Interactions between diurnal winds and floodplain mosaics control the insect boundary layer in a river corridor

Insect flight along river corridors is a fundamental process that facilitates sustainable succession and diversity of aquatic and terrestrial insect communities in highly dynamic fluvial environments. This study examines variations in the thickness of the insect boundary layer (i.e., the pre-surface atmosphere layer in which air velocity does not exceed the sustained speed of flying insects) caused by interactions between diurnal winds and the heterogenous habitat mosaics in the floodplain of a braided river. Based on advective–diffusive theory, we develop and test a semi-empirical model that relates vertical flux of flying insects to vertical profiles of diurnal winds. Our model suggests that, in the logarithmic layer of wind, the density of insect fluxes decreases exponentially with the altitude due to the strong physical forcing. Inside the insect boundary layer, the insect fluxes can increase with the altitude while the winds speed remains nearly constant. We suggest a hypothesis that there is a close correspondence between the height of discontinuity points in the insect profiles (e.g. points with abrupt changes of the insect flux) and the displacement heights of the wind profiles (e.g. points above which the wind profile is logarithmic). Vertical profiles were sampled during three time-intervals at three different habitat locations in the river corridor: a bare gravel bar, a gravel bar with shrubs, and an island with trees and shrubs. Insects and wind speed were sampled and measured simultaneously over each location at 1.5-m intervals up to approximately 17 m elevation. The results support our working hypothesis on close correspondence between discontinuity and displacement points. The thickness of the insect boundary layer matches the height of the discontinuity points and was about 5 m above the bare gravel bar and the gravel bar with shrubs. Above the island, the structure of the insect boundary layer was more complex and consisted of two discontinuity points, one at the mean height of the trees’ crowns (ca. 15 m), and a second, internal boundary layer at the top of the shrubs (ca. 5 m). Our findings improve the understanding of how vegetation can influence longitudinal and lateral dispersal patterns of flying insects in river corridors and floodplain systems. It also highlights the importance of preserving terrestrial habitat diversity in river floodplains as an important driver of both biotic and abiotic (i.e., morphology and airscape) heterogeneity

Interactions between diurnal winds and floodplain mosaics control the insect boundary layer in a river corridor

Insect flight along river corridors is a fundamental process that facilitates sustainable succession and diversity of aquatic and terrestrial insect communities in highly dynamic fluvial environments. This study examines variations in the thickness of the insect boundary layer (i.e., the pre-surface atmosphere layer in which air velocity does not exceed the sustained speed of flying insects) caused by interactions between diurnal winds and the heterogenous habitat mosaics in the floodplain of a braided river. Based on advective–diffusive theory, we develop and test a semi-empirical model that relates vertical flux of flying insects to vertical profiles of diurnal winds. Our model suggests that, in the logarithmic layer of wind, the density of insect fluxes decreases exponentially with the altitude due to the strong physical forcing. Inside the insect boundary layer, the insect fluxes can increase with the altitude while the winds speed remains nearly constant. We suggest a hypothesis that there is a close correspondence between the height of discontinuity points in the insect profiles (e.g. points with abrupt changes of the insect flux) and the displacement heights of the wind profiles (e.g. points above which the wind profile is logarithmic). Vertical profiles were sampled during three time-intervals at three different habitat locations in the river corridor: a bare gravel bar, a gravel bar with shrubs, and an island with trees and shrubs. Insects and wind speed were sampled and measured simultaneously over each location at 1.5-m intervals up to approximately 17 m elevation. The results support our working hypothesis on close correspondence between discontinuity and displacement points. The thickness of the insect boundary layer matches the height of the discontinuity points and was about 5 m above the bare gravel bar and the gravel bar with shrubs. Above the island, the structure of the insect boundary layer was more complex and consisted of two discontinuity points, one at the mean height of the trees’ crowns (ca. 15 m), and a second, internal boundary layer at the top of the shrubs (ca. 5 m). Our findings improve the understanding of how vegetation can influence longitudinal and lateral dispersal patterns of flying insects in river corridors and floodplain systems. It also highlights the importance of preserving terrestrial habitat diversity in river floodplains as an important driver of both biotic and abiotic (i.e., morphology and airscape) heterogeneit

Impact of the Russia–Ukraine armed conflict on water resources and water infrastructure

The armed conflict between Ukraine and Russia that began in late February 2022 has far-reaching environmental consequences, especially regarding water resources and management. Here we analysed the multifaceted impacts of the military actions on freshwater resources and water infrastructure during the first three months of the conflict. We identified the nature of the impacts, the kind of pressures imposed on the water sector and the negative consequences for the availability and quality of freshwater resources for the civilian population. Our results showed that many water infrastructures such as dams at reservoirs, water supply and treatment systems and subsurface mines have been impacted or are at risk from military actions. Continuation of the conflict will have multiple negative sustainability implications not only in Ukraine but also on a global scale, hampering achievement of clean water and sanitation, conservation and sustainable use of water resources, and energy and food security

A Conceptual Framework for Understanding the Biogeochemistry of Dry Riverbeds Through the Lens of Soil Science

Intermittent rivers and ephemeral streams (IRES) encompass fluvial ecosystems that eventually stop flowing and run dry at some point in space and time. During the dry phase, channels of IRES consist mainly of dry riverbeds (DRBs), prevalent yet widely unexplored ecotones between dry and wet phases that can strongly influence the biogeochemistry of fluvial networks. DRBs are often overlooked because they do not strictly belong to either domain of soil or freshwater science. Due to this dual character of DRBs, we suggest that concepts and knowledge from soil science can be used to expand the understanding of IRES biogeochemistry. Based on this idea, we propose that DRBs can be conceptually understood as early stage soils exhibiting many similarities with soils through two main forces: i) time since last sediment transport event, and ii) the development status of stabilizing structures (e.g. soil crusts and/or vascular plants). Our analysis suggests that while DRBs and soils may differ in master physical attributes (e.g. soil horizons vs fluvial sedimentary facies), they become rapidly comparable in terms of microbial communities and biogeochemical processes. We further propose that drivers of DRBs biogeochemistry are similar to those of soils and, hence, concepts and methods used in soil science are transferable to DRBs research. Finally, our paper presents future research directions to advance the knowledge of DRBs and to understand their role in the biogeochemistry of intermittent fluvial networks

Simulating rewetting events in intermittent rivers and ephemeral streams: a global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56‐98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached organic matter. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events

Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the ex‐ tent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (precon‐ ditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experi‐ mentally simulated, under standard laboratory conditions, rewetting of leaves, river‐ bed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative character‐ istics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dis‐ solved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contrib‐ uted most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental vari‐ ables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached sub‐ stances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying event

Vernachlässigte Aspekte in der Veränderung von Flussabfluss und Stoffdynamik: eine globale Perspektive

Table of contents List of figures 7 Supplementary figures 7 List of tables 8 Supplementary tables 8 Summary 9 Zusammenfassung 12 Thesis outline 15 1\. General introduction 17 1.1. Unique role of rivers on Earth 17 1.2. Global challenges that rivers are facing nowadays 17 1.3 Thesis structure 22 References 25 2\. Floating organic matter: A neglected component affecting the ecological and geomorphic integrity of rivers 28 2.1. Abstract 29 2.2. Introduction 29 2.3. Composition and dynamics of FOM in river ecosystems 32 2.4. The functional role of FOM in rivers 36 2.4.1. FOM as a geomorphological agent 36 2.4.2. FOM: a key dispersal vector for terrestrial animals 38 2.4.3. Habitat function 40 2.4.4. FOM: a resource along river corridors 41 2.5. Management of FOM 44 2.6. Conclusions and research gaps 46 Acknowledgments 47 Glossary 48 References 49 3\. Pulsed release of nutrients and organic matter during simulated rewetting events in intermittent rivers and ephemeral streams: a global analysis 63 3.1. Abstract 64 3.2. Introduction 64 3.3. Material and methods 66 3.3.1. Sampling sites, substrate collection and environmental variables 66 3.3.2. Samples preparation and laboratory procedure 67 3.3.3. Analytical measurements 69 3.3.4. Size exclusion chromatography 70 3.3.5. Spectroscopic analysis 70 3.3.6. Calculation of the total areal flux of nutrients and OM 71 3.3.7. Statistical analysis 71 3.4. Results 75 3.4.1. Leaching rates of organic matter and nutrient species 75 3.4.2. Impact of environmental variables and substrate characteristics 81 3.4.3. Areal fluxes of nutrients and organic matter from the river beds 83 3.5 Discussion 86 3.5.1. Leaching of organic matter and nutrients 86 3.5.2. Drivers of leachates characteristics 88 3.5.3. Areal fluxes from dry river beds 89 3.6. Conclusions 90 References 91 4\. Global water transfer megaprojects planned or under construction 96 4.1. Abstract 97 4.2. Introduction 97 4.3. Methods 99 4.3.1. Water transfer megaproject definition 99 4.3.2. Data collection sources and criteria 99 4.4. Results 100 4.4.1. Distribution and purposes of existing and future WTMP 100 4.4.2. Water transfer volumes and distances of existing and future WTMP 100 4.4.3. Estimated costs of future WTMP 103 4.5. Discussion 103 4.6. Conclusions 106 Acknowledgments 107 References 108 5\. General discussion 111 5.1. Key research findings 111 5.2. Implications for ecosystem processes and management 113 5.2.1. Management of FOM accumulations at dams 113 5.2.2. Incorporation of intermittent rivers in models of nutrient load 113 5.2.3. Assessment of water transfer megaprojects and their inclusion in global hydrological models 114 5.3. Suggestions for further research 115 5.3.1. Contribution of FOM to species dispersal 115 5.3.2. Refining the role of intermittent rivers in global biogeochemical cycles 115 5.3.3. The role of water transfer megaprojects in altering river continuum 116 5.4. Conclusions 117 References 118 Appendix A 120 Appendix B 128 Appendix C 135 Appendix D 145 Statement of academic integrity 157 Curriculum Vitae 158 Acknowledgments 161The present thesis focuses on three currently understudied alterations in flow and material dynamics within river networks, namely (i) on the dynamics of floating organic matter (FOM) and its modification in dammed rivers, (ii) on river intermittency and its effects on nutrient and organic matter (OM) dynamics, and (iii) on major future water transfer megaprojects (WTMP). Construction and operation of dams cause modifications in water flow and material fluxes in rivers, such as of FOM. River damming, climate change and water extraction for human needs also lead to a rapid expansion in number and extent of intermittent rivers worldwide, with major biogeochemical consequences on both regional and global scales. Increased intermittency of river networks in turn forces people to implement engineering solutions, such as WTMP, which help to supply water to places of demand. WTMP introduce artificial links among freshwater bodies modifying the hydrological balance. Impacts of abovementioned activities on freshwaters have been assessed in single case studies. Current thesis aimed to integrate the existing knowledge on these impacts and allow a generalization of their globally applicable meaning for ecosystems. The role of FOM in rivers as a geomorphological agent, a resource, a dispersal vector and a biogeochemical component was investigated based on an extensive literature review. Collected information allowed for conceptualizing its natural cycle and dynamics, applicable to a wide range of rivers. Data on FOM accumulations at 31 dams located within catchments of 13 rivers from North America and Europe showed that damming leads to FOM entrapment and modifies its natural cycling. The results of a spatial analysis considering environmental properties revealed that catchment characteristics can explain around 57% in the variation of trapped FOM amounts. Effect of rewetting events on the release of nutrients and OM from bed sediments and course particulate organic materials (CPOM, leaves and biofilms) accumulated in IRES was studied in laboratory experiments using samples from 205 rivers. Results showed that the release of nutrients and OM is substrate and climate specific. On a global scale, dissolved organic carbon, phenolics, and nitrate dominated the flux from riverbeds upon rewetting. The highest amount of nutrients and OM per gram of substrate was released from leaves, but sediments were the main contributors to the total areal flux from rivers due to their higher mass within the riverbeds. Leachates with the highest quality in terms of potential influence on ecosystem processes (low aromaticity, high content of biopolymers) were released from biofilms. A set of nine environmental variables used to explain leachate concentration across climate zones performed best for sediments in the continental and tropical zones. The inventory of the future WTMP compiled in this thesis is based on various peer- and non peer-reviewed literature sources and revealed 60 WTMP planned or under construction. The results showed that North America, Asia and Africa will be the most affected by future WTMP having the highest densities of projects and the largest water transfer distances and volumes. If all projects were completed by 2050, the total water transfer distances would reach 77,063 km transferring more than 1,249 km3 per year. Overall, the results of the current thesis showed the importance of the studied alterations in river flow and organic matter dynamic on the global scale. Studied alterations therefore should be considered in global hydrological and biogeochemical models, as well as in sustainable management of rivers.Die vorliegende Arbeit behandelt drei wissenschaftlich bisher vernachlässigte Veränderungen in Fließ- und Stoffdynamik innerhalb von Flussnetzen, nämlich (i) die Dynamik von schwimmenden organischen Stoffen (FOM) und deren Änderung in gestauten Flüssen, (ii) die Flussperiodizität und deren Effekt auf die Dynamik von Nährstoffen und organischer Materie (OM) und (iii) die großen zukünftigen Wassertransferprojekte (WTMP). Der Bau und der Betrieb von Staudämmen beeinflussen den Wasser- und Stofftransport, zum Beispiel FOM, in Flüssen. Das Stauen von Flüssen, der Klimawandel und die Wasserextraktion zum menschlichen Nutzen führen weltweit zu einer raschen Ausbreitung temporärer Flüsse in Anzahl und Fläche. Das hat beträchtliche biogeochemische Konsequenzen im regionalen und globalen Maßstab. Zunehmende Periodizität von Flussnetzen zwingt Menschen dazu, Baumaßnahmen, wie WTMP, vorzunehmen um die Wasserversorgung zu sichern. WTMP verursachen künstliche Verbindungen zwischen Süßgewässern, die das hydrologische Gleichgewicht verschieben. Die Auswirkungen der oben genannten Faktoren auf Süßgewässer wurden in einzelnen Fallstudien untersucht. Das Ziel dieser Doktorarbeit ist das existierende Wissen über diese Aspekte zu integrieren und die Generalisierung von deren Folgen zu ermöglichen. Die Rolle von FOM in Flüssen als geomorphologisches Element, als Ressource, als Ausbreitungsvektor und als biogeochemischer Bestandteil wurde mit Hilfe einer ausführlichen Literaturrecherche untersucht. Daten über die FOM-Anhäufung an 31 Dämmen innerhalb der Einzugsgebiete von 13 Flüssen in Nord-Amerika und Europa zeigten, dass Stauung von Flüssen zur Akkumulation von FOM führt und deren natürlichen Kreislauf beeinflusst. Das Ergebnis einer räumlichen Analyse, die die Umwelteigenschaften miteinbezieht, zeigte, dass die Eigenschaften des Einzugsgebietes 57% der Mengenunterschiede an akkumuliertem FOM erklären können. Der Einfluss von Wiedervernässungsereignissen auf die Freisetzung von Nährstoffen und OM aus Flussbettsedimenten und grober partikulärer organischer Substanz (CPOM, Blätter und Biofilme), die sich in IRES angehäuft hat, wurde in Laborexperimenten anhand von Proben aus 205 Flüssen untersucht. Es zeigte sich, dass die Eigenschaften von freigesetzten Substanzen von Klimazone und Substrat abhängig sind. Im globalen Maßstab dominieren gelöster organischer Kohlenstoff, Phenole und Nitrat die Stoffflüsse während der Wiedervernässungsereignisse. Die höchste Menge an Nährstoffen und OM pro Gram Substrat wurde von Blättern freigesetzt, wobei Sedimente wegen ihrer höheren Masse den größten Beitrag zur räumlichen Durchflussmenge ausmacht. Die freigesetzten Substanzen mit der höchsten Qualität im Sinne von potenziellem Einfluss auf die Prozesse in Ökosystemen (niedrige Aromatizität, hoher Anteil an Biopolymeren) wurden von Biofilmen freigesetzt. Der Effekt von Umweltvariablen auf Nährstoffkonzentrationen und die Qualität von OM konnte besser für Sedimente als für andere Substrate vorhergesagt werden mit dem größten Anteil der Varianzaufklärung in den kontinentalen und tropischen Zonen. Die globale Zusammenstellung zukünftiger WTMP, die in dieser Doktorarbeit gesammelt wurde, gründet sich auf Daten aus verschiedenen Literaturquellen, die von Experten begutachtet wurden. Insgesamt wurden 60 WTMP, die in Planung oder im Bau sind, identifiziert. Die Ergebnisse zeigten, dass Nordamerika, Asien und Afrika am meisten von den zukünftigen WTMP betroffen sind, weil sie die höchste Dichte an Projekten und die längsten Strecken und größten Volumina im Wassertransfer haben. Wenn alle Projekte bis 2050 fertiggestellt würden, würde die gesamte Wassertransferstrecke 77,063 km betragen und ein Volumen von mehr als 1,249 km3 pro Jahr umgeleitet werden. Insgesamt zeigen die Ergebnisse die Bedeutung der Veränderung von Flussabfluss und Stoffdynamik auf globaler Ebene. Die untersuchten Veränderungen müssen deshalb sowohl in der globalen hydrologischen und biogeochemischen Modellierung als auch im nachhaltigen Management von Flüssen berücksichtigt werden

Neglected aspects in the alteration of river flow and riverine organic matter dynamics: a global perspective

In the current era of the Anthropocene, human activities are powerful forces that affect the geosphere, atmosphere, and biosphere – globally, fundamentally, and in most cases irreversibly. In freshwaters, land use change, chemical pollution, decline in biodiversity, spread of invasive species, climate change, and shifts in the hydrological regime are among the key drivers of changes. In the 21st century, major water engineering projects such as large dams and water diversion schemes will fundamentally alter the natural hydrological regime of entire landscapes and even continents. At the same time, the hydrological regime is the governing variable for biodiversity, ecosystem functions and services in river networks. Indeed, there will be an increasing conflict between managing water as a resource for human use and waters as highly valuable ecosystems. Therefore, research needs to unravel the challenges that the freshwaters are facing, understand their potential drivers and impacts, and develop sustainable management practices – for the benefit of humans and ecosystems alike. The present thesis focuses on three currently understudied alterations in flow and material dynamics within river networks, namely (i) on the dynamics of floating organic matter (FOM) and its modification in dammed rivers, (ii) on river intermittency and its effects on nutrient and organic matter (OM) dynamics, and (iii) on major future water transfer schemes. Massive construction and operation of dams cause modification of water flow and material fluxes in rivers, such as of FOM. FOM serves as an essential component of river integrity, but a comprehensive understanding of its dynamics is still lacking. River damming, climate change and water extraction for human needs lead to a rapid expansion in number and extent of intermittent rivers worldwide, with major biogeochemical consequences on both regional and global scales. Increased intermittency of river networks also forces people to implement engineering solutions, such as water transfer schemes, which help to supply water to places of demand. Water transfer projects introduce artificial links among freshwater bodies modifying the hydrological balance. Impacts of abovementioned activities on freshwaters have been assessed in single case studies. However, the current knowledge does not allow a generalization of their globally applicable meaning for ecosystems. Furthermore, mostly neglected aspects of these alterations, such as the potential consequences of FOM extraction from rivers, the biogeochemical role of intermittent rivers upon rewetting, and the current scale of water transfers require better understanding before bold conclusions could be made. By combining research methods such as extensive literature reviews, laboratory experiments and quantitative analyses including spatial analyses with Geographic Information Systems, I investigated (1) the natural cycle, functions, and amounts of FOM in rivers fragmented by dams, (2) effects of rewetting events on the pulsed release of nutrients and OM in intermittent rivers and ephemeral streams (IRES), and (3) the potential extent of water transfer megaprojects (WTMP) that are currently under construction or in the planning phase and their role in modifying the global freshwater landscape. In all three cases, I provide a global perspective. The role of FOM in rivers as a geomorphological agent, a resource, a dispersal vector and a biogeochemical component was investigated based on an extensive literature review. Collected information allowed for conceptualizing its natural cycle and dynamics, applicable to a wide range of rivers. Data on FOM accumulations at 31 dams located within catchments of 13 rivers showed that damming leads to FOM entrapment (partly or completely) and modifies its natural cycling. The results of a spatial analysis considering environmental properties revealed that catchment characteristics can explain around 57% in the variation of amounts of trapped FOM. Effects of rewetting events on the release of nutrients and OM from bed sediments and course particulate organic materials (CPOM) accumulated in IRES was studied in laboratory experiments. Using a large set of samples collected from 205 rivers, located in 27 countries and distributed across five major climate zones, I determined the concentrations and qualitative characteristics of nutrients and OM released from sediments and CPOM. I also assessed how these characteristics can be predicted based on environmental variables within sampled IRES. In addition, I calculated area-specific fluxes of nutrients and OM from dry river beds. I found that the characteristics of released substances are climate specific. In the Continental zone I found the highest concentrations of released nutrients, but the lowest quality of OM in terms of its potential bioavailability. In contrast, in the Arid zone the concentrations of released nutrients were the lowest, but the quality of OM the highest. The effect of environmental variables on the concentrations of nutrients and the quality of OM was better predicted for sediments than for other substrates with the highest share of explained variance in the Continental and Tropical zones. On the global scale, dissolved organic carbon, phenolics, and nitrate dominate fluxes released during rewetting events. Overall, this study emphasized that on the global scale rewetting events in IRES represent biogeochemical “hot moments”, but characteristics of released nutrients and OM differ greatly among climate zones. The present thesis fills also a major knowledge gap on the global distribution of large water transfer schemes (referred to as “megaprojects”) that are actually planned or under construction. To provide an inventory of WTMP, I collected data from various literature sources, ranging from published academic studies, the official web-sites of water transfer projects, environmental impact assessments, reports of non-governmental organizations, and information available in on-line newspapers. In total, 60 WTMP were identified. Information on spatial location, distances and volumes of water transfer, costs, and purposes of WTMP was collected and compared with those of existing schemes. The results showed that North America, Asia and Africa will be the most affected by future WTMP having the highest densities of projects and the largest water transfer distances and volumes. If all projects were completed by 2050, the total water transfer distances would reach 77,063 km transferring more than 1,249 km3 per year, which corresponds to about 20 times the annual flow of the river Rhine. The outcomes of the thesis provide major implications for environmental management. Natural FOM is an important component for sustaining the ecological and geomorphic integrity of rivers and, therefore, should be managed appropriately. Intermittent rivers must be considered in models quantifying nutrient and OM fluxes in river networks. First flush events in particular release huge amounts of nutrients and OM, which may cause dramatic metabolic effects on downstream receiving waters. Finally, the future WTMP alter the hydrological balance of entire river basins and continents. They require multiple assessments before construction and careful management practices for sustainable operation in order to consider both freshwater as a resource as well as freshwaters as pivotal ecosystems

Дослідження впливу евтрофікації на вторинне забруднення Бузького лиману важкими металами

On the research basis and monitoring data the eutrophication impact on repeated pollution of Bug estuary with heavy metals has been examined. Correlation dependences between eutrophication and variation of heavy metals content have been determined. On the basis of received data the recommendations for preventing negative impact of pollution processes on surface water objects in future have been developed.На основании собственных исследований и данных постов мониторинга изучено влияние эвтрофикации на вторичное загрязнение Бугского лимана тяжелыми металлами. Выявлены корреляционные зависимости между проявлениями явления эвтрофикации и колебаниями содержания тяжелых металлов. Исследовательно влияние данных явлений на состояние гидробионтов. На основании полученных результатов предложены механизм и способы преодоления негативного влияния изучаемых процессов загрязнения на состояние поверхностных водных объектов. На підставі власних досліджень та даних постів моніторингу вивчено вплив евтрофікації на вторинне забруднення Бузького лиману важкими металами. Виявлено кореляційні залежності між проявами явища евтрофікації та коливанням вмісту важких металів. Досліджено вплив даних явищ на стан гідробіонтів. На підставі отриманих результатів запропоновано механізм та способи подолання негативного впливу досліджуваних процесів забруднення на стан поверхневих водних об’єктів

Оцінка ризику потрапляння інвазивних і патогенних видів у водну екосистему Дніпро-Бузького лиману шляхом перенесення судновими баластними водами

The data received due to the control of the water ballast of vessels which touched at the Sea Commercial Port of Mykolayiv since April 2001 till May 2005 is analyzed and systematized. The possibility of getting into the water area of the port and survival there  invasive and pathogenic species, the contribution of different geographic regions of the World Ocean as the donors of the species, accidentally brought, is analyzed. Проанализированы и систематизированы данные по проведению контроля водного балласта судов, которые в период с апреля 2001 по май 2005 г . заходили в Николаевский морской торговый порт. Изучена возможность попадания и выживания в акватории порта инвазивных и патогенных видов, проанализирован вклад различных географических районов Мирового океана как доноров случайно завезенных видов.Проаналізовано та систематизовано дані щодо проведення контролю водного баласту суден, які в період з квітня 2001 по травень 2005 р., а також в останні роки заходили до Миколаївського морського торговельного порту. Досліджено можливість потрапляння і виживання в акваторії порту інвазивних і патогенних видів, проаналізовано внесок різноманітних географічних районів Світового океану як донорів випадково завезених видів