scholarly journals Analysis of groundwater table variability and trend using ordinary kriging: the case study of Sylhet, Bangladesh

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Khairul Hasan ◽  
Sondipon Paul ◽  
Tareq Jamal Chy ◽  
Anzhelika Antipova
Keyword(s):  
Developing Countries ◽  
Water Table ◽  
Groundwater Level ◽  
Ordinary Kriging ◽  
Groundwater Resources ◽  
Monitoring Network ◽  
Spatial And Temporal Variation ◽  
Geostatistical Methods ◽  
Management Actions ◽  
Observation Wells

AbstractMany developing countries experience widespread groundwater declination. Sustainable management actions include generation of an accurate groundwater distribution based on an extensive groundwater monitoring network which is often cost prohibiting in the context of a developing country such as Bangladesh. Further, such knowledge is lacking for the Sylhet region where groundwater was documented to be under tremendous pressure. Specifically, the gap in the current literature exists regarding groundwater trends and its areal extent for this region. This paper bridges the gap in research by focusing on trends and spatial and temporal variation of groundwater level changes for this area. This study addresses this problem by creating groundwater level predictions at the ungauged areas using geostatistical methods applied to a detailed set of data. In this study, the spatial variability of annual-average depth to the water table at 46 observation wells in the Sylhet division in Bangladesh is analyzed for 2000, 2005, 2010, and 2015. The geostatistical analysis applies the ordinary kriging method with cross-validation to create the water table maps for the study area. The results indicate a substantial increase in groundwater depths during the studied period from 2000 to 2015 in some locations in the study area. Importantly, this work identifies the vulnerable zones in the area due to the groundwater lowering trend. The study adds to the groundwater management research in developing countries and focuses on the spatial and temporal groundwater variation. The findings from the modeling exercise contribute to identification of the vulnerable areas and therefore help policymakers in making informed decisions to manage groundwater resources in this sensitive region sustainably.

Design of Groundwater Level Monitoring Network with Ordinary Kriging

2008 ◽  
Vol 20 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Feng-guang Yang ◽  
Shu-you Cao ◽  
Xing-nian Liu ◽  
Ke-jun Yang
Keyword(s):  
Groundwater Level ◽  
Ordinary Kriging ◽  
Monitoring Network ◽  
Level Monitoring

scholarly journals A decision support tool for optimising groundwater-level monitoring networks using an adaptive genetic algorithm

2021 ◽  
Author(s):  
Antonios Parasyris ◽  
Katerina Spanoudaki ◽  
Emmanouil A. Varouchakis ◽  
Nikolaos A. Kampanis
Keyword(s):  
Genetic Algorithm ◽  
Groundwater Level ◽  
Monitoring Network ◽  
Decision Support Tool ◽  
Adaptive Method ◽  
Adaptive Genetic Algorithm ◽  
Monitoring Networks ◽  
Support Tool ◽  
Groundwater Levels ◽  
Geostatistical Methods

Abstract Mapping of the spatial variability of sparse groundwater-level measurements is usually achieved by means of geostatistical methods. This work tackles the problem of deficient sampling of an aquifer, by employing an innovative integer adaptive Genetic Algorithm (iaGA) coupled with geostatistical modelling by means of ordinary kriging, to optimise the monitoring network. Fitness functions based on three different errors are used for removing a constant number of boreholes from the monitoring network. The developed methodology has been applied to the Mires basin in Crete, Greece. The methodological improvement proposed concerns the adaptive method for the GA, which affects the crossover–mutation fractions depending on the stall parameter, aiming at higher accuracy and faster convergence of the GA. The initial dataset consists of 70 monitoring boreholes and the applied methodology shows that as many as 40 boreholes can be removed, while still retaining an accurate mapping of groundwater levels. The proposed scenario for optimising the monitoring network consists of removing 30 boreholes, in which case the estimated uncertainty is considerably smaller. A sensitivity analysis is conducted to compare the performance of the standard GA with the proposed iaGA. The integrated methodology presented is easily replicable for other areas for efficient monitoring networks design.

scholarly journals Evaluation of drought impact on groundwater recharge rate using SWAT and Hydrus models on an agricultural island in western Japan

2015 ◽  
Vol 371 ◽  
pp. 143-148 ◽  
Author(s):  
G. Jin ◽  
Y. Shimizu ◽  
S. Onodera ◽  
M. Saito ◽  
K. Matsumori
Keyword(s):  
Groundwater Recharge ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Water Discharge ◽  
Swat Model ◽  
Spatial And Temporal Variation ◽  
Hydrological Process ◽  
Aquifer Recharge ◽  
Recharge Rate ◽  
Groundwater Recharge Rate

Abstract. Clarifying the variations of groundwater recharge response to a changing non-stationary hydrological process is important for efficiently managing groundwater resources, particularly in regions with limited precipitation that face the risk of water shortage. However, the rate of aquifer recharge is difficult to evaluate in terms of large annual-variations and frequency of flood events. In our research, we attempt to simulate related groundwater recharge processes under variable climate conditions using the SWAT Model, and validate the groundwater recharge using the Hydrus Model. The results show that annual average groundwater recharge comprised approximately 33% of total precipitation, however, larger variation was found for groundwater recharge and surface runoff compared to evapotranspiration, which fluctuated with annual precipitation variations. The annual variation of groundwater resources is shown to be related to precipitation. In spatial variations, the upstream is the main surface water discharge area; the middle and downstream areas are the main groundwater recharge areas. Validation by the Hydrus Model shows that the estimated and simulated groundwater levels are consistent in our research area. The groundwater level shows a quick response to the groundwater recharge rate. The rainfall intensity had a great impact on the changes of the groundwater level. Consequently, it was estimated that large spatial and temporal variation of the groundwater recharge rate would be affected by precipitation uncertainty in future.

scholarly journals Estimation of Groundwater Evapotranspiration of Different Dominant Phreatophytes in the Mu Us Sandy Region

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 440
Author(s):  
Wuhui Jia ◽  
Lihe Yin ◽  
Maosheng Zhang ◽  
Kun Yu ◽  
Luchen Wang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Table ◽  
Groundwater Resources ◽  
Limited Area ◽  
Populus Alba ◽  
Mean Values ◽  
Pressure Transducers ◽  
Groundwater Evapotranspiration ◽  
Diurnal Water Table Fluctuations ◽  
Observation Wells

Groundwater evapotranspiration (ETG) estimation is an important issue in semiarid areas for groundwater resources management and environmental protection. It is widely estimated by diurnal water table fluctuations. In this study, the ETG at four sites with different plants was estimated using both diurnal water table and soil moisture fluctuations in the northeastern Mu Us sandy region, in order to identify the groundwater utilization strategy by different dominant phreatophytes. Groundwater level was monitored by ventilatory pressure transducers (Solinst LevelVent, Solinst Canada Ltd.; accuracy ±3 mm), while soil moisture was monitored using EM50 loggers (Decagon Devices Inc., Pullman, USA) in K1 and K14 and simulated by Hydrus-1D in other observation wells. A significant spatial variation of ETG was found within a limited area, indicating a poor representativeness of site ETG for regional estimation. The mean values of ETG are 4.01 mm/d, 6.03 mm/d, 8.96 mm/d, and 12.26 mm/d at the Achnatherum splendens site, Carex stenophylla site, Salix psammophila site and Populus alba site, respectively, for the whole growing season. ETG is more sensitive to depth to water table (DWT) in the Carex stenophylla site than in the Achnatherum splendens site for grass-dominated areas and more sensitive to DWT in the Populus alba site than in Salix psammophila site for tree-dominated areas. Groundwater extinction depths are estimated at 4.1 m, 2.4 m, 7.1 m, and 2.9 m in the Achnatherum splendens site, Carex stenophylla site, Salix psammophila site and Populus alba site, respectively.

scholarly journals ASSESSMENT OF SPATIO-TEMPORAL FLUCTUATIONS IN GROUNDWATER LEVEL AND ITS IMPACT ON TUBEWELL ENERGY NEXUS

2020 ◽  
pp. 161-165
Author(s):  
Hafiz M. Awais ◽  
Aamir Shakoor
Keyword(s):  
Water Table ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Management Strategies ◽  
Canal Water ◽  
Shallow Water Table ◽  
Total Cost ◽  
North East ◽  
Spatio Temporal ◽  
Over Exploitation

Over exploitation of groundwater to fulfill the crop water requirements due to insufficient canal water supply can pose a major threat of water table lowering in semi-arid regions like Pakistan. So, it is necessary to analyze the seasonal groundwater level variations for appropriate management strategies to sustainable groundwater use. Water table declining has adverse economic impacts on total cost of agricultural inputs, as more than 50% of irrigation demand is being fulfilled from groundwater resources. Therefore, this research was aimed to draw the groundwater level zones and to determine the impacts of lowering water table on tubewell energy nexus in district Hafizabad, Pakistan. Water table depth was categorized in three zones i.e., shallow (<10 m), moderate (10-15 m) and deep (>15 m) for years 2003, 2008 and 2013. It was found that water table was shallow on north-east boundary, moderate on the Centre and deep on west-south boundary. During the study period, the area under shallow water table zone reduced from 38.6 to 23%, moderate area expanded from 52.3 to 59.2% and deep area increased from 9.1 to 17.9%. The difference between total cost of shallow and moderate water table was minor. The total cost (construction and operational) of tubewell for 36 m deep water table was 3 times higher than shallow depth (9 m). Thus, lowering of water table should be controlled by increasing share of canal water in deeper zone and introducing artificial recharge methods

Update of the Surat Underground Water Impact Report

2016 ◽  
Vol 56 (2) ◽  
pp. 547
Author(s):  
Randall Cox ◽  
Keith Phillipson
Keyword(s):  
Groundwater Flow ◽  
Water Pressure ◽  
Groundwater Resources ◽  
Monitoring Network ◽  
Underground Water ◽  
Water Monitoring ◽  
Water Extraction ◽  
Water Impact ◽  
Management Actions ◽  
The Impact

The production of coal seam gas (CSG) involves the pumping of large volumes of groundwater to lower water pressure in coal seams. This has the potential to affect groundwater resources in the coal-bearing formations and in adjacent aquifers connected to the coal formations. The formations that are the target for CSG development in the Surat Basin in Queensland are part of the Great Artesian Basin multi-layered aquifer system and also underlie important alluvial water resources. There are multiple major CSG projects being developed in the area. Queensland has a regulatory framework to manage the impact of CSG water extraction on groundwater resources that includes cumulative management arrangements for areas of intensive development, where the groundwater impacts of multiple projects overlap. In a declared Cumulative Management Area, the Office of Groundwater Impact Assessment (OGIA) carries out a regional assessment of impacts of CSG water extraction, specifies an integrated regional water monitoring network, and assigns responsibilities to individual CSG companies to implement individual parts of the water monitoring network and other management actions. OGIA sets out the results in an underground water impact report (UWIR), which on approval becomes a statutory instrument. OGIA is an independent entity fully funded by a levy on petroleum tenure holders. The first Surat UWIR was approved in 2012. In early 2016, OGIA revised the Surat UWIR using a new regional groundwater flow model that incorporates updated knowledge of the groundwater flow system. The key content of the revised Surat UWIR is presented.

scholarly journals Future Projected Groundwater Level Trend Analysis using GIS Techniques

2020 ◽  
Vol 9 (4) ◽  
pp. 1286-1294
Keyword(s):  
Trend Analysis ◽  
Urban Sprawl ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Level Fluctuation ◽  
Gis Techniques ◽  
Groundwater Level Fluctuation ◽  
High Population Growth ◽  
Spatio Temporal ◽  
Observation Wells

High Population Growth and increase the urban sprawl in earth to less the groundwater resources causes degradation of groundwater Level in India. Water is very important for our life and natural resources. There are various uses of groundwater just as drinking, irrigation, and manufacturing. Today we are facing the shortage of groundwater level. The main goal of study is, because of increase in the population there is increase the number of bore well in earth surface this the reason to declination of groundwater level, so in these study to analysis of spatio-temporal changes in groundwater level fluctuation in Bhopal district in Madhya Pradesh, India. According to censes in Huzur Tehsil, M.P, Bhopal District, in 2001 population is 1429132 and 2011 population is 1834493. Collected the total of 350 observation wells Huzur Tehsil, Bhopal district for point observations. And using the GIS techniques spatial Analysis tools in ArcGIS10.5 to find out different Change of Groundwater Level Fluctuation since period (1996-2015) and using Matlab to generate the GWL (groundwater level) modeling .Generate the Future projected Groundwater level Fluctuation(2016-2050) and Trend Analysis of Groundwater Level (1996-2015) and Future Projected Groundwater level (2016-2050).

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 A New Automatic Monitoring Network of Surface Waters in Greece: Preliminary Data Quality Checks and Visualization

Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 33
Author(s):  
Yiannis Panagopoulos ◽  
Anna Konstantinidou ◽  
Konstantinos Lazogiannis ◽  
Anastasios Papadopoulos ◽  
Elias Dimitriou
Keyword(s):  
Data Quality ◽  
Surface Waters ◽  
Data Dissemination ◽  
Monitoring Program ◽  
Monitoring Network ◽  
Automatic Monitoring ◽  
Water Monitoring ◽  
Marine Research ◽  
Management Actions ◽  
Quality Checks

The monitoring of surface waters is of fundamental importance for their preservation under good quantitative and qualitative conditions, as it can facilitate the understanding of the actual status of water and indicate suitable management actions. Taking advantage of the experience gained from the coordination of the national water monitoring program in Greece and the available funding from two ongoing infrastructure projects, the Institute of Inland Waters of the Hellenic Centre for Marine Research has developed the first homogeneous real-time network of automatic water monitoring across many Greek rivers. In this paper, its installation and maintenance procedures are presented with emphasis on the data quality checks, based on values range and variability tests, before their online publication and dissemination to end-users. Preliminary analyses revealed that the water pH and dissolved oxygen (DO) sensors and produced data need increased maintenance and quality checks respectively, compared to the more reliably recorded water stage, temperature (T) and electrical conductivity (EC). Moreover, the data dissemination platform and selected data visualization options are demonstrated and the need for both this platform and the monitoring network to be maintained and potentially expanded after the termination of the funding projects is highlighted.

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