations at peak discharge and baseflow). We compared storm-based and annualized concentration-discharge (C-Q) relationships for NO3-N, soluble reactive phosphorus (SRP), total P (TP), and dissolved organic carbon (DOC) to land use and climate variables. Together, these provide insight into nutrient storage zones and transport pathways at the small watershed scale. Our results suggest these landscapes have plentiful and widely distributed sources of nitrogen (N) that are activated in the spring, which we observed as chemostatic behavior (i.e., concentration remained relatively constant during different flows). While this has been shown at larger scales in agricultural watersheds, these patterns are challenging to parse at the small watershed scale. We saw concentrating effects (i.e., increased concentrations as flow increased) for DOC, TP, and SRP during storms, suggesting activation of flow-paths connecting land-based sources to receiving streams. We also noted faster travel times in the winter for all four constituents when subsurface tile drains are most active and plant uptake is negligible. Our results differentiate nutrient delivery mechanisms and can aid management decisions by identifying environmental factors that most influence transport and selecting conservation practices that target these nutrient pathways. Keywords: Agriculture, Carbon, Concentration-discharge, Hysteresis, Nitrogen, Phosphorus, Watershed management.

Towards Autonomous, Optimal Water Sampling with Aerial and Surface Vehicles for Rapid Water Quality Assessment

Highlights A practical workflow for optimizing sampling tours for a team of surface and aerial vehicles was developed. Proposed workflow considers unique sensing capabilities of surface vehicles when assigning sampling locations. Likely optimal tours can be found in less than 30 s for practical water quality sampling requirements. Abstract. Most current marine aquaculture operations are located in coastal estuarine areas within one mile of the shoreline, and water quality in these production areas can quickly become unfavorable due to hydrodynamic processes and excessive runoff. The deployment of autonomous, robotic systems can improve the speed and spatiotemporal resolution of water sampling and sensing in mariculture production areas to assess water quality in the context of food safety. Specifically, teams of both aerial and surface vehicles can be deployed simultaneously to capitalize on the benefits of each system; however, a method to optimally design a feasible sampling tour for each robot is needed to maximize sample capacity and ensure efficient water sampling missions. This research brief presents the problem formulation and a solution method to determine optimal tours for a team of aquatic surface and aerial vehicles while considering different vehicle sampling capacities and endurance constraints. This method was implemented to design sampling missions of 15, 20, and 30 samples in both a 0.25 km2 and 3.9 km2 site, using sampling capacity and endurance constraints corresponding to real-world robots used for water sampling in mariculture environments. Results indicate that this optimization problem can be solved in near-real time in the field and yields feasible sampling tours for surface and aerial vehicles under different constraints. This work is a practical step towards developing teams of collaborative robots to persistently monitor adverse mariculture growing conditions so producers can implement data-driven, timely management strategies. Keywords: Mariculture, Robotics, Traveling salesperson problem, Vehicle routing.

Assessment of pollution load on surface water in the down-lower part of the Tapung Kiri river, Kampar regency, Riau

The Tapung Kiri River is experiencing degradation especially due to the increase in the oil palm plantation industry and sand mining activities. The research was conducted from June to August 2024 to determine the pollution load of the Tapung Kiri River in down-lower by analyzing physical, chemical, and biological water quality samples. Water samples were taken triple, including TSS, BOD, COD, Nitrate, Phosphate, and E.Coli parameters. The quality of the Tapung River is compared to the quality standards according to The Regulation of Government of the Republic of Indonesia (RGRI) Number 22/2021 Class III. The results of the analysis of the pollution load were 472.5 kg/day (TSS), 15.75 kg/day (BOD), 94.5 kg/day (COD), 34.44 kg/day (nitrate), and 0.37 kg/day total phosphate. The actual pollution load in the Tapung Kiri River is lower than the maximum pollution load.

Geoinformatics of Spring Water Quality in Small Village

Geoinformatics is spatial information based on characteristics and analysis regarding spatial data. Water is the main component of human life with clean water, especially drinking water found from various sources, including spring water. Water quality is a global standard as a chemical, physical, and biological parameter. The study aims to determine the potential spring water based on spatial analysis of water quality standards for potential use. The method used to determine the potential utilization of springs using geographic information system analysis. Data is based on the difference in height, slope, and distance from springs to settlements and discharge. Water quality samples are analyzed using mobile and laboratory tests. The result found that physical parameters from five locations, Sirah Citanggulun, Cikerebek, Cijati, Cijati 2, and Galumpit, have good quality to meet the utilization requirements, especially for water designation class. Chemically parameters, water quality, is relatively good based on several parameters such as pH, Nitrite, dissolved iron, and zinc, which do not exceed the required quality standard threshold. The biological parameters, five samples are contaminated by bacteria Escherichia coli and total coliform. Regarding the literature review, this research found that biological contaminants are unsuitable for drinking water, but it is still good to become another used. The research concluded that the spring water in a small village could become potential uses for drinking water based on the parameter of water quality for daily use, especially for drinking water, regarding biological parameters that spring water must be boiled to drink.

Assessment of agricultural water protection strategies at a catchment scale: case of Finland

For decades, water quality monitoring programmes, agri-environment schemes and environmental permits for animal farms have targeted a decrease in agricultural loads. These have been supplemented with more recent policies related to nutrient recycling and a circular economy. However, eutrophication of surface water bodies remains a widespread problem. In this paper, we focus on the nutrient loading and recycling in the catchment of Eurajoki River, Finland. We statistically examine the generation of nutrient loading and its variation on a sub-catchment scale. We extend this examination to the factors behind the loading and estimate the impact of nutrient recycling on it. Our analysis reveals shortcomings in the availability and collection of data on the agricultural nutrient loadings and the parcel-specific data on the presence and application of manure and fertilisers. Nine sub-catchments were responsible for roughly half of the TP loading from the 46 sub-catchments studied. To reveal such hot spots and to better target agricultural water protection measures, we recommend short-term water quality sampling campaigns. Judging from our data, the rate of manure recycling is not high enough to reduce the regional P surplus to manageable levels. Therefore, we suggest facilitated collaboration between animal and crop farms to decrease the nutrient surplus. We also propose setting up a national database containing parcel-specific information, for example, on soil P content, manure and fertiliser application, agricultural practices and the presence of acid sulphate soils. We also suggest an independent soil fertility sampling to provide valid baseline soil P data for field parcels.

Analysis of water quality on growth performance bamboo lobster (Panulirus versicolor) in Tanjung Limau, Bontang City, East Kalimantan

Lobster is one of the commodities that have high economic value in the world market. Thus, the export opportunities for lobster commodities are still promising. One area that can produce lobster in Indonesia is Bontang, East Kalimantan. The area which is the sea waters is very potential for lobster rearing cultivation. This study was conducted with the aim of analyzing good water quality in lobster rearing cultivation in Bontang, East Kalimantan. The study used 3 floating net cages by taking water samples 4 times and 5 lobsters each sampling. Water quality samples include physics (color, smell and taste, temperature, brightness), chemistry (pH, DO, nitrite, salinity), biology (coliform), heavy metals (hg, pb, cu). Lobster samples were measured by weight. The results showed that Fsignificant > 0.05 so that the water quality parameters had no effect on growth. The cause of the ineffectiveness of water quality parameters is due to the contamination of waters in Bontang, East Kalimantan.Keywords: Bamboo Lobster; Contamination; Floating Net Cage; Heavy Metal.

Retrieving Lake Chla concentration from remote Sensing: Sampling time matters

Remote sensing is a promising technology for global water eutrophication monitoring, and the quantity and representativeness of the observed samples influence its accuracy. Due to limitations in high costs in situ monitoring, current remote sensing of lakes often relies on models trained with water quality samples from a single season. However, the generalization ability of these single-season trained models to other seasons has not been extensively studied. In this study, focusing on 38 major lakes in the Yangtze River Basin, we utilized monthly chlorophyll-a (Chla) monitoring data and Sentinel-2 image datasets from 2016 to 2021 to assess the impact of different seasonal data-trained models on the performance of Chla concentration retrieval in lakes. The results indicate that: (a) The sampling time for lake Chla significantly affects the performance of the retrieval model. Based on the seasonal data, the trained models show an R2 range of 0.523 to 0.699, with a Bias ranging from −7.06 % to 7.74 %, while the models trained with full-season samples perform between the various seasonal models. (b) When models built with seasonal data are applied to full-season data retrieval, there is a noticeable decrease in performance. The R2 of the spring-winter data trained model drops by 18.2 %, with RMSL and MAPE increasing by 11.4 % and 4.2 %, respectively. Similarly, the model trained from summer-autumn data shows a 4.02 % decrease in R2, with RMSLE and MAPE rising by 2.76 % and 13.56 %, respectively. This suggests that using models established from seasonal samples to infer full-season Chla concentrations can amplify errors. (c) Compared to seasonal models, full-season models based on different seasonal sampling exhibit better performance (R2 = 0.585, RMSLE = 0.337, Bias = -3.12 %, MAPE = 34.71 %). R2, RMSLE, and MAPE are all superior to seasonal models. Therefore, when performing full-time and long-term retrieval of Chla concentrations in water bodies, it is necessary to use data sampled in different seasons to reduce the errors introduced by seasonal sampling. (d) Chla retrieval models were established for 38 typical lakes and reservoirs in the Yangtze River Basin using the full-time dataset, revealing that 25 % (7/28) of the lakes and 20 % (2/10) of the reservoirs showed significant alteration trends. The number of lakes with increasing Chla concentrations exceeded those with decreasing concentrations, indicating that there is still a substantial risk of eutrophication in the lakes and reservoirs of the Yangtze River Basin.

Water Quality and Pollution Level in Plawangan Barat, Segara Anakan, Cilacap Based on Pollution Index Approach

Segara Anakan is a lagoon located in Cilacap, Central Java. It is characterized as a fragile ecosystem that is very susceptible to the impacts of alterations and land development. This region is susceptible to habitat degradation caused by human activity, resulting in alterations in water quality and pollution. The objective of this study was to provide a comprehensive description of water quality by analysing its physical and chemical properties. Additionally, the study intended to assess the level of water pollution by employing the Nemerow Sumitomo Pollution Index (PI) approach. The water quality sampling was conducted in the western region of Segara Anakan, namely Plawangan Barat. The obtained data were compared to the established standard quality for marine organisms, as outlined in the PP RI No. 22/2021. The classification of the water pollution level was determined according to Minister of Environment Decree No. 115/2003. The findings of this study indicate that the parameters of temperature, salinity, pH, dissolved oxygen (DO), and biological oxygen demand (BOD) in the water remain suitable for marine life throughout all study stations. However, it was observed that the levels of Total Suspended Solid (TSS), phosphate, and nitrate did not match the established safety thresholds. The pollution index indicated that the water quality in West Plawangan shows varying pollution levels, ranging from light to moderate pollution. Based on the findings obtained, it can be concluded that the Segara Anakan lagoon exhibits a diminished level of suitability for the life of marine organisms.Keywords: Water Quality, Index PI, Nemerow Sumitomo, Plawangan Barat, Marine Pollution

Near real-time satellite detection and monitoring of aquatic algae and cyanobacteria: how a combination of chlorophyll-a indices and water-quality sampling was applied to north Texas reservoirs

Near real-time satellite detection and monitoring of aquatic algae and cyanobacteria: how a combination of chlorophyll-a indices and water-quality sampling was applied to north Texas reservoirs

A random forest approach to improve estimates of tributary nutrient loading

Estimating constituent loads from discrete water quality samples coupled with stream discharge measurements is critical for management of freshwater resources. Nutrient loads calculated based on discharge-concentration relationships form the basis of government nutrient load targets and scientific studies of the response of receiving waters to external loads. In this study, a new model is developed using random forests and applied to estimate concentrations and loads of total phosphorus, dissolved phosphorus, total nitrogen, and chloride, using data from 17 tributaries to Lake Champlain monitored from 1992 to 2021. I benchmark this model against one of the most widespread models currently used to estimate nutrient loads, Weighted Regressions on Time, Discharge, and Season (WRTDS). The random forest model outperformed both the base WRTDS model and an extension of the WRTDS model using Kalman filtering in the great majority of cases, likely due to the inclusion of rate-of-change in discharge and antecedent discharge over different leading windows as predictors, and to the flexibility of the random forest to model predictor-response relationships. The random forest also had useful visualization capabilities which provided important process insights. WRTDS remains a useful model for many applications, but this study represents a promising new approach for load estimation which can be applied easily to existing datasets, and which is easy to customize for different applications.

Exploring storm petrel pattering and sea-anchoring using deep reinforcement learning

Developing hybrid aerial-aquatic vehicles that can interact with water surfaces while remaining aloft is valuable for various tasks, including ecological monitoring, water quality sampling, and search and rescue operations. Storm petrels are a group of pelagic seabirds that exhibit a unique locomotion pattern known as ‘pattering’ or ‘sea-anchoring,’ which is hypothesized to support forward locomotion and/or stationary posture at the water surface. In this study, we use morphological measurements of three storm petrel species and aero/hydrodynamic models to develop a computational storm petrel model and interact it with a hybrid fluid environment. Using deep reinforcement learning algorithms, we find that the storm petrel model exhibits high maneuverability and stability under a wide range of constant wind velocities after training. We also verify in the simulation that the storm petrel can use its ‘pattering’ or ‘sea-anchoring’ behavior to achieve different biomechanical sub-tasks (e.g. weight support, forward locomotion, stabilization) and adapt it under different wind speeds and optimization objectives. Specifically, we observe an adjustment in storm petrel’s movement patterns as wind velocity increases and quantitively analyze its biomechanics underneath. Our results provide new insights into how storm petrels achieve efficient locomotion and dynamic stability at the air–water interface and adapt their behaviors to different wind velocities and tasks in open environments. Ultimately, our study will guide the design of next-generation biomimetic petrel-inspired robots for tasks requiring proximity to the water interface and efficiency.

Methodological Approach for an Online Water Quality Monitoring System in an Iron Ore Tailing Dam

Monitoring the concentration of potentially toxic elements (PTEs) in the aquatic ecosystems of the Amazon is critical to guarantee the maintenance of the ecological balance and the life quality of human populations that reside in or use these environments for survival. In this sense, many rivers in the region are dammed to form lakes for depositing mining tailings. Among these, the Gelado Project has the largest iron ore dam in the Amazon that occupies about 13.5 km2 of surface area with 142 million m3 of water and tailings volume, which are currently being mined for exploration, and its upstream waters and downstream are historically used by traditional populations. Based on this, to monitor the impacts of this activity, an online system for sampling and automatic analysis of water quality, composed of three process analyzers monitoring more than 20 parameters, including the PTEs (Cd, Pb, Fe, Mn, Ni, and Cu), was installed downstream of this dam. Therefore, this short communication describes this system’s development, installation, operation, and main advantage over conventional methods.

Pollution Index Analysis of Seawater in Nickel Smelter Bantaeng’s Port

Good water quality conditions are significant for supporting the life of organisms and providing security for community activities. Water quality status determination is needed to monitor water quality pollution. Seawater quality is a critical aspect of environmental science and ecological research due to its profound impact on marine ecosystems, human health, and various community activities. It has been a significant concern because of its direct influence on marine ecosystems, human activities, and public health. This study aims to determine the pollution index referred to as physical-chemical-dissolved metal parameters in the nickel smelter port in Bantaeng Regency. A sampling of water quality was carried out at three sampling points. Then the results were compared with seawater quality standards for marine biota referred to the Keputusan Menteri Lingkungan Hidup No. 51/2004 on Seawater Quality Standards. Observation and analysis of water conditions are conducted in situ and ex-situ, with testing carried out at Ak-Manufaktur Laboratory and BBIHP Laboratory. The results of the pollution index calculation show that the waters around the nickel smelter port are in the moderately polluted category. The pollution index values were obtained in the moderately dirty variety at points 1: 8.515, 2: 9.652, and 3: 9.792. Environmental parameters still following quality standards for marine biota include temperature, pH, salinity, DO, and nickel (Ni).Keywords: pollution index; physical; chemical; metals; smelter

Studies on plankton community and physico-chemical parameters of Elechi Creek, Eagle Island, Port Harcourt

Studies on the plankton communities and physico-chemical characteristics of Elechi Creek were carried out for six months, from January to June. Fourteen physico-chemical parameters were evaluated, and monthly plankton alteration was investigated. Water quality samples and plankton analyses were obtained simultaneously. Water temperature was in the range of (29.4–35.5⁰C) across the (3) study locations. The results revealed no spatial dissimilarity (P˃0.05) of all physicochemical factors while results of the monthly variations test showed significant elevations (P˂0.05) for some parameters between (April and June), except for Turbidity, Nitrate, pH, Sulphate and Chloride. The mean concentration levels in total hardness (1600 mg/L), chloride (1075.8 mg/L) and sulphate (621.6 mg/L), were found considerably above the acceptable levels. Most plankton showed negative changes subsequent to these elevations. Phytoplankton identified comprised two families, of which Bacillariophyceae (diatoms) were higher followed by Cyanophyceae. Bacillariophyceae, cell density (46 cells L-1) contributed the highest (80.7%) sum phytoplankton cell–density while Cyanophyceae had (11 cells L-1) contributing (19.3%). The zooplankton density was from (17 L-1 - 1190 L-1). Copepoda recorded the utmost percentage population, contributing (91%) zooplankton, followed by Cladocera (4.8%), Crustaceae (2.9%) and most reduced (1.3%) contribution by Rotifera. Monthly variations of Plankton density showed that most families recorded higher density during the wet months (April–June). The occurrence of these factors and conditions in Elechi Creek underscore pollution therefore, aquatic organisms from such water are almost unsafe for food. Hence, standard checking of the creek is advocated to ensure seafood safety.

Road salt intrusion dynamics in an ex-urban native wetland complex

Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase in salinity due to road salt runoff during winter months. Salinization affects soil texture, contaminant transport, microbial activity, and plant growth in wetlands. Therefore, there is a pressing need to understand the dynamics of road salt intrusion in urbanized freshwater ecosystems. We used distributed high-resolution sensors to evaluate the dynamics of road salt intrusion into a wetland complex, Gensburg Markham Prairie (GMP), located in the ex-urban area outside Chicago, Illinois (USA). The in situ sensors measure electrical conductivity (EC), surface and groundwater level, precipitation, water temperature, and air temperature at 30-minute intervals. Water samples were collected monthly from 13 shallow groundwater wells and eight surface water locations and analyzed for Cl-, Mg2+, Na+, Ca2+, and K+. Two-years of continuous data show periodic spikes in EC during winter months, generally by an order-of-magnitude, due to intrusion of road salt applied on nearby roads. However, this behavior was not evident from monthly water samples, indicating that traditional water quality sampling methods likely miss such abrupt salt intrusion dynamics caused by rapid snowmelt runoff events. Higher levels of EC and Cl- occurred at the periphery of GMP near roadways, as well as in a preferential flow path to the interior of the wetland. Spectral analysis of EC time-series in ditches suggests that there is no correlation between salinity dynamics at super-annual timescales. This indicates that the salinity dynamics at GMP are event-driven, and the introduced solutes are rapidly exported from the site. This research supports development of improved de-icing strategies by local agencies and informs site-specific management of wetland ecosystems under anthropogenic stressors.

Assessment of Bacteriological Quality and Physiochemical Parameters of Domestic Water Sources in Jenin Governorate: A Case Study.

Water quality of drinking water is a concern in Palestine due to possible pollution sources. There is a demand for investigating the quality of municipal water supply. This study aimed to assess the quality of domestic water in Jenin Governorate located in the north of the West Bank. The methodology of this research was based on field sampling and laboratory standard testing. The tested parameters included (1) physicochemical parameters of electrical conductivity, turbidity, total hardness, salinity, pH, and total alkalinity, (2) chemical contents including the contents of nitrate, nitrite, sulfate, chloride, sodium, potassium, aluminum, and fluoride, and (3) biological contents including total coliforms and fecal coliforms. The water quality parameters were compared with the acceptable limits set by local and international standards. The findings confirm that most of the values of the investigated parameters are within the acceptable standard limits. No pollution of heavy metals is detectable. On the other hand, there are limited pollution contents in terms of the total dissolved solid (TDS), total hardness, and calcium. Furthermore, the biological parameters indicate that there are low to very high risks in a fraction of the water quality samples in terms of total coliforms and fecal coliforms. This is believed to be due to the presence of septic tanks in the neighborhoods of the sampling locations. For these cases, biological disinfection treatments are recommended before human use with an essential need for the construction of urban sewer systems. Furthermore, water treatment for harness removal may be required.

Predicting water quality variability in a Mediterranean hypereutrophic monomictic reservoir using Sentinel 2 MSI: the importance of considering model functional form.

Anthropogenic eutrophication is a global environmental problem threatening the ecological functions of many inland freshwaters and diminishing their abilities to meet their designated uses. Water authorities worldwide are being pressed to improve their abilities to monitor, predict, and manage the incidence of harmful algal blooms (HABs). While most water quality management decisions are still based on conventional monitoring programs that lack the needed spatio-temporal resolution for effective lake/reservoir management, recent advances in remote sensing are providing new opportunities towards better understanding water quality variability in these important freshwater systems. This study assessed the potential of using the Sentinel 2 Multispectral Instrument to predict and assess the spatio-temporal variability in the water quality of the Qaraoun Reservoir, a poorly monitored Mediterranean hypereutrophic monomictic reservoir that is subject to extensive periods of HABs. The work first evaluated the ability to transfer and recalibrate previously developed reservoir-specific Landsat 7 and 8 water quality models when used with Sentinel 2 data. The results showed poor transferability between Landsat and Sentinel 2, with most models experiencing a significant drop in their predictive skill even after recalibration. Sentinel 2 models were then developed for the reservoir based on 153 water quality samples collected over 2 years. The models explored different functional forms, including multiple linear regressions (MLR), multivariate adaptive regression splines (MARS), random forests (RF), and support vector regressions (SVR). The results showed that the RF models outperformed their MLR, MARS, and SVR counterparts with regard to predicting chlorophyll-a, total suspended solids, Secchi disk depth, and phycocyanin. The coefficient of determination (R2) for the RF models varied between 85% for TSS up to 95% for SDD. Moreover, the study explored the potential of quantifying cyanotoxin concentrations indirectly from the Sentinel 2 MSI imagery by benefiting from the strong relationship between cyanotoxin levels and chlorophyll-a concentrations.

Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand

Mountains dominate global denudation fluxes of solutes to the oceans despite being only a modest portion of the Earth's surface. Determining the flux of material exhumed from mountains as dissolved load, however, requires careful measurement of ionic concentrations and discharge that may be hard to obtain. We reconstruct the dissolved load and total dissolved solids yield from pre-existing discharge measurements and 32-years on monthly water quality sampling in a headwater catchment in the Southern Alps/Ka Tiritiri o te Moana, New Zealand. The dissolved weathering yield of the Haast/Awarua River for 1971–2020 was 218 ± 48 t km−2 a−1. The flux of dissolved material from the mountain catchment has a seasonal signal, with higher TDS concentrations during winter, but greater chemical weathering yields during summer. Hydrographic behaviour is an important control of weathering yields with 70 % of dissolved load being transported during event flow. Variations in chemical weathering yields are sensitive to changes in stream flow associated with broader climate oscillations, which will have a direct effect on estimations of chemical weathering rates since dissolved flux is strongly correlated to changes in stream flow.

Water Quality Sampling and Multi-Parameter Monitoring System Based on Multi-Rotor UAV Implementation

Water quality sampling and monitoring are fundamental to water environmental protection. The purpose of this study was to develop a water quality sampling and multi-parameter monitoring system mounted on a multi-rotor unmanned aerial vehicle (UAV). The system consisted of the UAV, water sampling and multi-parameter detection device, and path planning algorithm. The water sampling device was composed of a rotating drum, a direct current (DC) reduction motor, water suction hose, high-pressure isolation pump, sampling bottles, and microcontroller. The multi-parameter detection device consisted of sensors for potential of hydrogen (pH), turbidity, total dissolved solids (TDS), and a microcontroller. The flight path of the UAV was optimized using the proposed layered hybrid improved particle swarm optimization (LHIPSO) and rapidly-exploring random trees (RRT) obstacle avoidance path planning algorithm, in order to improve the sampling efficiency. Simulation experiments were conducted that compared the LHIPSO algorithm with the particle swarm optimization (PSO) algorithm and the dynamic adjustment (DAPSO) algorithm. The simulation results showed that the LHIPSO algorithm had improved global optimization capability and stability compared to the other algorithms, validating the effectiveness of the proposed algorithm. Field experiments were conducted at an aquaculture fish farm, and the device achieved real-time monitoring of three water quality parameters (pH, TDS, turbidity) at depths of 1 m and 2 m. A rapid analysis of three parameters (ammonia nitrogen, nitrite, dissolved oxygen) was performed in the laboratory on the collected water samples, and validated the feasibility of this study.

Water quality and financial feasibility analysis of the development of milkfish (Chanos sp.) farms in Pabean Ilir Village, Indramayu, West Java

The tidal flood that occurred in the coastal area of Indramayu in 2020 caused the farmers to fail the Vannamei shrimp harvest in Pabean Ilir Village. After the disaster, the farmers resumed their commodity with milkfish. To analyze if this strategy can compensate for the loss, it is essential to perform the feasibility and profitability of the new farming system. Water quality sampling, which referred to the standard method (APHA), was conducted at several sites in the pond. We elucidated the pattern of several water quality parameters such as water temperature, pH, salinity, dissolved oxygen, nitrite, nitrate, and ammonia, while the financial feasibility was assessed with a cost-benefit analysis. The data to conduct the analysis was collected by arriving series of structured face-to-face interviews and focus group discussions. A sensitivity analysis was carried out to measure the influence of changes in fish production and feed price. It is concluded that the water quality was suitable and safe for milkfish cultivation. We also noticed that the new aquaculture system was financially feasible, as indicated by the calculated net present value, benefit-cost ratio, and internal rate return.