Wyniki wyszukiwania - BazTech

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Investigation and calibration of thermal and salinity layering in surface water resources using Ce-Qual-W2 model

Chen Tzu-Chia, Yu Shu-Yan, Wang Chang-Ming, Xie Sen, Barazandeh Hanif

Journal of Water and Land Development

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2021

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no. 51

117--123

EN

In the discussion of water quality control, the first and most effective parameter that affects other variables and water quality parameters is the temperature situation and water temperature parameters that control many ecological and chemical processes in reservoirs. Additionally, one of the most important quality parameters studied in the quality of water resources of dams and reservoirs is the study of water quality in terms of salinity. The salinity of the reservoirs is primarily due to the rivers leading into them. The control of error in the reservoirs is always considered because the outlet water of the reservoirs, depending on the type of consumption, should always be standard in terms of salinity. Therefore, in this study, using the available statistics, the Ce-Qual-W2 two-dimensional model was used to simulate the heat and salinity layering of the Latyan Dam reservoir. The results showed that with warming and shifting from spring to late summer, the slope of temperature changes at depth increases and thermal layering intensifies, and a severe temperature difference occurs at depth. The results of sensitivity analysis also showed that by decreasing the wind shear coefficient (WSC), the reservoir water temperature increases, so that by increasing or decreasing the value of this coefficient by 0.4, the average water temperature by 0.56°C changes inversely, and the results also show that by increasing or decreasing the value of the shade coefficient by 0.85, the average water temperature changes by about 7.62°C, directly.

2

Low cost artificial recreational coastal lagoon: Hydrographic, and design guidelines in development resorts

El Gohary Rasha I.M.

Journal of Water and Land Development

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2020

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no. 46

45--59

EN

The objective of the research is to find low cost alternative for conventional recreational lagoons that consume water and energy used for desalination which is the only alternative for water treatment in most touristic villages all over the world. The study uses low cost recreational lagoon with new technology that use brackish water from deep wells and purify this water before entering the lagoon by controlled pulses and energyefficient ultrasound filtration. This allows to maintain the water within predefined parameters, guaranteeing standardized water quality in all lagoons. The research introduces the lagoon new technology and its low cost design including feeding and drainage wells, second, the hydrographic surveying for the coastline in the study area, third water quality modelling for the production and injection wells, fourth, use SOBEK 1-2 Mathematical Model for determine the water depth and perspective water volume for the designed lagoon. The aim of this model: Determine the relation between the water depth and the water volume for the canal and the lakes. Second, calculate the evaporation rate from the surface, Determine the number and capacity of the water wells needed to fill the canal and the lakes, and Find out the relationship between the discharge and the time needed to circulate the water in the canal and the lakes to keep their water quality. The results of the measurements from the observation well prove that the optimal discharge per each well is 0.022 m3·s–1. The construction of suggested new green technology lagoon are very low cost, completely environmentally friendly, in addition fulfils the highest standards of environmental safety.

3

Challenges in modelling of water quantity and quality in two contrasting meso-scale catchments in Poland

Marcinkowski P., Piniewski M., Kardel I., Srinivasan R., Okruszko T.

Journal of Water and Land Development

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2016

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no. 31

97--111

EN

This study presents an application of the SWAT model (Soil and Water Assessment Tool) in two meso- -scale catchments in Poland (Upper Narew and Barycz), contrasting in terms of human pressures on water quantity and quality. The main objective was multi-variable and multi-site calibration and validation of the model against daily discharge, sediment and nutrient loads as well as discussion of challenges encountered in calibration phase. Multi-site calibration and validation gave varied results ranging from very good (daily discharge) to acceptable (sediment, nitrogen and phosphorus loads in most of gauges) and rather poor (individual gauges for all variables) in both catchments. The calibrated models enabled spatial quantification of water yield, sediment and nutrient loads, indicating areas of special concern in terms of pollution, as well as estimation of contribution of pollution from different sources, indicating agriculture as the most important source in both catchments. During the calibration process a number of significant issues were encountered: (i) global vs. local parametrization, (ii) simulation of different pools of water quality parameters in reservoirs and streams and (iii) underestimation of NO3-N loads in winter due to farmers practices. Discussion of these issues is hoped to aid SWAT model users in Poland in a deeper understanding of mechanisms of multi-variable and multi-site calibration.

PL

W niniejszej pracy przedstawiono zastosowanie modelu SWAT (Soil and Water Assessment Tool) w dwóch zlewniach w Polsce (Górnej Narwi i Baryczy), kontrastowych pod względem antropopresji w odniesieniu do ilości i jakości wód. Głównym celem była przestrzenna kalibracja i weryfikacja modelu w zakresie przepływów dobowych, ładunków zawiesiny i biogenów oraz dyskusja nad wyzwaniami napotkanymi w trakcie procesu kalibracji. Wyniki przestrzennej (wielopunktowej) kalibracji i weryfikacji są zróżnicowane – od dobrych (przepływ dobowy), poprzez akceptowalne (zawiesina, azot i fosfor w większości punktów monitoringu), do złych (pojedyncze punkty monitoringu dla każdej ze zmiennych). Skalibrowany model umożliwił przestrzenną kwantyfikację warstwy odpływu, ładunków zawiesiny i biogenów oraz wskazanie obszarów szczególnie narażonych na zanieczyszczenia z różnych źródeł, jednocześnie wskazując rolnictwo jako główne źródło. Podczas kalibracji modelu napotkano następujące problemy: (1) identyfikacja parametrów globalnych w odniesieniu do lokalnych, (2) symulacja różnych form parametrów jakościowych w zbiornikach wodnych i ciekach oraz (3) niedoszacowanie ładunków azotanów w okresie zimowym spowodowane praktykami rolniczymi. Dyskusja nad poruszonymi aspektami umożliwi innym użytkownikom modelu SWAT lepsze zrozumienie mechanizmu wielopunktowej i wieloparametrycznej kalibracji.