The Interrelationship between Climate Change, Human Activities and Hydrological Processes, Volume II

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Water and Climate Change".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 17221

Special Issue Editors


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Guest Editor
College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350116, China
Interests: drought; climate change; hydrological model
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Institute of Geography, Fujian Normal University, Fuzhou 350007, China
Interests: hydrology modeling; climate change; water resources; hydrology cycle
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
2. Pacific Northwest National Laboratory, Joint Global Change Research Institute at the University of Maryland-College Park, 5825 University Research Court, Suite 3500, College Park, MD 20740, USA
Interests: urban soil hydrology; soil retention curve; soil carbon cycle; global change; soil respiration; meta-analysis
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Climate change affects hydrological processes through factors such as temperature, humidity and precipitation. In the context of climate change, human activities will also cause corresponding hydrological effects. With the increase in social productivity, the increase in land use intensity and the increasingly complex forms of land use, the impact of land use/land cover changes on hydrology and water resources has gradually deepened. The changes in hydrological processes and their impact mechanisms are complex. On the one hand, climate change and human activities affect the hydrological process. On the other hand, changes in hydrological processes will further affect climate and human activities. This bi-directionality and uncertainty make research more complicated. It is precisely because of this complexity that there have been many related studies. However, how climate change and human activities affect hydrological processes, and how hydrological processes react to climate change and human activities, still have many issues to be solved. The authors of the world's hydrological communities are welcome to submit appropriate manuscripts. Topics to be addressed include, but are not limited to, the following:

  1. Hydrological effects of climate change and human activities;
  2. The influence of hydrological factors on climate and human activities;
  3. Hydrological processes and hydrological ecology;
  4. Interaction of climate change, human activities and hydrological processes;
  5. Drought or heatwave characteristics caused by climate change or human activities;
  6. Water security issues caused by climate change and human activities;
  7. Changes in vegetation, soil and rock hydrological processes caused by climate change and human activities.

Dr. Qianfeng Wang
Dr. Haijun Deng
Dr. Jinshi Jian
Guest Editors

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Keywords

  • climate change
  • hydrological processes
  • water resource
  • vegetation
  • soil
  • rock
  • drought
  • heatwave
  • mutual effect

Published Papers (15 papers)

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Research

19 pages, 4750 KiB  
Article
Unveiling Torrential Flood Dynamics: A Comprehensive Study of Spatio-Temporal Patterns in the Šumadija Region, Serbia
by Ana M. Petrović, Igor Leščešen and Ivan Radevski
Water 2024, 16(7), 991; https://doi.org/10.3390/w16070991 - 29 Mar 2024
Viewed by 548
Abstract
This paper presents a comprehensive analysis of flood frequency and a spatio-temporal characterization of historical torrential floods in the Šumadija region using water discharge datasets and documented events. A chronology of 344 recorded torrential flood events, spanning from 1929 to 2020, illustrates the [...] Read more.
This paper presents a comprehensive analysis of flood frequency and a spatio-temporal characterization of historical torrential floods in the Šumadija region using water discharge datasets and documented events. A chronology of 344 recorded torrential flood events, spanning from 1929 to 2020, illustrates the region’s vulnerability, with a death toll exceeding 43. The study defines the intra-annual primary and secondary peaks of torrential flood occurrences and explains their spatial distribution. Furthermore, the identification of suitable probability distribution functions underscores the necessity of tailored approaches for effective flood risk management in this diverse geographical environment. The study employed Flood Frequency Analysis (FFA) and goodness-of-fit tests, including the Kolmogorov–Smirnov (K-S) and Cramér–von Mises (CvM) tests, to assess the frequency and magnitude of flood events and evaluate diverse distribution functions. The main results include the identification of suitable probability distribution functions for each river within the region, emphasizing the need for tailored approaches in flood risk management. Additionally, discharge values for various return periods offer crucial insights for informed decision-making in flood risk management and infrastructure planning. Full article
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18 pages, 5010 KiB  
Article
Synoptic Analysis of Flood-Causing Rainfall and Flood Characteristics in the Source Area of the Yellow River
by Lijun Jin, Changsheng Yan, Baojun Yuan, Jing Liu and Jifeng Liu
Water 2024, 16(6), 857; https://doi.org/10.3390/w16060857 - 16 Mar 2024
Viewed by 612
Abstract
The source area of the Yellow River (SAYR) in China is an important water yield and water-conservation area in the Yellow River. Understanding the variability in rainfall and flood over the SAYR region and the related mechanism of flood-causing rainfall is of great [...] Read more.
The source area of the Yellow River (SAYR) in China is an important water yield and water-conservation area in the Yellow River. Understanding the variability in rainfall and flood over the SAYR region and the related mechanism of flood-causing rainfall is of great importance for the utilization of flood water resources through the optimal operation of cascade reservoirs over the upper Yellow River such as Longyangxia and Liujiaxia, and even for the prevention of flood and drought disasters for the entire Yellow River. Based on the flow data of Tangnaihai hydrological station, the rainfall data of the SAYR region and NCEP-NCAR reanalysis data from 1961 to 2020, three meteorological conceptual models of flood-causing rainfall—namely westerly trough type, low vortex shear type, and subtropical high southwest flow type—are established by using the weather-type method. The mechanism of flood-causing rainfall and the corresponding flood characteristics of each weather type were investigated. The results show that during the process of flood-causing rainfall, in the westerly trough type, the mid- and high-latitude circulation is flat and fluctuating. In the low vortex shear type, the high pressures over the Ural Mountains and the Okhotsk Sea are stronger compared to other types in the same period, and a low vortex shear line is formed in the west of the SAYR region at the low level. The rain is formed during the eastward movement of the shear line. In the subtropical high southwest flow type, the low trough of Lake Balkhash and the subtropical high are stronger compared to other types in the same period. Flood-causing rainfall generally occurs in areas with low-level convergence, high-level negative vorticity, low-level positive vorticity, convergence of water vapor flux, a certain amount of atmospheric precipitable water, and low-level cold advection. In terms of flood peak increment and the maximum accumulated flood volume, the westerly trough type has a long duration and small flood volume, and the low vortex shear type and the subtropical high southwest flow type have a short duration and large flood volume. Full article
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16 pages, 3148 KiB  
Article
The Implementation Effect of China’s River and Lake Chief System
by Tao Song, Yuntong Zhao, Min Wang and Zhe Cheng
Water 2024, 16(6), 815; https://doi.org/10.3390/w16060815 - 10 Mar 2024
Viewed by 809
Abstract
The river and lake chief system offers a valuable policy toolkit to mitigate the degradation of water ecology, thereby bolstering water resource management for sustainable water development in China. To evaluate the effects of implementation and improve policy, this study took Beijing as [...] Read more.
The river and lake chief system offers a valuable policy toolkit to mitigate the degradation of water ecology, thereby bolstering water resource management for sustainable water development in China. To evaluate the effects of implementation and improve policy, this study took Beijing as a typical case and conducted a quantitative assessment using multidimensional data. The findings suggest that while the river and lake chief system in Beijing is effective and has significantly contributed to the ecological management of rivers and lakes, there are also notable regional disparities and urban–rural divergences. In addition, human activities are the main sources of environmental pollution in rivers and lakes, which should be the focus of the river and lake chief system. The river and lake chief system needs to embed more public participation and cooperative governance. This research aids in better understanding China’s river and lake chief system for both researchers and practitioners, facilitating the advancement of the knowledge body of global water policy and governance. Full article
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18 pages, 12059 KiB  
Article
Hydrological Changes and Sediment Dynamics in the Inner Mongolia Section of the Yellow River: Implications for Reservoir Management
by Jingjing Xu, Ying Zhao, Yin Chen, Pengfei Du and Liqin Qu
Water 2024, 16(6), 810; https://doi.org/10.3390/w16060810 - 08 Mar 2024
Viewed by 664
Abstract
The Inner Mongolia section of the Yellow River is a primary alluvial segment of the main channel. The variations in water and sediment not only alter the cross-sectional morphology and flow capacity of the river but also impact the scheduling of upstream cascade [...] Read more.
The Inner Mongolia section of the Yellow River is a primary alluvial segment of the main channel. The variations in water and sediment not only alter the cross-sectional morphology and flow capacity of the river but also impact the scheduling of upstream cascade reservoirs. Based on runoff and sediment load data and topographic information from typical hydrological stations, the characteristics of runoff and sediment load variations and the evolutionary pattern of siltation in the Inner Mongolia River section were analyzed via trend analysis methods, Mann–Kendall test methods, the sediment load transport rate method, and the water level–flow relationship. The results showed that the water and sediment loads at the hydrological stations in the Inner Mongolia River section significantly changed from the 1960s to after 2000, with runoff decreasing by approximately 22% to 32% and the sediment load decreasing by approximately 65% to 73%. Sedimentation in the river section generally increased, and the average annual siltation amount reached 0.144 billion t. The joint utilization of the Longyangxia and Liujiaxia reservoirs in 1987 was the main reason for the rapid increase in siltation, and siltation in the Inner Mongolia River section was slightly reduced after 2005. In addition, the critical sediment load coefficients of the Bayangaole–Sanhuhekou and Sanhuhekou–Toudaoguai River sections were 0.0073 and 0.0051 kg·s/m6, respectively, from 1952 to 1968, and 0.0053 and 0.0037 kg·s/m6, respectively, from 1969 to 2020. This study could provide technical support for river flood control and reservoir water sediment regulation in Inner Mongolia. Full article
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19 pages, 8133 KiB  
Article
Groundwater Hydrochemistry and Recharge Process Impacted by Human Activities in an Oasis–Desert in Central Asia
by Yuan Yao, Chenwei Tu, Gaojia Hu, Yuhan Zhang, Hanyuan Cao, Wanrui Wang and Weihua Wang
Water 2024, 16(5), 763; https://doi.org/10.3390/w16050763 - 03 Mar 2024
Viewed by 837
Abstract
Intense anthropogenic activities in arid regions remarkably affect groundwater by causing phreatic decline and water environmental deterioration. A systematic understanding of groundwater hydrochemical evolution and recharge is critical to regional water, ecological and agricultural security in arid regions, but is not well known [...] Read more.
Intense anthropogenic activities in arid regions remarkably affect groundwater by causing phreatic decline and water environmental deterioration. A systematic understanding of groundwater hydrochemical evolution and recharge is critical to regional water, ecological and agricultural security in arid regions, but is not well known in arid oasis–deserts. This research identified groundwater recharge processes and assessed the impact of anthropogenic activities on groundwater hydrochemical evolution in a representative oasis–desert in Central Asia using stable isotopic indicators (δ2H and δ18O) and hydrochemical data. Results indicated that the normalized difference vegetation index (NDVI) and cultivated land area exhibited a significant increasing trend during 2000 to 2020. Stable water isotopes and the ionic composition of both groundwater and surface water exhibited obviously spatial heterogeneity and seasonal variation. Generally, the spatial distribution pattern of major dissolved ions for shallow groundwater was consistent and increased along the groundwater flow direction from midstream to downstream. Surface water and groundwater were both characterized by higher δ18O and total dissolved solids (TDS) in the non-flood season than those in the flood season. Shallow groundwater had a larger seasonal variation in δ18O and TDS than other water components. Groundwater level in monitored wells generally presented a decreasing trend from 2018 to 2021, accompanied by a decrease in phreatic water TDS and NDVI in the desert area. Gypsum dissolution and weathering of silicate and halite had an important role in forming groundwater hydrochemistry. Anthropogenic activities significantly affected groundwater hydrochemistry and recharge. Shallow groundwater received its primary recharge from surface water and lateral groundwater flow, constituting 73% and 27% of the total recharge, respectively. Agricultural activities and groundwater overexploitation were the main factors for variations in groundwater level and quality in the oasis area, and directly affected groundwater and natural vegetation in the desert area. The results would be helpful to deeply understand groundwater hydrochemical evolution and cycling, and beneficial for groundwater efficient utilization and desert ecosystem restoration in the arid areas. Full article
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19 pages, 6852 KiB  
Article
Spatial-Temporal Variations of Drought-Flood Abrupt Alternation Events in Southeast China
by Bowen Zhang, Ying Chen, Xingwei Chen, Lu Gao and Meibing Liu
Water 2024, 16(3), 498; https://doi.org/10.3390/w16030498 - 04 Feb 2024
Viewed by 857
Abstract
Under climate change, the frequency of drought-flood abrupt alternation (DFAA) events is increasing in Southeast China. However, there is limited research on the evolution characteristics of DFAA in this region. This study evaluated the effectiveness of the drought and flood indexes including SPI [...] Read more.
Under climate change, the frequency of drought-flood abrupt alternation (DFAA) events is increasing in Southeast China. However, there is limited research on the evolution characteristics of DFAA in this region. This study evaluated the effectiveness of the drought and flood indexes including SPI (Standardized Precipitation Index), SPEI (Standardized Precipitation Evapotranspiration Index), and SWAP (Standardized Weighted Average Precipitation Index) in identifying DFAA events under varying days of antecedent precipitation. Additionally, the evolution characteristics of DFAA events in Fujian Province from 1961 to 2021 were explored. The results indicate that (1) SPI-12d had the advantages of high effectiveness, optimal generalization accuracy, and strong generalization ability of identification results, and it can be used as the optimal identification index of DFAA events in Southeast China. (2) There was an overall increase in DFAA events at a rate of 1.8 events/10a. The frequency of DFAA events showed a gradual increase from the northwest to the southeast. (3) DTF events were characterized by moderate drought to flood, particularly in February, July, and August, while FTD events were characterized by light/moderate flood to drought, with more events occurring from June to October. (4) DTF event intensity increased in the northern and western regions from 1961 to 2021. For FTD events, the intensity notably increased in the western region from 1961 to 2001, while a significant increase occurred in all regions except the central region from 2001 to 2021. These findings emphasize the need for precautionary measures to address the increasing frequency and severity of DFAA events in Southeast China. Full article
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18 pages, 1461 KiB  
Article
Understanding Hydrologic, Human, and Climate System Feedback Loops: Results of a Participatory Modeling Workshop
by Jefferson K. Rajah, Ashley E. P. Atkins, Christine Tang, Kathelijne Bax, Brooke Wilkerson, Alexander G. Fernald and Saeed P. Langarudi
Water 2024, 16(3), 396; https://doi.org/10.3390/w16030396 - 24 Jan 2024
Viewed by 809
Abstract
Groundwater depletion threatens global freshwater resources, necessitating urgent water management and policies to meet current and future needs. However, existing data-intensive approaches to assessments do not fully account for the complex human, climate, and water interactions within transboundary groundwater systems. Here, we present [...] Read more.
Groundwater depletion threatens global freshwater resources, necessitating urgent water management and policies to meet current and future needs. However, existing data-intensive approaches to assessments do not fully account for the complex human, climate, and water interactions within transboundary groundwater systems. Here, we present the design of and findings from a pilot participatory modeling workshop aiming to advance understanding of the hydrologic–human–climate feedback loops underpinning groundwater systems. Using participatory modeling tools and methods from the system dynamics tradition, we captured the mental models of researchers from water, social, data, and systems sciences. A total of 54 feedback loops were identified, demonstrating the potential of this methodology to adequately capture the complexity of groundwater systems. Based on the workshop outcomes, as an illustrative example, we discuss the value of participatory system modeling as a conceptualization tool, bridging perspectives across disciplinary silos. We further discuss how outcomes may inform future research on existing knowledge gaps around groundwater issues, and in doing so, advance interdisciplinary, use-inspired research for water decision-making more broadly. Full article
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20 pages, 20921 KiB  
Article
Integrated Hydrological Modeling for Watershed Analysis, Flood Prediction, and Mitigation Using Meteorological and Morphometric Data, SCS-CN, HEC-HMS/RAS, and QGIS
by Heba El-Bagoury and Ahmed Gad
Water 2024, 16(2), 356; https://doi.org/10.3390/w16020356 - 21 Jan 2024
Cited by 1 | Viewed by 1661
Abstract
Flooding is a natural disaster with extensive impacts. Desert regions face altered flooding patterns owing to climate change, water scarcity, regulations, and rising water demands. This study assessed and predicted flash flood hazards by calculating discharge volume, peak flow, flood depth, and velocity [...] Read more.
Flooding is a natural disaster with extensive impacts. Desert regions face altered flooding patterns owing to climate change, water scarcity, regulations, and rising water demands. This study assessed and predicted flash flood hazards by calculating discharge volume, peak flow, flood depth, and velocity using the Hydrologic Engineering Centre-River Analysis System and Hydrologic Modelling System (HEC-HMS and HEC-RAS) software. We employed meteorological and morphological data analyses, incorporating the soil conservation service (SCS) curve number method for precipitation losses and the SCS-Hydrograph for runoff transformation. The model was applied to two drainage basins (An-Nawayah and Al-Rashrash) in southeastern Cairo, Egypt, which recently encountered several destructive floods. The applied model revealed that 25-, 50-, and 100-year storms produced runoff volumes of 2461.8 × 103, 4299.6 × 103, and 5204.5 × 103 m3 for An-Nawayah and 6212 × 103, 8129.4 × 103, and 10,330.6 × 103 m3 for Al-Rashrash, respectively. Flood risk levels, categorised as high (35.6%), extreme (21.9%), and medium (21.12%) were assessed in low- and very-low-hazard areas. The study highlighted that the areas closer to the Nile River mouth faced greater flood impacts from torrential rain. Our findings demonstrate the effectiveness of these methods in assessing and predicting flood risk. As a mitigation measure, this study recommends the construction of five 10 m high dams to create storage lakes. This integrated approach can be applied to flood risk assessment and mitigation in comparable regions. Full article
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18 pages, 4554 KiB  
Article
Appraisal of Daily Temperature and Rainfall Events in the Context of Global Warming in South Australia
by Federico Ferrelli, Melisa Pontrelli Albisetti, Andrea Soledad Brendel, Andrés Iván Casoni and Patrick Alan Hesp
Water 2024, 16(2), 351; https://doi.org/10.3390/w16020351 - 21 Jan 2024
Viewed by 1585
Abstract
In recent decades, there have been significant problems worldwide related to global warming and the intensification of extreme temperature and rainfall events. This research evaluated daily temperature and rainfall indices trends to identify whether warming signals have occurred in South Australia over the [...] Read more.
In recent decades, there have been significant problems worldwide related to global warming and the intensification of extreme temperature and rainfall events. This research evaluated daily temperature and rainfall indices trends to identify whether warming signals have occurred in South Australia over the past fifty years. Extreme cold, hot, and rainfall events were calculated using climatic data from 37 weather stations. A Mann–Kendall test was used for trend analysis with Sen’s estimator. As a result, we determined that for the 1970–2021 period, the maximum and minimum temperatures increased by 1.1 and 0.7 °C, respectively, while precipitation had a negative trend (−52.2 mm per period). Since statistical significance was found in analysing extreme cold and hot events, we find that warming signals have several impacts on South Australia. In the case of rainfall events, we identified a heterogeneous pattern characterised by a reduction in the annual amount and an increase in extreme rainfall events. The findings enable us to conclude that the area shows signs of global warming that could affect the intensity and magnitude of droughts. This information is essential for continuing with current management strategies to adapt and mitigate the effects of global warming in South Australia. Full article
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18 pages, 960 KiB  
Article
Assessing the Connection between Land Use Planning, Water Resources, and Global Climate Change
by Dimitrios Kalfas, Stavros Kalogiannidis, Olympia Papaevangelou and Fotios Chatzitheodoridis
Water 2024, 16(2), 333; https://doi.org/10.3390/w16020333 - 19 Jan 2024
Cited by 2 | Viewed by 1185
Abstract
The complex interplay between land use planning, water resource management, and the effects of global climate change continues to attract global attention. This study assessed the connection between land use planning, water resources, and global climate change. Data were collected using an online [...] Read more.
The complex interplay between land use planning, water resource management, and the effects of global climate change continues to attract global attention. This study assessed the connection between land use planning, water resources, and global climate change. Data were collected using an online questionnaire that was emailed to 320 professionals in the land and environmental sectors in Greece and Europe. The results showed a significant relationship between land use planning, water resources, and their policies with global climate change. It was also revealed that proper land use planning can guide the establishment of waste management systems that minimize methane emissions, and that land use planning influences agricultural practices, which, in turn, impact greenhouse gas emissions. It was also revealed that changes in precipitation patterns can lead to an increased frequency and severity of droughts, and that changes in water temperature and flow can lead to habitat loss. This study also confirmed that strong policy support helps in the conservation of land and water resources, and stakeholder engagement promotes a shared planning process, leading to commonly agreed-upon spatial measures. This study recommends that governments and policymakers should integrate climate change, land use, and water management policies to ensure a coherent and effective approach towards sustainable development. Full article
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19 pages, 3211 KiB  
Article
Phototactic Behavioral Responses of Mesozooplankton in the Barents Sea as an Indicator of Anthropogenic Impact
by Victor Dyomin, Yuri Morgalev, Sergey Morgalev, Alexandra Davydova, Oksana Kondratova, Tamara Morgaleva and Igor Polovtsev
Water 2023, 15(22), 3901; https://doi.org/10.3390/w15223901 - 08 Nov 2023
Viewed by 976
Abstract
The behavioral responses of autochthonous organisms have recently been used for a system to monitor the state of fresh and sea waters for bioindication. The advantage of using the behavioral responses of mesozooplankton is determined by the higher sensitivity of such responses compared [...] Read more.
The behavioral responses of autochthonous organisms have recently been used for a system to monitor the state of fresh and sea waters for bioindication. The advantage of using the behavioral responses of mesozooplankton is determined by the higher sensitivity of such responses compared with changes in the composition of biota or the death of organisms. Earlier, we developed and tested in laboratory conditions and in freshwater reservoirs a submersible digital holographic camera as part of a hydrobiological probe, which allows one to determine the dimensions, shape and recognition of plankters in situ, as well as define the concentration of plankters in the working volume and perform photostimulation with attractive radiation with different levels of illuminance. This paper presents the data obtained during the expedition to the Barents Sea. The variability with regard to the immersion depth of the phototropic response and the interspecific and intraspecific diversity was determined. It was shown that within the framework of natural variability in natural factors (temperature, salinity, hydrostatic pressure, oxygen content, illumination) there are no reliable changes in the indicator response, unlike changes in the concentration of plankton associated with tidal currents. The anthropogenic distortion of water quality was modeled by introducing a saturated salt solution dropwise. There were no significant changes in the intraspecific and interspecific diversity index during the external impact, and the rhythms of tidal changes in the concentration of plankters were suppressed. The fact of increased phototropic sensitivity in crustaceans with a size of less than 120 μm was found. It was established that the most essential marker of the alternating factor was the suppression of the phototropic response. The identified patterns of behavioral responses of autochthonous zooplankton make it possible to create a network of continuous control over the environmental health of water bodies subject to increased anthropogenic impact (oil production zones beyond the Arctic Circle, estuaries and deltas of rivers carrying industrial waste). Full article
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14 pages, 4690 KiB  
Article
Automatic Extraction Method of Aquaculture Sea Based on Improved SegNet Model
by Weiyi Xie, Yuan Ding, Xiaoping Rui, Yarong Zou and Yating Zhan
Water 2023, 15(20), 3610; https://doi.org/10.3390/w15203610 - 16 Oct 2023
Cited by 1 | Viewed by 1058
Abstract
Timely, accurate, and efficient extraction of aquaculture sea is important for the scientific and rational utilization of marine resources and protection of the marine environment. To improve the classification accuracy of remote sensing of aquaculture seas, this study proposes an automatic extraction method [...] Read more.
Timely, accurate, and efficient extraction of aquaculture sea is important for the scientific and rational utilization of marine resources and protection of the marine environment. To improve the classification accuracy of remote sensing of aquaculture seas, this study proposes an automatic extraction method for aquaculture seas based on the improved SegNet model. This method adds a pyramid convolution module and a convolutional block attention module based on the SegNet network model, which can effectively increase the utilization ability of features and capture more global image information. Taking the Gaofen-1D image as an example, the effectiveness of the improved method was proven through ablation experiments on the two modules. The prediction results of the proposed method were compared with those of the U-Net, SegNet, and DenseNet models, as well as with those of the traditional support vector machine and random forest methods. The results showed that the improved model has a stronger generalization ability and higher extraction accuracy. The overall accuracy, mean intersection over union, and F1 score of the three test areas were 94.86%, 87.23%, and 96.59%, respectively. The accuracy of the method is significantly higher than those of the other methods, which proves the effectiveness of the method for the extraction of aquaculture seas and provides new technical support for automatic extraction of such areas. Full article
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16 pages, 3995 KiB  
Article
Phototropic Behavioral Responses of Zooplankton in Lake Baikal In Situ and during the Anthropogenic Impact Modeling
by Victor Dyomin, Yuri Morgalev, Igor Polovtsev, Sergey Morgalev, Tamara Morgaleva, Alexandra Davydova and Oksana Kondratova
Water 2023, 15(16), 2957; https://doi.org/10.3390/w15162957 - 16 Aug 2023
Cited by 1 | Viewed by 752
Abstract
Earlier, we showed that the registration of the behavioral responses of autochthonous mesozooplankton communities in situ is a more dynamic methodological approach in the biological assessment of the environmental well-being of aquatic ecosystems, as well as an alternative method to generally accepted tests [...] Read more.
Earlier, we showed that the registration of the behavioral responses of autochthonous mesozooplankton communities in situ is a more dynamic methodological approach in the biological assessment of the environmental well-being of aquatic ecosystems, as well as an alternative method to generally accepted tests on mortality and immobilization. The change in behavioral responses, including phototropic responses, may occur at lower concentrations of pollutants, leading to the inhibition of the risk-avoidance response of predatory fish attack and, ultimately, to the change in zooplankton abundance and biodiversity. The biological significance of such changes is quite high since zooplankters form the basis of food chains. This work studies the possibility of biomonitoring the quality of fresh water in Lake Baikal according to the state of the autochthonous mesozooplankton community in summer and winter using a digital holographic camera developed and tested by us in laboratory conditions. This method makes it possible to determine the concentration of plankters in the controlled volume of the DHC and perform photostimulation with different levels of illuminance. The depth profilometry of the phototropic response was compared with the profilometry of plankton concentration, intraspecific diversity of crustaceans according to the Pielou index, and the results of catching using the Juday net in the natural environment of the lake and during the modeling of the anthropogenic impact (introduction of table salt solution into the local area close to the registration probe). The circadian rhythm parameters were determined by the spectral analysis of the long-term registration of the phototropic response dynamics. It was noted that the inhibition of the phototropic response was the most adequate marker of the exogenous impact and the appearance of an alternating factor among the studied indicators of the state of the plankton community, namely, intraspecific diversity, synchronism of circadian rhythms, and response to paired photostimulation. The revealed patterns of behavioral responses of autochthonous zooplankton in natural and artificially modified conditions will allow for the implementation of long-term continuous control over the environmental well-being of water areas, including the collection ponds of treatment facilities, cooling ponds of nuclear power plants, and other water areas in contact with potentially hazardous facilities. The comparison of the identified patterns with the behavioral responses of euryhaline mesozooplankton will expand this method to assess the well-being of salt-water and marine reservoirs under the anthropogenic impact and will make it possible to create a continuous monitoring system. Full article
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18 pages, 10410 KiB  
Article
Projections of Global Drought and Their Climate Drivers Using CMIP6 Global Climate Models
by Feng Xu, Virgílio A. Bento, Yanping Qu and Qianfeng Wang
Water 2023, 15(12), 2272; https://doi.org/10.3390/w15122272 - 17 Jun 2023
Cited by 3 | Viewed by 2333
Abstract
Due to the complex coupling between drought and climatic factors, the future drought conditions that might occur under climate change is still unclear. In this research, we used the daily SPEI algorithm to project global drought conditions during 2016–2100 based on the data [...] Read more.
Due to the complex coupling between drought and climatic factors, the future drought conditions that might occur under climate change is still unclear. In this research, we used the daily SPEI algorithm to project global drought conditions during 2016–2100 based on the data from phase 6 of the Coupled Model Intercomparison Project (CMIP6). We also employed partial correlation analysis to explore the influence of climate factors on drought. Our analyses show the following: (1) Drought conditions projected by CMIP6 under different models are similar; however, they can vary widely across regions. (2) According to the MK trend test, drought conditions in most regions around the world are expected to become increasingly severe in the future, and this trend is significant. (3) Based on the results of the partial correlation analysis results, it is understood that drought events in most regions worldwide are primarily driven by precipitation. This study contributes to the discussion of projecting future drought conditions and expands the application by utilizing the state−of−the−art CMIP6 climate models and scenarios.Highlight Full article
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17 pages, 10266 KiB  
Article
Hydro-Meteorological Characteristics of the 1973 Catastrophic Flood in the Mahi Basin, India
by Uttam Pawar, Pramodkumar Hire, Ranjan Sarukkalige and Upaka Rathnayake
Water 2023, 15(9), 1648; https://doi.org/10.3390/w15091648 - 23 Apr 2023
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Abstract
The September 1973 flood in the Mahi Basin was one of the most catastrophic and widespread in the 20th century. However, the hydro-meteorological characteristics of the 1973 flood were not studied. Therefore, an attempt has been made to analyze the meteorological and hydrological [...] Read more.
The September 1973 flood in the Mahi Basin was one of the most catastrophic and widespread in the 20th century. However, the hydro-meteorological characteristics of the 1973 flood were not studied. Therefore, an attempt has been made to analyze the meteorological and hydrological processes that led to the 1973 flood. Accordingly, daily rainfall data, river discharge, and cross-section data were obtained for the analysis. The 1973 flood was associated with very heavy rainfall resulting from two successive low-pressure systems (LPS) from 26 to 31 August 1973 and 2 to 5 September 1973. The rainfall variability in the Mahi Basin was 24% (annual) and 25% (monsoon) in 1973. The analysis showed that out of 69 rainfall stations, 13 stations received 100% rainfall in the monsoon season in 1973. Under the influence of the second LPS (7 and 9 September 1973), 21 rain gauge stations recorded very heavy rainfall (124.5–244.4 mm) on 8 September. As a result, the maximum discharge of the Mahi River (40,663 m3/s) was observed at Wanakbori on 9 September. The flood hydrograph denoted two flood peaks of 28,125 m3/s and 33,097 m3/s magnitudes resulting from LPS at Kadana. A newly constructed bridge (in 1972) on the Mahi River at the Kailashpuri village washed out due to a large discharge of 21,553 m3/s magnitude on 7 September 1973. The hydro-meteorological analysis of the 1973 flood specified the significance of the LPS in a flash flood disaster in the Mahi Basin. This study will benefit hydrologists and civil engineers creating design floods for the construction of the hydraulic structures in the Mahi Basin, and will help to avoid any future catastrophic floods. Full article
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