scholarly journals Ionic Runoff as a Way to Determine the Degree of Karst Denudation (Case Study Jasov Plateau, Slovak Karst, Slovakia)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1449
Author(s):  
Alena Gessert ◽  
Imrich Sládek ◽  
Veronika Straková ◽  
Mihály Braun ◽  
Enikő Heim ◽  
...  
Keyword(s):  
Heavy Rain ◽  
Similar Amount ◽  
Karst Water ◽  
Karst Spring ◽  
Snow Melting ◽  
Flow Rates ◽  
Karst Springs ◽  
Degree Of Protection ◽  
Episodic Events

Estimation of the catchment area of a karst spring is not possible in all areas for various reasons. The Slovak Karst is protected by the highest degree of protection and karst springs are used as a source of drinking water for the second largest city in Slovakia, Košice. From this reason, no results on ionic runoff or chemical denudation have been published from this area and the most appropriate way to obtain information about the denudation rate is to determine the ionic runoff. This paper provides an overview of ionic runoff results based on sampling and analysis of karst water from six springs in the period November 2013–October 2016 (three hydrological years) and periodic measurements. Springs have significantly fluctuated flow rates from 0 L/s in summer and autumn up to 192 L/s, and episodic events during the snow melting and heavy rain in the spring of 2013 are also known (more than 380 L/s). The total value of ionic runoff for the area of 40,847 m3/y.km2 is comparable with the Vracanska Plateau in Bulgaria, which lies at a similar altitude and with a similar amount of precipitation.

scholarly journals The Use of Laser Precipitation Monitor (LPM) of Disdrometer and Weather Radar to Determine the Microphysics Characteristics of Extreme Rainfall in Jakarta. (Jakarta Flood Case Study February 25, 2020)

2021 ◽  
Vol 893 (1) ◽  
pp. 012017
Author(s):  
I D G A Putra ◽  
A Sopaheluwakan ◽  
B P Adi ◽  
K A Sudama ◽  
J Rizal ◽  
...  
Keyword(s):  
Extreme Rainfall ◽  
Weather Radar ◽  
Heavy Rain ◽  
Maximum Diameter ◽  
Convective Clouds ◽  
Data Volume ◽  
Accumulated Rainfall ◽  
The One ◽  
The Relationship

Abstract Heavy rains on February 24, 2020, caused flooding in most parts of Jakarta and its surroundings. The one-day observation of accumulated rainfall from the Laser Precipitation Monitor (LPM) was recorded at 358.6 mm/day at the Kemayoran station on February 25, 2020, at 00.00 UTC (07.00 Jakarta Time). In this study, analysis of the microphysical characteristics of extreme rainfall using LPM installed at Kemayoran meteorology station and weather radar at Cengkareng meteorology station with a spatial radius of 250 km. LPM is used to measure the diameter of the raindrops, the velocity of falling raindrops, LPM reflectivity, and the amount of accumulated rainfall with time resolution per minute and stored in excel data format. While the weather radar is used to measure the reflectivity spatially and temporally in the data volume format (.vol). The method used is, first, to find the relationship between LPM reflectivity and the amount of LPM rainfall with regression analysis. Second, the radar reflectivity is converted into estimated rainfall intensity for the Jakarta area and its surroundings. The results of this study found a relationship between LPM reflectivity (X) and rainfall accumulation LPM (Y) to form a regression relationship with the formula Y = 0.013X with R2 = 0.3777. Based on the record of the LPM time series, the peak of rainfall occurred at 18.17 UTC with 1000 raindrops, the maximum fall speed was 10 m/s, and the maximum diameter is 8.5 millimeters. Based on the results of microphysical measurements of LPM, spatial plots, and vertical cross-section radar, it can be concluded that flooding in Jakarta is due to heavy rain from convective clouds.

scholarly journals Comments on “Incorporating the Effects of Moisture into a Dynamical Parameter: Moist Vorticity and Moist Divergence”

2016 ◽  
Vol 31 (4) ◽  
pp. 1393-1396 ◽  
Author(s):  
David M. Schultz ◽  
Thomas Spengler
Keyword(s):  
Relative Humidity ◽  
Potential Vorticity ◽  
Single Case ◽  
Heavy Rain ◽  
Relative Vorticity ◽  
Dynamical Parameter ◽  
Accumulated Rainfall ◽  
Moist Potential Vorticity ◽  
Model Precipitation

Abstract In a recent article, Qian et al. introduced the quantities moist vorticity and moist divergence to diagnose locations of heavy rain. These quantities are constructed by multiplying the relative vorticity and divergence by relative humidity to the power k, where k = 10 in their article. Their approach is similar to that for the previously constructed quantity generalized moist potential vorticity. This comment critiques the approach of Qian et al., demonstrating that the moist vorticity, moist divergence, and by extension generalized moist potential vorticity are flawed mathematically and meteorologically. Raising relative humidity to the 10th power is poorly justified and is based on a single case study at a single time. No meteorological evidence is presented for why areas of moist vorticity and moist divergence should overlap with regions of 24-h accumulated rainfall. All three quantities have not been verified against the output of precipitation directly from the model nor is the approach of combining meteorological quantities into a single parameter appropriate in an ingredients-based forecasting approach. Researchers and forecasters are advised to plot the model precipitation directly and employ an ingredients-based approach, rather than rely on these flawed quantities.

Fracture Prevention Following Offshore Well Blowouts: Selecting the Appropriate Capping Stack Shut-In Strategy

2020 ◽  
pp. 1-13
Author(s):  
Andreas Michael ◽  
Ipsita Gupta
Keyword(s):  
Fracture Initiation ◽  
Loss Of Control ◽  
Flow Rates ◽  
Discharge Flow ◽  
Well Control ◽  
Wellbore Integrity ◽  
Discharge Flow Rate ◽  
Critical Discharge ◽  
Control Situations

Summary Following uncontrolled discharge during loss of well control events, fracture initiation occurring during the post-blowout capping stage can lead to reservoir fluids broaching to the seafloor. A classic example is Union Oil's 1969 oil spill in Santa Barbara Channel, where fracture initiation at various locations caused thousands of gallons per hour to broach onto the ocean floor over a month before it could be controlled (Mullineaux 1970; Easton 1972). Disasters such as these could be prevented if the effects of the post-blowout loss of well control stages (uncontrolled discharge and capping) are incorporated into the shut-in procedures, and the wellbore architectures are modified accordingly. In this study, analytical models are used to simulate the loads on the wellbore during the different stages of loss of control. Capping pressure buildup during the shut-in is modeled to indicate fracture initiation points during the capping stage. Using these models, the critical capping pressure for a well is determined, and subsequent critical discharge flow rates are calculated. Fracture initiation would occur if the actual discharge flow rate is below the calculated critical discharge flow rate. A hypothetical case study using typical deepwater Gulf of Mexico (GOM) parameters is performed demonstrating the likelihood of fracture initiation during different discharge flow rates, discharge periods, and capping stack shut-in methods (single-step/“abrupt” or multistep/“incremental”). An abrupt shut-in for this case study leads to fracture initiation at approximately 8 hours after shut-in, while a five-step incremental shut-in is shown to prevent any fracture initiation during the 48 hours after the beginning of the shut-in. Reservoir depletion through longer discharge periods or higher discharge flow rates, despite the adverse environmental effect, can delay or even prevent fracture initiations during post-blowoutcapping. The ability to model these fracture failures enhances the understanding of wellbore integrity problems induced during loss of control situations and helps create workflows for predicting possible broaching scenarios during the post-blowout capping stage. Dimensionless plots are used to present fracture initiation for different cases—this is useful for drilling and wellbore integrity engineers for making contingency plans for dealing with loss of well control situations.

scholarly journals The career youth pastor: A contemporary reflection

2017 ◽  
Vol 73 (2) ◽  
Author(s):  
Garth Aziz ◽  
Malan Nel ◽  
Ronnie Davis
Keyword(s):  
Southern Africa ◽  
Youth Ministry ◽  
Youth Work ◽  
Similar Amount ◽  
Youth Worker ◽  
Youth Pastor ◽  
Practical Theological ◽  
Theological Argument ◽  
To Receive

There has been an increase of discussion and focus on matters of theological significance in the area of youth ministry. An area that remains neglected concerns the professional youth worker in Southern Africa. This focus on professional youth work has gained a great amount of urgency from the office of the presidency of Southern Africa, who in collaboration with the Commonwealth desk have prioritised the focus on youth work in South Africa. Unfortunately, the focus on the professional youth worker, the career youth pastor, within the church in Southern Africa fails to receive a similar amount of attention. The article will highlight the need to pursue a theological articulation around the office of the career youth pastor by building a practical theological argument for the office of career youth pastor. The article will address a case study of a mainline evangelical denomination regarding its theological articulation of the career youth pastor.

Transfer of Contamination from Motorways Towards Karst Water Sources: The Example of the Malenščica Karst Spring

2015 ◽  
pp. 299-312
Author(s):  
Martin Knez ◽  
Tadej Slabe ◽  
Franci Gabrovšek ◽  
Janja Kogovšek ◽  
Andrej Kranjc ◽  
...  
Keyword(s):  
Water Sources ◽  
Karst Water ◽  
Karst Spring

scholarly journals Re-assessing the Upper Permian Stratigraphic Succession of the Northern Sydney Basin, Australia, by CA-IDTIMS

Geosciences ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 474
Author(s):  
Angelos G. Maravelis ◽  
Jake Breckenridge ◽  
Kevin Ruming ◽  
Erin Holmes ◽  
Yuri Amelin ◽  
...  
Keyword(s):  
Upper Permian ◽  
Time Interval ◽  
Stratigraphic Correlation ◽  
Short Time Interval ◽  
Episodic Events ◽  
Ionisation Mass Spectrometry ◽  
Short Time ◽  
Marker Beds ◽  
Stratigraphic Succession

High precision Chemical abrasion-isotope dilution thermal ionisation mass spectrometry (CA-IDTIMS) U-Pb zircon results from tuff marker beds that are interstratified within the Upper Permian deposits of the northern Sydney Basin add constraints on the timing of sediment deposition, and afford a better understanding of the regional stratigraphy. The results indicate a magmatic influence during the deposition of the sediments, with episodic events spanning at least from 255.65 ± 0.08 to 255.08 ± 0.09 Ma. The zircon data suggest that the studied sedimentary rocks and tuffs have accumulated simultaneously over a short time interval, which contrasts with current stratigraphic models that suggest a much greater period of deposition and stratigraphic thickness. Therefore, an updated stratigraphic correlation of the basin is suggested, which combines the presently defined Lambton, Adamstown, and Boolaroo sub-groups into a single Lambton sub-group. This updated correlation framework is stratigraphically and geochronologically constrained and provides a more precise exploration model for the northern Sydney Basin. This case study highlights the valuable contribution of the CA-IDTIMS method in intrabasinal correlations of sedimentary successions, when integrated with a robust sedimentological framework, to minimize the stratigraphic uncertainties.

Sign in / Sign up

Export Citation Format

Share Document