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Przepływy środowiskowe - jak wybrać właściwą klasyfikację cieków?

Grela Jerzy, Kokoszka Rafał

Gospodarka Wodna

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2023

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Nr 1

22--30

PL

W artykule przeanalizowano zagadnienie doboru najkorzystniejszego podziału wód powierzchniowych w Polsce pod kątem wprowadzenia do polskiego prawa przepływów środowiskowych. Ze względu na konieczność uśredniania parametrów wyznaczających te przepływy w obrębie kategorii ważnym zagadnieniem jest podobieństwo hydrologiczne cieków w obrębie kategorii, aby ograniczyć do minimum niebezpieczeństwo niedoszacowania lub przeszacowania wartości przepływu środowiskowego. Rozpatrzono 6 typów kategoryzacji cieków i oceniono możliwość ich zastosowania w procedurze wdrażania przepływów środowiskowych.

EN

The article discusses the most beneficial classification of surface waters in Poland in terms of introducing the environmental flows to the Polish legislation. Due to the necessity to average parameters determining these flows within a category, an important issue is the hydrological similarity of watercourses within a category in order to limit the risk of underestimating or overestimating the value of the environmental flow. The article analyses 6 types of watercourse categorisation and assesses the possibility to use them in the procedure of environmental flows implementation.

2

Analysis of hydrological alteration and environmental flow in Sone river basin

Ranjan Ankit, Roshni Thendiyath

Acta Geophysica

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2023

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Vol. 71, no. 2

949--960

EN

Environmental flow is an important indicator of river health as it maintains the natural flow pattern of riverine ecosystem. Although numerous researches for analyzing the hydrological alterations are there, still insightful investigation of site specific knowledge should be required for riverine ecosystem protection. In this study, the objective is to analyze the hydrological status of the Sone river basin in Bihar region, India. This study also focuses to develop a flow duration curve (FDC) to show the time duration–frequency of low-flow events. The hydrological status of the basin was analyzed using indicators of hydrologic alteration (IHA). Low flows were estimated using period of record flow duration curve (POR FDC), and design environmental flow was assessed for 10-year and 100-year return period using stochastic flow duration curve (stochastic FDC). Daily discharge data collected from Koelwar station of Sone river for 1990–2020 period were used for the hydrological analysis. Depending on the quantitative and qualitative assessment of the hydrological alterations, it was found that the hydrological status of the river basin is in a "very altered" state. The POR FDC analyzed 7-day mean discharge values (7dQ) appropriate for determining low flows, and discharge values corresponding to 95% probability of exceedance (Q95) were considered as low flow for 7dQ. Stochastic FDCs generated 7-day mean flow duration curves for 10-year (7Q10) and 100-year (7Q100) recurrence intervals. Discharge values corresponding to 95% probability of exceedance for 7Q10 range from 120 to 125 cumec and those for 7Q100 range from 135 to 140 cumec. The methodology proposed in this work to design environmental flow considering the effects of hydrological alteration can help in making the long-term strategies to protect the riverine ecosystem in Sone river basin.

3

Comparative assessment of environmental fow using hydrological methods of low fow indexes, Smakhtin, Tennant and fow duration curve

Karimi Saman, Salarijazi Meysam, Ghorbani Khalil, Heydari Mohammad

Acta Geophysica

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2021

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Vol. 69, no. 1

285--293

EN

There are diferent methods in hydrological approach for estimating the environmental fow and a comparative assessment is necessary. The low fow indexes (7Q2 and 7Q10), Smakhtin, Tennent and fow duration curve were used to estimate the environmental fow of Zohreh River in the southwest of Iran. The Smakhtin, 7Q2, 7Q10 and Tennant methods resulted in the estimation of constant values of 27.2, 12.7, 5.9 and (8 and 24) cms, so that, on average 52.8, 26.9 and 12.3, 36.7 percent of the monthly fow is allocated to the environmental fow. The monthly environmental fow pattern for these methods does not ft well with the monthly fow pattern, and thus it can be concluded that the Smakhtin, 7Q2, 7Q10 and Tennant methods cannot be used in the initial form. The application of the fow duration curve leads to an environmental fow assessment in the range of 6.8–38 cms in diferent months, whose time pattern completely matched with the monthly fow pattern. In this method, on average, 30.8% (range 18–48%) of the monthly fow allocated to the environmental fow, which is reasonable and acceptable amounts. Investigating the results of this study shows that the time pattern of the results should be analyzed in comparison with the observational fow pattern to estimate the environmental fow with a hydrological approach. The results also suggest that the methods that provide a constant amount of environmental fow in diferent months of the year should be interpreted cautiously along with other methods.

4

Environmental Flows of Lowland Rivers with Disturbed Hydrological Regime on the Example of Mała Wełna River

Kanclerz J., Murat-Błażejewska S., Janicka E., Adamska A.

Rocznik Ochrona Środowiska

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2018

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Tom 20, cz. 1

873--886

EN

This work presents the rates of characteristic and contractual flows of Mała Wełna river, including hydrological instream flows and environmental flows based on hydrological observations, hydro-chemical analyses and ichthyofauna structure accomplished in the years 2000-2010. The volume of instream flows were established according to requirements for the usage conditions of the Warta water region’s waters, while environmental flows were calculated by three following methods: Tennant’s, Tessman’s and method based on flow duration curves (Q70% and Q90%). Results showed that the environmental flow rates were significantly higher than currently required instream flow rates.

PL

W pracy, na podstawie obserwacji i pomiarów hydrologicznych, badań hydrochemicznych wody oraz struktury ichtiofauny rzeki Mała Wełna w okresie 2000-2010 określono przepływy charakterystyczne i umowne w tym hydrologiczne: przepływy nienaruszalne oraz przepływy środowiskowe. Wielkości przepływów nienaruszalnych określono według wymagań warunków korzystania z wód regionu wodnego Warty, zaś przepływów środowiskowych obliczono trzema metodami: Tennanta, Tessmana oraz metodą odcięcia poziomów 70% i 90% krzywej czasów trwania wraz z wyższymi. Przeprowadzona analiza wyników obliczeń wykazał, że natężenia przepływów środowiskowych były znacznie wyższe od obecnie wymaganych natężeń przepływów nienaruszalnych.

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Economic aspects of implementation of environmental flows

Dubel A., Godyń I.

Ekonomia i Środowisko

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2018

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nr 4

133--142

EN

Sustainable management of water resources requires leaving in the rivers a flow that ensures biological life. Since 2014, water authorities have been seeking to develop a methodology for determining environmental flows that are to reflect the inherently time-changing environmental water needs. The paper presents economic aspects of the implementation of environmental flows that will bring environmental benefits from providing the necessary amount of water for aquatic ecosystems as well as for water dependent ecosystems. However, on the other hand, they can cause significant costs for existing water users and limitations in economic use of water resources in the future. The cost-benefit approach is developed to estimate costs and benefits from introducing environmental flows in river basins. As the result the unit costs and benefits indicators for different water users are estimated and applied for the economic analysis in six study areas. The outcomes provide new information and methodological approach for decision-making about implementation of environmental flows.

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Porównanie metod do wyznaczania przepływu środowiskowego na przykładzie zlewni górskiej

Młyński D., Wałęga A., Wachulec K.

Inżynieria Ekologiczna

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2015

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Nr 44

184--190

PL

W pracy wyznaczono wartości przepływów środowiskowych za pomocą metod: Tennanta, Tessmana i metodą bazującą na krzywych sum czasów trwania przepływów wraz z wyższymi oraz przepływ nienaruszalny za pomocą parametrycznej metody Kostrzewy. Obliczenia przeprowadzono dla zlewni potoku Młyniska (przekrój Zakopane), która jest położona w dorzeczu górnego Dunajca. Dane do obliczeń, w postaci serii obserwacyjnej przepływów dobowych z wielolecia 2000–2014, pozyskano z Instytutu Meteorologii i Gospodarki Wodnej PIB w Warszawie. Dane poddano weryfikacji pod kątem jednorodności i niezależności, przy wykorzystaniu testu Manna-Kendalla -Sneyersa. Obliczenia wykazały różnice pomiędzy wartościami przepływów nienaruszalnych i środowiskowych a także pozwoliły na stwierdzenie, że wyznaczone przepływy środowiskowe znajdowały się powyżej poziomu wyznaczonego przez przepływ najniższy w wieloleciu. Ponadto stwierdzono, że zasoby dyspozycyjne wód cieku Młyniska, przy różnych metodach do wyznaczania przepływu nienaruszalnego i środowiskowego nie różnią się istotnie.

EN

The paper describes the way of determining environmental flows, based on the use of Tennant and Tessman methods, a method based on flow duration curves, as well as instream flows using the methods of Kostrzewa. Calculations were conducted for the catchment of Młyniska River (cross-section Zakopane), which is located in upper Dunajec basin. Input data, obtained from the Institute of Meteorology and Water Management, National Research Institute in Warsawincluded observation series of daily flows for the years 2000–2014. The data were evaluated in terms of homogeneity and independence, using the Mann-Kendall-Sneyers. The calculations have shown differences between values of instream flow and environmental flow and also allowed us to conclude that the computed environmental flows were above the level determined by the absolutely low flow. Also conducted that disposable resources of water by Młyniska river, limited by instream flow and environmental flowdo not differ significantly.