scholarly journals Modelling Groundwater Hydraulics to Design a Groundwater Level Monitoring Network for Sustainable Management of Fresh Groundwater Lens in Lower Indus Basin, Pakistan

2020 ◽  
Vol 10 (15) ◽  
pp. 5200
Author(s):  
Waqas Ahmed ◽  
Zulfiqar Ali Rahimoon ◽  
Carlos Anthony Oroza ◽  
Salman Sarwar ◽  
Abdul Latif Qureshi ◽  
...  
Keyword(s):  
Monitoring Network ◽  
Principal Component ◽  
Water Levels ◽  
Indus Basin ◽  
Hydrogeological Model ◽  
Fresh Groundwater ◽  
Groundwater Levels ◽  
Hexagonal Pattern ◽  
Lower Indus Basin ◽  
Absolute Residual

The over-extraction of groundwater from thin fresh groundwater lenses is a threat to the livelihood of farmers in the Lower Indus Basin (LIB). It is essential to monitor and regulate this pumping to sustain fresh groundwater lenses. In this study, we applied a modelling approach in combination with geostatistical analysis to identify the critical locations to monitor the groundwater levels for sustaining fresh groundwater in the LIB. Our approach included four steps: (i) simulating temporal heads using a calibrated hydrogeological model; (ii) sampling monitoring locations using a hexagonal pattern of sampling; (iii) applying principal component analysis (PCA) of the temporal head observations, and selecting high scoring locations from the PCA; and (iv) minimizing the observation points to represent the water level contours. The calibrated model was able to replicate the hydro-dynamic behavior of the study area, with a root mean square of 0.95 and an absolute residual mean of 0.74 m. The hexagonal pattern of spatial sampling resulted in a 195 point network, but PCA reduced this network to 135 points and contour classification reduced it even further to 59 points. The 195, 135, and 59 point networks represented the water levels with average standard errors of 0.098, 0.318, and 0.610 m, respectively. Long-term simulations with increased pumping showed that the water levels would best be assessed by 195 monitoring points, although 135 and 59 points would represent the depleting area but would not capture the water logging area.

scholarly journals Effects on the groundwater levels of the May-June 2012 Emilia seismic sequence

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Marco Marcaccio ◽  
Giovanni Martinelli
Keyword(s):  
Monitoring Network ◽  
Automatic Monitoring ◽  
Water Levels ◽  
Sudden Increase ◽  
Seismic Sequence ◽  
Epicentral Area ◽  
Groundwater Levels ◽  
The Past ◽  
Set Up ◽  
Romagna Area

<p>A variety of phenomena were observed in the groundwaters in concomitance with the May-June 2012 seismic sequence that occurred in the Emilia Romagna area. In particular, phreatic wells close to the epicentral area were affected by a sudden increase in water level of up to 4 m. In some cases, the sands of aquifers were ejected outside wells, and &gt;700 liquefaction phenomena were recorded [Bertolini and Fioroni 2012, this volume]. Some automatic stations of the regional well network recorded variations in well levels. These data can be considered useful to understand the relationships between seismic events and the local groundwaters [see also Italiano et al. 2012, this volume]. […] In 1976, a regional network composed of 330 wells was set up with the purpose of monitoring the groundwater levels using manual techniques. These data have been used for environmental purposes and for water management. In recent years, the monitoring network managed by Agenzia Regionale Prevenzione e Ambiente (ARPA) has increased the number of wells (to about 600), and chemical analyses are also periodically carried out for environmental monitoring activities. In the past three years, an automatic monitoring network composed of 40 stations was set up and this has allowed the monitoring of the water levels and the temperatures, at a rate of one measure per hour, and to broadcast the data to the host center located in Bologna. […]</p>

Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 191
Author(s):  
Sherwan Sh. Qurtas
Keyword(s):  
Unconfined Aquifer ◽  
Middle Part ◽  
Water Levels ◽  
Specific Yield ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Water Table Fluctuation Method ◽  
Recharge Estimation ◽  
Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

scholarly journals Design of Optimal Rainfall Monitoring Network Using Radar and Road Networks

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 378
Author(s):  
Taeyong Kwon ◽  
Seongsim Yoon ◽  
Sanghoo Yoon
Keyword(s):  
Road Networks ◽  
Monitoring Network ◽  
Conditional Entropy ◽  
Radar Data ◽  
Disaster Risk ◽  
Water Levels ◽  
The Road ◽  
Dam Operation ◽  
A Site ◽  
High Degree

Uncertainty in the rainfall network can lead to mistakes in dam operation. Sudden increases in dam water levels due to rainfall uncertainty are a high disaster risk. In order to prevent these losses, it is necessary to configure an appropriate rainfall network that can effectively reflect the characteristics of the watershed. In this study, conditional entropy was used to calculate the uncertainty of the watershed using rainfall and radar data observed from 2018 to 2019 in the Goesan Dam and Hwacheon Dam watersheds. The results identified radar data suitable for the characteristics of the watershed and proposed a site for an additional rainfall gauge. It is also necessary to select the location of the additional rainfall gauged by limiting the points where smooth movement and installation, for example crossing national borders, are difficult. The proposed site emphasized accessibility and usability by leveraging road information and selecting a radar grid near the road. As a practice result, the uncertainty of precipitation in the Goesan and Hwacheon Dam watersheds could be decreased by 70.0% and 67.9%, respectively, when four and three additional gauge sites were installed without any restriction. When these were installed near to the road, with five and four additional gauge sites, the uncertainty in the Goesan Dam and Hwacheon Dam watersheds were reduced by up to 71.1%. Therefore, due to the high degree of uncertainty, it is necessary to measure precipitation. The operation of the rainfall gauge can provide a smooth site and configure an appropriate monitoring network.

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 An Overview of CBM Resources in Lower Indus Basin, Sindh, Pakistan

2017 ◽  
Vol 06 (01) ◽  
Author(s):  
Nazeer A ◽  
Habib Shah S ◽  
Abbasi SA ◽  
Solangi SH ◽  
Ahmad N
Keyword(s):  
Indus Basin ◽  
Lower Indus Basin

scholarly journals Gas-bearing sands appraisal for Zamzama Gas field in Pakistan through inverted elastic attributes assisted with PNN approximation of petrophysical properties

2021 ◽  
Author(s):  
Zahid U. Khan ◽  
◽  
Mona Lisa ◽  
Muyyassar Hussain ◽  
Syed A. Ahmed ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Clay Content ◽  
Seismic Inversion ◽  
Indus Basin ◽  
Minimal Risk ◽  
Gas Field ◽  
Lower Indus Basin ◽  
Heterogeneity Effects ◽  
Prestack Seismic Inversion ◽  
Gas Bearing

The Pab Formation of Zamzama block, lying in the Lower Indus Basin of Pakistan, is a prominent gas-producing sand reservoir. The optimized production is limited by water encroachment in producing wells, thus it is required to distinguish the gas-sand facies from the remainder of the wet sands and shales for additional drilling zones. An approach is adopted based on a relation between petrophysical and elastic properties to characterize the prospect locations. Petro-elastic models for the identified facies are generated to discriminate lithologies in their elastic ranges. Several elastic properties, including p-impedance (11,600-12,100 m/s*g/cc), s-impedance (7,000-7,330 m/s*g/cc), and Vp/Vs ratio (1.57-1.62), are calculated from the simultaneous prestack seismic inversion, allowing the identification of gas sands in the field. Furthermore, inverted elastic attributes and well-based lithologies are incorporated into the Bayesian framework to evaluate the probability of gas sands. To better determine reservoir quality, bulk volumes of PHIE and clay are estimated using elastic volumes trained on well logs employing Probabilistic Neural Networking (PNN), which effectively handles heterogeneity effects. The results showed that the channelized gas-sands passing through existing well locations exhibited reduced clay content and maximum effective porosities of 9%, confirming the reservoir's good quality. Such approaches can be widely implemented in producing fields to completely assess litho-facies and achieve maximum production with minimal risk.

scholarly journals Assessment of the groundwater quantitative status in the Aosta Plain (North-West Italy): applicability of the national guidelines defined by ISPRA

2020 ◽  
Author(s):  
Gennaro A. Stefania ◽  
Michele Bigoni ◽  
Chiara Zanotti ◽  
Marco Rotiroti ◽  
Fulvio Simonetto ◽  
...  
Keyword(s):  
Monitoring Network ◽  
Water Bodies ◽  
National Guidelines ◽  
Groundwater Levels ◽  
North West ◽  
Future Assessment ◽  
Surface Water Bodies ◽  
Nw Italy ◽  
The Eu ◽  
Critical Aspects

The EU Water Framework Directive requires Member States to assess the quantitative and qualitative status of groundwater bodies and to achieve a good status by 2027. The present study was developed in order to assess the groundwater quantitative status in the Aosta Plain (NW Italy), following the methodology proposed through a guideline defined by the Italian Institute for Environmental Protection and Research (ISPRA), with the aim of supporting local authorities in their periodic assessment of water bodies status. In the study area, during the period 2000-2017, groundwater levels were measured in 213 wells and piezometers. Performing the four tests required by the abovementioned guideline, the quantitative status was assessed on the basis of multi-year groundwater level variations, water balance and the interconnections of groundwater with surface water bodies and groundwaterdependent ecosystems. A good status was assessed for the study area, although some critical aspects emerged from the application of the guideline methodology: the data collected by the monitoring network are not sufficiently robust in terms of sample size, spatial distribution, temporal interval and frequency to fulfill the requirements of the guideline methodology. Therefore, some recommendations to improve the data quality and better address the future assessment of groundwater quantitative status were given.

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