Station S1 Research Articles

Assessment of Ecological Hazards in the Inaouen Wadi and Its Tributaries Using the Presence of Potentially Toxic Elements in Its Sediments

Inaouen wadi is the second largest tributary of the Sebou river, one of Morocco’s major rivers, which holds significant economic and social importance. Unfortunately, this watercourse is severely impacted by pollution from various human activities, particularly industrial sources. However, available data on the presence of potentially toxic elements (PTEs) that could harm human health in this region remain limited. PTEs pose major environmental risks due to their toxicity, persistence, and bioaccumulation. This study aimed to assess the concentrations of PTEs in the sediments of Inaouen wadi and its main tributaries based on sediment samples collected from 12 locations in 2019. The concentrations of Cd, Pb, Cr, Ag, Al, Cu, Fe, and Zn were measured using inductively coupled plasma atomic emission spectroscopy (ICP–AES), and sediment contamination levels were evaluated using multiple indices: the enrichment factor (EF), the geo-accumulation index (Igeo), the potential ecological hazard index (RI), and the modified ecological risk index (MRI). The results indicate that concentrations of Pb, Cd, Cr, Cu, Fe, and Zn are significantly influenced by urban discharges, particularly at sites S1, S3, and S5 near the cities of Taza and Oued-Amlil. The maximum values recorded were 7.01 g/kg for Pb, 0.9 g/kg for Cd, 0.1 g/kg for Cr, 19.9 g/kg for Fe and 1.9 g/kg for Zn. The enrichment factor (EF) revealed anthropogenic sources of Fe and Pb, confirming the human origin of these elements. The geo-accumulation index (Igeo) showed that the areas around stations S1, S3, and S5 are highly contaminated by Pb, Cd, and Fe, a finding also supported by the MRI. The study identified potential ecological risks at stations S1, S3, and S5, highlighting the urgent need for improved pollution management practices to mitigate environmental risks.

Monitoring and measuring noise pollution in urban environments (Case study: Khorramabad city)

Introduction: Environmental noise, caused by traffic, leads to increased risk of health problems. Nowadays, noise pollution is one of the most important problems in the communities which adversely affects the health. The aim of this study was to assess the noise pollution in Khorramabad city. Materials and methods: To measure the noise level in the city, 39 stations near to sensitive places such as hospitals, educational centers, and so on were selected. Measurements were performed, for 30 min, in the mornings (7-10 AM) and evenings (5-8 PM) using a standard sound level meter. The measurements were made on working days during the week and assuming the traffic load was the same. Results: The sound level in all 39 considered stations was higher than the standard of residential-commercial in more than 90% of the stations compared to the environmental standard. The mean of sound measured in the monitored stations was equal to 68.28±2.6 dB. The maximum measured sound level belonged to station S2. In station S2, the maximum measured sound was reported as 81.72±11.3 dB. The findings showed that sound level in the evenings were slightly higher than the mornings. Also, in the evening, the highest and lowest measured sound values belonged to stations S1 and S20. The amount of measured sound level at stations S1 and S20 was equal to 80.9 and 39.7 dB, respectively. Based on findings, the highest and lowest sound recorded belonged to stations S39 and S20 which area type of stations S20 and S39 was commercial and residential, respectively. Conclusion: This study showed that the average level of sound pressure was higher than the permissible limit, so the necessity of planning is suggested to reduce the level of noise pollution and consequently reduce the anxiety level of citizens and increase health.

Microplastic pollution and ecological risk assessment of a pond ecosystem.

Microplastic (MP) pollution has been observed in various ecosystems as a result of the rapid increase in plastic production over the past half-century. Nevertheless, the extent of MP pollution in different ecosystems, particularly in freshwater ecosystems, has not been well-studied, and there are limited investigations on this particular topic, specifically in Türkiye. Here, we quantify the occurrence and distribution of MPs in surface water samples collected from Topçu Pond (Türkiye) for the first time. Water samples were collected at five stations and filtered (30 L for each station) through stacked stainless steel sieves (5mm, 328µm, and 61µm mesh size) with a diameter of 30cm. The abundance, size, color, shape, and type of collected debris samples were analyzed after the wet peroxide oxidation process. MP particles were observed in all samples at an average abundance of 2.4 MPs/L. The most abundant MP size class and type were 0-999µm and fiber respectively. On the other hand, prevalent colors were black and colorless in general. According to the Raman analysis results, the identified MP derivatives were polypropylene (40%), polyamide (30%), ethylene acrylic acid (20%), and polyvinylchloride (10%). Moreover, the pollution load index (PLI) index was used to determine the pollution status. PLI values were determined as 1.91 at station S1, 1.73 at station S2, 1.31 at station S3, 1 at station S4 and 1.24 at station S5. The PLI value determined for the overall pond was 1.4. The results of this research show that MP pollution is present in Topçu Pond and contributes to the expanding literature on MP pollution in pond ecosystems.

Comprehensive assessment of water and sediment quality to support sustainable management practices and mitigate potential risks of trace metal pollution in the Johor River Basin, South Peninsular Malaysia

Human activities have caused concerns over the contamination of trace elements in aquatic systems due to their toxicity, long-lasting nature, and ability to accumulate in living organisms. This study evaluated the spatial pattern, environmental hazard, and potential health hazard of 13 trace metals in water and sediment samples collected from the Johor River basin using multivariate statistical techniques in order to identify the impact of both natural and human-related factors on the presence of trace metals in the area. The increased levels of metals in Station S1 indicated a significant impact from municipal, domestic, and industrial waste. The Geo-accumulation Index (Igeo) values for pollution and ecological indices in the sediment of the Johor River Basin ranged from -9.44 to 6.27. The Pollution Load Index (PLI) values ranged from 0.05 to 0.18, and the Potential Ecological Risk Assessment (RI) values ranged from 2.15 to 11.18. These results indicate that the sediments in the Johor River Basin have a low risk of contamination from trace metals. The water's hazard quotient (HQ) had an average value of 0.0001, while the hazard index (HI) had an average value of 0.0003. It is important to increase stakeholders' understanding and concerns regarding the potential long-term human health and ecological implications associated with trace metals in Johor River water. The results of this study offer essential initial information for government entities to implement sustainable management strategies, reducing the likelihood of future trace metal contamination issues in the Johor River basin and similar regions.

Observational Analysis of Vertical Heat Flux Caused by Typhoon‐Induced Near‐Inertial Waves Under the Modulation of Mesoscale Eddies

AbstractTropical cyclones (TCs) induce heat pump and cold suction in the upper ocean layer. However, limited research investigated whether this heat can be effectively transported into the deep ocean. The present study shows that seawater at Station S2 is anomalously warmer in the deep ocean layer than at S1 and S3 during Typhoon Kalmaegi (2014) in the South China Sea. The turbulence‐induced vertical heat flux is estimated based on fine‐scale mixing parameterization but it cannot explain the warming rate below the thermocline. Therefore, a new method is proposed to estimate the vertical velocity, allowing us to calculate the heat flux more accurately. To elucidate the underlying causes of the observed differences, we analyze horizontal velocity to examine the role of mesoscale eddies in modulating near‐inertial waves (NIWs)‐induced vertical heat flux. Station S1 is located inside a cyclonic eddy while S2 and S3 are within two distinct anticyclonic eddies. According to the “Chimney Effect” theory, cyclonic (anticyclonic) eddies tend to limit (enhance) the vertical propagation of the NIWs. While this theory explains the confined heat flux at S1, it fails to explain the differences observed at S2 and S3. Further examination of the vertical structures and intensities of the two anticyclonic eddies reveals that the eddy at S2 extends much deeper and is stronger than that at S3, allowing the NIWs to propagate and transport heat deeper at S2 than at S3. The study demonstrates the role of TC‐induced NIWs in deep ocean heat transport under the influence of mesoscale eddies.

Risk assessment and pollution loads of potentially toxic elements in water of four rivers flowing into the Mediterranean Sea

One of the main sources of metal accumulation in the marine environment is transport by rivers. Using data from 2014 to 2017 for various stations, this study analysed the distribution of potential toxic element (PTE) concentrations in surface waters, the pollution loads and the water quality index of the large rivers flowing into the Mediterranean Sea (Manavgat, Göksu, Seyhan and Ceyhan). 13 different elements (As, Cd, Cr, Co, Cu, Fe,Pb, Li, Mn, Ni, Se, Zn, Al) were determined within the scope of the study. While the estimation of risk assessments for both adults and children via dermal and ingestion pathways using the United States Environmental Agency (USEPA) formulas. Pollution indexes such as Chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI) and carcinogenic risk (CR) were calculated. Additionally, water quality index (WQI), pollution load ındex (PLI) and contamination factors (CF) were also determined. Since it is a detailed monitoring study of three years, all findings are evaluated using average values for each river. The highest mean PTE concentrations across all rivers were found at stations S4 (Seyhan), S1 and M1 (Manavgat) with Ni (0.1895) > Se (0.0618) > Al (0.0598), respectively. The values of PLI were found to be generally high (3−6) and very high (>6) in all studied rivers. Additionally, these rivers are subject to significant contamination with Pb, as CF>5, indicating very high levels of contamination, was found as a minimum of 166 for Pb in all rivers. Considering all risk assessments, it is concluded that children are more sensitive to ingestion and dermal exposure pathways than adults, and their carcinogenic risk is 4.5 times greater than adults. Besides, according to the statistical analysis, the strong and weak correlation of Al with other elements indicates that the source of the pollution is natural and anthropogenic processes, respectively.

Epilithic Diatom Assemblages and Indicators for the Assessment of Water Quality of Munzur Stream, Turkey

The epilithic diatoms of Munzur Stream, together with the chemistry and physical variables of the water, were examined in the samples taken annually from 3 stations on the creek between October 2016 and September 2017. A total of 69 diatom taxa were identified benthic habitat. Cocconeis placentula, Cymbella affinis, Cymbella excisiformis , Didymosphenia geminata, Gomphonema olivaceum, and Hannaea arcus became diatoms at all that reached significant relative abundance. Shannon-diversity (H’), species evenness (J’), species richness (S) in each station varied between stations and months. Regarding diversity (H), values ranged from 1.54 (in December, at S3) to 2.99 (in October, at S3). Evenness ranged from 0.09 to 0.22 at station S3 in September (at S1, in September). Evenness ranged from 0.09 at site S3 in September, to 0.22 at S1, in September. All stations and species were close to 1 value. Canonical correspondence analysis indicated that three environmental variables (TN,TP, PO4-3) significantly affected the distribution of epilithic diatom. The studied part of stream was characterized by the species susceptible to nutrients such as Didymosphenia geminata, Cymbella excisiformis and Hannaea arcus which are found in the regions located in high lands having advanced ecological status. The results of the present study highlighted the importance of diatoms as a bio-indicator for health condition of a stream.

Evaluation of the Genotoxic and Histological Effects in Neotropical Fish Prochilodus Lacustris (Pisces, Prochilodontidae) in Conservation Area of the Brazilian Northeast.

Human activities significantly impact the aquatic biota in lacustrine environments, leading to negative environmental consequences. Due to this, this study was carried out to evaluate the genotoxic and histological biomarkers in the gills and kidneys of Prochilodus lacustris. The collection of fish and water was conducted in three distinct stations (S1, S2, S3) in an international protected area in northeast Brazil. The histological alterations index was used to assess changes in the gills and kidneys at a histological level. In addition, micronucleus and nuclear abnormalities tests were employed to examine damage to the genetic material. According to the frequency of Micronucleus, nuclear injuries, and the histopathology of gills and kidneys, it can be inferred that station S1 had the highest impact on the fish, causing significant harm. Based on our findings, the organisms residing in Lake Açu are adversely affected by the poor environmental conditions. This raises doubts about the effectiveness of the Protection Area by Humid Zone of International Interest in Northeast Brazil.

Deep learning versus hybrid regularized extreme learning machine for multi-month drought forecasting: A comparative study and trend analysis in tropical region

Drought is a hazardous natural disaster that can negatively affect the environment, water resources, agriculture, and the economy. Precise drought forecasting and trend assessment are essential for water management to reduce the detrimental effects of drought. However, some existing drought modeling techniques have limitations that hinder precise forecasting, necessitating the exploration of suitable approaches. This study examines two forecasting models, Long Short-Term Memory (LSTM) and a hybrid model integrating regularized extreme learning machine and Snake algorithm, to forecast hydrological droughts for one to six months in advance. Using the Multivariate Standardized Streamflow Index (MSSI) computed from 58 years of streamflow data for two drier Malaysian stations, the models forecast droughts and were compared to classical models such as gradient boosting regression and K-nearest model for validation purposes. The RELM-SO model outperformed other models for forecasting one month ahead at station S1, with lower root mean square error (RMSE = 0.1453), mean absolute error (MAE = 0.1164), and a higher Nash-Sutcliffe efficiency index (NSE = 0.9012) and Willmott index (WI = 0.9966). Similarly, at station S2, the hybrid model had lower (RMSE = 0.1211 and MAE = 0.0909), and higher (NSE = 0.8941 and WI = 0.9960), indicating improved accuracy compared to comparable models. Due to significant autocorrelation in the drought data, traditional statistical metrics may be inadequate for selecting the optimal model. Therefore, this study introduced a novel parameter to evaluate the model's effectiveness in accurately capturing the turning points in the data. Accordingly, the hybrid model significantly improved forecast accuracy from 19.32 % to 21.52 % when compared with LSTM. Besides, the reliability analysis showed that the hybrid model was the most accurate for providing long-term forecasts. Additionally, innovative trend analysis, an effective method, was used to analyze hydrological drought trends. The study revealed that October, November, and December experienced higher occurrences of drought than other months. This research advances accurate drought forecasting and trend assessment, providing valuable insights for water management and decision-making in drought-prone regions.

Mesopelagic particulate nitrogen dynamics in the subarctic and subtropical regions of the western North Pacific

Recently, new spatiotemporal-scale particle observations by autonomous profiling floats equipped with bio-optical sensors have revealed that, in addition to gravitational particle sinking, the downward transport of surface particles by physical mixing events, which has been overlooked, contributes to particulate organic carbon export. However, the subsequent behavior of these exported particles in the mesopelagic zone (e.g., particle fragmentation and degradation) remains unclear, although it may influence the efficiency of carbon transport to further depths. This study successfully depicted the new annual mean mesopelagic particulate nitrogen (PN) dynamics with multi-layer, steady-state suspended PN pools by reanalyzing seasonal data on the stable nitrogen isotopic compositions of both suspended and sinking particles, each with different profiles, from subarctic station K2 and subtropical station S1 in the North Pacific, which are both CO2 sinks but in different oceanic settings. As analytical conditions, we assumed that the net loss of sinking PN was entirely due to abiotic fragmentation of particle aggregates to non-sinking particles and that the apparent 15N enrichment associated with heterotrophic degradation in the suspended PN pools was vertically constant. The 15N mass balance for the PN supply to the uppermost mesopelagic pool, derived from such constraints, allowed estimating the PN export by the mixed-layer pump, which was 1.6 times greater at K2 than at S1. However, its contribution to the total export (including gravitational PN sinking) from the surface layer was approximately 20% at both stations. Moreover, the ratio of PN supplied to the uppermost pool by the mixed-layer pump and by the fragmentation of particle aggregates was also similar at both stations, approximately 1:1. Using these ratios, together with separate observations of the mixed-layer pump-driven flux, it may be possible to estimate the efficiency of the particulate organic carbon transport due to the biological gravitational pump responsible for carbon sequestration in the deep sea.

Marine plastics on the beaches of Cuddalore coast, Southeast coast of India: A assessment of their abundance during Covid lockdown and post lockdown

Despite their widespread use and versatility, plastics pose a threat to the environment due to emerging contaminants in coastal and marine ecosystems. The present investigation focused on anthropogenic activities like tourism, fishing, and recreation while surveying plastic waste along the Cuddalore the coast. The survey was carried out during the summer season of 2021 (the lockdown) and the post monsoon season (post lockdown) of 2022. During the summer lockdown, station S1 had the highest abundance of plastic with 18.8 ± 5 items/m2, followed by S3 (4.7 ± 1.2 items/m2), S2 (4.3 ± 1.0 items/m2), and S4 (3.6 ± 1.2 items/m2). Nevertheless, after the lockdown, the highest abundance of plastic was observed at station S1 (25.6 ± 3.5 items/m2), followed by S3 (20.9 ± 9.7 items/m2), S2 (17.5 ± 8.5 items/m2), and S4 (14.6 ± 4.9 items/m2). The abundance of plastic items on the study beaches significantly increased (p<0.05) during the post lockdown period. White, translucent, green, yellow, and blue plastic was found in abundance on all four study beaches. To assess the health status, the Clean Coast Index (CCIi), which shows silver beaches (57.08%), Samyarpettai (43.34%), Periyakuppam (34.88%), and Puthukuppm (31.2%), all of which are highly polluted. The abundance of marine plastic trash along the Cuddalore the coast has been significantly affected by extensive fishing, recreation, tourist, and rituals. To better understand marine plastic pollution and the need for better waste management throughout the Indian coast, this study builds a baseline for beach littering and provides an explanatory framework for further study.

Diel, seasonal and vertical changes in the abundance, biomass and community structure of pelagic polychaetes at the subtropical station S1 in the western North Pacific: comparison with the results from the subarctic station K2.

Information on pelagic polychaete community structure in the western North Pacific is available for the subarctic region (Station K2) but not for the subtropical region. Hence, we analyzed day-night vertically stratified samples collected in eight layers within the first 1000m of the water column during four seasons in 1year, using the same sampling method as St. K2, at the subtropical region (Station S1). At St. S1, 27 species of pelagic polychaetes belonging to 13 genera and six families were identified. The annual mean abundance was 35.0 ind. 1000m-3 and the biomass was 17.3mg WW 1000m-3. At St. S1, the numbers of genera and species were higher and the annual mean abundance and biomasses were much lower than St. K2. The pelagic polychaetes often peaked in the mesopelagic layer at St. K2, with the carnivores and particle feeders peaking in the epipelagic and mesopelagic layers, respectively. At St.S1, the carnivorous species predominated throughout the entire water column, and were most abundant in the epipelagic layer. Thus, In the western Pacific Ocean, the subarctic pelagic polychaete community structure changed vertically with feeding ecology. On the other hand, the subtropical community may be adapted to conditions of high irradiance and light transmission.

Research on water quality spatiotemporal forecasting model based on ST-BIGRU-SVR neural network.

With the serious deterioration of the water environment, accurate prediction of water quality changes has become a topic of increasing concern. To further improve the accuracy of water quality prediction and the stability and generalization ability of the model, we propose a new water quality spatiotemporal forecast model to predict future water quality. To capture the spatiotemporal characteristics of water quality pollution data, the three sites (station S1, station S2, station S4) with the highest temperature time series concentration correlation at the experimental sites were first extracted to predict the water temperature at station S1, and 17,380 records were collected at each monitoring station, and the spatiotemporal characteristics were extracted by BiGRU-SVR network model. This paper's prediction test is based on the actual water quality data of the Qinhuangdao sea area in Hebei province from 2 September to 26 September 2013 and compared with other baseline models. The experimental results show that the proposed model is better than other baseline models and effectively improves the accuracy of water quality prediction, and the mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R2) are 0.071, 0.076, and 0.957, respectively, which have good robustness.

Validity of the Lower Zab River Sediments for Road and Asphalt Works - Southwest of Kirkuk/Northern Iraq

In this study, a geotechnical assessment of gravel and sand deposits were conducted on both sides of the Lower Zab River in the southwest of Kirkuk Governorate/Northern Iraq. geologically the sediment related to Quaternary age and tectonically located at the unstable zone. 5 samples were collected from the study area for the purpose of conducting various geotechnical tests on them and their validity for road works to the sub-base layer and the base layer for asphalt works.&#x0D; The results of the physical tests were shown by grain size analysis of thes aggregates for the samples of the study area, and it was found that they are identical to class (A) According to the American Standard [1], and suitable for use in road works for the sub-base layer. The moisture ratio ranging between (1.95 - 4.26) %. The tests of flatness and elongation showed that the highest percentage of flat-shaped particles was (29%) and longitudinal-shaped particles (19%).&#x0D; The laboratory tests results showed the durability tests such as - Los Angeles test the highest percentage of weight loss was (20.06%), and thus it is valid according to the Iraqi Standard Specification [2] for use in road works. the highest result of test the aggregate impact value of samples is 7.8%, It conforms to the requirements of specifications that must be provided for road works for a sub base layer. Accordingly it is valid for road works. It was found from Proctor test for (5) samples from the study area that the values of the maximum dry density ranged between (2.14-2.28 gm/cm3), and the values of the optimum moisture content ranged between (3.1-2.41%).&#x0D; An asphalt typical mixture was designed for the base layer from the aggregate of the first station S1 as represent station consisting of coarse crushed aggregate 12%, medium crushed aggregate 22%, fine crushed aggregate 20%, river sand 40% and the proportion of filler 6%. The results of the asphalt tests for the ideal station S1 showed that the ideal percentage of asphalt from the weight of the mixture in the asphalt mixture is 4.1, which is within the limits of the specification Roads and Bridges [3]. The percentage of asphalt to the weight of the aggregate after adding the ideal percentage of asphalt showed that its value was 4.3%, As for the stability test result (Marshall), it reached 11.4 kN, and the result of the creep test (Marshall) reached 2.9 mm, and the density was 2.362&#x0D;

Changes of Macrobenthic Diversity and Functional Groups in Saltmarsh Habitat under Different Seasons and Climatic Variables from a Subtropical Coast

Saltmarsh is one of the most productive coastal habitats in the marine environment, and the macroinvertebrate community is crucial to its ecology and productivity. These productive ecosystems are currently under threat due to climate change and anthropogenic activities. However, macroinvertebrate communities and their functionality in saltmarsh from subtropical coastal areas have previously been largely ignored. In this study, we aimed to elucidate (i) the diversity and community assemblages, (ii) trophic structure, and (iii) changes of macroinvertebrate diversity under different seasons and climatic variables from a subtropical saltmarsh habitat. A total of 29 taxa in the eight (8) major groups were recorded in both seasons, with polychaetes being dominant (64%) in monsoon and crustaceans (50%) in post-monsoon. Among the trophic groups identified, surface deposit feeders and omnivores were dominant, accounting for 78.52% of the total groups. The highest value of diversity index (2.04) was observed at station S3 in monsoon and the lowest (1.408) at station S2 in post-monsoon. Strong seasonal variability was confirmed by two-way ANOVA and PERMANOVA, and SIMPER analysis identified that shrimp larvae (Macrobrachium sp.) were the taxa that contributed the most to grouping patterns between areas and seasons. In addition, non-metric multidimensional scaling (nMDS) revealed a great dissimilarity of macrobenthic faunal assemblages among the study stations and seasons. Spearman’s rank correlation analysis and canonical correspondence analysis (CCA) results revealed that the climatic factors water temperature, salinity, and alkalinity variation influenced the benthic community diversity.

A holistic approach to the eco-geochemical risk assessment of trace elements in the estuarine sediments of the Southeastern Black Sea

The estuarine sediments were sampled seasonally along the southeast coast of the Black Sea, to assess the concentrations, sources, distributions, and possible ecological risks of trace elements (TEs). The mean concentrations of TEs (mg/kg) were ranked as Fe (56,659.83) > Al (39,758.00) > Mn (1168.53) > Zn (155.03) > Cr (120.75) > Pb (93.71) > Cu (82.66) > Ni (44.93) > Co (17.98) > As (13.66) > Cd (0.99) > Hg (0.18), respectively. The stations S4 and S6 showed “very high contamination” for Pb, “significantly enrichment” for Pb and Cd, “high ecological risk” for Cd, and “heavily polluted” for Pb and Cd according to the results of CF, EF, Eri, Igeo, respectively. The rest of the stations were in the low or moderate contamination through the all seasons as assessed by different eco-geochemical risk assessment indices. The integrated risk evaluation indices indicated no contamination in stations S3 and S5.

Simulation-based educational approach toward improving thermal outdoor comfort for pedestrians in semi-arid climate

Abstract The urban cooling is the most effective strategy to fight the urban climate change effects in summertime. Thus, searching urban cool islands can remedy the rise of urban temperatures. This study aims to consider cool urban pathways offering optimal levels of thermal comfort in downtown Guelma during summer overheating. This involves researching the appropriate tree ratio and typology, tree layout and suitable configurations of water bodies of outdoor spaces. The scientific methodology is made through either straightforward step included on-site measurements and calculating the difference of urban temperatures to select five outdoor spaces with maximum heat stress. As our study also aims to improve the outdoor thermal comfort by natural elements, it simulates different scenarios of the selected stations using ENVI-Met model and exploiting the real field measurement of the urban microclimate. The most significant reductions in thermal comfort levels (UTCI) over three thermal phases identify the coolest urban pathways. Consequently, we confirmed that considering cool pathways spanning from station S2 to station S8 is possible with optimal thermal comfort levels over the day; 0.46–6.9°C in the morning phase, 0.94–3.87°C in the hot thermal phase and 1.42–3.54°C in the thermal relief phase. The findings indicate three main effects of microclimatic regulation underlie the improvement of the thermal comfort levels: tree cooling effect with (Ta ≤ 1.1°C), cooling effect of water bodies (Ta ≤ 0.3°C) and cooling effect of trees in combination with water bodies (Ta ≤ 1.9°C).

Hydrodynamics in the tidal flat in semi-enclosed Xiangshan Bay

Tidal flats provide a foundation for biological diversity and marine economy. Xiangshan Bay is a semi-enclosed bay that shelters large areas of tidal flats, and is known for its aquaculture. In this study, field trips were conducted in late autumn to measure the water level, current, water temperature, tidal flat temperature, and turbidity data of the tidal flat in the bay during Typhoon Lingling. The field data were well calibrated and used to investigate the hydrodynamics, temperature, and turbidity of the tidal flat. The results showed that the spring-neap tidal cycles at the sea surface level were well captured at both stations. The maximum tidal range was 5.5 m and 1.5 m during spring and neap tides, respectively. The tidal flat was occasionally exposed to air occasionally (30 min). The current velocity (&amp;lt;0.2 m/s) and waves (&amp;lt;0.15 m) at the field stations were weak, and the direction of flow was controlled by the geomorphology, even during Typhoon Lingling. Water was more turbid at station S2 (&amp;lt;0.8 kg/m3) than at station S1 (&amp;lt;0.2 kg/m3). The sea water temperature and tidal flat temperature were affected by tidal cycles, with larger variations occurring during spring tides than during neap tides. The maximum value of seawater temperature at S1 station was greater than that at station S2 during spring tides. The intrinsic mode functions (IMFs) of sea water temperature and surface tidal flat temperature were similar, as they are both subject to sea-air-tidal flat interactions. The IMFs of the middle and bottom layers in the tidal flat were less correlated. Temperature fluctuations in seawater and tidal flats were mainly affected by air temperature and tides. Small-scale features (&amp;gt;0.5 Hz) were important for water and tidal flat temperatures, particularly during typhoons. These findings provide field data for future studies on eco-hydrology and coastal engineering in tidal flats.

Cypermethrin insecticide residue, water quality and phytoplankton diversity in the lychee plantation catchment area

&lt;abstract&gt; &lt;p&gt;Lychee plantation areas are typically located at varying elevations on mountains to ensure proper drainage. This placement has direct effects on stream and river water flows and consequently influences pesticide residue, water quality and aquatic biodiversity. This research aims to examine the relationships between cypermethrin residue, water quality and phytoplankton diversity in the lychee plantation catchment area in Phayao Province, Thailand, from January to May 2022. The study area was divided into six sampling sites. Water samples were collected for the investigation of cypermethrin residual, physicochemical and biological water quality parameters. The water quality index was used as an overall measurement of water quality. The study also examined the diversity of phytoplankton species and the relationship among cypermethrin residue, water quality and phytoplankton diversity were studied using canonical correspondence analysis. The findings revealed an increasing trend of cypermethrin residue, with the maximum concentration reaching 29.43 mg/L in March. The trend of decreasing water quality scores from Station S1 to Station S5 indicated the influence of land use changes and human activities, especially in the community area (S5), which was characterized by deterioration of water quality. A total of 174 phytoplankton species were categorized into 5 divisions, with Chlorophyta accounting for 61.49% of the total, followed by Bacillariophyta (28.16%) and Cyanophyta (6.32%). The highest Shannon's diversity index and evenness were observed at Stations S3 and S4, respectively. The canonical correspondence analysis revealed an interesting relationship among cypermethrin residue, ammonia nitrogen, chlorophyll a and three algal species: &lt;italic&gt;Pediastrum simplex&lt;/italic&gt; var. &lt;italic&gt;echinulatum&lt;/italic&gt;, &lt;italic&gt;Pediastrum duplex&lt;/italic&gt; var. &lt;italic&gt;duplex&lt;/italic&gt; and &lt;italic&gt;Scenedesmus acutus&lt;/italic&gt; at Station S3. This research implies that pesticide residue and water quality have a direct impact on phytoplankton distribution, illustrating the environmental challenges that occur in various geographical areas. This information can be applied to assist in the development of future sustainable land use management initiatives.&lt;/p&gt; &lt;/abstract&gt;

Investigation of the biological diversity of Trichoptera larvae in the streams of the Kastamonu (Cide)-Sinop (Ayancık) coastal region of Türkiye

This study was carried out to determine the biodiversity and densities of Trichoptera larvae at stations in the Kastamonu (Cide)-Sinop (Ayanc?k) coastal region. Benthic macroinvertebrate samples were collected from each of the 19 stations using the kick-net sampling method with a D-frame net (500-?m mesh). Using the data from collected Trichoptera larvae, the similarity, diversity, dominance and population density relationships among habitats were measured. According to the calculated Shannon-Wiener and Simpson diversity index results, the station with the highest Trichoptera diversity was determined at S2, and the station with the least diversity was S14. Similar results were obtained for the calculated population density values. Station S2 was the most balanced station in population density. Thus, biodiversity was directly related to habitat structure, anthropogenic impact and geographical conditions, and environmental factors suppress biological species diversity. It was concluded that species diversity is greater in undestroyed habitats and less in heavily destroyed habitats. In addition, the species that dominate in biodiversity similarity rates prefer their habitat.