Groundwater Level At Two Different Locations Biology Essay
The chief undertakings for this undertaking are making desk survey and field survey on groundwater degree at two different locations in Belfast. The locations of the boreholes which have been chosen for this undertaking are Lady Dixon and Orchardville which located at River Lagan. The informations are collected and extracted from the well, and so it has to be analyzed and evaluated.
This undertaking has been supervised by Dr. Ulrich Ofterdinger.Data has been gathered from different beginnings such as the old research workers from Queen ‘s University Belfast, Geological Survey of Northern Ireland ( GSNI ) and Northern Ireland Environmental Agency ( NIEA ) . Based on the information gathered, the history of the country showed that there is fluctuation on the H2O degree twelvemonth by twelvemonth. In the technology field, the features and behaviour of the groundwater are of import to cognize as it is needed in the planning of a building undertaking of a edifice or any constructions. Groundwater is still a valuable beginning of H2O for imbibing H2O and for mundane use. The informations are utile as it gives the belongingss and behaviour of the aquifers of the two different locations.
Degree centigrades: UsersAmniPicturesUntitled.pngFigure 1 shows where the location of the recorded information taken. The xanthous grade represents the site location.All the informations have been collected and used for this study is from 7th October 2009 to 28th January 2010 which about 4 months of monitoring. The old records are besides utilizing for comparings.
All the informations on H2O degree and barometric force per unit area are recorded every 30 proceedingss every twenty-four hours. From 12.00am to 11.30pm, the informations are collected each twenty-four hours.The groundwater of the two locations, Lady Dixon Park and Orchardville Park has been monitored for many old ages. For both these countries, the boreholes are installed at these locations where the H2O degree and barometric force per unit area can be measured above ordinary data point.
By analysing the given informations, it can be seen that there are different types of aquifer and dirt at each borehole. By placing the barometric efficiency at this borehole ; it can find whether the belowground dirt is permeable or impermeable.The barometric efficiency is used to extinguish any barometric force per unit area nowadays in the H2O degrees in the well during the aquifer trial. This can supply more aid in happening out the H2O storage in the dirt. Both Wellss at Lady Dixon Park and Orchardville Park were equipped with Solinst lumberman or barologger.
Figure 2 represents how the device expression likes.Degree centigrades: UsersAmniPicturesandomSOLINST-Direct-Read-Communication-BEN-_i_VS_138581.jpgFigure 2 shows the Solinst device which to mensurate the land water-level and barometric-pressure.There are several methods for ciphering the barometric efficiency of groundwater. In this study, the Clark method has been used from other methods such as the graphical method, norm of ratios, average ratios, and incline, to gauge the barometric efficiency. Although Clark method sometime gives overestimated values and does non give 100 % truth but it gives consistence of value barometric efficiency, and has been used for recent twenty-four hours as it is simple to do usage of it.The chief purposes of this undertaking is to find the belongingss of the aquifer and the groundwater degree at country of River Lagan in Belfast by utilizing long-run monitoring records by the old research workers.There are much type of methods to find the belongingss of the aquifer and the groundwater degree.
By analysing the informations given from the old pupils, the barometric force per unit area and groundwater degree is altering from clip to clip. With plotting graph with these two values against clip, barometric efficiency can be made. Then the barometric efficiency will find whether the aquifer is permeable or impermeable.The aims are: -To analyse and understand the information of H2O degree given in order to do certain that the land is sufficiently equal for any purposed of constructions.To find the porousness of the aquifers by cognizing the storage of H2O in the land.To depict the feature of the Sherwood Sandstone aquifers.
To be familiar with the dirt around the location country.To be independent and competent to manage the undertaking good.Manage to form and finish the undertaking within the clip given.
Chapter 2 – Literature reappraisals
Background of Location
2.1.1 Lady Dixons Park Borehole
The co-ordinates of the borehole is 367490 Northing and 330374 Easting.
For Orchardville ‘s well is located at 370512 Northing and 330179 Easting.
An aquifer is belowground bed deposited by stuffs such as sand, silt, stones, crushed rocks and etc which saturated with H2O. Aquifer can besides move as storage and transit of H2O resistance. It can be categorized into two types of aquifers which are unconfined and confined aquifer. In add-on, the jointing of sandstone plays a important function in the conveyance of groundwater within the aquifer ( Bennett, 1976 ) . Figure 3 shows how the bed of the aquifer expression likes.hypertext transfer protocol: //gcuonline.
georgian.edu/wootton_l/confined_unconfined_aquifer.jpgFigure 3 shows the formation of the aquifers.
1 Unconfined Aquifer
Unconfined aquifer is portion of bed resistance which allow H2O from land surface entered under the land bed. This bed is where H2O tabular array is free to alter up and down, depending on the recharge or discharge rate of H2O.The H2O recharges from downward ooze through the unsaturated zone, sidelong land H2O flow, or upward ooze from underlying strata.
This type of aquifer is situated between two beds of low permeableness of aquifers which is known as aquitard. In confined aquifer, when the land is under force per unit area, the H2O degree in a well will lift above the upper boundary of the aquifer.
From the debut earlier, the definition of barometric efficiency which is the ratio of alterations in H2O degree caused by a barometric-pressure to the barometric force per unit area alterations ( Clark, 1967 ) .Where,? is the barometric efficiency,?W is the H2O degree alteration in a welland?B is the barometric force per unit area alteration.An addition in H2O degree during given clip interval have a positive alteration and if the force per unit area is addition during a clip interval will hold negative alteration ( less than nothing ) ( Clark, 1967 ; Batu, 1998 ; USGS, 2007 ) .
Barometric efficiency is dimensionless and ranges from zero to one.If the barometric force per unit area is increase, normally the water-level in an unfastened well will diminish by an sum governed by the barometric efficiency ( Todd, 1959 ; Ferris and others, 1962 ; Freeze and Cherry, 1979 ; Kruseman and de Ridder, 1991 ; Landmeyer, 1996 ; Rasmussen and Crawford ; 1997 ; and Batu, 1998 ) . It characterizes aquifer coni¬?nement and snap, presence of borehole/skin ei¬ˆects, and pneumatic dii¬ˆusivity in the unsaturated zone ( Rasmussen, 1997 ) . Therefore, barometric efficiency can gauge the storage of H2O and the belongingss of the aquifer.
Properties of Aquifer
Specific conduction is a measuring of electric conductivity in H2O which measure the H2O ‘s ionic activity and content. It besides can be used to mensurate H2O quality and indirectly prove the pollutant of H2O in the land. The more ions present in the H2O, the conductive it be.
How the H2O resistance contains conductive ions, it is because from the sea or river H2O flow, from rain H2O and sometimes sway or dirt may let go of ions when H2O base on balls over them.It is measured by utilizing a detector placed into the well, and step the electric conduction. But in this study, electric conduction does non truly related to barometric efficiency computation. It is to look into the quality of H2O in the land whether the H2O is in good or bad status. Still it is really of import for the applied scientist to cognize about it.
2.4.2 Porosity of Aquifer
Porosity is the presence of nothingnesss or infinites between the dirt stuffs underground which determines how easy H2O to flux through. The higher the porousness in the dirt, the more permeable the aquifer and the lower the porousness, it can do the aquifer impermeable which will indurate the dirt on it. This porousness plays a major function on the stiffness of the dirt whether a construction can construct on it or non.The alterations in the volume of pore H2O in the dirt will impact the water-level attitudes in a well that will hold an opposite sense to alterations in atmospheric force per unit area.
The porousness normally depends on the grains size distribution, stuffing of grain and form of the grains.Unconfined aquifer and confined aquifer can be responded by the Earth tide and alterations in atmospheric force per unit area which H2O will be released from or taken into storage in it by compaction or enlargement of aquifer skeleton and the volume of pore H2O ( Ferris and other, 1962 ; Bredehoeft, 1967 ) . This is because the aquifers are elastic ( Lohman, 1979 )Equation for porousness of aquifer skeleton is related to specific storage and an elastic belongings of an aquifer is shown below ( modified from Lohman, 1979 ) :Where,Ss is the specific storage ( in metre ) ;is the specific weight of H2O which equal to 9.
087 KN/m ;? is squeezability of H2O =? is the porousness of aquifer skeleton ( dimensionless ) ; andTocopherol is the snap of aquifer skeleton.Harmonizing to Jacob 1940, equation for specific storage is besides related to barometric efficiency and porousness of aquifer skeleton:where,? is the barometric efficiency ( dimensionless ) ;? is the specific weight of H2O ;? is the squeezability of H2O ;? is the porousness of aquifer skeleton ( dimensionless ) ; andSg is the specific storage.
Factors Influencing Water-level Change
There are possible activities that can act upon the water-level alteration such as barometric-pressure alteration, recharge, seasonal or long-run tendencies, local or regional pumping, Earth tides, ocean tides, evapotranspiration and surface-water fluctuation. These causes can be grouped into one term which is ?Wi at clip intervals:?Wi = ?Wb+ ?Wr+ ?Wl+ ?Wp+ ?Wg+ ?Wm +?We +?WsWhere,?Wb is the water-level alteration caused by barometric-pressure alteration ;?Wr is the water-level-change caused by recharge ;?Wl is the water-level-change caused by seasonal or long-run tendencies ;?Wp is the water-level-change caused by local or regional pumping ;?Wg is the water-level-change caused by Earth tides ;?Wm is the water-level-change caused by ocean tides ;?We is the water-level-change caused by evapotranspiration and ;?Ws is the water-level-change caused by surface-water fluctuations.Barometric-pressure alteration normally effects on the water-level changed in the land ( ?Wb ) . Water-level changed which is caused by recharge because of rain events or snow thaw ( ?Wr ) .
Seasonal or long-run tendencies ( ?Wl ) involve water-level alterations for a long continuance when it is greater than barometric fluctuation. When aquifer trials and other local pumping or other regional pumping occur, it caused ground-water-level alterations ( ?Wp ) .Due to gravitative influence from the Sun and Moon with the motion of Sun and Moon, it changes the gravitative forces on the Earth which caused the water-level alterations ( ?Wg ) ( Rinehart, 1975 ) .
Water-level alterations caused by ocean tides ( ?Wm ) can be from the compaction of a confined aquifer due to the weight of ocean H2O during high tide ( Robinson and Bell, 1971 ; Batu, 1998 ) .Effectss of evatransporation causes water-level alterations ( ?We ) , is greatest during the warm season and usually will non hold effects on the water-level alterations during winter when the temperature is below stop deading. Wells that have breaks straight connected to surface-bodies ( include pools and watercourses ) may react straight to surface-water fluctuation ( ?Ws ) which caused alterations in ground-water-level.There is a clip slowdown between barometric force per unit area and H2O degree which caused by skin effects ( i.e. a decrease in hydraulic conduction between borehole and undisturbed aquifers ) , storage of borehole, and clip for the force per unit area moving ridge to be transmitted through the vadose country ( D.
Rush, 2002 ) . Vadose zone is the upper bed of the Earth that contain a three-phase system of solid, liquid, and gaseous stuff which can besides be called as unsaturated zone. When plotting the graph of H2O degree against barometric force per unit area, a multiple additive arrested development should be used to gauge the barometric response map.Table 1 represents the sum-up of factors that will effects the fluctuation of groundwater-level.Table 1 shows the sum-up of mechanism leads to fluctuation of groundwater.
2.6 Alternate method to cipher Barometric Efficiency
2.6.1 Clark method
The lineation regulations to cipher barometric efficiency by utilizing this method are: -When ?B is equal to zero, ignore ?W to obtain ??W,When ?B and ?W have same marks, add ?W to obtain ??W,And if ?B and ?W have unequal marks, so deduct ?W to acquire ??W.By utilizing Clark ‘s method, the values of barometric efficiency can be overestimated or when the barometric force per unit area or H2O degree alteration is instantaneous ( David and Rasmussen, 1993 ) .
The Clark method presents a gestural trial on ?W compared to the mark of ?B for each clip interval ;And,Where,is the go oning amount of ?Wj after the jth clip interval ;is the go oning amount of ?Wj-1 after the ( j-1 ) Thursday interval ;is the absolute value of ?Wj ;is the go oning amount of ?Bj after the jth clip interval ;is the go oning amount of ?Bj after the ( j-1 ) Thursday clip interval ; andis the absolute value of.Since the Clark method is depending on the mark of water-level alteration and barometric-pressure alteration, the absolute value of ?Wj and absolute value of ?Bj is introduced in this equation. At a specific clip interval, ground-water-level rises whereas the barometric-pressure autumn or frailty versa. So if the mark of ?Wj agrees with the mark of ?Bj, so the absolute value for ?Wj will be positive. The absolute value of ?Wj will be negative if the mark of ?Wj disagrees with the mark of ?Bj ( U.
S. Geological Survey, 2007 ) .By plotting the value of on the y-axis and the values of on the x-axis, the incline of the best fit line drawn on the graph is the estimation of barometric efficiency.
6.2 Slope Method
This method has been introduced by Ferris and others ( 1962 ) on the incline of ?W and ?B with several clip intervals. By plotting a graph of water-level alterations at y-axis, ?W against atmospheric force per unit area alterations at x-axis, ?B, and a best additive consecutive line is fitted to the aforethought points. The incline of additive line estimates the value of barometric efficiency. Harmonizing to USG-2007, the equation for gauging barometric efficiency had been modified from ( Ott, 1988 ) is shown below.WhereAndWhere,J designates the jth clip interval ;is the mean H2O degree for all clip intervalAndis the norm of barometric force per unit area alteration for all clip intervals.By plotting a graph of H2O degree ( W ) on y-axis against barometric force per unit area ( B ) , the barometric efficiency can be estimated utilizing incline method ( Hare and Morse, 1999 ; UGS, 2007 ) . But it is recommended to utilize water-level alteration ( ?W ) and barometric-pressure alteration ( ?B ) plotting the graph instead than W and B because ?W and ?B is more mathematical accurate since the definition of barometric efficiency is the relationship between water-level alteration and barometric force per unit area alteration ( ?W/?B ) .
2.6.3 Graphical Method
Graphic method is used to gauge the barometric efficiency by utilizing uninterrupted water-level and barometric-pressure informations from old research worker. Continuous informations present more information than distinct informations to gauge barometric efficiency ( USG, 2007 ) . An Egg-shaped cringle will be shown on the graph by utilizing this graphical method.At the horizontal x-axis dual barometric-pressure alterations ( is plotted and on the perpendicular y-axis is the dual water-level alterations. The equations below show the expression to happen the and:andWhere,J is for the jth barometric-pressure or water-level cringle or fluctuationBj1, Bj2, Bj3 and Bj4 are values of barometric-pressure at clip t1, t2, t3, and t4, severally,andWj1, Wj2, Wj3 and Wj4 are values of water-level at clip t1, t2, t3, and t4, severally,When all the informations of water-level and barometric-pressure have convert to and, so graph of two water-level alterations against two barometric-pressures can be plot. Slope of this graph represents the appraisal of barometric efficiency utilizing a graphical method.
2.6.4 Average-of-Ratios Method
By utilizing this method, plotting the graph of water-level alteration against barometric efficiency is non necessary because it used the mean ratios of water-level alteration to barometric-pressure ( ?W/?B ) for many clip intervals to gauge the value of barometric efficiency. This is the simplest mathematical method to happen barometric efficiency. Equation below shows the mean ratio of ?W/?B:Expressing equation above as the amount of mane ( n ) clip intervals outputs:Where,n? is, where each ?Wbj/?Bj is a changeless value for every clip interval J.Arrange the equation:Where,? is the barometric efficiency appraisal.The value of barometric efficiency is peers to the norm of ?W/?B minus the mean values of ?Wi/?B.
This construct is somewhat similar to noise-reduction experiment which is used in contemplation seismic ( Yilmaz and Doherty, 1987 ) .
The unity of each ground-water-level records is evaluated for intervention effects on H2O degrees caused by nearby pumpage ( water-level informations caused by this pumpage is non used to find the barometric efficiency ) and Earth tidal influence, for Wellss near the seashore ( Landmeyer, 1996 ) .Pump trial is besides known as aquifer trial and this trial can find the belongingss of unconfined or confined aquifer ( i.e.transmissivity, conduction, storativity and specific output ) , every bit good as detecting the aquifer response ( drawdown ) in observation of Wellss. Drawdown is the alteration of hydraulic caput observed at a well in an aquifer. Pumping at a changeless rate should be used during the trial.
The consequence of specific output for aquifer is non that satisfied to depict the drainage phenomena in the fact-finding solution used for pumping analyses ( Nwankwor et al. , 1984 ; 1992 ) . It is a fact that the drainage procedure happening during a pumping trial in an unconfined aquifer is ill understood. That is why understanding the procedures at the field-scale, elaborate observation of the relationship between hydraulic caput and wet content distribution during pumping trials are required ( Anthony, 2004 ) .In pump trial, there should be a recovery trial which mensurating the recoil of H2O degrees towards preexisting conditions instantly after pump trials ( US Army Corp, 1999 ) . Recovery trial besides provide of import aquifer information and normally when elastic storage effects have been dissipated, the clip hydraulic caput informations are analyzed by this recovery trial ( Kruseman and de Ridder, 2000 ) .
Chapter 3 – Methodology
From what has been given resorts from Geological Survey of Northern Ireland, they used a device called the ‘Sloinst Logger ‘ or the ‘Levelogger ‘ and barologger, so that the H2O degree and the barometric force per unit area can be recorded. For H2O degree measuring, the levelogger has been suspended by wire down the borehole beneath the H2O degree.
Manual dips have to be taken on occasion in order to graduate the informations and these H2O degrees of class have to take into history barometric fluctuations.The barologgers tend to be extremely similar to the logger down the well ; except they are normally more sensitive devices so will pick up much smaller fluctuations. It is suspended merely at the top of the boreholes, above the H2O degree. As a consequence, the barometric efficiency can be determined.From the methods that have been mentioned in Chapter2, the Clark method is used to cipher the estimation barometric efficiency. The graph of water-level against clip interval for both topographic points, Lady Dixon and Orchardville has plotted and shown under the analysis sub-heading below.By utilizing the Clark Method expression given, the values of ?W and ?B can be calculated. Hence by plotting the ?W on y-axis and ?B on x-axis, the incline gradient of the graph can be calculated.
Since all the points on the graph have scattered around, so the best additive line fitted through the points. This gradient of the graph is the estimation barometric efficiency ; this is the chief point for this undertaking.When the value of barometric efficiency has obtained, so the porousness of the aquifer can be calculated. By utilizing the expression that has shown on chapter 2:After ciphering the porousness of the aquifer, so compared the values for both good. The higher the value of porousness, more permeable will be the aquifer.As this undertaking is a uniting undertaking with other research workers, comparing the barometric efficiency and the porousness of aquifer at each location should be done.
The other research workers have monitored the water-level and barometric-pressure at Ashby and Glenburn. Barometric efficiency and porousness of the aquifer are besides been calculated and so these values can be compared.
Chapter 4 – Consequence
From what info that had been given by the Geological Survey of Northern Ireland, the type of aquifer found on Ochardville Park and Lady Dixon Park is Sherwood sandstone. Below show the consequence of water-level and barometric-pressure of Lady Dixon Park and Ochardville that had been calculated.
Lady Dixon Park
DateConsequencePressure mAOD( Water Level mH2O )10/7/200913.
6221/27/201014.1143541710.5121/28/201014.14712510.405Table 2 shows the value of water-level and barometric-pressure for Lady Dixon Park from 07/10/2009 to 28/01/2010.Figure 4 Graph of H2O degree against barometric, in metre at borehole Lady Dixon.From figure 4, by ciphering the incline gradient of the graph, the barometric efficiency value can be obtained ;B.
= -0.40From computation, the appraisal barometric efficiency is negative 0.40 and with r2=0.0574 value from the graph.For porousness,? = particular of H2O = 998.2 kg/m3? = squeezability of H2O = 4.693707 ten 10-9 m2/kg ( Lohman, 1979 )Specific storage ( Ss ) values of aquifer calculated by GSNI is 1.5148 ten 10-7m-1? =? = 0.
0129Porosity of aquifer at Lady Dixon is 0.0129.Figure 5 shows a graph represents water-level against clip from October-2009 to January-2010.Full information of water-level and barometric-pressure for Lady Dixon Park which have been taken for this period of times are in Appendix A.Figure 6 Graph of H2O degree ( ruddy line ) and barometric force per unit area ( bluish line ) against times.The great bead on the water-level is because of the pumping activity occurred during that clip. Since location of Lady Dixon Park is someplace close edifices, it is possible pump trial happened.
From figure 6, it shows that if an addition in water-level, the barometric-pressure lessening and frailty versa.
All the recorded water-level and barometric force per unit area have been tabulated below and have been used for this undertaking. These have been abstracted by Geological Survey Northern Ireland for past few months.day of the monthBaometric Pressure ( mH2O ) )H2O degree ( mAOD )10/7/200910.2666216.1850510/8/200910.
= -0.34The value of appraisal barometric efficiency is negative 0.34 and the r2 value is 0.2433.For porousness,? = particular of H2O = 998.2 kg/m3? = squeezability of H2O = 4.693707 ten 10-9 m2/kg ( Lohman, 1979 )Specific storage ( Ss ) values of aquifer calculated by GSNI is 1.5148 ten 10-7m-1? =? = 0.0109Porosity of aquifer at Lady Dixon is 0.0109.Figure 7 shows a graph of water-level and barometric-pressure against times.
Chapter 5 – Decision
It is proved that an addition in water-level will diminish in barometric-pressure in the land and frailty versa as shown on the analysis portion. From what had been given by Geological Survey of Northern Ireland, the type of aquifer at Ochardville and Lady Dixon is Sherwood Sandstone.Properties of the aquifer and barometric efficiency of aquifer had been analyzed in chapter 4.it shows that the type of aquifer that had been found at Orchardville Park and Lady Dixon Park is Sherwood sanstone.
Chapter 6 – Discussion
The Permian and Triassic sandstones offer the greatest groundwater abstraction potency throughout Northern Ireland. On figure 8 represent where the bed of Sherwood Sandstone at the River Lagan of Belfast from Geological Survey of Northern Ireland.Figure 8 shows the diagrammatic geological cross-section of the Lagan Valley South-West of Belfast.Analysiss of the available information showed that barometric efficiency values of -0.40 at Lady Dixon and -0.34 at Orchardville and have an norm of barometric efficiency of -0.37 for country around Lagan Valley aquifer.From the figure 6, it shows that water-level alterations when barometric-pressure alterations at Lady Dixon Park. The water-level at this country keeps on increasing each twelvemonth. The norm for water-level on oct-2005 to jan-2006 is about 10.385m and for oct-2009 to jan-2010 is about 14.115m. This is because of the lake nearby and high degree of land. The water-level beads on 13th November 2009 at clip 9.30a.m to 4.00p.m about 5.33mAOD but the mean value for water-level for that twenty-four hours is at 11.68mAOD. Due to pumpage and reload of H2O from lake nearby, it causes the fluctuation on the groundwater.For Orchardville Park, the figure shows that there is no pump trial occurred at that location. This was because of the residential country around it and it was hard to pumpage the well when there are many edifices surround it. Water-level has been recorded and monitored for past few old ages. It shows that the water-level at Orhardville has non been many alterations due to level lands.
The groundwater degree informations from 2005-2007 and October 2009 to January 2001 has been gathered and have been given by Clair Burn, PhD pupils of Queens University of Belfast. Both the H2O degree and barometric force per unit area are included in the information.Partially analysing the given informations of Lady Dixon and Orchardville. It seems that the H2O degree above sea degree at Orchardville is somewhat higher than H2O degree at Lady Dixon.It seems that both topographic points have increase in H2O degree for past few old ages, this is because H2O degree of sea has increase every twelvemonth.The belongingss and behaviour of the hydrogeology of Sherwood Sandstone aquifers are known from the information that been provided.Finding the barometric efficiency from H2O degree against clip graph and barometric force per unit area against clip graph.Calculation of storage porousness of aquifer at the borehole.The stableness of the land harmonizing on researching of barometric efficiency based on Clark Method.