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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
This fully revised edition provides a modern overview of the intersection of hydrology, water quality, and water management at the rural-urban interface. The book explores the ecosystem services available in wetlands, natural channels and ponds/lakes. As in the first edition, Part I examines the hydrologic cycle by providing strategies for quantifying each component: rainfall (with NOAH 14), infiltration, evapotranspiration and runoff. Part II examines field and farm scale water quality with an introduction to erosion prediction and water quality. Part III provides a concise examination of water management on the field and farm scale, emphasizing channel design, field control structures, measurement structures, groundwater processes and irrigation principles. Part IV then concludes the text with a treatment of basin-scale processes. A comprehensive suite of software tools is available for download, consisting of Excel spreadsheets, with some public domain models such as HY-8 culvert design, and software with public domain readers such as Mathematica, Maple and TK solver.
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Table of Contents
Cover
Title Page
Copyright
Acknowledgments
Preface
About the companion website
Chapter 1: Natural resources engineering opportunities
GOALS
1.1 Definitions
1.2 The hydrologic cycle and the water–soil–air–biotic continuum
1.3 Changing land uses due to societal forces
1.4 Natural resources and ecological engineering scope addressed in this text
1.5 Outlook
References
Part One: Quantifying the Hydrologic Cycle
Chapter 2: Precipitation
GOALS
2.1 Precipitation mechanisms, types, and measurement
2.2 Precipitation analysis
2.4 Local-scale precipitation analysis
2.5 Calculating storm magnitudes for design purposes
2.6 Pollution transport by precipitation
2.7 The water quality storm
2.8 Climate change and precipitation
2.9 Outlook
References
Chapter 3: Infiltration
GOALS
3.1 Infiltration, percolation, and subsurface flow defined
3.2 Factors affecting infiltration of aqueous materials
3.3 Darcy's law
3.4 Water infiltration and percolation prediction
3.5 Infiltration measurement
3.6 Pollutant transport by subsurface flow
3.7 Outlook
References
Chapter 4: Evapotranspiration
GOALS
4.1 Background and factors affecting evapotranspiration
4.2 Evaporation prediction approaches
4.3 Evaporation from water surfaces based solely on aerodynamic effects or mass balance
4.4 Evaporation prediction from the energy-balance–Bowen-ratio method
4.5 Reference evaporation prediction accounting for aerodynamic effects and energy balance – the Penman–Monteith combination equation method
4.7 Physical simulation and measurements of ET
4.8 Outlook
References
Chapter 5: Runoff
GOALS
5.1 Background
5.2 Watershed or catchment delineation 1
5.3 Runoff volume for a compact watershed
5.4 Peak runoff rate with compact watersheds
5.5 Selecting the design storm
5.6 Frequency analysis of runoff
5.7 Runoff from complex watersheds
5.8 Outlook
References
Part Two: Field- and Farm-Scale Water Quality
Chapter 6: Water erosion
GOALS
6.1 Background
6.2 Factors affecting water erosion
6.3 Soil erosion versus sediment yield
6.4 Soil loss tolerance
6.5 Water erosion types
6.6 Erosion mechanics
6.7 Predicting soil detachment and upland erosion
6.8 The weighted factor for average annual erosion computation
6.9 Prediction of sediment yield
6.10 Legal aspects
6.11 Modeling approaches for sediment yield prediction
6.12 Erosion control practices in agriculture
6.13 Erosion and sediment control with construction
6.14 Erosion and nutrient pollution
6.15 Outlook
References
Chapter 7: Water quality and management at farm/field scales
GOALS
7.1 Water quality background
7.2 Important concepts and selected pollution measurement techniques
7.3 Scale effects
7.4 Best management practices for nonpoint pollution abatement
7.5 Quantitative removal and renovation of selected pollution constituents
7.6 Modeling pollution fate and transport
7.8 Outlook
References
Part Three: Water management on the field and farm scales
Chapter 8: Open channel hydraulics–fundamentals
GOALS
8.1 Hydraulics fundamentals
8.2 Channel design and construction
8.3 Outlook
References
Chapter 9: Vegetated waterways and bioswales
GOALS
9.1 Vegetated waterways and diversions
9.2 Bioswales
9.3 Outlook
References
Chapter 10: On-site erosion management
GOALS
10.1 Terraces on the farm
10.2 Erosion and sediment control in urban areas
10.3 Outlook
References
Chapter 11: Hydraulics of water management structures
GOALS
11.1 Structure types
11.2 Hydraulic concepts
11.3 Stage–discharge relationships of weir inlets and flumes
11.4 Discharge relations of orifices and sluice gate inlet devices
11.5 Flow hydraulics of closed conduits
11.6 Stage–discharge curves for culverts and spillways
11.7 Closed conduit systems for urban storm water collection
11.8 Water measurement structures for irrigation and aquaculture
11.9 Ecologic suitability
11.10 Outlook
References
Chapter 12: Hydraulics of Impoundments
GOALS
12.1 Soils fundamentals for embankment construction
12.2 Flood routing through reservoirs and related structures
12.3 General pond design
12.4 Applications
12.5 Outlook
References
Chapter 13: Shallow Groundwater Management
GOALS
13.1 Surface drainage
13.2 Subsurface flow fundamentals
13.3 Pipe drainage
13.4 Shallow wells
13.5 Uniform infiltration and drainage to a nearby stream
13.6 Outlook
References
Chapter 14: Introduction to irrigation
GOALS
14.1 Irrigation systems overview
14.2 Soil–water–plant relations
14.3 Soil intake rate
14.4 Water quality issues and leaching requirement for crop well-being
14.5 Irrigation efficiency
14.6 Effective 4 rainfall and irrigation scheduling
14.7 Computing ET requirements – peak ET
14.8 Computing ET requirements – seasonal water use
14.9 Irrigation pumping rate for meeting ET requirements
14.10 Water rights and legal underpinnings
14.11 Manual or wheel-move lateral sprinkler system design
14.12 Center pivot system specification
14.13 Linear move irrigation machines
14.14 Design for nontraditional applications
14.15 Microirrigation system design with pressure compensated emitters
References
Part Four: Basin-scale Processes
Chapter 15: Ecological assessment and engineering
GOALS
15.1 Watershed assessment background
15.2 Watershed assessment methods
15.3 Principles of ecological engineering and ecosystem services
15.4 Outlook
References
Part Four: Basin-scale Processes
Appendix A: Ethics, stakeholder views, case studies, and precision
A catalog of ethical views 1
Making sense of the ethical catalogue – one person's view
Resource economics – “social traps”
Case study one – pitcher plant community viability
Case study 2 – a hypothetical case concerning clean water act compliance 3
Significant digits and presentation precision
References
Appendix B: Selected Excel® and other software package solutions
Selected symbolic solutions
Determining bottom width and depth in a trapezoidal channel with known slope, side slope, and permissible velocity
Determining depth and side slope in a triangular channel with known slope and permissible velocity
Determining slope and depth in a triangular channel with known flow rate, permissible velocity and side slope (
z
)
References
Appendix C: Tractive force method for waterway design
Riprap-lined or earthen waterways
Vegetated waterways
References
Appendix D: Land forming, structure selection, installation, and forces on conduits
Land forming computations
Impoundment and embankment volume calculations
Setting slope stakes for cuts and fills
Techniques for installation of channels and other structures
Layout of circular curves
Post-construction stormwater management options 2
Source (EPA post-construction) key definitions
Materials specifications for channels and structures
Rural road construction
Buried pipe loading
Trench safety
References
Appendix E: Selected units conversions
Index
End User License Agreement
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Guide
Cover
Table of Contents
Preface
Begin Reading
List of Illustrations
Chapter 1: Natural resources engineering opportunities
Figure 1.1 Schematic view of the hydrological cycle and related engineering topics associated with Natural Resources Engineering.
Figure 1.2 Land development relating to the social development of human societies.
Figure 1.3 Flooding in 2011 near the entrance of the Nzoia River to Lake Victoria near Kisumu, Kenya.
Figure 1.4 Tractor and trailer in a very wet field, reflecting that lack of drainage negatively affects the accomplishing of timely field operations. (Courtesy of https://www.youtube.com/watch?v=NHKTbT8fYYM, where additional images are also available.)
Figure 1.5 Center pivot-irrigated peanut production in South Georgia.
Figure 1.6 Schematic of a pump-and-treat bioremediation system. (Adapted from Nyer
et al
., 1996.)
Figure 1.7 Nutrient management plan showing sensitive areas, steep slopes, and acceptable application areas (left), as well as a drainage map of the site (right).
Figure 1.8 Stream in need of restoration. (From Figure 4.11 in NRCS, 1998.)
Figure 1.9 Reference quality stream with a sinuous channel and wide floodplain. (From Figure 4.11 in NRCS, 1998.)
Figure 1.10 Conceptual view of boundaries and interfaces relevant in a general ecological engineering problem space.
Figure 1.11 Schematic of mixed-use development invoking many tools of Natural Resource Engineering.
Chapter 2: Precipitation
Figure 2.1 (a) Weather station on a research farm, (b) details of the precipitation gage, and (c) a photograph of the tipping bucket inside the precipitation gage.
Figure 2.2 Depth–area rainfall reduction. (From Hershfield, 1961.)
Figure 2.3 Hypothetical rainfall mass curve showing the relation to rainfall intensity.
Figure 2.4 Rainfall hyetograph types.
Figure 2.5 Thiessen diagram for a small gaged watershed on a mountain side.
Figure 2.6 Depth–duration–frequency (DDF) curves for Atlanta, GA from the Perica
et al
. (2014) NOAA climatic atlas.
Figure 2.7 NRCS storm types by region in the United States. (From NRCS, 1986).
Figure 2.8 Probability plot of rainfall events in Atlanta, GA from 1996 to 2002 fit to an exponential distribution with confidence intervals, using data from the Georgia automated environmental monitoring network. The 85th percentile for this period is about 25 mm (1 in), which is close to the official 85th percentile value of 30.4 mm for the Georgia average water quality storm. Significant droughts occurred during this interval, which may account for the lower value.
Chapter 3: Infiltration
Figure 3.1 Infiltration rate as a function of time for indicated soil cover conditions.
Figure 3.2 Potentials involved in flow through porous media. Points 1 and 2 indicate respective head , measurement positions.
Figure 3.3 Schematic illustration of capillary or matric forces arising from the surface tension forces that arise with water in a small tube.
Figure 3.4 Infiltration scenario for the lined pond of Example 3.3.
Figure 3.5 Definition illustration for the Green–Ampt equation.
Figure 3.6 Cumulative infiltration and infiltration rate versus elapsed time under the conditions of Example 3.4.
Figure 3.7 Double ring infiltrometers installed in a tilled mulch for characterizing infiltration rate in a conservation tillage system.
Figure 3.8 Instrumentation for studying infiltration rate in the presence of simulated rainfall (Courtesy of Dr. D.E. Radcliffe, University of Georgia Crop and Soil Science Department).
Figure 3.9 Scenario depicting pollution transfer and transport from an infiltration basin to an existing groundwater aquifer.
Figure 3.10 (a) An infiltration problem situation. (b) Darcy flow scenario.
Chapter 4: Evapotranspiration
Figure 4.1 Heat balance for a water body with its top surface open to the atmosphere, and sides, incoming/outgoing streams, and bottom adjacent to earth. In Equation 4.4a is the net of and .
Figure 4.2 (a) Simplified evapotranspiration energy balance schematic. (b) Water vapor balance for the Penman–Monteith equation showing an expanded view of the control volume. There is also no net energy through the side walls of the control volume. Net sensible and latent energy moves vertically.
Figure 4.3 Vapor pressure density plot showing the Penman transformation, where we assume the transpiring surface was a leaf or water surface. The plot indicates an evaporating surface hotter than surrounding air. If the evaporating surface is cooler than ambient air, the effect on the Penman transformation is a negative sign in front of the slope . Other nomenclature is as follows: is the ambient temperature, is the saturation temperature, is the wet leaf temperature, is the vapor pressure at the wet leaf, and other nomenclature is as defined for Equation 4.1.
Figure 4.4 Schematic of a psychometric chart showing relationships between moisture content, saturation temperature, and dry bulb temperature.
Figure 4.5 Schematic showing energy movement paths for an evaporation pan versus those for a small reservoir.
Figure 4.6 Class A evaporation pan and anemometer as partof a weather station.
Figure 4.7 Schematic of a lysimeter.
Chapter 5: Runoff
Figure 5.1 Infiltration rate versus elapsed time with a 2 cm/h uniform rainfall event superimposed to show excess infiltration and runoff volume. Runoff begins within 20 min on the saturated soil versus 1.7 h on the dry soil.
Figure 5.2 Fields with bare soil (right) and vegetatively covered (left) after rainfall. More standing water is apparent on the bare soil side.
Figure 5.3 (a) Schematic of hypothetical hyetograph, hydrograph, and typical pollutant concentration graph from rainfall over a compact watershed. (b) The impact of decreasing watershed slope and increasing surface roughness on expected peak flow given a storm of equal duration and given the excess rain or runoff volume is the same.
Figure 5.4 (a) Delineation of watershed in Clarke County, GA on a topographic map produced using a Geographic Information System. The possible alteration of drainage paths by the indicated development is not considered, though such alterations may at times be substantial. Site visits are usually required to determine effects of development on flow paths. (b) Photograph of a three-dimensional representation of a generic compact watershed showing the delineation. (Courtesy of Ms. Annette Griffin and Professor Katherine Melcher of the Univesity of Georgia College of Environment and Design.)
Figure 5.5 A plot of the NRCS curve number equation (from NRCS, 2004).
Figure 5.6 Nomenclature for the NRCS curve number equation, showing the runoff as the net of precipitation , infiltration, and surface cover interception.
Figure 5.7 (a) A hypothetical compact watershed with a watershed gradient and composed of three sub-areas with different curve numbers and runoff coefficients . (b) Schematic of watershed showing overland flow and ditch travel to total travel time, equaling the time of concentration. Portions of overland flow in excess of 300 ft (90 m) are treated as extensions of the channel.
Figure 5.8 NRCS runoff curves for the Type 2 storm. Multiply csm/in by to obtain value in units of -mm-ha (from NRCS, 1986). See the listed references for additional storm type curves. The software in the downloads section mathematically describes all the NRCS storm types.
Figure 5.11 Normalized unit hydrograph obtained using Equations 14 and 15. The scaled hydrograph was computed on the indicated pulse of actual runoff.
Figure 5.9 Runoff hydrograph for the NRCS hydrograph method assuming a design storm equal to the time of concentration.
Figure 5.10 (a) Triangular unit hydrograph where uniform rain and excess rainfall ceases prior to time to peak; and (b) uniform rain and excess rainfall persisting beyond the peak time. Neither (a) nor (b) are unit hydrographs. The recession time to peak time ratio may vary in both cases depending on topography and cover.
Figure 5.12 Process schematic for computing a hydrograph for a specified storm duration. Rainfall may be measured or simulated using the NRCS distribution ordinates.
Figure 5.13 Image of a watershed in Kenya, using Google Earth Pro (Anon, 2006) for measuring distances, roughly delimiting the watershed contributing runoff across the 54 ha area in sugar production, with no riparian protection. The Nzoia River bounds the lower edge of the field.
Figure 5.14 Example flow–duration curve for Peace Creek near Sylvia. (From Studley, 1998.)
Chapter 6: Water erosion
Figure 6.1 An extreme example of gully erosion in the southeast United States.
Figure 6.2 General slope-shape categories.
Figure 6.3 Relationships between mean annual rainfall and indicated annual erosion. (From data provided by Hudson, 1971).
Figure 6.4 Miniature instrumented plot for quantifying interrill erosion. Also, note the rill outside the sampled area. (From Lal and Elliot, 1994; used with permission of St. Lucie Press).
Figure 6.5 Interrill erosion demonstrated near Griffin, Georgia, by placing a washer over the stake soon after a forested area was clear cut. Notice the difference in soil level, “A” versus “B,” after 6 months.
Figure 6.6 Raindrop impacting bare ground: (a) just before impact; (b) during impact; and (c) immediately after impact. The sequence required less than 0.1 s. (Provided by USDA-ARS.)
Figure 6.7 Relationships between rainfall kinetic energy and rainfall intensity for a variety of sites around the world. The units on the vertical axis are as follows: Joules per square meter soil area per millimeter rainfall depth. Kinetic energy is computed using , where is velocity (m/s) and is gravity . Velocity may be approximated using (see Smith, 1993), where is the droplet diameter in millimeters. (Redrawn from data provided by Hudson, 1971.)
Figure 6.8 Amplified view of a point in a hypothetical field highlighting forces due to raindrop impact and tractive force erosion mechanisms. Relations of the erosive forces to the sheet, rill, gully, and stream channel erosion mechanisms are shown. In reality, the detailed processes occur over the entire field, making process modeling very difficult.
Figure 6.9 Isoerodent map showing average annual erosivity for the USLE in SI units for the humid eastern United States. Units are ft-tons-in/(acre-in-year). To convert to SI units (MJ-mm/(ha-h-year) multiply indicated values by 17.02. (From Haan
et al
., 1994, who also provides maps for other parts of the US). The public domain software RUSLE2 enables computation in all parts of the US.
Figure 6.10 An example calculation for single storm given a rainfall mass curve.
Figure 6.11 Rainfall simulator and runoff sampling apparatus for quantifying soil erosion losses under field conditions.
Figure 6.12 Close-up of apparatus for quantifying runoff flowrate and sediment concentration from research plots.
Figure 6.13 (a) Definition schematic for a simple field showing nomenclature associated with the length and slope factors of the USLE. (b) Typical slope lengths. Slope A – If undisturbed forest soil above does not yield surface runoff, the top of slope starts with the edge of undisturbed forest soil and extends downslope to windrow if the runoff is concentrated by the windrow. Slope B – Point of origin of runoff to depression. Slope C – From the windrow to the channel. Slope D – point of origin of runoff to the road, which concentrates runoff. Slope E – From road to floodplain where deposition would occur. Slope F – from the top of the hill to floodplain where deposition would occur. Slope G – Point of origin of runoff to a slight depression where runoff would concentrate. In practice, (i) determine the slope length factor and (ii) the slope factor for each of the identified lengths, then (iii) take an average of the products to represent the field. (From Renard
et al
., 1997, courtesy of USDA-ARS).
Figure 6.14 Rainfall distribution by month for several regions of the United States.
Figure 6.15 The relationship between drainage area and sediment delivery ratio. The hatched area represents the confidence interval. One statute . (After Haan
et al
., 1994.)
Figure 6.16 The relationship between the relief ratio or watershed gradient to sediment delivery ratio. (After Renfro, 1975, courtesy of USDA-ARS.)
Figure 6.17 Stiff diagram for determining the relative contribution of the indicated factors to the reduction of sediment: ; . (From EPA, 1980).
Figure 6.18 The relationship between area within the EPA (1980) Stiff diagram and the sediment delivery ratio.
Figure 6.19 Stiff diagram for conditions of Example 6.2. (From EPA, 1980.)
Figure 6.20 Soil erodibility test apparatus using a single nozzle rainfall simulator. (From Haan
et al
., 1994; used with permission of Elsevier Publishers.)
Figure 6.21 Effect of travel downstream on sediment particle size distribution. (From Haan
et al
., 1994; used with permission of Elsevier Publishers.)
Figure 6.22 Strip cropping showing small grain (being harvested) and a row crop. (Courtesy NRCS.)
Figure 6.23 Forested riparian filter strips for protecting streams around the boundary of the agricultural field. (Courtesy NRCS.)
Figure 6.24 Cotton growing in a conservation tillage scheme. The crop residue forms the surface cover. (Courtesy NRCS.)
Figure 6.25 Straw bale barrier for excluding larger sediment size fractions from the culvert inlet.
Figure 6.26 Mass curve for determination.
Chapter 7: Water quality and management at farm/field scales
Figure 7.1 Chicken (broiler) litter application to a pasture using a spreader truck. Nutrient delivery trucks are currently upgrading to have variable rate application controlled by field nutrient maps and satellite positioning systems.
Figure 7.2 Cattle on sparse pasture or bare ground can cause extensive nonpoint or point pollution.
Figure 7.4 (a) The carbon cycle, showing natural cycling between the atmosphere and the flora and fauna on the left and cycling between the atmosphere and earth due to humankind's activities. The ocean is the largest sink, followed by fossil fuels and plants.
Figure 7.3 Schematic showing relationships between energetic, biotic, and chemical variables on the state of pollution in the water body. This chart shows the all-encompassing scale associated with nonpoint pollution management.
Figure 7.5 Development intensity and resulting water quality impacts.
Figure 7.6 Estimated spatial and temporal scales of five water quality parameters. The reality of spatial and temporal scale effects work to confound the determination of cause and effect relations in the environment.
Figure 7.7 Approximate spatial and temporal scales at work when a forested watershed undergoes timber harvest.
Figure 7.8 A decision aid for BMP selection.
Figure 7.9 Comparison and contrast of enrichment ratio versus the delivery ratio as a function of overland flow length.
Chapter 8: Open channel hydraulics–fundamentals
Figure 8.1 A trapezoidal waterway under construction. (Courtesy of Dr. Greg Jennings.)
Figure 8.2 Elements of a trapezoidal channel. The hydraulic depth is a calculated quantity. The slope is measured perpendicular to the cross-sectional area shown.
Figure 8.3 A definition sketch showing how topwidth relates to differentials of depth and area.
Figure 8.4 Hydraulic elements for a circular cross-section as a fraction of hydraulic elements at full pipe flow computed as shown.
Figure 8.5 Hydrostatic pressures arising from the presence of a fluid. Convert pressures to forces by integrating the pressure over the appropriate surface. Moment analyses may be employed to compute the position of the effective pressure.
Figure 8.6 Basic nomenclature for open channel flow energy computation.
Figure 8.7 Schematic of a channel showing components of the momentum balance along the direction of flow.
Figure 8.8 Simplified forces bearing upon uniform flow in an open channel.
Figure 8.9 Interrelationships among the channel design problem types discussed in this chapter. Satisfaction of Type B may or may not lead to satisfaction of Type C, and the optimum (C) may be erodible (B). After satisfying Type B, revisit Type A, particularly when flow is occasional and a capacity evaluation is appropriate.
Figure 8.10 Schematic of a flow transition problem.
Figure 8.11 Influence of a 10 000 m channel on a storm hydrograph with no inflow along the reach.
Figure 8.12 Schematic showing how the degree of curvature is defined for imperial and metric units, where is the deflection angle and Deg/2 is half the degree of curvature.
Figure 8.13 A decision aid for relating open channel flow design approaches. The conditional evaluations involving slope are approximate and should not regarded as rigorous breakpoints. Roughness, slope, cross-section type, and flow are assumed to be known, and other geometric elements are assumed unknown and yet to be determined.
Figure 8.14 A definition sketch showing the key nomenclature for a circular channel.
Figure 8.15 A schematic of a roadside curb.
Chapter 9: Vegetated waterways and bioswales
Figure 9.1 A vegetated waterway in an agricultural field. Vegetated waterways protect naturally occurring draws and serve as discharges for surface outlet terraces.
Figure 9.2 The relationship between the Manning roughness “” and product of velocity and hydraulic radius for each of five vegetation roughness classes ranging from very high (A) to very low (E). Also shown are parameters useful for representing the curves in computer modeling software.
Figure 9.3 Photograph and definition sketch of a bioswale.
Figure 9.4 A simple procedure for installing jute mat for stabilizing a newly constructed grassed waterway.
Figure 9.5 Design requirements summary for vegetated trapezoidal and parabolic channels. Note the general similarity with other channels types.
Chapter 10: On-site erosion management
Figure 10.1 Ancient bench terraces at Delphi, Greece.
Figure 10.2 Terrace nomenclature.
Figure 10.4 Bench terrace example used on steep slopes. This terrace is very expensive and requires deep soils.
Figure 10.5 Annotated comparison of parallel and nonparallel broadbase terrace channels. Parallel terraces follow the approximate contour and require cut and fill analyses. Parallel terraces facilitate equipment usage. Primary design goals are spacing, channel capacity, and channel slope. The slope length becomes the spacing between terraces instead of the entire width of the field.
Figure 10.6 Steep backslope erosion terrace with contour row cropping
Figure 10.7 Drawing showing broadbase and steep backslope terrace systems. Farmability of the broadbase system is assured when the various slopes each accommodate the largest equipment. Farmability of the steep backslope system is assured when an even number of passes of the widest machine are handled. The large assumption is possible because of the relative insensitivity of the result of the value used in the computations. ASABE (2012) recommends a minimum channel width of 0.9 m and ridge width of 0.9 m. For preliminary designs, we ignore the minimum widths. A 10% additional settlement increment is included for accounting for conditions just after construction that will ultimately settle.
Figure 10.8 Typical tile outlet terrace. The vertical riser has little protection and is vulnerable to machine damage.
Figure 10.9 Schematic of an underground outlet.
Figure 10.10 An underground outlet routing curve.
Figure 10.11 Hypothetical terracing situation involving three terraces with vegetated waterway outlet.
Figure 10.12 Erosion control strategies for a construction site near Athens, GA, including concrete-lined diversion channels, open-weave wood fiber impregnated with germinating grass seed, silt fencing, and rock linings.
Chapter 11: Hydraulics of water management structures
Figure 11.1 Gully stabilization structure built using rock gabions (wire-mesh packages of rock). Broad-crested weir hydraulics controls the flow.
Figure 11.5 Parshall flume for measuring the flowrate in an irrigation channel.
Figure 11.6 Schematic showing how four common spillway types are applicable for applications ranging from gully stabilization to pond principal spillways.
Figure 11.7 Common spillway inlets, conduits or conveyances, and outlets with energy dissipation structures. (A) Installation of a drop inlet spillway (Courtesy of the NRCS.) (B) Pipe conveyance and plunge pool, Nebraska. (Courtesy of National Register of Historic Places, Culvert on 522 Ave (Antelope County, Nebraska)) (C) Chute conveyance, Mountain Chute Dam, Quebec. (Courtesy of Qui1che). (D) Small bell-mouth pipe-drop spillway, Great Meadows National Wildlife Refuge, Concord, MA. (Courtesy of Wikimedia with permission to reuse in accordance with the provisions of the Creative Commons Attribution-Share Alike Unported License, unless otherwise indicated.)
Figure 11.8 Hydraulic jump schematic showing energy relationships (not to scale).
Figure 11.9 Energy relationships for a subcritical–supercritical flow transition used in quantifying discharge (not to scale).
Figure 11.10 Hydraulics of common flow control and inlet devices. Notational notes: imperial (FPS) units assumed; flowrate here is identical to ; weir coefficient is identical to ; and orifice coefficient ' is identical to .
Figure 11.11 Plan and side schematic views of a Parshall flume, along with dimensions. which are in millimeters unless indicated otherwise.
Figure 11.12 Flume and sampling equipment for measuring runoff hydrographs, sedimentation concentration versus time and pesticides concentrations versus time. A mechanical stage recorder is partially visible under the raised cover on the right. The sediment sampling apparatus is not visible in this photograph. The location is the University of Georgia Phil Campbell Research Farm (formerly USDA-ARS station) at Watkinsville, Georgia.
Figure 11.13 Three views of a
flume. The
and
flumes are similar in style with modified proportions to better accommodate larger flows.
Figure 11.14 Culvert longitudinal cross-section showing nomenclature.
Figure 11.21 Spillway cases for Example 11.11.
Figure 11.15 Selected possible scenarios of flow through a closed conduit. Consider the definition of the head in Categories A through C. Categories A and B are required when designing a free discharge culvert to pass a peak discharge subject to head limitations. These problems require a test (e.g., calculation of flow for each type and selecting minimum flow) to determine which of A or B controls. Category C is unique to communicating bodies of water, using the Category A equation with a modified definition for head. Categories D and E are solved using the weir equation at the entrance and the Manning equation plus energy equation as in the transition problem. The controlling category is the one providing minimum discharge. Categories D and E are helpful in stage–discharge relationships for spillways and related structures. Culverts with outlets that are submerged to a varying extent require advanced treatment beyond the scope of this text.
Figure 11.16 Culvert situation of Figure 11.14 showing the energy grade line and respective inverts and crown nomenclature.
Figure 11.17 Entrance and bend loss coefficients.
Figure 11.19 Flow relations for unsubmerged and submerged flow through a pipe entrance, highlighting the zone of unstable flow at a depth of 1 to 1.5 pipe diameters. Curves for both imperial and metric units are shown.
Figure 11.20 Schematic of a siphon spillway with projecting inlet. The schematic drawing indicates the tailwater elevations defining category A and category C flow types. Inlet flow control levels are noted. Siphon breaks at the lower depth will prime once depth exceeds upper depth for partial flow. Emergency spillway and siphon operates when depth exceeds the emergency spillway operation depth. Drawing is not to scale and necessary anchors for inlet, outlet, and fittings are not shown. Further calculation details are provided on the “SiphonCalcMoody.xlsx” spreadsheet in the online Supporting Material.
Figure 11.22 A schematic drawing showing an irrigation canal distribution box.
Figure 11.23 Sketch of a partially embedded culvert for fish passage.
Figure 11.24 Projection box inlet.
Chapter 12: Hydraulics of Impoundments
Figure 12.1 Unfilled reservoir showing the embankment, primary spillway inlet pipe riser, and concrete-lined emergency spillway in a newly constructed reservoir.
Figure 12.2 Phase diagram for soil.
Figure 12.3 Graph showing percent passing curves for two soil materials. The
D
15
,
D
50
, and
D
85
values are significant to soil filter design.
Figure 12.4 The USDA soil textural triangle and soil classification scheme.
Figure 12.5 Summary of the Unified Soil Classification system.
Figure 12.6 Unified Soil Classification system and associated uses.
Figure 12.7 Comparison and contrast of available soil classification systems. Each system was developed over time in reflection of the needs of the primary clientele served by the respective agencies. AASHTO serves highway construction, USDA serves agriculture, FAA serves airport runway construction, and USCS is a most general system.
Figure 12.8 The NRCS approximate detention basin routing for indicated rainfall types
Figure 12.9 Inflow and outflow hydrograph for the pond of The outflow peak represents the peak flow of the watershed prior to development. The hatched volume above represents an estimate of the required storage not to exceed the developed outflow peak runoff rate.
Figure 12.10 Schematic views of the hillside, levee, and watershed pond styles.
Figure 12.11 Approaches to developing sealed conditions for ponds and reservoirs: (A) largely impervious fill; (B) pervious fill and blanket seal; (C) impervious core with pervious fill; (D) clay liner installed in a lagoon with steep sidewalls where the seal was stair-stepped in lifts one machine width up the wall initially, then trimmed with cuttings becoming part of the bottom seal.
Figure 12.12 Detail of a rock toe filter recommended for the downstream side of a pond embankment. The filter keeps the flow through the embankment from eroding the embankment at the place where the flow tends to concentrate.
Figure 12.13 Applications of the slope stakes equation in the case of fill over an arbitrary bottom, showing the finished embankment with a dotted line.
Figure 12.14 Plan view and embankment cross-section for a watershed pond impoundment with important water elevations shown. (Redrawn from Schwab
et al
., 1993). Other impoundments for specialized purposes may not contain one or more of the following: flood storage, wave action allowances, an emergency spillway. Embankment height is determined by the liquid volume storage/depth requirements shown.
Figure 12.15 A drop inlet spillway with seepage collars. Other spillway types such as the drop inlet, siphon, flumes, weirs, and other structures may also serve as principal spillways.
Figure 12.16 Disks serving as seepage collars on the principal spillway conduit for a small pond.
Figure 12.17 Map showing the approximate size of a watershed necessary for long-term storage of 1 acre-ft of runoff for the continental United States. The contour values are roughly proportional to the ratio of evapotranspiration to rainfall for the region. One acre-ft is 0.1233 ha-m; 0.405 ha is 1 acre.
Figure 12.18 Schematic cross-section of a sedimentation and first flush stormwater management basin.
Figure 12.19 Fall velocity for spherical sand particles as a function of sediment size and specific gravity at 20 °C.
Figure 12.20 Ideal settling basin.
Figure 12.21 Surface area adjustment factor to account for effects of turbulence on sediment basin trapping efficiency.
Figure 12.22 Effect of baffling to diffuse fast moving flows over the basin width for increased effectiveness. The unbaffled basin (a) has dead space along with flow velocity much greater than the design velocity in the settling zone. Baffling as in (b) slows the incoming velocity and eliminates much dead space. Outlet flows are typically slow, not requiring outlet baffling.
Figure 12.23 Sediment distributions resulting from passage of incoming sediment distribution through structures having the indicated trapping efficiencies. The final size distributions may be plotted as follows: (i) determine the trapping efficiency
TE
; (ii) take the point on the initial percent finer (InitialPF, Initial concentration) distribution equaling to 100%. For example, if
TE
is 70%, plot the diameter of the particle at 30% finer at 100%. Other points on the final curve (FinalPF, Curve with indicated TE) arise from , where . Percent finer is identical to percent passing used by some writers.
Figure 12.24 Volume calculations for levee ponds and hillside ponds.
Figure 12.25 Pond and embankment for selected homework problems. A1–A7 denote areas enclosed by contours above the embankment (e.g., water surface area as a function of the stage).
Chapter 13: Shallow Groundwater Management
Figure 13.1 Drainage channel in North Carolina coastal plain providing nutrient management (denitrification through winter months), surface, and subsurface drainage and subirrigation capability during growing season.
Figure 13.3 Drain placement scenarios: (A) drain random depressions; (B) herringbone pattern for draining a large shallow basin; (C) gridiron pattern for draining a uniformly sloped surface; (D) placement of pipe for intercepting seepage; and (E) placement of tile for a structural drain.
Figure 13.2 Drainage collection sump with a diesel powered and belt driven low-head–high-flow pump.
Figure 13.4 Schematic of the vadose zone with pipe drainage lines overlying impeding layer showing nomenclature for steady state and nonsteady state flow equations. Note that the drawing shows the intermediate zone with the primary soil management zone in drainage applications. Depth
d
e
is the equivalent depth, not the actual depth. Equivalent depth
d
e
depends on actual depth
d
, spacing
Sp
, and to a minor extent the pipe radius.
Figure 13.5 Cross-section of a properly installed pipe drain.
Figure 13.6 Plastic drain tube installation with laser grade control.
Figure 13.7 Combination drainage/subirrigation system: ET, evapotranspiration; WT, water table; WTD, water table depth. (From Fouss
et al
., 1990; used with permission of ASABE.)
Figure 13.8 Drainage/subirrigation control structure schematic, with and without removable crest boards.
Figure 13.12 Water table control structure as viewed from above, used for nutrient management and subirrigation in the North Carolina coastal plains.
Figure 13.13 Schematic of an aquifer showing recharge zone and various flow conditions.
Figure 13.14 Schematic of a gravity well with recharge.
Figure 13.15 Definition sketches for the DF analysis of (a) unconfined and (b) confined wells.
Figure 13.16 Well installation in a bioremediation project in Atlanta, GA.
Figure 13.17 Bioremediation scenario involving pumping, treating, and injection.
Figure 13.18 Infiltration of rainfall or irrigation and drainage to a stream.
Chapter 14: Introduction to irrigation
Figure 14.1 (a) Moveable lateral sprinkler system. (
Source
: Reproduced with permission of TradeIndia.) (b) Wheel line irrigation system in an Idaho hayfield. Moved manually, frequently assisted by a small power source. The lateral system operates by attaching to a mainline (likely buried with vertical riser connecting points. (Courtesy of the NRCS.) (c) Linear move system with powered movement and draggable hose main supply. (Reproduced with permission of Reinke Irrigation Systems.) (d) Center pivot irrigation system in a peanut field. (e) Radio controlled big gun nozzle in a solid set pasture irrigation system. Riser height may vary with the crop. Guns are also used for center pivots ends, hose or cable-towed travelers, with lateral systems, and with solid set systems. (f) Surface drip irrigation and subsurface drip irrigation systems being installed at the University of Georgia Stripling Irrigation farm.
Figure 14.2 Generic water release curves. The range of available water for the medium textured soil is on the left.
Figure 14.3 Vadose zone features.
Figure 14.4 Mechanical impedance as a function of soil matric potential (absolute value), aeration, and compaction for a generic plant root.
Figure 14.5 Salinity in a sorghum field near Timbouctou, Mali. Salinity, indicated by the light areas, is a product of natural seepage, canal seepage, lack of drainage, and poor irrigation management. The salinity in this photograph is predominantly magnesium sulfate.
Figure 14.6 Lateral sprinkler system layouts.
Figure 14.7 Water distribution patterns from a typical sprinkler nozzle operated at low, optimal, and high pressure.
Figure 14.8 Schematic of pressure head components needed for lateral sprinkler design.
Figure 14.9 Schematic showing the components of the total dynamic head (TDH) and the net positive suction head (NPSH).
Figure 14.10 Elements of the total system curve at a given discharge. The curves represent an accumulation of all components below the indicated component.
Figure 14.11 The ideal centrifugal pump for a given system is one in which the system curve intersects the pump curve for the flow in the region of optimum efficiency. At the same time, the NPSH would exceed the available calculated NPSH. The affinity laws are useful for making speed or impeller diameter adjustments to move a given pump model closer to the optimum operating point.
Figure 14.12 Example 14.9 field layout. Four lateral sprinkler systems, two across from each other, operate simultaneously to each cover a quarter of the field. Arrows show the movement of the lateral systems over time.
Figure 14.13 Schematic of center pivot irrigation system showing area irrigated and the zone of maximum application rate.
Figure 14.14 Green and Ampt analysis of the scenario in Example 14.10 where the water application was modeled as a constant average intensity flow event for a time duration equal to the time to ponding, assuming an elliptical distribution pattern.
Figure 14.15 Growth rate as a function of water potential (absolute value) for
Phytophthora cinnamoni
in three soil textures.
Figure 14.16 Solid set sprinkler for a small land application system in Clarke County, GA.
Figure 14.17 Microirrigation lateral system in a peach orchard with emitters instrumented to measure soil water status versus distance from an emitter.
Figure 14.18 Microirrigation system in a hypothetical bioremediation application.
Figure 14.19 Details of chemical injection systems for irrigation with (a) diesel-powered system and (b) electrically powered system.
Figure 14.20 Field layout for Problem 14.3.
Chapter 15: Ecological assessment and engineering
Figure 15.1 Stream patterns from combined systems and individual shapes. Patterns a–c are the major general patterns for smaller streams. Patterns d and e are specialized descriptions usually reserved for large streams and river systems. (Adapted from Viessman and Lewis, 1996.)
Figure 15.2 Stream-order designation for a generic stream network, with a subjective correspondence between watershed area and mean discharge.
Figure 15.3 An observed sequence of channel changes in an urbanized stream. Observe the change from trapezoidal to parabolic shape. (
Source
: Whitlow and Gregory, 1989. Reproduced with the permission of John Wiley & Sons, Ltd.)
Figure 15.4 Summary of the Rosgen method for stream classification (Rosgen, 1996). Level 1 is a desk level, levels 2 and 3 reflect geomorphology data collection; and, level 4 represents hydraulic evaluation, modeling, and validation. One may find further details on the classification scheme in the reference. (
Source
: Reproduced with permission of Wildland Hydrology).
Figure 15.5 Hypothetical natural channel cross-section and a plan view showing nomenclature and design relationship as summarized by Huffman
et al
. (2013).
Figure 15.6 Schematic of rough boundary channel showing the log velocity profile, turbulent velocity components, and typical roughness elements. The mean velocity in the vertical direction is zero. The average velocity in the -direction (along the channel bottom) is the velocity being profiled. The protruding roughness elements exerting form drag are visualized in the close-up (b). Close up of channel bottom with log velocity profile shown. The angle is the effective friction angle (e.g., drag force over the weight at incipient particle movement).
Figure 15.7 A triangular weir for measuring runoff hydrographs for a small research watershed. The stage gauge is just out of the picture.
Figure 15.8 Price current meter with stabilizing weight.
Figure 15.9 A hypothetical channel showing measurement stations for integrating velocity over the area for total flow.
Figure 15.10 Schematic drawing showing zones or cells where acoustic Doppler measurements enable velocity profile information. The instrument also measures turbidity.
Figure 15.11 Sonar system coupled with precision GPS unit for bathymetric (depth) measurements in a stream. (
Source
: Reproduced with permission of Mr. Ken Swinson.)
Figure 15.12 Shield's curve for predicting the incipient motion of sediment particles.
Figure 15.13 (a) Rising stage sediment sampler. (b) Point-integrating suspended load sediment sampler US P-61, which enables integration over depth by steadily moving the sampling device over the profile while collecting the sample. Bed sampling devices are also available. (Interagency Committee on Water Resources, 1963.)
Figure 15.14 Schematic showing an advancing gully headwall with time.
Figure 15.15 (a) Slope erosion control scheme for bank stabilization of stream with a low flow. This approach is also applicable to other excavated banks. (b) Bioengineering techniques suggested for channel stabilization. (c) Suggested stream bank restoration approaches as a function of bank slope. (From NRCS, 1998.)
Figure 15.16 Habitat type designations are common in stream ecology. Littoral and profundal designations occur in depositing streams (lentic or lotic ecology). Light penetration distinguishes the littoral zone from the profundal zone (0.6–1.3 m limit usually) and the resulting flora. The littoral and profundal designation is not applicable for eroding streams.
Figure 15.17 Hypothetical dendritic watershed schematic showing predominant benthic characteristics as a function of relative distance from lake or ocean.
Figure 15.18 Survey of the number of species as a function of distance upstream for a river in Scotland. The aquatic survey is an important body of information for TMDL assessment. (Redrawn following Maitland, 1990.)
Figure 15.19 An example load-duration curve following a TMDL example in Chin (2013). (
Source
: Reproduced with the permission of John Wiley & Sons.)
Figure 15.20 Aquatic invertebrates and wetland vegetation in prairie freshwater marshes that drawdown due to drought, reemerge when rains return, and experience floating vegetation that submerges bringing about open water. The cycle repeats every 15–20 years or whenever droughts cause drawdown. (
Source
: Mitsch and Gosselink, 2000, Reproduced with the permission of John Wiley & Sons.)
Figure 15.21 Plan view and profile view of a constructed free water surface wetland.
Figure 15.22 Oxygen sag curve predicted using the Streeter–Phelps equations plotted versus time in a stream reach. The deficit curve is a solution of the model for oxygen utilization in Table 15.3. The oxygen concentration curve is the deficit subtracted from , which yields steam-oxygen status . (Adapted from Tchobanoglous and Schroeder, 1985.)
Figure 15.23 Lake circulation patterns and temperature profiles as a function of the season in temperate regions.
Figure 15.24 A schematic representation of the major differences between eutrophic and oligotrophic lakes.
Figure 15.25 Redox (pE) potential versus pH: (a) for a iron–carbonate–hydroxide system; (b) for a manganese–carbonate–hydroxide system. As redox drops and acid conditions develop, more soluble forms of manganese and iron predominate. (
Source
: Stumm and Morgan, 1981. Reproduced with the permission of John Wiley & Sons.)
Figure 15.26 Concentration diagrams as a function of redox potential with for (a) nitrogen, (b) nitrogen without , (c) iron and manganese, (d) sulfur, and (e) selected carbon species. Note that reduced forms of metals, sulfur, and other compounds are frequently more soluble than oxidized forms. (
Source
: Stumm and Morgan, 1981. Reproduced with the permission of John Wiley & Sons.)
Figure 15.27 Automated sampling system for stream organic and nutrient assessment.
Figure 15.28 Suggested turnover lengths for carbon of various forms in a stream with a flow of 3–: CPOM is coarse particulate organic matter; FPOM is fine particulate organic matter; UPOM is the ultrafine particulate organic matter; DOM is the dissolved organic matter. (
Source
: Newbold, 1996. Reprouced with permission of John Wiley & Sons)
Appendix A: Ethics, stakeholder views, case studies, and precision
Figure A.1 The pitcher plant case-study situation.
Appendix C: Tractive force method for waterway design
Figure C.1 Unit tractive force ratio on the channel sides (a) and bottom (b) in the indicated channels as a function of the bottom width (
b
) to normal depth (
d
) ratio. (After Lane and Carlson, 1953.)
Figure C.2 The angle of repose of particles as a function of stone geometry and size.
Figure C.3 Force balance on a particle on the side of the channel.
Figure C.4 (a) Critical tractive force for coarse textured particles of indicated average diameter (Lane and Carlson, 1953). (b) Critical tractive force versus void ratio for fine textured materials (Lane and Carlson, 1953). Imperial units may be converted to metric by lb/ft
2
× 48.57 to obtain Pa (N/m
2
).
Appendix D: Land forming, structure selection, installation, and forces on conduits
Figure D.1 Land leveling with a laser controlled scraper for precise slope modification. Laser control may be interfaced to conventional graders, bulldozers and drain tube laying equipment also.
Figure D.2 Example land surface shaping situation showing measured elevations in the grid and centroid calculations.
Figure D.3 Perspective schematic of hypothetical pond dam shown in two halves. Note the trapezoid cross-sections. Volume can be found knowing the area of each trapezoid and the length of the dam between the trapezoids and applying the average end-area formula, as indicated for half the dam above. The number of sections depends on the particular situation.
Figure D.4 Perspective view of a water body with contours denoting water level as a function of elevation. The water volume can be computed using the average area formula knowing contour intervals and surface area associated with each contour.
Figure D.5 Perspective view of small hill showing contour lines for soil volume calculation with the average end-area formula.
Figure D.6 A definition schematic showing slope stake positioning for a cut. For a fill such as a dam, the sign reverses on ΔE.
Figure D.7 Nomenclature for setting slope stakes for pond dam.
Figure D.8 Schematic for defining the radius of curvature for imperial and metric units (chordal method).
Figure D.9 Definition schematic for laying out a circular curve.
Figure D.10 Methods of establishing grade in the field.
Figure D.11 Staking procedure for graded terraces with a grassed waterway outlet.
Figure D.12 Crawler shovel with a pivoting scoop for finish work.
Figure D.15 Construction of a drainage ditch demonstrating the types of obstacles commonly found in urban areas. Backhoes and shovels are frequently used, although a small crane-dragline is in use here.
Figure D.16 Water quality only pond – stormwater management facilities only for detaining and treating the “first flush” volume of stormwater: WQV, water quality volume. All other storm frequencies (l-year to 100-year) pass through the outlet control structure (OCS). (Courtesy of Watermann Water Quality, Roswell, GA.)
Figure D.20 Dry detention ponds – stormwater management facility detains the peak flood control volume (2-year to 100-year) enabling flow releases at predeveloped conditions. (Courtesy of Watermann Water Quality, Roswell, GA.)
Figure D.21 Typical rural road profiles (a) With two-sided drainage – surfaces may be sloped to drain in one direction also. (b) Typical road construction where fill material is imported. Profile (b) supports a heavier wheel loading than does a profile (a). Shoulder width
W
s
in (b) depends on local specifications. Geotextiles may be placed beneath the subgrade of both (a) and (b) to provide additional load resistance.
Figure D.22 Load coefficients for underground tubing due to overburden weight for indicated soil conditions. (From Handy and Spangler (2007) reproduced with the permission of McGraw-Hill Publishers.)
Figure D.23 Definition schematic showing nomenclature for Boussinesq surface load equation useful for loads offset at
x
and
y
distances from the point directly over the loaded object.
Figure D.24 Schematic showing load factors resulting from various installation approaches. Installing pipe or tile on the trench bottom without shaping is considered unacceptable. Most tile drainage installations have a load factor of 1.5 and culvert installations have load factors of 1.9 or higher if adequately installed.
List of Tables
Chapter 2: Precipitation
Table 2.1 Rainfall mass data and 5-min and 30-min intensity computations
Table 2.2 Frequency factors (
K
RtPd
) for the lognormal probability distribution
Table 2.3 Sampling of Perica
et al
. (2014) NOAA Atlas 14 tabular data for Atlanta, GA
Table 2.4 NRCS (1973) storm coordinates where the entries are
P
(
t
)/
P
(24).
a
Table 2.5 Relative contributions of selected freshwater pollutants associated with nonpoint pollution
Chapter 3: Infiltration
Table 3.1 Approximate Green and Ampt infiltration parameters for selected soil textures.
a
Table 3.2 Retardation factors for selected compounds
Chapter 4: Evapotranspiration
Table 4.1 Reflectivity or albedo coefficients
Table 4.2 Mean solar radiation at the top of the atmosphere,
R
so
(MJ/m
2
day)
Table 4.3 Approximate crop coefficients “
K
c
”
a
for well-watered grass reference.
b
Table 4.4 Mean daily percentages (
P
BC
)
a
of annual daytime hours for different latitudes on a daily basis, representing the 15th day of the respective months
Chapter 5: Runoff
Table 5.1 Runoff curve numbers (CN) for agricultural soil-cover complexes for antecedent rainfall condition II
Table 5.2 Runoff curve numbers (CN) with antecedent condition II, for mainly nonagricultural applications
Table 5.3 Hydrologic soil group and hydrologic condition definitions
Table 5.4 Antecedent moisture conditions.
a
Table 5.6 Values of overland flow time-of-concentration coefficient “
a
of
” for use in Equation 5.10a
Table 5.7 Rational equation runoff coefficients (C
rat
)
Table 5.8 Factors to modify Rational coefficients for group B to other soil groups
Table 5.9 Swamp factor “
F
p
” for the graphical NRCS TR-55 runoff equation
Table 5.10 Runoff coefficients for the ASABE (2012) land drainage equation
Table 5.11 Example effective rainfall computation based on the Green and Ampt infiltration method.
a
Table 5.12 Calculation Table for NRCS curve number method for 3 h storm.
a
Table 5.13 Computed unit hydrograph for Example 5.5
Table 5.14 Simulated storm for Example 5.5
Table 5.15 Incremental rainfall for Example 5.5
Table 5.16 Partial results of applying the unit hydrograph (uh) to each element of incremental rainfall in Example 5.5
Table 5.17 Hydrograph for Example 5.5
Table 5.18 Stage-discharge relationship for Problem 5.1.
Chapter 6: Water erosion
Table 6.1 Rainfall erosivity values for selected locations
Table 6.2 Abbreviated soil loss ratio table
Table 6.3 Values for the contouring practice subfactor, P
c,
and the strip crop practice subfactor, Ps
Table 6.4 Example of weighted
C
factor calculation (peanut–corn–meadow–meadow rotation) for an agricultural problem of erosion in North Georgia.
2
,a
Table 6.5 Example weighted
C
prac
factor calculation for construction induced erosion in North Georgia
Chapter 7: Water quality and management at farm/field scales
Table 7.1 Selected drinking water standards (USEPA, 2009)
Table 7.2 Efficacy of selected managerial BMPs for controlling nonpoint source pollution at or very near the pollution source.
a
Table 7.3 Structural BMPs for remediating nonpoint source pollution at points downstream of the pollution source
Table 7.4 Managerial and structural BMP summary for agricultural crop production, but note that BMPs are site-specific in nature
Table 7.5 Managerial and structural BMP summary for agricultural crop and livestock production, but note that BMPs are site-specific in nature
Table 7.6 Removal and renovation mechanisms for selected nonpoint pollutant classes
Chapter 8: Open channel hydraulics–fundamentals
Table 8.1 Hydraulic elements for common channel cross sections.
a
Table 8.2 Permissible velocity and Manning roughness values for naturally lined channels
Table 8.3 Typical Manning equation roughness n values for a variety of artificially lined channels or conduits
Table 8.4 Constraining
z
values for general trapezoidal channels, natural linings as specified, or optimum
y
/
b
values in the case of other indicated geometries
Table 8.5 Suggested energy loss coefficients (
K
tran
) associated with selected channel transitions
Table 8.6 Maximum curvatures for curves as a function of slope and channel width
Table 8.7 Construction machinery for channels
Table 8.8 Customer requirements and engineering factors prompt sheet for application to open channel design problems
Chapter 9: Vegetated waterways and bioswales
Table 9.1 Vegetation selection guide
Table 9.2 Vegetal cover classification according to retardance
Table 9.3 Permissible velocities
v
p
for vegetated channels
Chapter 10: On-site erosion management
Table 10.1 Suggested maximum and minimum terrace grades
Table 10.2 Maximum allowable velocity
a
values (
v
pktable
) in perforated underground pipe as a function of soil type.
a
Table 10.3 Comparison of erosion control practices on the farm and at the construction site
Table 10.4 Comparison and contrast of selected channel design solution types and attributes
Chapter 11: Hydraulics of water management structures
Table 11.1 General guidance for selecting outlet structure based on the head drop and discharge
Table 11.2 Selected geometric elements for
H
x
flumes
Table 11.3 Summary of estimated parameters for the generalized
H
x
flume critical flow equation at selected flow conditions.
a
Table 11.4 Variable sheet and rule sheet for TK® solver model for a principle spillway, Case A, vertical riser
Table 11.5 Results Table that shows the different components of the vertical riser discharge (qtot) for the model in Table 11.4: all flows expressed in m
3
/s
Table 11.6 Rules and output for stage–discharge determination with mechanical pipe spillway and no vertical riser based on Example 11.7
Table 11.7 Prompt sheet for assessing customer and technical requirements
Chapter 12: Hydraulics of Impoundments
Table 12.1 Storage routing curve calculations.
a
Table 12.2 Hydrologic flood routing computations table
Table 12.4 Comparison key inputs and outputs of Example 10.3 computed using the Beasley
et al
. (1984) method and the HydroCAD (Anon., 2010) computer modeling approach. The approach applies to many agricultural and urban water management problems
Table 12.6 Water requirements (working volumes) for agricultural uses
Table 12.7 Surface area requirements of sediment traps and basins
Table 12.8 Customer requirement and technical requirement prompts for impoundments
Table 12.9 Stage storage and inflow data for problem 12.8.
Table 12.10 Data for the scenario of problem 12.13.
Chapter 13: Shallow Groundwater Management
Table 13.1 Selected row drain, field drains, and collection lateral dimensions for surface drainage
Table 13.2 Table 13.2. Parallel surface drain channel specifications for water Table control
Table 13.3 Suggested spacing and drain depths for humid areas.
a
Table 13.4 Minimum slopes for tile drains
Table 13.5 Drainage coefficients (
D
c
) for humid areas
Table 13.6 Soil properties for use in simple water well design problems
Chapter 14: Introduction to irrigation
Table 14.1 Summary of selected irrigation system attributes as affected by site and situation factors
Table 14.2 Summary of mean values versus the textural class of selected soil properties relevant to irrigation design
Table 14.3 Summary of effective rooting depths and peak water use for selected crops
Table 14.4 Approximate water intake rates as a function of topography and cultural practices
Table 14.5 Critical salinity conductivity values and tolerance ratings for selected crops.
a
Table 14.6 The arrangement of calculations for distribution uniformity determination
Table 14.7 Information for Example 14.6 irrigation scheduling problem
Table 14.8 Irrigation water balance for irrigation scheduling in Example 14.6
Table 14.9 Economic comparison of selected sprinkler irrigation equipment
Table 14.10 Typical nozzle performance data for medium pressure sprinklers
Table 14.11 Approximate effects of wind velocity on the sprinkler and lateral spacings
Table 14.12 Christiansen's factors for multiple outlets for smooth and rough pipe types
Table 14.13 Summary of friction losses with indicated (bold) lateral system and mainline diameters for Example 14.9
Table 14.14 Summary of friction losses with the example microirrigation system with chosen diameters indicated (bold)
Table 14.15 Data for Problem 4.
Chapter 15: Ecological assessment and engineering
Table 15.1 Flow rate calculations from data gathered at the bridge crossing at the location of Figure 15.8b
Table 15.3 Data for problem 15.3.
Table 15.2 Characteristics of eutrophic and oligotrophic lakes as a function of selected physical attributes
Appendex A: Ethics, stakeholder views, case studies, and precision
Table A.1 Correspondences between ethics, values and morals
Table A.2 Summary of historic ethical positions or worldviews from a Western perspective.
a
Table A.3 Relationships between significant digits and engineering usage
Appendix C: Tractive force method for waterway design
Table C.1 Properties of vegetal retardance classes
Table C.2 Values of
a
and
b
in Equation C6
Appendix D: Land forming, structure selection, installation, and forces on conduits
Table D.1 Chord length calculations for an example problem
Table D.2 Representative loads or strength moduli associated with failure for indicated pipe or material types.
a
Design loads divided by the installation load factor must not exceed the design bearing load tabulated below
Appendix E: Selected units conversions
Table E.1 Selected unit conversion factors.
a
