Spectral Analysis of Water Level and Velocity Data from Crescent City Harbor During the April 1, 2014 Chilean Tsunami

2017 ◽  
Vol 174 (8) ◽  
pp. 2987-3002 ◽  
Author(s):  
Gregory B. Crawford ◽  
Amanda R. Admire ◽  
Lori A. Dengler
Keyword(s):  
Spectral Analysis ◽  
Water Level ◽  
Velocity Data ◽  
Crescent City ◽  
Chilean Tsunami

scholarly journals Assessing Stream-Aquifer Connectivity in a Coastal California Watershed

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 416
Author(s):  
Bwalya Malama ◽  
Devin Pritchard-Peterson ◽  
John J. Jasbinsek ◽  
Christopher Surfleet
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Water Level ◽  
Time Series Data ◽  
Series Data ◽  
Low Permeability ◽  
Pumping Tests ◽  
Stream Flows ◽  
The Impact

We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence of a thin low permeability silt-clay aquitard unit between the main aquifer and the stream. This suggested a three layer conceptual model of the subsurface comprising unconfined and confined aquifers separated by an aquitard layer. This was broadly confirmed by resistivity surveys and pumping tests, the latter of which indicated the occurrence of leakage across the aquitard. The aquitard was determined to be 2–3 orders of magnitude less permeable than the aquifer, which is indicative of weak stream-aquifer connectivity and was confirmed by spectral analysis of stream-aquifer water level time series. The results illustrate the importance of site-specific investigations and suggest that even in systems where the stream is not in direct hydraulic contact with the producing aquifer, long-term stream depletion can occur due to leakage across low permeability units. This has implications for management of stream flows, groundwater abstraction, and water resources management during prolonged periods of drought.

scholarly journals An Illustrated Guide to Estimation of Water Velocity in Unregulated River for Hydrokinetic Performance Analysis Studies in East Malaysia

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1330
Author(s):  
Almalik Mohd Saupi ◽  
Nashiren Mailah ◽  
Mohd Mohd Radzi ◽  
Kamarul Mohamad ◽  
Saiful Ahmad ◽  
...  
Keyword(s):  
Regression Model ◽  
Water Level ◽  
Rural Areas ◽  
Electrical Energy ◽  
Peninsular Malaysia ◽  
Water Velocity ◽  
Velocity Estimation ◽  
Coefficient Of Determination ◽  
Velocity Data ◽  
Model Equations

Electrification coverage in Sarawak is the lowest at 78.74%, compared to Peninsular Malaysia at 99.62% and Sabah at 82.51%. Kapit, Sarawak, with 88.4% of its population located in rural areas and mostly situated along the main riverbanks, has great potential to generate electrical energy with a hydrokinetic system. Yearly water velocity data is the most significant parameter with which to perform a hydrokinetic analysis study. Nevertheless, the data retrieved from local river databases are inadequate for river energy analysis, thus hindering its progression. Instead, flow rates and rainfall data had been utilized to estimate the water velocity data. Till present, there is still no publication has been found on estimating of water velocity data in unregulated river using water level. Therefore, a novel technique of estimating the daily average water velocity data in unregulated rivers is proposed. The modelling of regression equation for water velocity estimation was performed and two regression model equations were generated to estimate both water level and water velocity on-site and proven to be valid as the coefficient of determination values had been R2 = 87.4% and R2 = 87.9%, respectively. The combination of both regression model equations can be used to estimate long-term time series water velocity data for type-C unregulated river in remote areas.

scholarly journals Wetland Dynamics Inferred from Spectral Analyses of Hydro-Meteorological Signals and Landsat Derived Vegetation Indices

2019 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Subrina Tahsin ◽  
Stephen C. Medeiros ◽  
Arvind Singh
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Frequency Domain ◽  
Water Level ◽  
Vegetation Index ◽  
Time Lag ◽  
Forested Wetlands ◽  
Wetland Dynamics ◽  
Apalachicola Bay ◽  
Emergent Wetlands

The dynamic response of coastal wetlands (CWs) to hydro-meteorological signals is a key indicator for understanding climate driven variations in wetland ecosystems. This study explored the response of CW dynamics to hydro-meteorological signals using time series of Landsat-derived normalized difference vegetation index (NDVI) values at six locations and hydro-meteorological time-series from 1984 to 2015 in Apalachicola Bay, Florida. Spectral analysis revealed more persistence in NDVI values for forested wetlands in the annual frequency domain, compared to scrub and emergent wetlands. This behavior reversed in the decadal frequency domain, where scrub and emergent wetlands had a more persistent NDVI than forested wetlands. The wetland dynamics were found to be driven mostly by the Apalachicola Bay water level and precipitation. Cross-spectral analysis indicated a maximum time-lag of 2.7 months between temperature and NDVI, whereas NDVI lagged water level by a maximum of 2.2 months. The quantification of persistent behavior and subsequent understanding that CW dynamics are mostly driven by water level and precipitation suggests that the severity of droughts, floods, and storm surges will be a driving factor in the future sustainability of CW ecosystems.

scholarly journals High Resolution Analysis of the 1960 Chilean Tsunami at Crescent City, California

2008 ◽  
Author(s):  
T. R. Kendall ◽  
L. Dean ◽  
O. T. Magoon ◽  
L. A. Dengler ◽  
R. E. Flick ◽  
...  
Keyword(s):  
High Resolution ◽  
Crescent City ◽  
High Resolution Analysis ◽  
Resolution Analysis ◽  
Chilean Tsunami

scholarly journals Hydrokinetic Energy Assessment in Unregulated River for Hydrokinetic Performance Analysis Studies in East Malaysia

2018 ◽  
Author(s):  
Almalik Faisel Mohd Saupi ◽  
Nashiren Farzilah Mailah ◽  
Mohd Amran Mohd Radzi ◽  
Saiful Zuhaimi Ahmad ◽  
Azimi Che Soh
Keyword(s):  
Regression Model ◽  
Water Level ◽  
Rural Areas ◽  
Electrical Energy ◽  
Peninsular Malaysia ◽  
Water Velocity ◽  
Velocity Estimation ◽  
Coefficient Of Determination ◽  
Velocity Data ◽  
Model Equations

Electrification coverage in Sarawak is the lowest at 78.74%, compared to Peninsular Malaysia at 99.62% and Sabah at 82.51%. Kapit, Sarawak with its 88.4% populations located in rural areas and mostly situated along the main riverbanks has great potential to generate electrical energy by hydrokinetic system. Yearly water velocity data is the most significant parameter to perform hydrokinetic analysis study. Nevertheless, the data retrieved from local river databases are inadequate for river energy analysis, thus hindering its progression. Instead, flow rates and rainfall data had been utilised to estimate the water velocity data. This signifies no estimation of water velocity in an unregulated river by using water level data had been made. Therefore, a novel technique of estimating the daily average water velocity data in unregulated rivers is proposed. The modelling of regression equation for water velocity estimation was performed and two regression model equations were generated to estimate both water level and water velocity on-site and proven to be valid as the coefficient of determination values had been R2 = 87.4% and R2=87.9%, respectively. The combination of both regression model equations can be used to estimate long-term time series water velocity data for type-C unregulated river in remote areas.

SPECTRAL ANALYSIS OF TIDAL FLUCTUATIONS IN GROUND WATER LEVEL

2000 ◽  
Vol 36 (5) ◽  
pp. 1087-1099 ◽  
Author(s):  
David Ching-Fang Shih ◽  
Chin-Dee Lee ◽  
Kin-Forie Chiou ◽  
Shi-Ming Tsai
Keyword(s):  
Spectral Analysis ◽  
Ground Water ◽  
Water Level ◽  
Ground Water Level

scholarly journals Spectral analysis of water level fluctuations in Belarusian and Polish lakes

2017 ◽  
Vol 12 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Aleksander Volchak ◽  
Adam Choiński ◽  
Ivan Kirviel ◽  
Siergiej Parfomuk
Keyword(s):  
Spectral Analysis ◽  
Water Level ◽  
Water Level Fluctuations ◽  
Key Factors ◽  
Smooth Curves ◽  
Lake Water Level ◽  
The Third ◽  
Two Factors ◽  
Observation Sequence ◽  
Data Continuity

Abstract Data regarding 25 lakes (9 Belarusian and 16 Polish) provided the basis for spectral analysis of water level fluctuations. The obtained output data concerned a 55-year observation sequence covering the years 1956-2010. The selection of lakes was determined by two factors, i.e. data continuity and inconsiderable anthropogenic impact. The lakes were divided into three groups depending on the course of the water level spectrum. The first group included the highest number of lakes (14) which were distinguished by smooth curves with no significant peaks (e.g. Lake Wygonoszczańskie). The second group shows a four-year variability (e.g. Lake Łukomskie). The third group is distinguished by an even peak of three-year water fluctuation (e.g. Lake Łebsko). The location of the lakes categorised into those three groups suggests a certain regionalisation. The first group is represented by lakes of central and northern Belarus, and eastern Poland. The second group includes lakes of eastern Belarus, and the third group - lakes of central and northern Poland. This suggests that alongside local factors, the location of the distinguished groups of lakes may also be determined by regional factors. Presumably, continentalism of climate increasing in an eastwards direction is one of the key factors responsible for the detected regional diversity of lake water level fluctuations.

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