scholarly journals Wildfire Impacts on Groundwater Aquifers: A Case Study of the 1996 Honey Boy Fire in Beaver County, Utah, USA

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2279
Author(s):  
Benjamin T. Johnk ◽  
David C. Mays
Keyword(s):  
Groundwater Level ◽  
Temporary Reduction ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Monitoring Wells ◽  
Groundwater Aquifers ◽  
Before And After ◽  
Beaver County ◽  
Level Reduction

It is well known that wildfires destroy vegetation and form soil crusts, both of which increase stormwater runoff that accelerates erosion, but less attention has been given to wildfire impacts on groundwater aquifers. Here, we present a systematic study across the contiguous United States to test the hypothesis that wildfires reduce infiltration, indicated by temporary reductions in groundwater levels. Geographic information systems (GIS) analysis performed using structured queried language (SQL) categorized wildfires by their proximity to wells with publicly available monitoring data. Although numerous wildfires were identified with nearby monitoring wells, most of these data were confounded by unknown processes, preventing a clear acceptance or rejection of the hypothesis. However, this analysis did identify a particular case study, the 1996 Honey Boy Fire in Beaver County, Utah, USA that supports the hypothesis. At this site, daily groundwater data from a well located 790 m from the centroid of the wildfire were used to assess the groundwater level before and after the wildfire. A sinusoidal time series adjusted for annual precipitation matches groundwater level fluctuations before the wildfire but cannot explain the approximately two-year groundwater level reduction after the wildfire. Thus, for this case study, there is a correlation, which may be causal, between the wildfire and temporary reduction in groundwater levels. Generalizing this result will require further research.

scholarly journals Groundwater Level Fluctuation Analysis in a Semi-Urban Area Using Statistical Methods and Data Mining Techniques—A Case Study in Wrocław, Poland

2020 ◽  
Vol 10 (10) ◽  
pp. 3553
Author(s):  
Magdalena Worsa-Kozak ◽  
Radosław Zimroz ◽  
Anna Michalak ◽  
Christian Wolkersdorfer ◽  
Agnieszka Wyłomańska ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Groundwater Level ◽  
Environmental Changes ◽  
Fluctuation Analysis ◽  
Urban District ◽  
Seasonal Behavior ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Multiple Data Sets

Long-term groundwater level analysis, which is usually based on traditionally defined hydrological years is essential in an era of global warming and other climatic and environmental changes, especially in urban areas. A complex interplay of multiple factors influencing the groundwater level makes the investigation of their interdependencies a challenge. Based on multiple data sets and a long time series available as well as specific geological and hydrological conditions, a semi-urban district of Wrocław/Poland was selected as a case study for investigating these dependencies. This paper presents an interdisciplinary approach to the analysis of groundwater level fluctuations by combining mathematics, signal processing, hydrogeology, and meteorology. Applying well-known methods from disciplines other than hydrogeology, the authors investigated seasonal behavior and similarity of groundwater level fluctuations during 15 hydrological years. Based on segmentation and agglomerative clustering (AHP), five classes of groundwater levels fluctuations for predefined hydrologic years and the corresponding seasons were identified and compared to the classification scheme by Pleczyński. Additionally, the relationship between precipitation and groundwater level was investigated using Pearson, Kendall and Spearman correlations. This led to the identification of “typical” and “untypical” seasons for the correlation between the cumulative precipitation sum and groundwater levels. The results presented here will be used for further investigations of groundwater level fluctuations using additional factors and statistical methods. These aim to identify periods that describe similarities better than the commonly used hydrological year.

scholarly journals Seismically induced changes in groundwater levels and temperatures following the ML5.8 (ML5.1) Gyeongju earthquake in South Korea

2021 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
Jae Min Lee ◽  
Sang-Ho Moon ◽  
Kyoochul Ha ◽  
Yongcheol Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Groundwater Level ◽  
Seismic Waves ◽  
Groundwater Resources ◽  
Fluid Pressure ◽  
Water Levels ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Gyeongju Earthquake

AbstractHydrogeological responses to earthquakes such as changes in groundwater level, temperature, and chemistry, have been observed for several decades. This study examines behavior associated with ML 5.8 and ML 5.1 earthquakes that occurred on 12 September 2016 near Gyeongju, a city located on the southeast coast of the Korean peninsula. The ML 5.8 event stands as the largest recorded earthquake in South Korea since the advent of modern recording systems. There was considerable damage associated with the earthquakes and many aftershocks. Records from monitoring wells located about 135 km west of the epicenter displayed various patterns of change in both water level and temperature. There were transient-type, step-like-type (up and down), and persistent-type (rise and fall) changes in water levels. The water temperature changes were of transient, shift-change, and tendency-change types. Transient changes in the groundwater level and temperature were particularly well developed in monitoring wells installed along a major boundary fault that bisected the study area. These changes were interpreted as representing an aquifer system deformed by seismic waves. The various patterns in groundwater level and temperature, therefore, suggested that seismic waves impacted the fractured units through the reactivation of fractures, joints, and microcracks, which resulted from a pulse in fluid pressure. This study points to the value of long-term monitoring efforts, which in this case were able to provide detailed information needed to manage the groundwater resources in areas potentially affected by further earthquakes.

scholarly journals The Role of Environmental Background Processes in Determining Groundwater Level Variability—An Investigation of a Record Flood Event Using Dynamic Factor Analysis

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2336
Author(s):  
Balázs Trásy ◽  
Norbert Magyar ◽  
Tímea Havril ◽  
József Kovács ◽  
Tamás Garamhegyi
Keyword(s):  
Factor Analysis ◽  
Groundwater Level ◽  
Coefficient Of Determination ◽  
Dynamic Factor Analysis ◽  
Dynamic Factor ◽  
Climate Change Scenarios ◽  
Background Factors ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Environmental Background

Since groundwater is a major source of water for drinking and for industrial and irrigation uses, the identification of the environmental processes determining groundwater level fluctuation is potentially a matter of great consequence, especially in light of the fact that the frequency of extreme climate events may be expected to increase, causing changes in groundwater recharge systems. In the recent study, data measured at a frequency of one hour were collected from the Szigetköz, an inland delta of the Danube. These were then used to determine the presence, or not, and magnitude of any hidden environmental background factors that may be causing groundwater level fluctuations. Through the application of dynamic factor analysis, it was revealed that changes in groundwater level are mainly determined by (i) the water level of neighboring rivers and (ii) evapotranspiration. The intensity of these factors may also be estimated spatially. If the background factors determined by dynamic factor analysis do indeed figure in the linear model as variables, then the time series of groundwater levels can be said to have been accurately estimated with the use of linear regression. The accuracy of the estimate is indicated by the fact that adjusted coefficient of determination exceeds 0.9 in 80% of the wells. The results, via an enhanced understanding of the reasons for changes in the fluctuation of groundwater, could assist in the development of sustainable water management and irrigation strategies and the preparation for varying potential climate change scenarios.

scholarly journals Groundwater Modeling with Machine Learning Techniques: Ljubljana polje Aquifer

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 697 ◽  
Author(s):  
Klemen Kenda ◽  
Matej Čerin ◽  
Mark Bogataj ◽  
Matej Senožetnik ◽  
Kristina Klemen ◽  
...  
Keyword(s):  
Machine Learning ◽  
Groundwater Level ◽  
Groundwater Modeling ◽  
Machine Learning Techniques ◽  
Physical Parameters ◽  
Strongly Correlated ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Decision Making Processes ◽  
Input Variables

In this study a thorough analysis is conducted concerning the prediction of groundwater levels of Ljubljana polje aquifer. Machine learning methodologies are implemented using strongly correlated physical parameters as input variables. The results show that data-driven modelling approaches can perform sufficiently well in predicting groundwater level changes. Different evaluation metrics confirm and highlight the capability of these models to catch the trend of groundwater level fluctuations. Despite the overall adequate performance, further investigation is needed towards improving their accuracy in order to be comprised in decision making processes.

Quantification of the impact of lunar semidiurnal tides on groundwater dynamics in estuarine aquifers

2020 ◽  
Author(s):  
Xiaoying Zhang ◽  
Zhenxue Dai ◽  
Bill Hu ◽  
Heng Dai ◽  
Ziqi Ma ◽  
...  
Keyword(s):  
River Estuary ◽  
Pearl River Estuary ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Groundwater Dynamics ◽  
Groundwater Aquifers ◽  
Tidal Constituents ◽  
The Pearl River ◽  
Heterogeneous Sediments ◽  
The Impact

<p>The influences of lunar semidiurnal tides on coastal groundwater aquifers have been conceptualized for decades. However, in estuarine aquifers, comprehensive work is needed to quantify the impact of the tides on groundwater dynamics due to the widely distributed waterways and heterogeneous sediments. Taking the Pearl River estuary in southeast China as a study site, the tidal impacts on the groundwater dynamics have been investigated through wavelet and time series analysis. The groundwater level and electrical conductivity (EC) in four monitoring wells, along with waterway water level (tidal level) at three tidal stations, were monitored every 30 minutes over a 2-month period to determine how nearshore groundwater responds to tidal forcing. The results show that the estuarine groundwater fluctuations have two significant short periodicities (0.51 and 1 day), which correspond to the major tidal constituents in the tides: M<sub>2</sub><sub> </sub>(semidiurnal), K<sub>1</sub><sub> </sub>and O<sub>1</sub> (diurnal) signals. The significant impacts decrease with increasing distance inland of the locations of the wells. Additionally, the coherence analysis displays a higher correlation between tides and groundwater levels for the spring tide than for the neap tide. The tidal influences on groundwater EC are weaker. In addition, when the tide level increases, the EC decreases in the wells located in the estuarine entrance. This phenomenon is related to the high salinity of retained paleo-seawater in the strata lens. A conceptual model is proposed to illustrate the complex groundwater flow dynamics, which provides useful insights into understanding groundwater systems in other geographically similar coastal estuarine regions.</p>

scholarly journals Modelling groundwater level fluctuation in an Indian coastal aquifer

Water SA ◽  
2020 ◽  
Vol 46 (4 October) ◽  
Author(s):  
Safieh Javadinejad ◽  
Rebwar Dara ◽  
Forough Jafary
Keyword(s):  
Groundwater Level ◽  
Coastal Aquifer ◽  
M5 Model Tree ◽  
Groundwater Levels ◽  
Proposed Model ◽  
Soft Computing Techniques ◽  
Input Variables ◽  
Lag Times ◽  
Observation Wells

Estimating groundwater level (GWL) fluctuations is a vital requirement in hydrology and hydraulic engineering, and is commonly addressed through artificial intelligence (AI) models. The purpose of this research was to estimate groundwater levels using new modelling methods. The implementation of two separate soft computing techniques, a multilayer perceptron neural network (MLPNN) and an M5 model tree (M5-MT), was examined. The models are used in the estimation of monthly GWLs observed in a shallow unconfined coastal aquifer. Data for the water level were collected from observation wells located near Ganjimatta, India, and used to estimate GWL fluctuation. To do this, two scenarios were provided to achieve optimal input variables for modelling the GWL at the present time. The input parameters applied for developing the proposed models were a monthly time-series of summed rainfall, the mean temperature (within its lag times that have an effect on groundwater), and historical GWL observations throughout the period 1996–2006. The efficiency of each proposed model for Ganjimatt was investigated in stages of trial and error. A performance evaluation showed that the M5-MT outperformed the MLPNN model in estimating the GWL in the aquifer case study. Based on the M5-MT approach, the development of this model gives acceptable results for the Indian coastal aquifers. It is recommended that water managers and decision makers apply these new methods to monitor groundwater conditions and inform future planning.

scholarly journals Modelling of the Complex Groundwater Level Dynamics during Episodic Rainfall Events of a Surficial Aquifer in Southern Italy

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2916
Author(s):  
Nicola Pastore ◽  
Claudia Cherubini ◽  
Angelo Doglioni ◽  
Concetta Immacolata Giasi ◽  
Vincenzo Simeone
Keyword(s):  
Groundwater Level ◽  
Southern Italy ◽  
Infiltration Rate ◽  
Water Volume ◽  
Rainfall Events ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Groundwater Supply ◽  
Non Linear ◽  
Surficial Aquifer

We analyzed the complex dynamics that are involved the groundwater level variations due to the episodic rainfall supply in the Ionian coastal plain surficial aquifer located in Southern Italy. In this aquifer, as a consequence of the particular hydrogeological framework, both direct and lateral recharge mechanisms coexist. Hence, the dynamics of groundwater level variations are quite complex and strongly non-linear. Our focus was essentially on the short-term behavior of groundwater levels, with a specific analysis on episodic rainfall events. To model these dynamics, due to the presence of the preferential pathways in the infiltration processes, a kinematic dispersion wave model was used. Specifically, a one-dimensional and non-linear particle-based numerical model was developed. It uses ideal particles with constant water volume travel, according to celerity and hydraulic dispersion, to simulate the infiltration rate wave through the vadose zone. The infiltration rate that reaches the water table represents the input function to evaluate the aquifer groundwater level fluctuations. As a consequence of the special lithological and storage capacity characteristics of the surficial layers, groundwater flow conditions change from unconfined to confined. The developed model analyzes the direct groundwater supply under natural conditions, including episodic rainfall, and it has been validated using a high-resolution time series of rainfall data and groundwater level obtained from the monitoring station Terra Montonata.

scholarly journals The dynamics of cultivation and floods in arable lands of Central Argentina

2009 ◽  
Vol 13 (4) ◽  
pp. 491-502 ◽  
Author(s):  
E. F. Viglizzo ◽  
E. G. Jobbágy ◽  
L. Carreño ◽  
F. C. Frank ◽  
R. Aragón ◽  
...  
Keyword(s):  
Land Use ◽  
Groundwater Level ◽  
Time Lag ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Central Argentina ◽  
Cyclic Mechanism ◽  
Subsurface Lateral Flow ◽  
Flooded Area ◽  
One Year

Abstract. Although floods in watersheds have been associated with land-use change since ancient times, the dynamics of flooding is still incompletely understood. In this paper we explored the relations between rainfall, groundwater level, and cultivation to explain the dynamics of floods in the extremely flat and valuable arable lands of the Quinto river watershed, in central Argentina. The analysis involved an area of 12.4 million hectare during a 26-year period (1978–2003), which comprised two extensive flooding episodes in 1983–1988 and 1996–2003. Supported by information from surveys as well as field and remote sensing measurements, we explored the correlation among precipitation, groundwater levels, flooded area and land use. Flood extension was associated to the dynamics of groundwater level. While no correlation with rainfall was recorded in lowlands, a significant correlation (P<0.01) between groundwater and rainfall in highlands was found when estimations comprise a time lag of one year. Correlations between groundwater level and flood extension were positive in all cases, but while highly significant relations (P<0.01) were found in highlands, non significant relations (P>0.05) predominate in lowlands. Our analysis supports the existence of a cyclic mechanism driven by the reciprocal influence between cultivation and groundwater in highlands. This cycle would involve the following stages: (a) cultivation boosts the elevation of groundwater levels through decreased evapotranspiration; (b) as groundwater level rises, floods spread causing a decline of land cultivation; (c) flooding propitiates higher evapotranspiration favouring its own retraction; (d) cultivation expands again following the retreat of floods. Thus, cultivation would trigger a destabilizing feedback self affecting future cultivation in the highlands. It is unlikely that such sequence can work in lowlands. The results suggest that rather than responding directly and solely to the same mechanism, floods in lowlands may be the combined result of various factors like local rainfall, groundwater level fluctuations, surface and subsurface lateral flow, and water-body interlinking. Although the hypothetical mechanisms proposed here require additional understanding efforts, they suggest a promising avenue of environmental management in which cultivation could be steered in the region to smooth the undesirable impacts of floods.

scholarly journals The Effect Of Rainfall Relationship periode 2003 – 2013 Of Groundwater South Jakarta Region

2020 ◽  
Vol 11 (3) ◽  
pp. 125
Author(s):  
Arini Dian ◽  
Nana Sulaksana ◽  
A. Asseggaf
Keyword(s):  
Groundwater Level ◽  
Rainy Season ◽  
Rainfall Intensity ◽  
Rainfall Event ◽  
Clean Water ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Fine Grained ◽  
Groundwater Basin

ABSTRAKKebutuhan air bersih di Jakarta sangat meningkat sehingga pemerintah daerah mulai melakukan pengamatan muka airtanah. Penelitian ini dilakukan dengan menganalisis fluktuasi muka airtanah pada AWLR, intensitas curah hujan, dan penampang bawah permukaan pada beberapa buah titik logbor selama tahun 2003 - 2013 di wilayah Jakarta Selatan. Jumlah curah hujan di daerah penelitian berkisar antara 0,2 - 831,4 mm/bulan. Dari data AWLR dapat diketahui ketinggian muka airtanah berkisar antara 9,29 - 13,97 m aml, terdangkal terjadi pada bulan Oktober - Febuari (ketika musim penghujan) dan ketinggian muka airtanah terdalam berkisar antara14,60 - 20,41 m aml terjadi pada bulan Maret - September (ketika musim kemarau). Penelitian ini dilakukan untuk mengidentifikasi adanya pengaruh hubungan curah hujan dan muka airtanah dengan karakteristik sistem akuifer yang berada pada daerah penelitian sekitarnya khususnya di Jakarta Selatan. Berdasarkan analisis tenggang waktu dan fluktuasi muka airtanah yang dipengaruhi oleh intensitas curah hujan.Serta adanya lapisan akuitar pada penampang geologi dan posisi muka airtanah yang terdapat dibagian atas lapisan akuifer, maka dapat dikatakan bahwa sistem akuifer yang terdapat di daerah penelitian bersifat semi tertekan. Sistem akuifer tersebut pada bagian atasnya merupakan material berbutir halus (akuitar) sehingga airtanah masih memungkinkan untuk bergerak di dalamnya.Kata kunci: airtanah, AWLR, curah hujan, fluktuasi, JakartaABSTRACTThe need for clean water in Jakarta has increased significantly, so the groundwater levels of Jakarta Groundwater Basin need to be researched. This research was conducted by analyzing the fluctuation of the groundwater level using the AWLR data, rainfall intensity, and subsurface sections to several logbor during the year of 2003 - 2013 in South Jakarta area. Rainfall event in the area is in range of 0.2 mm/year up to 831.4 mm/year. From the AWLR data, the highest groundwater level were at 9.29 - 13.97 masl in October - Febuari (during rainy season) and the deepest groundwater level were at 14.60 - 20.41 masl) in March - September (during dry season). Based on the analysis of the timescale and the groundwater level fluctuations that influenced by rainfall, and the aquitard layer in the geology section, and groundwater level exist above the aquifer, so that the aquifer system in this regions is classified as semi depressed aquifer. In this aquifer system, the underlying material is fine grained (aquitard) that allows groundwater moving inside the layer.Keywords: groundwater, AWLR, rainfall, fluctuation, Jakarta

Sign in / Sign up

Export Citation Format

Share Document