Revitalization of Small Watercourse Jitka Chromíková; Veronika Rogozná; Tomáš Dvorský
Engineering proceedings,
12/2023, Letnik:
57, Številka:
1
Journal Article
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The paper deals with a proposal for a small-watercourse revitalization measure, which is currently regulated by a post-local treatment. The sections of the watercourse are relatively straight and ...direct. The current shape of the stream does not retain water in the landscape. Any surface water in the watercourse is quickly transferred to the receiving watercourse, which is the important Hvozdnice watercourse. The practical part includes the design of revitalization measures, a new longitudinal profile, and sections. The watercourse is loosened by curves and the total length of the watercourse has been extended by 161.56 m. The route includes a wetland, four pools, and two pond wedges. An economic estimate of the proposed measure was made.
River networks are hierarchical dendritic habitats embedded within the terrestrial landscape, with varying connectivity between sites depending on their positions along the network. This physical ...organisation influences the dispersal of organisms, which ultimately affects metacommunity dynamics and biodiversity patterns.
We provide a conceptual synthesis of the role of river networks in structuring metacommunities in relation to dispersal processes in riverine ecosystems. We explore where the river network best explains observed metacommunity structure compared to other measurements of physical connectivity. We mostly focus on invertebrates, but also consider other taxonomic groups, including microbes, fishes, plants, and amphibians.
Synthesising studies that compared multiple spatial distance metrics, we found that the importance of the river network itself in explaining metacommunity patterns depended on a variety of factors, including dispersal mode (aquatic versus aerial versus terrestrial) and landscape type (arid versus mesic), as well as location‐specific factors, such as network connectivity, land use, topographic heterogeneity, and biotic interactions. The river network appears to be less important for strong aerial dispersers and insects in arid systems than for other groups and biomes, but there is considerable variability. Borrowing from other literature, particularly landscape genetics, we developed a conceptual model that predicts that the explanatory power of the river network peaks in mesic systems for obligate aquatic dispersers.
We propose directions of future avenues of research, including the use of manipulative field and laboratory experiments that test metacommunity theory in river networks. While field and laboratory experiments have their own benefits and drawbacks (e.g. reality, control, cost), both are powerful approaches for understanding the mechanisms structuring metacommunities, by teasing apart dispersal and niche‐related factors.
Finally, improving our knowledge of dispersal in river networks will benefit from expanding the breadth of cost‐distance modelling to better infer dispersal from observational data; an improved understanding of life‐history strategies rather than relying on independent traits; exploring individual‐level variation in dispersal through detailed genetic studies; detailed studies on fine‐scale environmental (e.g. daily hydrology) and organismal spatiotemporal variability; and synthesising comparative, experimental, and theoretical work. Expanding in these areas will help to push the current state of the science from a largely pattern‐detection mode into a new phase of more mechanistically driven research.
A novel methodology for the optimal placement of sensors in watercourses is presented. The methodology aimed at finding the optimal locations for the placement of sensors to maximize the amount of ...information to monitor flow and velocity in watercourses. The methodology is based on the maximization of the Gram determinant of the sensor responses at each possible location or a combination of locations. Two illustrative examples are presented wherein locations for one- and two-sensor cases for the velocity and flow monitoring of the Venero Claro River Basin, Spain, are selected. The kinematic wave method was used to evaluate the sensor response at every possible location. The results confirm the suitability of this methodology for finding the optimal locations for sensors to monitor flow or velocity in watercourses.
The temporal variation of the microplastic concentration was studied in the Langueyú stream, which is located in the department of Tandil, in the southeast of the Buenos Aires province in Argentina. ...This stream receives discharge from the wastewater treatment plants from a medium-sized city. A quantitative analysis of the microplastic concentration was carried out in different samplings, corresponding to different seasons. The study focused on the most contaminated point, located after the discharge of effluents from plants. Higher concentrations of MPs were found in winter (dry season), having approximately 6 times the concentrations found in summer and autumn (wet seasons). However, these differences would not be a direct consequence of the amount precipitation, but rather would be associated with a seasonal variation of human activities, mainly with respect to the type of clothing used in the cold season. The microfibers correspond to around 60-90% of microplastics found. The discharge from the plants causes changes in the parameters of the stream water, such as high electrical conductivity values, and also provide metallic contaminants such as Ca, Zn, and in smaller amounts Pb, Fe, Ni and Cu, which were found adhered to the microplastics and remain in the stream water in high quantities 3 km after the study point. The microplastic concentration presents a linear empirical correlation with the conductivity, and it was found that conductivity measurements would serve as an indicator of the microplastic concentration in the system under study.
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•Streambed temperatures monitored for 22 months in an international watercourse.•Six methods for deriving seepage flux from temperature time series are benchmarked.•Hydraulic gradient ...data are utilized to evaluate the consistency of each method.
The importance of the interaction between groundwater and surface water is increasingly being recognized for both understanding and managing water systems. Many efforts have been made to characterize and quantify groundwater–surface water exchange. In particular, temperature–based methods have quickly established themselves given their monetary and practical advantages. In the last 15 years, several methods for interpreting passive temperature time series measured in the streambed have been developed. Still, the benchmarking of these methods has only been carried out in specific and distinct hydrological conditions.
This article aims to fill this research gap by benchmarking the performance of six commonly used methods for deriving seepage fluxes using a two-year-long temperature time series covering various meteorological and thermal conditions. This work compares three analytical methods that calculate seepage flux using the amplitude and/or phase of the temperature signals, and three numerical methods that use different schemes to inversely solve the one–dimensional heat transport equation in the streambed. The temperature measurements were made in the context of an international dispute between Chile and Bolivia over the status and use of the waters of the Silala River, Northern Chile. Flux estimations are tested against Darcy’s flux derived from measured hydraulic gradient and hydraulic conductivity.
Flux estimations from the benchmarked methods ranged from −0.5 to 3.5 m/d (with positive fluxes directed downwards), whereas fluxes estimated using Darcy’s law ranged from 0.5 to 6 m/d. Results show that the amplitude method is the best–performing method. This method is best suited for estimating the direction of the fluxes, while the method using both the thermal amplitude and phase is best suited for monthly flux trends, and the combination of a Local Polynomial (LP) method and a Maximum Likelihood Estimator (MLE) method (LPMLEn) is appropriate for estimating flux in transient conditions.
The use of heat as a tracer proved to be an effective tool for monitoring groundwater–surface water exchange in a river reach for two years, and yielded exchange flux estimates with lower point-scale variability than Darcy’s law.
Tajikistan and Kyrgyzstan are the two countries in Central Asia that have a huge reserve of hydro resources of the region. It is important to recognize the significance of the part played by the ...micro-hydropower plants (HPP) in the electric power generation in Tajikistan and Kyrgyzstan from the point of view of sustainable economic development. After all, the construction of micro-HPPs in mountainous areas will reliably ensure the development of small and medium-sized enterprises in the field of agriculture and livestock, industry, tourism, improve the social conditions of the population, as well as ensure the production of “green” hydrogen, which will contribute to the development of an environmentally friendly transport system in the regions. Micro HPPs gained recognition as a good alternative to traditional power generation for many developing countries around the world.
This study presents a structural model and methodology of choice of a feasible type of micro HPP using the developed algorithm for calculation of hydro turbines’ characteristics based on the hydrological characteristics of small and shallow watercourses located in Central Asian countries, such as Kyrgyzstan and Tajikistan. Based on this model, the software “Calculation and choosing the type of hydro turbines for micro HPPs” has been developed. Depending on the load, a consumer can choose one of the suggested types of micro-hydroelectric power plants to meet his requirements. When choosing the type of micro-hydroelectric power station, a consumer should also take into account the factor of the seasonality of the water level, the constancy and speed of the water, and the volume of river water, since in some places the water freezes in winter.
This contribution deals with surveyor activities that are associated with the measurement of watercourses and their closest terrain. It clarifies the specifics and complications of the solutions of ...the complex tasks of water management in geodetic practice. The article is devoted to activities that are directly connected with the realization of measuring, used technologies, and interpretation results’ outputs in digital form.
Considering the conflicting interests of states over their shared basin-wide transboundary water resources, various basin states follow different international legal theories of transboundary ...watercourses. This paper focuses on the aforenamed watercourse theories in light of the practices of the Nile River Basin.In an attempt to correlate the theories of International Transboundary Watercourse vis-à-vis the case of the Nile River basin, this paper addresses whether the Nile riparian countries follow a particular transboundary watercourse theory or not? Whether the upstream and/or downstream countries follow the same or different doctrinal theory or not? Whether the theories they follow have practical significance in showing the origin of where the Nile controversy lies or not?In addressing the aforementioned issues, this paper finally shows the origin of where the Nile River Basin controversies emanated from — as their conflicting and uncompromising attitudes over their international theoretical standing point, lead their practical basin-wide negotiations to a never-ending Nile controversy.
Ülkelerin havza çapında ortak olarak paylaştıkları sınıraşan su kaynakları ile ilgili çatışan çıkarları dikkate alındığında, çeşitli havza ülkeleri sınıraşan sular ile ilgili farklı uluslararası hukuk teorilerini tercih etmektedir. Bu makale, Nil Nehri Havzası uygulamalarıyla ilgili olarak sınıraşan sularının teorik doktrinine odaklanmaktadır.Uluslararası sınıraşan suları teorilerini Nil Nehri Havzası ile ilişkilendirmek çabasıyla, bu makale Nil’e kıyıdaş ülkelerin belirli bir Sınıraşan Suları teorisini takip edip etmediklerini ele almaktadır. Nehrin kaynağına doğru ve/veya nehrin akıntı yönünde bulunan ülkeler aynı veya farklı doktriner teoriyi takip ediyor mu, etmiyor mu? Takip ettikleri teorilerin, Nil tartışmasının kökenini göstermede pratik bir önemi var mı, yok mu?Makale yukarıda bahsedilen konuları ele alırken nihayet Nil Nehri Havzası ihtilafının kaynaklandığı yeri, asla bitmeyen bir Nil tartışmasına yol açan havza ülkelerinin pratik müzakerelerinin, uluslararası teorideki duruşları hakkındaki çatışan ve uzlaşmaz tavırları olarak göstermektedir.
The urbanization of catchments is consistently accompanied by a decrease of the stream condition. The case study concerns one of the urban streams in Krakow (Poland). The aim was to show the ...pollutant load which can enter the Vistula River from even a very small inflow. Samples of water, suspended particulate matter and bottom sediment were collected. Values of pH, Eh and electrolytic conductivity were measured in situ and the contents of macroelements—cations and inorganic anions—as well as trace elements were analysed by means of different instrumental methods. The results obtained are related to normative values, geochemical background and different classifications. The exceedance of permissible values for water by electrical conductivity, calcium, chlorides and cadmium concentrations in all of the sampling locations was stated. The high content of heavy metals in the bottom sediment was found especially for zinc (to 929 mg/kg), lead (to 131 mg/kg) and cadmium (to 10 mg/kg). It is shown that pollutants carried along with the waters and sediments of the stream constitute a continuous source of pollution of the Vistula River. It seems important to measure the concentration of some elements not only in the sediment of the biggest rivers but also in the smaller streams, ditches and rain collectors. Only management in the entire catchment system and inventory of pollution sources can give some positive results in improving the quality of urban watercourses.
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