scholarly journals Comprehensive Evaluation of Hydrogeological Impact of Tunnel Construction in Karst Aquifers by 3D Numerical Simulations and Water Balance Models

2021 ◽  
Vol 861 (3) ◽  
pp. 032011
Author(s):  
Xiaokang Zheng ◽  
Bing-Qi Zhou ◽  
Zhibing Yang ◽  
Sheng Wang ◽  
Ran Hu ◽  
...  
Keyword(s):  
Water Balance ◽  
Numerical Simulations ◽  
Comprehensive Evaluation ◽  
Tunnel Construction ◽  
Karst Aquifers ◽  
Water Balance Models ◽  
Hydrogeological Impact

Effects of climate change and human interactions on water balance dynamics in the River Vistula basin

2021 ◽  
Author(s):  
Renata Romanowicz ◽  
Emilia Karamuz ◽  
Jaroslaw Napiorkowski ◽  
Tesfaye Senbeta
Keyword(s):  
Water Balance ◽  
Groundwater Level ◽  
Structural Model ◽  
Human Impacts ◽  
Management Scenarios ◽  
Annual Water Balance ◽  
Catchment Size ◽  
Dryness Index ◽  
Water Balance Models ◽  
Annual Water

<div> <p>Water balance modelling is often applied in studies of climate and human impacts on water resources. Annual water balance is usually derived based on precipitation, discharge and temperature observations under an assumption of negligible changes in annual water storage in a catchment. However, that assumption might be violated during very dry or very wet years. In this study we apply groundwater level measurements to improve water balance modelling in nine sub-catchments of the River Vistula basin starting from the river sources downstream. Annual and inter-annual water balance is studied using a Budyko framework to assess actual evapotranspiration and total water supply. We apply the concept of effective precipitation to account for possible losses due to water interception by vegetation. Generalised Likelihood Uncertainty Estimation GLUE is used to account for parameter and structural model uncertainty, together with the application of eight Budyko-type equations. Seasonal water balance models show large errors for winter seasons while summer and annual water balance models follow the Budyko framework. The dryness index is much smaller in winter than in summer for all sub-catchments. The spatial variability of water balance modelling errors indicate an increasing uncertainty of model predictions with an increase in catchment size. The results show that the added information on storage changes in the catchments provided by groundwater level observations largely improves model accuracy. The results also indicate the need to model groundwater level variability depending on external factors such as precipitation and evapotranspiration and human interventions. The modelling tools developed will be used to assess future water balance in the River Vistula basin under different water management scenarios and climate variability.</p> </div>

scholarly journals Soil Water Balance and Vegetation Dynamics in a Semi-arid Mediterranean Ecosystem

Proceedings ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 76
Author(s):  
Ioannis N. Daliakopoulos ◽  
Ioanna Panagea ◽  
Luca Brocca ◽  
Erik van den Elsen
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Availability ◽  
Vegetation Dynamics ◽  
Soil Water Balance ◽  
Mediterranean Ecosystem ◽  
Limiting Factor ◽  
Arid Conditions ◽  
Water Balance Models ◽  
Semi Arid

Under arid conditions, where water availability is the limiting factor for plant survival, water balance models can be used to explain vegetation dynamics. [...]

scholarly journals A new approach to estimating Mean Flow in the UK

2002 ◽  
Vol 6 (4) ◽  
pp. 709-720 ◽  
Author(s):  
M. G. R. Holmes ◽  
A. R. Young ◽  
A. Gustard ◽  
R. Grew
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Accurate Estimation ◽  
Mean Flow ◽  
Time Step ◽  
Runoff Water ◽  
Data Set ◽  
Water Balance Models ◽  
The Uk ◽  
Drying Curve

Abstract. Traditionally, the estimation of Mean Flow (MF) in ungauged catchments has been approached using conceptual water balance models or empirical formulae relating climatic inputs to stream flow. In the UK, these types of models have difficulty in predicting MF in low rainfall areas because the conceptualisation of soil moisture behaviour and its relationship with evaporation rates used is rather simplistic. However, it is in these dry regions where the accurate estimation of flows is most critical to effective management of a scarce resource. A novel approach to estimating MF, specifically designed to improve estimation of runoff in dry catchments, has been developed using a regionalisation of the Penman drying curve theory. The dynamic water balance style Daily Soil Moisture Accounting (DSMA) model operates at a daily time step, using inputs of precipitation and potential evaporation and simulates the development of soil moisture deficits explicitly. The model has been calibrated using measured MFs from a large data set of catchments in the United Kingdom. The performance of the DSMA model is superior to existing established steady state and dynamic water-balance models over the entire data set considered and the largest improvement is observed in very low rainfall catchments. It is concluded that the performance of all models in high rainfall areas is likely to be limited by the spatial representation of rainfall. Keywords: hydrological models, regionalisation, water resources, mean flow, runoff, water balance, Penman drying curve, soil moisture model

scholarly journals Analysis of Input Voltage Switching Ripple in Three-Phase Four-Wire Split Capacitor PWM Inverters

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5076 ◽  
Author(s):  
Manel Hammami ◽  
Riccardo Mandrioli ◽  
Aleksandr Viatkin ◽  
Mattia Ricco ◽  
Gabriele Grandi
Keyword(s):  
Numerical Simulations ◽  
Comprehensive Evaluation ◽  
Experimental Tests ◽  
Input Voltage ◽  
Switching Voltage ◽  
Two Phase ◽  
Voltage Ripple ◽  
Battery Chargers ◽  
Three Phase ◽  
Split Capacitor

Three-phase, four-wire split capacitor inverters are currently employed in many applications, such as photovoltaic systems, battery chargers for electric vehicles, active power filters, and, in general, in all grid-tied applications that deal with possible grid voltage and/or current unbalances. This paper provides a comprehensive evaluation of the capacitor-switching voltage ripple and dc-link switching voltage ripple for the three-phase, four-wire, split capacitor inverters. Specifically, analytical formulations of the peak-to-peak and rms values of the voltage ripples are originally pointed out in this paper and determined in the case of balanced three-phase and unbalanced (two-phase and single-phase) output (ac) currents. The obtained results can help in designing the considered inverter and sizing of the dc-link capacitors. Reference is made to the sinusoidal PWM modulation and sinusoidal three-phase output currents with an almost unity power factor, representing a grid-connected application. Extensive numerical simulations have been carried out to thoroughly verify all the analytical developments presented in this paper. Furthermore, some experimental tests, having balanced output currents on the ac side, have been accomplished, validating numerical simulations and analytical developments.

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