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w słowach kluczowych: modelowanie relacji opad–odpływ

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Co-occurrence probability of water balance elements in a mountain catchment on the example of the upper Nysa Kłodzka River

Perz Adam, Sobkowiak Leszek, Wrzesiński Dariusz

Acta Geophysica

2022

Vol. 70, no 3

1301--1315

Conditions of the formation of key elements of the water balance, such as precipitation and runoff, and relations between them in the mountain catchment area are very complicated, conditioned both by the climatic factor and the physiographic characteristics of the catchment area. The aim of the study is to determine relations between precipitation and runoff in the Kłodzka Valley (KV) located in mountain areas of south-western Poland. Analyzes were based on precipitation in KV and discharges of the Nysa Kłodzka River and its tributaries, recorded in hydrological years 1974–2013. The bivariate Archimedean copulas were used to describe the degree of synchronicity between these variables. The study area shows a considerable variability in the conditions of transformation of precipitation into runoff. It is conditioned both by the pluvial regime and the physical-geographical characteristics of the catchment area. As a result, sub-catchments with diversified hydrological activity and their role in the formation of water resources of the entire KV were identified. Among them, the Biała Lądecka River sub-catchment was found to be the most hydrologically active, and the sub-catchment of Bystrzyca Dusznicka River the most inert, despite e.g. quite similar synchronicity of precipitation compared to the average precipitation in KV. At the same time, the KV rivers are characterized by different types of runoff regime and characteristic of the water balance structure. The methodology presented can be useful in determining dependencies between selected elements of the water balance and evaluation of water resources availability in source areas of mountain rivers.

Assessment of two loss methods for estimation of surface runoff in Zaafrania urban catchment, North-East of Algeria

Dahdouh Y., Ouerdachi L.

Journal of Water and Land Development

2018

no. 36

37--43

Surface runoff is a major problem in urban catchments; its generation is always related to the amount of effective rainfall dropped over the surface, however in urban catchments the process is considerably altered by the emergence of impervious areas. In this study the Soil Consevation Service – curve number (SCS-CN) and the Green–Ampt loss methods were used in rainfall-runoff modelling in the Zaafrania urban catchment which is located in Annaba city in the north east of Algeria. The two loss methods were carried out within Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS), the choice of the appropriate method for simulating runoff hydrographs in the study area was made by comparing the simulated hydrographs versus observed data using visual inspection and statistical analysis. The results indicate that SCS-CN loss method fit better in the case of 100 years return period NSE (0.462) than in 10 years NSE (0.346) and the results of calibration of Green– Ampt loss method for the 100 years return period NSE (0.417) provide best fit than the case of 10 years NSE (0.381). Furthermore, the results of both return periods (10 and 100 years) of SCS-CN loss method provide best fit than the results of return periods (10 and 100 years) of Green–Ampt loss method. It could be concluded that SCS-CN method is preferred to the Green–Ampt method for event based rainfall-runoff modelling.

Spływ powierzchniowy jest głównym problemem w miejskich zlewniach. Spływ jest zawsze uzależniony od opadu, jednak w miejskich zlewniach proces ulega znaczącej modyfikacji z powodu obecności powierzchni nieprzepuszczalnych. W badaniach prezentowanych w niniejszej pracy zastosowano dwie metody – SCS-CN (ang. Soil Coservation Service – curve number) i Green–Ampt do modelowania relacji opad–odpływ w miejskiej zlewni Zaafrania na terenie miasta Annaba na północnym wschodzie Algierii. Obie metody realizowano w ramach modelu HEC-HMS. Odpowiednią metodę symulowania hydrogramu odpływu dobrano na podstawie wizualnej oceny i analizy statystycznej. Wyniki dowodzą, że metoda SCS-CN dawała lepsze dopasowanie w przypadku stuletniego okresu powtarzalności (NSE = 0,462) niż w przypadku okresu dziesięcioletniego (NSE = 0,346). Wyniki kalibracji metodą Green–Ampt zapewniały lepsze dopasowanie dla stuletniego niż dla dziesięcioletniego okresu powtarzalności (NSE odpowiednio 0,417 i 0,381). Ponadto wyniki metody SCS-CN dla obu okresów (10 i 100 lat) wykazywały lepsze dopasowanie niż wyniki uzyskane za pomocą metody Green– Ampt dla tych okresów. Można wnioskować, że metoda SCS-CN ma przewagę nad metodą Green–Ampt w modelowaniu relacji opad–odpływ w odniesieniu do poszczególnych zdarzeń.