Tidal Area Research Articles

Energy Characteristics in the Flow Channel of the Shaft-Type Tubular Pumping Station Considering Tides

The shaft-type tubular pumping station has the remarkable characteristics of a large flow rate and high efficiency. It can realize the functions of irrigation, pumping, and drainage through pumping and generating conditions considering tides. Moreover, it is widely used in the plain area of eastern China and the tidal area along the marine region. Due to the different topological features of the airfoil of the impeller, the energy evolution characteristics of the shaft-type tubular pumping station during pumping and generating conditions remain unclear. The entropy generation theory was introduced to numerically simulate the flow pattern and energy characteristics in the shaft-type channel, impeller, and straight channel in operation conditions. The results show that the flow pattern is stable when the shaft-type channel and the straight-type channel are used as the inlet channel under pumping and generating conditions, and a low-pressure region occurs in the contraction section of the shaft-type channel. The velocity of sections of the inlet and outlet and the middle section of the impeller in the generating condition is larger than that in the pumping condition. In addition, the difference in the static pressure on the blade surface nearby the hub is large. With a change in the position of the wingspan, the difference gradually decreases from the small flow condition to the large flow condition. There is a high-entropy production rate zone in the channel contraction section and the shaft-type wall surface of the shaft-type flow channel. When the straight-type channel is used as the outlet flow channel, a high-entropy production region appears near the inlet water surface. In the pumping condition, a high-entropy production area is found at the inlet of the impeller, the blade groove channel, and the inlet of the guide vane. In the generating condition, a high-entropy production area is found at the out-of-impeller outlet, the blade groove channel, and the outlet of the guide vane. These research achievements have some reference value for the design of the shaft-type tubular pumping station considering tides and the study of hydraulic performance, along with the energy characteristics of the channels.

Enhancing Seedling Performance Direct Seeded Rice Under Anaerobic Germination Condition by Seed Invigoration

In an effort to address labor scarcity and enhance the cropping index in tidal swamp areas, farmers utilize direct seeding techniques. However, flooded conditions due to tides and ebb can hinder seed germination. This study aimed to obtain the best invigoration treatment for improving seedling establishment and growth in South Sumatra's tidal swamp hotspots. In the first part of the study, 19 different seed treatments were tested on the swamp rice variety, Inpara 9, in a greenhouse. These treatments included hardening, priming, thermal treatment, and controls. Soluble sugar content and α-amylase activities of treated seeds were analyzed in the lab. The results showed that the invigorated seeds outperformed the control group in terms of seedling growth and development when they were planted directly in the ground under both anaerobic germination (AG) and anaerobic germination with extra FeSO4 added to the soil (AG+Fe) conditions. All treated seeds also exhibited higher soluble sugar and α-amylase activities. A follow-up experiment in a hotspot area assessed the effectiveness of the top nine seed treatments from the first experiment under AG conditions. The flooded level was managed at around 10 cm during the experiment and Inpara-9 was the variety planted. All invigorated seeds exhibited superior seedling establishment and growth compared to the control on in-situ swampy land. Hardening using Trichoderma yielded the highest seedling establishment and performance, indicated by greater root and shoot dry weight than other treatments, followed by hardening with Methylobacterium td-J7 and Methylobacterium td-tpb3.

Plasticity of circadian and circatidal rhythms in activity and transcriptomic dynamics in a freshwater snail

Organisms have diverse biological clocks synchronised with environmental cycles depending on their habitats. Anticipation of tidal changes has driven the evolution of circatidal rhythms in some marine species. In the freshwater snail, Semisulcospira reiniana, individuals in nontidal areas exhibit circadian rhythms, whereas those in tidal areas exhibit both circadian and circatidal rhythms. We investigated whether the circatidal rhythms are genetically determined or induced by environmental cycles. The exposure to a simulated tidal cycle did not change the intensity of circatidal rhythm in individuals in the nontidal population. However, snails in the tidal population showed different activity rhythms depending on the presence or absence of the exposure. Transcriptome analysis revealed that genes with circatidal oscillation increased due to entrainment to the tidal cycle in both populations and dominant rhythmicity was consistent with the environmental cycle. These results suggest plasticity in the endogenous rhythm in the gene expression in both populations. Note that circatidal oscillating genes were more abundant in the tidal population than in the nontidal population, suggesting that a greater number of genes are associated with circatidal clocks in the tidal population compared to the nontidal population. This increase of circatidal clock–controlled genes in the tidal population could be caused by genetic changes in the biological clock or the experience of tidal cycle in the early life stage. Our findings suggest that the plasticity of biological rhythms may have contributed to the adaptation to the tidal environment in S. reiniana.

Studi Keragaman dan Habitat Gastropoda di Daerah Litoral Muara Sungai Ketahun Bengkulu Utara

This research aims to identify the abundance, diversity, dominance and evenness of gastropods at the mouth of the Ketahun River, North Bengkulu. The method used is the "purposive" method. The sampling location was divided into 4 (four) stations, namely in the tidal area and on the right and left in the downstream part of the estuary. The sampling technique uses transects, at each station measuring 20m. Gastropod data analysis uses the Shannon Wiener index, Simpson index, and Pielou index. The research results showed that at the mouth of the Ketahun river, 18 species of gastropods were obtained consisting of 7 genera and 3 families. The diversity index shows, a) station I has an index value of 1.81 (medium category); b) station II has an index value of 0.49 (low category); c) station III has an index value of 1.89 (medium category); d) station IV has an index value of 0.82 (low category). The dominance index shows, a) station I has an index value of 0.23 (low category); b) station II has an index value of 0.70 (medium category); c) station III has an index value of 0.19 (low category); d) station IV has an index value of 0.63 (medium category). The evenness index shows, a) station I has an index value of 0.62 (high category); b) station II has an index value of 0.17 (small category); c) station III has an index value of 0.65 (high category); d) station IV has an index value of 0.28 (small category). The most common gastropod found is the genus Clithon with a total of 1369 individuals. Abundance, diversity, dominance and evenness are determined by abiotic parameters and environmental conditions such as substrate and water quality. Keywords: Bengkulu, Gastropods, Ketahun River

Dredging wastewater discharge from shrimp ponds affects mangrove soil physical-chemical properties and enzyme activities

Dredging wastewater discharge is a significant environmental concern for mariculture near mangrove ecosystems. However, little attention has been paid to its effects on the soil physical-chemical properties and enzyme activities in mangrove habitats. This study compared the soil physical-chemical properties and enzyme activities in the polluted area that received dredging wastewater from a shrimp pond with those in the control area without wastewater to explore the effects of wastewater discharge on the soil physical-chemical properties and enzyme activities. Variations in soil physical-chemical properties and enzyme activities across different tidal flat areas and depths were also examined. The polluted area exhibited lower soil salinity (10.47 ± 0.58 vs. 15.64 ± 0.54) and moisture content (41.85 ± 1.03 % vs. 45.81 ± 1.06 %) than the control area. Wastewater discharge increased soil enzyme activities, (acid phosphatase, protease, and catalase), resulting in higher inorganic nitrogen (13.20 ± 0.00 μg g−1 vs. 11.60 ± 0.03 μg g−1) but lower total nitrogen (0.93 ± 0.01 mg g−1 vs. 1.62 ± 0.11 mg g−1) in the contaminated zone. From the control to polluted area, there was an approximate increase of 0.43 and 0.83 mg g−1 in soil total phosphorus and soluble phosphate, driven by increased acid phosphatase. However, soil humus and organic matter decreased by 0.04 and 1.22 %, respectively, because of wastewater discharge. The impact of wastewater discharge on the soil physical-chemical properties and enzyme activities was most pronounced in the landward and surface soil layers (0–5 cm). The results showed that wastewater discharge altered soil physical-chemical properties and enzyme activities, accumulating soil bioavailable nutrients (inorganic nitrogen and soluble phosphate), but at the cost of reduced soil quality, especially organic matter, further adversely affecting the overall health of mangrove ecosystems. Prioritizing the management of wastewater discharged from mariculture adjacent to mangrove forests is crucial for mangrove conservation.

Quantitative Characterization of Respiratory Patterns on Dynamic Higher Temporal Resolution MRI to Stratify Postacute Covid-19 Patients by Cardiopulmonary Symptom Burden.

Postacute Covid-19 patients commonly present with respiratory symptoms; however, a noninvasive imaging method for quantitative characterization of respiratory patterns is lacking. To evaluate if quantitative characterization of respiratory pattern on free-breathing higher temporal resolution MRI stratifies patients by cardiopulmonary symptom burden. Prospective analysis of retrospectively acquired data. A total of 37 postacute Covid-19 patients (25 male; median [interquartile range (IQR)] age: 58 [42-64] years; median [IQR] days from acute infection: 335 [186-449]). 0.55 T/two-dimensional coronal true fast imaging with steady-state free precession (trueFISP) at higher temporal resolution. Patients were stratified into three groups based on presence of no (N = 11), 1 (N = 14), or ≥2 (N = 14) cardiopulmonary symptoms, assessed using a standardized symptom inventory within 1 month of MRI. An automated lung postprocessing workflow segmented each lung in each trueFISP image (temporal resolution 0.2 seconds) and respiratory curves were generated. Quantitative parameters were derived including tidal lung area, rates of inspiration and expiration, lung area coefficient of variability (CV), and respiratory incoherence (departure from sinusoidal pattern) were. Pulmonary function tests were recorded if within 1 month of MRI. Qualitative assessment of respiratory pattern and lung opacity was performed by three independent readers with 6, 9, and 23 years of experience. Analysis of variance to assess differences in demographic, clinical, and quantitative MRI parameters among groups; univariable analysis and multinomial logistic regression modeling to determine features predictive of patient symptom status; Akaike information criterion to compare the quality of regression models; Cohen and Fleiss kappa (κ) to quantify inter-reader reliability. Two-sided 5% significance level was used. Tidal area and lung area CV were significantly higher in patients with two or more symptoms than in those with one or no symptoms (area: 15.4 cm2 vs. 12.9 cm2 vs. 12.8 cm2 ; CV: 0.072, 0.067, and 0.058). Respiratory incoherence was significantly higher in patients with two or more symptoms than in those with one or no symptoms (0.05 vs. 0.043 vs. 0.033). There were no significant differences in patient age (P = 0.19), sex (P = 0.88), lung opacity severity (P = 0.48), or pulmonary function tests (P = 0.35-0.97) among groups. Qualitative reader assessment did not distinguish between groups and showed slight inter-reader agreement (κ = 0.05-0.11). Quantitative respiratory pattern measures derived from dynamic higher-temporal resolution MRI have potential to stratify patients by symptom burden in a postacute Covid-19 cohort. 3 TECHNICAL EFFICACY: Stage 3.

HUMAN RIGHTS TO HEALTH AND WELLBEING FOR VULNERABLE GROUPS IN TIDAL FLOOD AREAS: A POLICY BRIEF

Objective: Mental health problems in vulnerable groups in tidal flood areas include impaired self-concept, stress, and anxiety. Many policies regulate flood management especially to manage mental health problems in disaster areas. However, during tidal floods, the implementation of programs to handle psychosocial problems was not optimal. This research aims to develop policy recommendations to meet the need for the right to a healthy and prosperous life among vulnerable groups in tidal flood areas. Method: This research is a review type of research that examines the policies and legal norms that apply in Indonesia and is related to the tidal flood disaster situation. Prescriptive analysis is carried out by researchers so that researchers can describe problems based on the perspective of policy studies and legal norms that have been studied and analyzed using literature studies. Result: Various efforts to deal with tidal floods have been carried out, but they still focus on improving the physical environment and dealing with physical health problems. Mental health problems are still ignored because they tend not to be studied and presented by society and the government. Fulfillment of the right to health is unequal because it is not implemented holistically. Conclusion: Exposure to tidal floods that cannot be changed and prevented requires the existence of policies that regulate the prevention and treatment of mental health problems. Existing policies need to be integrated with each other so that they can be implemented technically by carrying out continuous mental health efforts.

Area- and latitude- shaped shorebird diversity patterns reveal constraints of migratory bottlenecks along the Yellow sea coast of China

Migratory stopping regions are regarded as geographic bottlenecks. However, knowledge about constraints on migratory communities remains limited. This study proposed hypothetical spatial constraints (SCs) and tested the predictions by examining the response of multifaceted shorebird diversity to the tidal flat area and latitude of the stopping sites along the Yellow Sea coast. We estimated species richness (SR), phylogenetic and functional diversity (PD and FD) by building a species-level phylogenetic tree and measuring five functional traits of all species, using data on the shorebird community at 11 internationally important stopping sites of 2020–2021. We used multiple linear regression models and null models to examine the relationships between diversity metrics and stopping site variables (area and latitude). Functional and phylogenetic rarity of non-least concern species was calculated to estimate their risk of disappearance. The three dimensions of biodiversity decreased with decreasing area despite different slopes (i.e., FD was less sensitive to area than SR, whereas PD was lost more rapidly in smaller areas). In addition, only FD increased at sites approaching the terminal stopping area, implying that SR and PD were restricted from growing by latitude. Inferred from the PD and FD patterns, competitive exclusion tends be the dominant mechanism structuring the community, and the FD-inferred process was intensified in smaller sites toward the northerly terminal site. The area- and latitude-shaped diversity patterns indicate SCs on the migratory community, while a more intensive process of competitive exclusion tends to take place in smaller and near-terminal stopping sites. Consequently, the threatened shorebirds with less competitive capacity may be more prone than others in the SCs. This study highlighting the significance of the multifaceted biodiversity in monitoring the impacts of SCs and facilitating the development of conservation strategies in internationally critical migration bottlenecks.

Identification of the characteristics of the physical vulnerability level of the Kendari Bay coastal landscape to tidal floods using the Quantum Geographic Information System

Kendari City has a coastal stretch that runs into the sea and is feared to be vulnerable to tidal floods. This study aims to identify the tidal flood vulnerability of the coastal landscape of Kendari City, especially in terms of its relationship to the characteristics of the physical aspects of the landscape, distribution mapping, and the extent of tidal flood vulnerability areas in coastal areas. The research method uses spatial descriptive analytics to explain the tidal flood phenomenon in relation to physical aspects of the coastal landscape such as topography, distance from the beach, distance from rivers, and land use aspects. The data collected consists of primary data in the form of observation data on the physical aspects of coastal areas and secondary data in the form of satellite image data and data from related agencies. The analysis technique for describing tidal flood vulnerability uses buffer and overlay analysis, assisted by the QGIS application. The results of the research showed that the level of physical vulnerability to tidal flooding was obtained by three vulnerability classes and their areas: low physical vulnerability at 17,096.82 ha, medium physical vulnerability at 8,169.69 ha, and high physical vulnerability at 1,722.17 ha.

The study of water salinity distribution for supporting agriculture in Katingan I lowland irrigation area, Central Kalimantan

The Katingan I tidal lowland irrigation area (DIR Katingan I) is a sensitive area to salinity changes. This study aims to identify and estimate the spatial distribution of salinity in DIR Katingan I. The method used in this study is field measurement for collecting tidal and salinity data in the Katingan River as well as in several locations of primary and secondary canals. The measured data at the upstream canal, Katingan River, and primary canal as boundary conditions and calibration for hydraulic and water quality simulations. The simulations used HEC-RAS software to estimate salinity spatial distribution under tidal conditions at primary and secondary canals. The results showed that the distribution of water salinity can reach lower primary canals. It is necessary to take anticipatory actions to reduce the salinity intrusion. To overcome the problem, alternative recommended solutions that can be done are sluice gates installation on the lower primary canal, right primary canal, and left primary canal about 1 to 3 km from the mouth of the primary canal. The prediction of salinity spatial distribution is expected to be a useful recommendation for water management in DIR Katingan I, and it is expected to increase agricultural productivity.

The Threat of Saltwater Intrusion on Rice Farming in Katingan I Lowland Irrigation Area, Central Kalimantan

The Katingan I Lowlands Irrigation Area (LIA) is one of tidal lowlands irrigation area in Central Kalimantan, Indonesia. Because the Katingan I LIA utilizes water from the estuary, the occurence of saltwater intrusion is likely to occur. Assessing water salinity due to saltwater intrusion provides essential information for farmers to manage water appropriately. In addition, this information can also be used by the government to develop policies and management strategies for Katingan I LIA. Saltwater intrusion that occurs when sea water flows into irrigation canals and agricultural land can lead to increased salinity. High salinity levels can affect agricultural productivity, especially in rice crops. Therefore, a thorough salinity study is needed to support the development of rice farming. This study aims to evaluate salinity levels due to saltwater intrusion and understand the factors affecting them. The study measured tidal (water level elevation), electrical conductivity (EC), and salinity data of the Katingan River and several locations in the primary and secondary channels. Data collection methods included continuous and instantaneous measurements using portable data logger installations and handheld devices. The existing water salinity conditions at Katingan I LIA obtained the maximum water salinity value from the three locations of 14,536 ppm and the lowest water salinity value of 3.02 ppm. The maximum water salinity value that enters the primary canal is 5,547 ppm, higher than the thershold salinity value for rice farming (5,120 ppm). Therefore, anticipatory measuers must be conducted to reduce salinity intrusion, such as optitmizing water channels, making water gates, and managing the water use efficiently. It is also recommended that measurements be carried out during the dry season to see the comparison of results and the magnitude of the maximum water salinity value that occurs because salinity problems occur more during the dry season

Revisiting the effectiveness of biodiversity offsets in coastal wetlands of China through landscape connectivity

We modified the landscape connectivity calculation method and applied it to assess changes in temporal connectivity under different offsetting scenarios in the Yellow River Delta High-efficiency Ecological Economic Zone of China. We evaluated landscape connectivity based on resistance surfaces, least-cost distances, habitat areas, and the probability of dispersal between wetland patches in the landscape. The landscape connectivity declined between 1980 and 2015, with the degree of decline varying with the type of wetland. The cumulative percentages of freshwater marsh, salt marsh, and tidal marsh habitat areas that could be offset were 100 %, 100 %, and 34 %, respectively. However, the maximum landscape connectivity that was compensated for was only 1.2–10.4 %. When the offset patches were restored to freshwater marsh, the highest connectivity of coastal wetlands was achieved. There were substantial gaps between the area of habitat restoration offset required to achieve no net loss and the landscape connectivity that would ensure ecological effectiveness. The compensation area required to achieve no net loss of landscape connectivity was greater than that required to achieve no net loss of habitat area. We provide guidance for policy makers on how to implement offsetting to develop and manage green corridors, thus allowing movement that will ensure species’ survival. It was suggested that the passive restoration of isolated coastal wetland may be difficult to achieve. Policies that seek to increase landscape connectivity offsets can effectively promote population diffusion and migration, avoid habitat fragmentation, and are key to improving no net loss effectiveness.

Analysis of Mangrove Vegetation in Lohgung Village, Brondong Sub-District, Lamongan Regency

Mangroves are vegetation that grows in muddy areas in tidal areas, coastal areas , and river estuaries. Mangrove forests have an ecological function as providing food for marine biota, preventing tidal waves and tsunamis, preventing sea water intrusion, preventing coastal erosion and absorbing waste. This research aims to determine the species and Importance Value Index in the mangrove area of Lohgung Village, Brondong District, Lamongan Regency, which included Relative Density (KR), Relative Frequency (FR), and Relative Dominance (DR). This research was carried out in Lohgung Village, Brondong District, Lamongan Regency from May to June 2023. The method used in sampling used a combination of the line method (line transect) and the plot line method (quadrant transect). The results showed that the types of vegetation found in Lohgung Village, Brondong District, Lamongan Regency consisted of 8 species from 5 different families, namely Sonneratia alba, Rhizophora apiculata, Rhizophora mucronata, Bruguiera gymnorrhiza, Ceriops tagal, Lumnitzera racemosa, Excoecaria agallocha L., and Xylocarpus moluccensis. The results of calculating the values of Density (K), Relative Density (KR), Frequency (F), Relative Frequency (FR), Dominance (D), Relative Dominance (DR), and Importance Value Index (IVI) in all categories, trees, saplings and seedlings showed that the highest value that dominated was Rhizophora mucronata with an IVI value of 102.08%, 68.73% for saplings and 75.40% for seedlings.

Spatio-temporal changes and hydrological forces of wetland landscape pattern in the Yellow River Delta during 1986–2022

ContextEstuarine wetlands provide valuable ecosystem services, but 20–78% of coastal wetlands are facing the risk of loss by the end of the century. The Yellow River Delta (YRD) wetland, one of the most productive delta areas in the world, has undergone dramatic changes under the influence of a precipitous drop of sediment delivery and runoff, coupled with the invasion of Spartina alterniflora. Monitoring the spatio-temporal patterns, thresholds, and drivers of change in wetland landscapes is critical for sustainable management of delta wetlands.ObjectivesGenerate annual mapping of salt marsh vegetation in the YRD wetland from 1986 to 2022, analyze the trends of wetland patch area and landscape pattern, and explain the hydrological drivers of landscape pattern evolution.MethodsWe combined Landsat 5‒8 and Sentinel-2 images, vegetation phenology, remote sensing indices, and Random Forest supervised classification to map the typical salt marsh vegetation of the YRD. We applied piecewise linear regression to analyze YRD wetland changes and stepwise multiple linear regression to assess the impact of hydrological factors on landscape pattern.ResultsWe identified three stages of landscape pattern evolution with 1997 and 2009 as critical junctures, including the rapid expansion stage, gradual decline stage, and bio-invasion stage. In the rapid expansion stage, the wetland area expanded by 70%, while the typical salt marsh vegetation (Phragmites australis) area was reduced by 25%. In the gradual decline stage, the wetland was reduced by 21% and the Phragmites australis area was reduced by 16%. In the bio-invasion stage, coverage of Spartina alterniflora expanded rapidly, with a 68-fold increase in area relative to 2009, expanding at an average rate of 344 hm2 per year.ConclusionsAreas of total wetland, tidal flat, and Phragmites australis were significantly influenced by cumulative sediment delivery and cumulative runoff, which together explained 61.5%, 75.7% and 63.8% of their variation, respectively. Wetland and tidal flat areas increased with cumulative sediment delivery, while cumulative runoff had a weak negative effect. For Phragmites australis, cumulative runoff had a positive effect, whereas cumulative sediment delivery had a negative effect. Water resources regulation measures should be taken to prevent the degradation of wetland ecosystems, and intervention measures can be implemented during the seedling stage to control the invasion of Spartina alterniflora.

Kajian Empirik Pilihan Rasional dan Jaringan Nelayan Tani Di Kawasan Danau Tempe

This study aims to assess the rationality and social networks formed among fishermen farmers who live and run farms in tidal areas in the Tempe Lake area. The study was conducted in Tempe Lake area, covering Salo Menraleng and Laelo villages, Tempe sub-district, Wajo district from April to May 2016. The assessment method used was the Rapid Rural Appraisal method. Interviews were conducted repeatedly with 2-3 people from the community who work as farmers-fishermen, heads of farmer groups, community leaders and local agricultural extension workers. The interview was considered complete when it had reached a saturation point, i.e. there were no more things to ask. The process of forming rational choices of fishermen farmers who live and run farms in tidal areas in the Tempe Lake area is the existence of actors in this case are fishermen farmers and resources (land) where the relationship between the two is power and interests. The power here means that the landowner fishermen farmers have the right to work on anything in the natural conditions that occur in the Tempe Lake area to fulfill their interests or goals. The goal is to fulfill food needs and a source of family income. This is the reason and background they make decisions or actions in the form of farming methods, cropping patterns, selection of rice varieties and switching from secondary crops to rice. The social network formed among fishermen farmers is a sense of knowing each other, informing each other, reminding and helping in carrying out or overcoming something. Social networks will not materialize without being based on norms and mutual trust. The network of farmer group formation can be used as a means to learn to increase the productivity of their rice farming land.

Short Communication: New records of Mactra clams (Bivalvia: Mactridae) from Madura Island, Indonesia

Abstract. Wijaya CB, Ambarwati R, Isnaningsih NR. 2023. Short Communication: New records of Mactra clams (Bivalvia: Mactridae) from Madura Island, Indonesia. Biodiversitas 24: 6684-6691. Mactridae is a family of bivalves found in shallow waters, such as living at high tide lines, in tidal areas, and below low tide lines. More mactrid bivalves could be discovered, and further studies are needed in Indonesian waters. Madura Island has a variety of bivalves, and Mactra clams could also be discovered on this island. Therefore, this study aimed to identify Mactra clams from Madura Island, Indonesia, and analyze their morphological characters. Samples were collected at Nepa and Badur Beaches during low tides, and then identified based on morphological characteristics. A stereo microscope observation and detailed descriptions were carried out to obtain the qualitative characteristics, while the quantitative ones, included shell length and height, palial line height, and diameter. The environmental parameters of this two-beach were also evaluated. Data were analyzed descriptively. The results showed two new records of Mactridae members at both beaches, namely Mactra luzonica Reeve, 1854, Mactra dissimilis Reeve, 1854. Mactra dissimilis revealed morphological variation, namely in the coloration on both the exterior and interior of the shell. There were three variations of M. dissimilis, namely bluish-white shell, brownish-white shell, and white shell. The findings of M. dissimilis and M. luzonica are regarded as new records for Madura Island, Indonesia.

Study on the correlation between indoor accelerated corrosion testing of concrete epoxy polysiloxane coating and real-sea environmental testing in the East China Sea

In order to reveal the correlation between the accelerated corrosion test of epoxy polysiloxane coating and the real sea environmental test, the real sea environmental test was carried out in the atmosphere and tidal range area of Zhairuoshan Island in the East China Sea, and the multi-factor coupling test I (Cycle of 7-day xenon lamp aging test + 7-day Wetting-drying test) and test II (Cycle of 7-day xenon lamp aging test + 3-day damp heat test + 4-day salt spray test) were designed with reference to the environment of the East China Sea. The correlation between indoor accelerated corrosion test and real sea environmental test was analyzed by using Grey Relation Analysis, Spearman's rank correlation coefficient and Acceleration factor conversion method. The results show that both the indoor accelerated corrosion test and the real sea environmental test have corrosive effects on the epoxy polysiloxane coating of concrete. In the indoor accelerated corrosion test, it was found that the Wetting-drying test caused the highest loss of light rate. In the real sea environmental test, the loss of light rate of the coating in the atmosphere is higher than that in the tidal area, and the color difference is slightly lower. When the loss of light rate is used as the criterion, the grey correlation coefficient between the multi-factor coupling test I and the tidal range test is 0.63, and the maximum acceleration factor during the test is 5.3, indicating a good correlation between the two tests. Through this study, an effective indoor accelerated corrosion test method with good correlation and acceleration characteristics to the loss of light rate of concrete epoxy polysiloxane coating in a real sea environment was obtained.

A Novel Approach for Instantaneous Waterline Extraction for Tidal Flats

For many remote sensing applications, the instantaneous waterline on the image is critical boundary information to separate land and water and for other purposes. Accurate waterline extraction from satellite images is a desirable feature in such applications. Due to the complex topography of low tidal flats and their indistinct spatial and spectral characteristics on satellite imagery, the waterline extraction for tidal flats (especially at low tides) from remote sensing images has always been a technically challenging problem. We developed a novel method to extract waterline from satellite images, assuming that the waterline’s elevation is level. This paper explores the utilization of bathymetry during waterline extraction and presents a novel approach to tackle the waterline extraction issue, especially for low tidal flats, using remote sensing images at mid/high tide, when most of the tidal flat area is filled with seawater. Repeated optical satellite images are easily accessible in the current days; the proposed approach first generates the bathymetry map using the mid/high-tide satellite image, and then the initial waterline is extracted using traditional methods from the low-tide satellite image; the isobath (depth contour lines of bathymetry), which corresponds to the initial waterline is robustly estimated, and finally an area-based optimization algorithm is proposed and applied to both isobath and initial waterline to obtain the final optimized waterline. A series of experiments using Sentinel-2 multispectral images are conducted on Jibei Island of Penghu Archipelago and Chongming Island to demonstrate this proposed strategy. The results from the proposed approach are compared with the Normalized Difference Water Index (NDWI) and Support Vector Machine (SVM) methods. The results indicate that more accurate waterlines can be extracted using the proposed approach, and it is very suitable for waterline extraction for tidal flats, especially at low tides.

Development of a regional climate change model for Aedes vigilax and Aedes camptorhynchus (Diptera: Culicidae) in Perth, Western Australia.

Mosquito-borne disease is a significant public health issue and within Australia Ross River virus (RRV) is the most reported. This study combines a mechanistic model of mosquito development for two mosquito vectors; Aedes vigilax and Aedes camptorhynchus, with climate projections from three climate models for two Representative Concentration Pathways (RCPs), to examine the possible effects of climate change and sea-level rise on a temperate tidal saltmarsh habitat in Perth, Western Australia. The projections were run under no accretion and accretion scenarios using a known mosquito habitat as a case study. This improves our understanding of the possible implications of sea-level rise, accretion and climate change for mosquito control programmes for similar habitats across temperate tidal areas found in Southwest Western Australia. The output of the model indicate that the proportion of the year mosquitoes are active increases. Population abundances of the two Aedes species increase markedly. The main drivers of changes in mosquito population abundances are increases in the frequency of inundation of the tidal wetland and size of the area inundated, increased minimum water temperature, and decreased daily temperature fluctuations as water depth increases due to sea level changes, particularly under the model with no accretion. The effects on mosquito populations are more marked for RCP 8.5 when compared to RCP 4.5 but were consistent among the three climate change models. The results indicate that Ae. vigilax is likely to be the most abundant species in 2030 and 2050, but that by 2070 Aedes camptorhynchus may become the more abundant species. This increase would put considerable pressure on existing mosquito control programmes and increase the risk of mosquito-borne disease and nuisance biting to the local community, and planning to mitigate these potential impacts should commence now.

Evaluation of historical and future coastal wetland change in the Yellow and Bohai Seas using satellite images and a land use model

Predicting the future distribution of coastal wetlands and characterizing changes in the area of wetlands between historical and future periods are important for the formulation of wetland conservation and management plans. Here, we used a cellular automata–Markov model and satellite images to simulate the future distribution of coastal wetlands under the business-as-usual scenario (BAU) and ecological protection scenario (EP) along the Yellow and Bohai Seas in China; we also explored historical (from 1990 to 2020) and future (from 2020 to 2050) changes in wetlands and the factors driving these changes. We found that the area of tidal flats gradually decreased because of increases in the area of saltpans, and the aquaculture area increased because of land reclamation and the invasion of Spartina alterniflora; most of the tidal flat area was fragmented into multiple small patches. If the current rate of degradation continues (BAU), the area of tidal flats will decrease by 21.25%, and the area of saltpans and aquaculture will increase by 13.83% and 21.25%, respectively. By contrast, under EP, the area of tidal flats will increase by 13.81%, and this increase will mainly stem from the conversion of areas with S. alterniflora (174.49 km2, 33.22%) to aquaculture areas (155.17 km2, 29.54%). Clear differences between historical and future periods were observed among Liaohe Estuary, Bohai Bay, Laizhou Bay, and the Yancheng–Nantong coasts. Land reclamation is the main factor inducing changes in the area of tidal flats, saltpans, and aquaculture in Liaohe Estuary, Bohai Bay, and Laizhou Bay. Land reclamation and the S. alterniflora invasion both affect the distribution of wetlands along the Yancheng–Nantong coasts.