Sen / ?en Practical and Applied Hydrogeology

1. Auflage 2014
ISBN: 978-0-12-800581-1
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 424 Seiten

Applications in Hydrogeology for Geoscientists presents the most recent scientific developments in the field that are accessible yet rigorous enough for industry professionals and academic researchers alike. A multi-contributed reference that features the knowledge and experience of the field's experts, the book's chapters span the full scope of hydrogeology, introducing new approaches and progress in conceptualization, simulation of groundwater flow and transport, and progressive hydro-geophysical methods. Each chapter includes examples of recent developments in hydrogeology, groundwater, and hydrology that are underscored with perspectives regarding the challenges that are facing industry professionals, researchers, and academia. Several sub-themes-including theoretical advances in conceptualization and modeling of hydro-geologic challenges-connect the chapters and weave the topics together holistically. Advances in research are aided by insights arising from observations from both field and laboratory work. - Introduces new approaches and progress in hydrogeology, including conceptualization, simulated groundwater flow and transport, and cutting edge hydro-geophysical methods - Features more than 100 figures, diagrams, and illustrations to highlight major themes and aid in the retention of key concepts - Presents a holistic approach to advances in hydrogeology, from the most recent developments in reservoirs and hydraulics to analytic modeling of transient multi-layer flow and aquifer flow theory - Integrates real life data, examples and processes, making the content practical and immediately implementable

Dr. Zekai Sen obtained his B. Sc. and M. Sc Degrees from the Technical University of Istanbul, Civil Engineering Faculty, in 1972. His post-graduate studies were carried out at the University of London, Imperial College of Science and Technology. He was granted a Diploma of Imperial College (DIC) in 1972, M. Sc. in Engineering Hydrology in 1973 and his Ph. D. in stochastic hydrology in 1974. He worked in different countries such as England, Norway, Saudi Arabia and Turkey. He worked in different universities such as the King Abdulaziz University, Faculty of Earth Sciences, Hydrogeology Department; Istanbul Technical University, Faculty of Astronautics and Aeronautics, Meteorology Department. His main interests are hydrology, water resources, hydrogeology, atmospheric sciences, hydrometeorology, hydraulics, science philosophy and history. He has published about 230 SCI scientific papers in different international top journals and has seven book publications, including the forthcoming Practical and Applied Hydrogeology (2014).

Autoren/Hrsg.

Sen, Zekâi

?en, Zekƒi

Inhaltsverzeichnis

1;Front Cover;1
2;PRACTICAL AND APPLIED HYDROGEOLOGY;4
3;Copyright;5
4;Dedication;6
5;Contents;8
6;Preface;10
7;Chapter 1 - Water Science Basic Information;12
7.1;1.1 HYDROLOGY (WATER SCIENCE) ELEMENTS;12
7.2;1.2 HYDROLOGIC CYCLE;14
7.3;1.3 RAINFALL;15
7.4;1.4 EVAPORATION AND EVAPOTRANSPIRATION;26
7.5;1.5 INFILTRATION;34
7.6;1.6 RUNOFF;42
7.7;1.7 GROUNDWATER;44
7.8;1.8 CLIMATE CHANGE AND GROUND WATER;44
7.9;1.9 GEOLOGY AND GROUNDWATER;46
7.10;1.10 GROUNDWATER USE IN PETROLEUM;50
7.11;References;51
8;Chapter 2 - Basic Porous Medium Concepts;54
8.1;2.1 GEOLOGIC CONSIDERATIONS;55
8.2;2.2 GRAIN SIZE;55
8.3;2.3 RESERVOIR CLASSIFICATIONS;57
8.4;2.4 HYDRAULIC TERMINOLOGIES;58
8.5;2.5 EQUIPOTENTIAL LINES;62
8.6;2.6 AQUIFER TYPES;65
8.7;2.7 AQUIFER PARAMETERS;67
8.8;2.8 DARCY'S LAW;89
8.9;2.9 HETEROGENEITY AND ANISOTROPY;96
8.10;2.10 WATER BUDGET;100
8.11;2.11 GROUNDWATER ELEMENTS;105
8.12;References;107
9;Chapter 3 - Groundwater Hydraulics and Confined Aquifers;110
9.1;3.1 GROUNDWATER WELLS;111
9.2;3.2 FIELD MEASUREMENTS AND TESTS;124
9.3;3.3 AQUIFER TEST ANALYSES;133
9.4;3.4 RADIAL STEADY STATE FLOW IN CONFINED AQUIFERS;134
9.5;3.5 RADIAL STEADY STATE GROUNDWATER FLOW IN LEAKY AQUIFERS;144
9.6;3.6 UNSTEADY STATE FLOW IN AQUIFERS;146
9.7;3.7 SLOPE METHOD;156
9.8;3.8 ÇIMEN METHOD;165
9.9;3.9 COOPER-JACOB (CJ) STRAIGHT-LINE METHODS;168
9.10;3.10 DIMENSIONLESS STRAIGHT-LINE ANALYSIS;172
9.11;3.11 VARIABLE DISCHARGE TYPE CURVES;181
9.12;3.12 QUASI-STEADY STATE FLOW STORAGE CALCULATION;190
9.13;3.13 UNSTEADY RADIAL FLOW IN A LEAKY AQUIFER TEST;192
9.14;3.14 LARGE DIAMETER WELL HYDRAULICS;198
9.15;3.15 AQUIFER DOUBLE TEST;203
9.16;3.16 RECOVERY METHOD;205
9.17;3.17 WELL TEST (STEP-DRAWDOWN TEST);208
9.18;3.18 AQUIFER CLASSIFICATION BY FUZZY HYDROGEOLOGICAL PARAMETER DESCRIPTIONS;210
9.19;References;217
10;Chapter 4 - Unconfined Aquifers;220
10.1;4.1 UNCONFINED AQUIFER PROPERTIES;221
10.2;4.2 QUATERNARY DEPOSIT AQUIFERS;222
10.3;4.3 FRACTURED ROCKS;224
10.4;4.4 KARSTIC MEDIA;225
10.5;4.5 HYDRAULIC STRUCTURES;226
10.6;4.6 GROUNDWATER HYDRAULICS;233
10.7;4.7 STEADY STATE FLOW TO WELLS;235
10.8;4.8 GROUNDWATER RECHARGE;244
10.9;4.9 UNSTEADY RADIAL FLOW IN UNCONFINED AQUIFERS;246
10.10;4.10 NATURAL GROUNDWATER RECHARGE;258
10.11;4.11 RECHARGE OUTCROP RELATION (ROR) METHOD;267
10.12;4.12 CHLORIDE MASS BALANCE (CMB) METHOD;270
10.13;4.13 ARTIFICIAL GROUNDWATER RECHARGE;276
10.14;4.14 AQUIFER PROPERTIES AND GROUNDWATER AVAILABILITY CALCULATIONS;278
10.15;4.15 CLIMATE CHANGE AND GROUNDWATER RECHARGE;284
10.16;4.16 UPCONING;286
10.17;References;287
11;Chapter 5 - Groundwater Quality;290
11.1;5.1 HYDROCHEMISTRY;291
11.2;5.2 IONIC CONSTITUENTS;291
11.3;5.3 MAJOR IONS;292
11.4;5.4 CHEMICAL UNITS AND BALANCE;294
11.5;5.5 GROUNDWATER SAMPLING AND ANALYSIS;297
11.6;5.6 COMPOSITE QUALITY INDICATORS;298
11.7;5.7 COMPOSITE VARIABLE RELATIONSHIPS;306
11.8;5.8 WATER QUALITY GRAPHICAL REPRESENTATIONS;307
11.9;5.9 THE GHYBEN–HERZBERG RELATION;316
11.10;5.10 ARTIFICIAL GROUNDWATER MIXTURE;318
11.11;5.11 ENVIRONMENTAL ISOTOPES;322
11.12;5.12 GROUNDWATER RISE AND QUALITY VARIATIONS;325
11.13;5.13 STANDARD ION INDEX FOR GROUNDWATER QUALITY EVOLUTION;326
11.14;5.14 GROUNDWATER QUALITY VARIATION ASSESSMENT INDICES;332
11.15;5.15 FUZZY GROUNDWATER CLASSIFICATION RULE DERIVATION FROM QUALITY MAPS;338
11.16;5.16 CLIMATE CHANGE AND GROUNDWATER QUALITY;345
11.17;References;348
12;Chapter 6 - Groundwater Management;352
12.1;6.1 GENERAL;353
12.2;6.2 MANAGEMENT PLANNING;353
12.3;6.3 MANAGEMENT ENVIRONMENTS;355
12.4;6.4 LOCAL CONDITIONS;356
12.5;6.5 PRELIMINARY MANAGEMENT REQUIREMENTS;357
12.6;6.6 GROUNDWATER MANAGEMENT OBJECTIVES;358
12.7;6.7 INTEGRATED GROUNDWATER MANAGEMENT;363
12.8;6.8 BASIC MANAGEMENT VARIABLES;364
12.9;6.9 HYDROGEOLOGICAL MANAGEMENT;367
12.10;6.10 BASIC MANAGEMENT MODELS FOR AQUIFERS;370
12.11;6.11 PROBABILISTIC RISK MANAGEMENT IN AN AQUIFER;379
12.12;6.12 GROUNDWATER LEVEL RISE MODELING IN CITIES;385
12.13;6.13 AQUIFER UNCERTAINTIES AND STRATEGIC PLANNING;389
12.14;6.14 OPTIMUM YIELD AND MANAGEMENT IN A WELL FIELD;390
12.15;6.15 WATER STORAGE VOLUME RISK CALCULATION;399
12.16;6.16 AQUIFER UNCERTAINTIES AND MANAGEMENT;403
12.17;References;407
13;Index;410

Leseproben

4.5. Hydraulic Structures

There are few practically and frequently used special hydraulic structures for groundwater abstraction from unconfined aquifers.

FIGURE 4.6 Well cross-sections (a) circular, (b) rectangular, (c) irregular.

4.5.1. Vertical Large Diameter Wells

Cross section of water well is important for different functions so as to have the optimum performance during planning, design, operation, and management stages of water supply. In calculating discharge or identification of aquifer parameters, the geometrical shapes of flow and equipotential lines in the vicinity of the well provide restrictive conditions (Chapter 2). For instance, if the well boundary is smooth without any discontinuity (corners, fractures) then the flow lines will end up without any dilemma. Existence of corners on the well periphery gives rise to complications in the stream and equipotential lines, which may cause extra energy loss around the well vicinity as shown in Figure 4.6.

In regular cross sections the equipotential and flow lines take simple regular shapes. For instance, in Figure 4.6(a) the equipotential lines are concentric circles, whereas the flow lines are radial straight lines, but in Figures 4.6(b) and (c) they have irregular shapes. As has been explained in Chapter 3 the calculation of discharge depends on the streamline positions, which is rather difficult to measure or visualize around the irregular well cross sections. The longer the stream lines the more will be the energy loss. Well shapes as in Figure 4.6(c) is used commonly for temporary purposes as shallow wells that are dug by simple excavation machines. They are filled by debris and sedimentation after each flood and water is hauled from these wells by suction pumps for nearby consumption centers for domestic, husbandry, or agriculture purposes.

4.5.2. Collector Wells

As a general setup, these wells have two main parts, namely, a vertical and circular cross-sectional water storage volume acting as a collector and horizontally driven radial drains close to the collector base as horizontal groundwater conveyors from the aquifer (see Figure 4.7). The collector has groundwater seepage neither from its wall nor bottom but only from the radial conveyors through gate valves which are operated from the top.

The water collector is essentially a large diameter, usually 4–5 m, water-tight tank. After the completion of this tank from reinforced concrete with a sealed bottom by pouring a thick concrete plug heavy enough to resist the buoyancy, lateral pipes, made of steel, having 15–20% slot area, are driven horizontally into the groundwater reservoir by special hydraulic jacks. There may be more than one layer of conveyor pipes, especially if the groundwater reservoir is dissected by clay layers preventing free vertical movement.

Collector wells are constructed in alluvial deposit unconfined groundwater reservoirs. They prove especially useful for large irrigation supplies with a permanent source as a result of continuous recharge from lakes, perennial streams, or water-logged areas irrigated by big canal systems. These wells yield large supplies of water from relatively thin shallow unconfined aquifers. The advantages of these wells are:

FIGURE 4.7 Collector well.

1. Availability of large filtered sterilized water supply,

2. Reduced operation and maintenance costs,

3. Suitability in thin aquifers,

4. Reduced wear of pumping due to the entrance velocities, resulting in sand free water.

Collector wells have the following differences from common well types.

1. The initial cost exceeds that of a vertical well.

2. The maintenance cost is less than other wells.

3. They have large yields under low pumping heads.

4. The maximum head difference between the water level in the well and in the adjacent aquifer occurs at the time of well construction completion.

5. Horizontal drains in various directions have very big chance to intersect with more fractures than vertical borehole wells. Hence, the well productivity increases significantly.

6. Hydraulic head losses, that is, drawdowns around the collector wells are smaller than the drilled wells, and therefore, the sanding problem does not occur in the collector wells.

7. The saline groundwater generally lies at big depths of the saturation thickness. Use of the collector wells will not give rise to groundwater quality deterioration due to the mixing of deep lying saline water with overlying relatively fresh water.

4.5.3. Injection and Scavenger Wells

Artificial recharge is possible through injection wells after each rainfall event behind the surface water impoundment dams for groundwater recharge purposes. In general, these wells help to place surface water into the groundwater storages in the possible short time durations so as to avoid evaporation losses. These wells have additional wide range of uses such as waste disposal, oil production enhancement, mining, and salt water intrusion prevention through scavenger wells. They can be used as means to control saline water upconing in the coastal aquifers. They stop the advancement of salt water toward inlands and also stabilize the interface between the fresh and salt waters (see Figure 4.8). Through the scavenger wells nonpotable water or alike must be injected. Scavenger wells are useful to prevent the contaminated water from reaching the production well.

FIGURE 4.8 a) Static case, (b) upconing, (c) scavenger well role.

An injection well is a vertical pipe in the ground into which water is pumped or allowed to flow. They are frequently used in arid regions to lead the surface water into groundwater reservoirs after each storm rainfall and especially flash floods. There are different types of injection wells.

1. In arid regions, irregularly excavated shallow ditches are prepared for surface water trap and their direct use for a while by tanker transportations and in the meantime the groundwater is also recharged (Figure 4.6(c)). They may be filled with sedimentation partially or fully after runoff, but simple instruments are used for cleaning or digging another series of ditches for the next storm rainfall.

2. In some semiarid regions large diameter wells with radius reaching even to 10 m are dug for groundwater recharge along the Quaternary deposit valleys (wadis).

3. In extremely dry regions occasional flash floods bring abundant surface water (runoff), that is lost either in the desert areas or confluence areas next to seas. These huge amounts of occasional water volumes can be gained for later exploitation, if they can be injected into the unconfined aquifers in the shortest possible time. For this purpose, vertical injection pipes are used behind small surface dams at convenient locations along the valley. The main purpose of such surface dams in arid regions is for speedy groundwater recharge, but they can also be combined with vertical injection pipes for better groundwater recharge efficiency. Figure 4.9 indicates the configuration of surface dams with vertical recharge pipes within the impoundment area.

The injection pipes are located at convenient places within the dam reservoir area. If necessary, prior to dam construction, vertical geophysical sounding prospecting method can be used to explore the subsurface geological compositions and geometrical dimensions. In Figure 4.9, as the surface water level in the reservoir subsides then the lower taps are opened for clean water to infiltrate into the Quaternary deposits for groundwater recharge enhancement. The lower taps are located above the levels of dam bottom sedimentation accumulation.

FIGURE 4.9 Injection pipes, (a) longitudinal cross-section, (b) plan view.

Another point of worth in practice is to open a ditch along the main channel before dam construction and fill it with coarse materials that will help speedy groundwater flow downward. In this manner, unconfined aquifer will be replenished and downstream settlements will have more water at their disposal and the groundwater quality will improve.

4.5.4. Horizontal Man-Made Conduits—Qanats

A system of wells connected together by a gallery that brings water from the foothills to the plains is called “qanats” as shown in Figure 4.10. They have various local names in different countries. For instance, in Saudi Arabia, they are known as ayn (or ayun in plural) shat-at-ir in Marocco, foggariur in Algeria, falaj (or aflaj in plural) in Oman, shariz in Yemen, and karez in Pakistan, Iraq, and Afghanistan. They were constructed first around 800 BC in the Middle East. In addition to their hydrologic importance, maintenance, and specific properties, a detailed account of qanats construction in the arid zones is given by Amin et al. (1983).

FIGURE 4.10 Qanats.

The first stage in the construction of qanats is to dig large diameter exploratory wells (vertical shafts) along the potential aquifer. These wells are about 300–400 m apart and may reach down to 30–50 m depth and they have large diameter of at least 0.75–1.0 m....