Techniques Manual
March, 2000
( NOTE: This manual was compiled by the staff of the Division of Water Resources Instream Flow Unit as a supplement to supervised training and as a quick reference. This manual should not be considered a substitute for supervised training nor a thorough treatise on the subjects discussed nor meant to reflect the state of the art of stream flow data collection and analysis. Those seeking to learn or use the techniques discussed should seek supervised, professional training and review the references provided at the end. The Division of Water Resources cannot be held responsible for the misinterpretation or misuse of techniques or programs discussed.)
[ Back to Site Map ] [ Back to Instream Flow Procedures ]
CONTENTS
| I. FIELD PREPARATION | ||
|---|---|---|
| A. Equipment List | B. Equipment Maintenance | C. Research Hydrologic Records |
| 1. Strip maps | ||
| 2. Drainage area information | ||
| 3. Statistical programs | ||
| II. FIELD DATA COLLECTION | |||
|---|---|---|---|
| A. Site Inspection | B. Surveying | C. Discharge Measurements | D. Before Leaving the Site |
| 1. Habitat mapping | 1. Survey instrument setup | 1. Price AA and pygmy flow meter operation |
|
| 2. Stream reach coefficient | 2. Survey instrument readings | 2. Transect selection | |
| 3. Data collection | 3. Placement and number of velocity measurements |
||
| a. Transect substrate | 4. Data collection | ||
| b. Transect survey | 5. Data entry | ||
| c. Data entry | 6. Photographic documentation | ||
| d. Transect substrate | 7. Subsequent data sets | ||
| e. Water surface elevation survey |
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| f. Tying benchmarks | |||
| g. Turning points and loop closure |
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| h. Stage at zero flow | |||
| III. DATA PROCESSING | |
|---|---|
| A. First Data Set | B. Subsequent Data Sets |
| 1. Discharge calculation | 1. Discharge calculation |
| 2. Creating transect *.DAT file | 2. Stage discharge curves |
| 3. Running wetted perimeter program | |
| 4. Plotting wetted perimeter output | |
| 5. Determine further data needs | |
| IV. DATA ANALYSIS | ||
|---|---|---|
| A. Straight Wetted Perimeter | B. Incremental Wetted Perimeter | C. Statistical programs |
| 1. Manual analysis | 1. Completing spreadsheet | |
| 2. Computer analysis | 2. Plotting output | |
| V. REFERENCES |
|---|
| References |
TABLES AND FIGURES
List of Tables
Table 1. Instream flow field checklist.
Table 2. Equipment maintenance schedule.
Table 3. Drainage area information data sheet.
Table 5. Layout of data book page with staff gage readings from site visit.
Table 6. Layout of data book page with nail and transect locations from site visit.
Table 7. Layout of data sheet for survey of transect.
Table 9. Layout of data sheet for flow data collected on transect.
Table 10. Layout of data book photography log for transects.
Table 11. Layout of summary data sheet for three site visits.
List of Figures
Figure 1. Strip map of study reach with water bodies, gage site, access area and mileage markers highlighted.
Figure 2. Illustration of habitat mapping of stream reach study site.
Figure 3. Top view of Wild Heerbrugg NAK1 survey instrument.
Figure 4. View of rod through eyepiece of survey instrument.
Figure 5. Example of transect survey for wetted perimeter.
Figure 6. Relating elevation of one benchmark, nail one (N1), to a second benchmark, nail two (N2).
Figure 7. Using a turning point between two distant nails.
Figure 8. Relating four nails with three turning points.
Figure 9. Stage at zero flow (SZF) for pool with downstream control.
Figure 10. Proper rod setting for whole number depths.
Figure 11. Proper rod setting for fractional number depths
Figure 12. First Setting: Depth x 2 = Setting.
Figure 13. Second Setting: Depth x 0.5 = Setting.
I. FIELD PREPARATION
A. Equipment List ( See Table 1 )
B. Equipment Maintenance
- Inspect and maintain survey, flow and miscellaneous field equipment periodically ( see Table 2 )
- Procure needed equipment and supplies prior to field visit
[ Up to CONTENTS ]
C. Research Hydrologic Records
1. Strip maps
For many projects a photocopy is made of the U.S. Geological Survey (USGS) topographic map (7.5 minute, scale = 1:24000) of the river or stream that is being studied to help in field reconnaissance and site and transect selection ( see Figure 1 ). The photocopies are trimmed, aligned, and taped together to make a strip map of the stream. Using a map wheel and coloring pencils, draw a purple triangle marker for each stream mile to the end of the study area. The stream or river and its tributaries are colored blue, any gages or dams are red, and access areas are orange. Use colored pencils instead of ink markers to prevent smearing when wet.
| Figure 1. Strip map of study reach with water bodies, gage site, access area and mileage markers highlighted. |
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[ Up to FIGURES ]
[ Up to CONTENTS ]
2. Drainage area information
Assemble data from the strip maps, drainage area book (Meikle 1983) and low flow file. The data sheet in Table 3 will be helpful in making sure the needed information is collected.
[ Up to CONTENTS ]
3. Statistical programs
Use GAGETABLE, other Hisars or SAS programs to retrieve additional flow information, if required, for a specific site.
[ Up to CONTENTS ]
| TABLE 1. INSTREAM FLOW FIELD CHECKLIST | |||||
|---|---|---|---|---|---|
| ITEM | OUT | IN | ITEM | OUT | IN |
| COUNTY ROAD MAPS | FLAGGING | ||||
| STRIP MAPS | STAFF GAGE | ||||
| FIELD FOLDERS | SMALL STAFF GAGE | ||||
| DATA BOOKS | MACHETE | ||||
| CLIP BOARDS | BUSH AXE | ||||
| CALCULATOR | COLLAPSIBLE RULER | ||||
| 4' FLOW METER ROD | GLOVES: LEATHER \ NEOPRENE | ||||
| 6' FLOW METER ROD | BOOTS: SHORT \ HIP | ||||
| AA FLOW METER | WADERS: LIGHT \ NEOPRENE | ||||
| PYGMY METER | RAIN SUIT: TOP \ BOTTOM | ||||
| HEADPHONES | CANOE | ||||
| BEEPER BOXES | LIFE JACKET | ||||
| DIGITIZER | PADDLES | ||||
| FIBER OPTIC BOX & CABLE | ROPE | ||||
| STOPWATCH | TAPE: 300' \ 150' \ 100' | ||||
| PENCIL | TAPE CLIPS | ||||
| SURVEY LEVEL | HAMMER | ||||
| SURVEY ROD | WADER PATCH KIT | ||||
| ROD LEVEL | GEAR OIL | ||||
| LEVEL TRIPOD | CAMERA | ||||
| STAKES | FILM | ||||
| REBAR | WATERPROOF CAMERA BAG | ||||
| NAILS: ALUMINUM / PK | BOOT SOCKS | ||||
| SPRAY PAINT | TP | ||||
| FIRST AID KIT | WATERPROOF STUFF SACK | ||||
| BUG REPELLANT | BATTERIES | ||||
| FLASHLIGHT | OTHER: | ||||
[ Up to TABLES ]
| TABLE 2. INSTREAM FLOW EQUIPMENT MAINTENANCE SCHEDULE | ||
|---|---|---|
| ITEM | TASK | DATE |
| FLOW METER RODS | CHECK WIRES / SCREWS | 1ST WEEK IN MARCH; BEFORE AND AFTER EACH TRIP; LAST WEEK IN OCTOBER. |
| AA / PYGMY FLOW METERS | CLEAN, CALIBRATE, OIL,CHECK PIVOT POINTS | SAME AS ABOVE |
| HEADPHONES | CHECK BATTERIES / ALL CONNECTIONS | SAME AS ABOVE |
| BEEPER BOXES | CHECK BATTERIES / ALL CONNECTIONS | SAME AS ABOVE |
| DIGITIZER | CHECK CHARGE / ALL SWITCHES | SAME AS ABOVE |
| FIBER OPTIC COUNTER | CHECK BATTERY / ALL SWITCHES / CALIBRATION | SAME AS ABOVE |
| STOPWATCH | CHECK BATTERY / ALL CONNECTIONS | SAME AS ABOVE |
| SURVEY LEVEL | RECALIBRATION | 2ND WEEK IN MARCH; 1ST WEEK IN AUGUST |
| REBAR / WOODEN STAKES | CHECK SUPPLY IN STOCK | EARLY SPRING AND LATE FALL |
| NAILS | CHECK SUPPLY IN STOCK | SAME AS ABOVE |
| FLAGGING | CHECK SUPPLY IN STOCK | SAME AS ABOVE |
| SMALL STAFF GAGES | REPLACE TAPE | SAME AS ABOVE |
| CANOE | CHECK HULL, FLOTATION, LASHRINGS | 1ST WEEK IN MARCH; LAST WEEK IN OCTOBER |
[ Up to TABLES ]
| TABLE 3. DRAINAGE AREA INFORMATION DATA SHEET | ||||||
|---|---|---|---|---|---|---|
| Date: | ||||||
| Stream: | ||||||
| Location: | ||||||
| USGS Quad Name: | Map Number: | |||||
| Station: | ||||||
| Drainage Area (mi2): | Source: | Page: | ||||
| Mean Annual Flow: | MAF/mi2: | Source: | ||||
| 7Q10: | 7Q10/mi2: | Source: | ||||
| Nearby Gages or Low Flow File Stations: | ||||||
| Station Number | Stream / Location | DA | MAF | MAF/mi2 | 7Q10 | 7Q10/mi2 |
| Selected Gages or Stations: | ||||||
| Ratioed to location of interest: | ||||||
| Station Number | September Median |
SepMed/mi2 | 7Q10/mi2 | SepMed | 7Q10 | |
[ Up to CONTENTS ]
II. FIELD DATA COLLECTION
A. Site Inspection
1. Habitat mapping
Examine the study site from beginning to end by canoe, foot and/or bridge observations. Pay close attention to the habitat types and what each type represents in terms of substrate, cover, gradient and other habitat characteristics.
The next step is to determine how much of the stream reach falls under each habitat type. This can be done by dividing the stream into equal segments while walking the channel and keeping a running account of distances and the habitat type associated with each measured length. Another approach involves determining habitat type at set intervals along the stream. This is done at least 30 times and the frequency of each habitat type is used for weighting. This technique is especially useful for long stretches where measuring is difficult. The weighting factors determined are used to establish the number and location of transects needed to represent the stream. The best way to record this information is to map the study area: labeling the transects, noting important stream changes, and measuring the lengths of these areas ( see Figure 2 ). Indicate the actual transects and assign other sections of habitat to the representative transect.
[ Up to CONTENTS ]
2. Stream reach coefficient
After the reach is documented, determine the total length of each representative transect by totaling similar habitat areas and list by transect ( see Table 4 ). Stream Reach Coefficient (SRC) is the proportion of the stream represented by the habitat characteristics of each transect. To obtain the SRC, total the transect lengths and divide each transect length by the total length.
| STREAM REACH COEFFICIENT (SRC) = Transect Length / Site Total Length |
[ Up to FIGURES ]
| Figure 2. Illustration of habitat mapping of stream reach study site. |
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 |
[ Up to TABLES ]
| Table 4. Determination of stream reach coefficient by representative transect based on proportion of habitat type within study reach. | ||
|---|---|---|
| Transect Number | Length | SRC |
| 1 | 416 | 0.1184 |
| 2 | 400 | 0.1139 |
| 3 | 75 | 0.0213 |
| 4 | 595 | 0.1694 |
| 5 | 206 | 0.0586 |
| 6 | 531 | 0.1512 |
| 7 | 177 | 0.0504 |
| 8 | 307 | 0.0874 |
| 9 | 122 | 0.0347 |
| 10 | 215 | 0.0612 |
| 11 | 211 | 0.0601 |
| 12 | 258 | 0.0734 |
| TOTAL | 3513 | 1.0000 |
[ Up to CONTENTS ]
B. Surveying
1. Survey instrument setup
On the tripod, a cover is attached at the top to protect the surface on which the instrument is mounted. To attach the survey instrument to the tripod, the cover is removed by unscrewing it from beneath. Place the cover in the instrument box when not on the tripod. Attach the survey instrument--the N.C. Division of Water Resources uses a Wild Heerbrugg NAK1 level--to the top of the tripod using the same screw that held the cover.
Upon arrival at the study site, find a location to set up the instrument where it is possible to survey from bank to bank with no obstructions. The setup should be high enough to see the transect stakes and the benchmark nail but not so high that the rodperson must use an excessive amount of rod. Once a location is found, unscrew and gently lower the tripod legs. Tighten the screws and step on each foot to secure the tripod. Begin leveling the instrument by raising or lowering the legs of the tripod. On the survey instrument, locate the three black adjusting nuts that are used for leveling ( see Figure 3 ). Before leveling be sure that these nuts are lowered as far as possible so that the instrument is close to the tripod. Use the leveling nuts to move the bubble into the circle in the middle of the fluid cell. Rotate the instrument 180 degrees and recheck the bubble. The bubble should still be centered. If the bubble is not, use the leveling knobs to return the bubble to the center. Rotate the instrument 180 degrees. Repeat the procedure until the instrument is level.
[ Up to FIGURES ]
| Figure 3. Top view of Wild Heerbrugg NAK1 survey instrument. | |
|---|---|
| To level: align scope of instrument over a leveling nut (3); use two nuts (2 and 3) to put the bubble on the edge of the fluid cell and in line with the scope; use the third nut (1) to move the bubble into the center circle. |  |
[ Up to CONTENTS ]
2. Survey instrument readings
When looking through the eyepiece of the survey instrument, notice that there are three cross hairs. Be certain that at all times the middle cross hair is used to read the survey rod. The accuracy and validity of a study depend on the ability to correctly read the numbers on the survey rod. Errors in reading the rod are easy, so, recheck each reading. Figure 4 provides a view of the survey rod through the eyepiece of the survey instrument with correct readings of increments.
The red numbers are whole feet and the black numbers are tenths of a foot. The distance between the bottom and the top of each black mark represents a change of 0.01 feet. If the red number can not be seen, have the rodperson slowly raise the rod until the red number comes into view.
[ Up to FIGURES ]
| Figure 4. View of survey rod through eyepiece of survey instrument or level. |
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[ Up to CONTENTS ]
3. Data Collection
a. Transect selection
- Try for the most uniform cross section available--depths and velocities do not vary much.
- Current should be perpendicular to the tape for the entire width. Avoid swirls, bends and eddies.
- When a transect is selected, place a stake in the ground on both sides of the stream and string a tape measure between them. The stakes should be above the high water level, hammered to a depth in stable substrate so they won't wobble and in a location where they won't be vandalized. A nail in a tree may substitute for a stake.
- Establish a survey benchmark (BM) by locating a permanent, prominent natural or man-made feature that is near the transect and is easily relocated. If no such feature exists, a nail in a tree will suffice.
- The tape should be above the water to avoid immersion but close enough for easy reading. The tape MUST be perpendicular to the direction of the current. The tape can be strung with zero on either the left or right bank--the N.C. Division of Water Resources always references zero from the left bank looking upstream; whichever is selected, ALWAYS use the same configuration and note it in the data book.
[ Up to CONTENTS ]
b. Transect survey
When the instrument is level, the nail or benchmark is surveyed. The benchmark is permanently fixed, an elevation reference for the site survey and resurveyed on future trips to compare different data sets. The nail should be established in a sturdy tree trunk or root that can be surveyed from a setup for a transect. Surveying the nail provides the height of instrument (HI). Once the nail is shot and a tape is stretched from stake to stake, the transect is ready for surveying.
The amount of stream bottom, in feet, that is wetted at a selected water elevation is wetted perimeter (WP). Figure 5 illustrates surveying a transect for a wetted perimeter study. The points represent rod placements. The following are guidelines for the rodperson to follow when surveying a transect.
[ Up to FIGURES ]
| Figure 5. Example of transect survey for wetted perimeter. |
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- Select breaks in the substrate.
- Select dramatic changes in depth.
- Define limits of terrestrial vegetation.
- Choose enough points to define the cross section.
- Define fringe areas where WP is gained rapidly. This will assist the selections of the point of inflection (POI). See Data Analysis section for description of POI.
[ Up to CONTENTS ]
c. Data entry
The first page in the data book will show a rough drawing of the section of stream under study. The drawing will show tributaries, transect locations, substrate and cover types and access areas ( see Figure 2 ).
The second page is for staff gage readings ( see Table 5 ). The staff gage is an important tool. It indicates how much and how fast the water level changes. A record of stage fluctuations is essential when collecting data. The data set will not be accurate if the water level fluctuates too much. A stable reading is best for determining water surface level (WSL) and discharge (Q).
[ Up to TABLES ]
| Table 5. Layout of data book page with staff gage readings from site visit. | |
|---|---|
| Date: | Page 2 |
| Deep River Near Randleman at lift station access | |
| Time | Gage Reading |
| 10:16 am | 10.5" |
| 11:42 am | 10.5" |
| 1:00 pm | 10.6" |
The third page includes survey nails, or benchmarks, and transect locations ( see Table 6 ). Some abbreviations are used to save space in the data book and expedite the survey. Common abbreviations are T (transect), N (nail), DS (downstream), US (upstream), LB (left bank), RB (right bank), and LB/US (left bank while looking upstream).
[ Up to TABLES ]
| Table 6. Layout of data book page with nail and transect locations from site visit. | ||
|---|---|---|
| Nail and transect locations | Date: | Page 3 |
| Below Randleman Dam | ||
| N1 - LB/US next to overhanging holly tree trunk 7 feet DS of T1 | ||
| T1 - Boulder run, below tributary on LB/US, US of large bedrock ledge | ||
The next two pages in the data book are for survey readings ( see Table 7 ). Location (LOC) represents the surveyed nail, tape distances and WSL locations. Backsight (BS) is a survey reading of a nail with a known elevation; surveying the nails to a monument to obtain elevations above mean sea level is not necessary, and rarely done. The nail is surveyed a second time upon completion of a transect and before the survey instrument is moved, or another transect is shot, to guarantee the reading is the same as the initial reading. A check mark is placed beside the BS reading to signify that it was rechecked. Rechecking the nail determines whether the survey instrument moved and the readings taken at the site are true.
[ Up to TABLES ]
| Table 7. Layout of data sheet for survey of transect. | ||||||
|---|---|---|---|---|---|---|
| Deep River | Transect 1 | DATE: | Page 4 | |||
| LOC | BS | HI | FS | ELEVATION | SUBSTATE/COVER | TIME / REMARKS |
| Nail 1 | 1.10 |
101.10 | 100.0 | |||
| Stake1,LB\US | ||||||
| 0.0 | .06 | TV | ||||
| 5.0 | 1.01 | TV | ||||
| 8.0 | 1.13 | TV | ||||
| 8.5 | Water surface edge | |||||
| 9.0 | 2.68 | BOL,OHV | ||||
| 10.3 | 3.71 | BOL,COB | ||||
| 11.1 | Water surface edge | |||||
| 11.5 | 1.99 | BOL | ||||
| 12.0 | Water surface edge | |||||
| 12.5 | 2.54 | COB | ||||
| - - - et cetera- - - | ||||||
| 25.6 | 2.86 | BOL | ||||
| 29.8 | 3.43 | BOL | ||||
| 30.5 | 2.97 | SA,GR | ||||
| 31.0 | Water surface edge | |||||
| 35.5 | 2.38 | COB,SA | ||||
| 37.0 | 2.43 | GR | Possible Spawning Bed | |||
| 38.0 | 2.01 | TV,OHV | ||||
| 40.0 | 0.56 | TV,UCB | ||||
| Stake2,RB/US | ||||||
The HI is the sight height of the survey instrument. The HI is the elevation of a nail--which is usually assumed to be 100.00 unless tied to another nail--plus the BS. This number is entered in the HI column as the first HI.
The FS is a survey reading for a specific LOC with an unknown elevation. The WSL reading--entered in the FS column--taken at a setup is subtracted from the HI for that setup to obtain the elevation (ELEV) of the WSL.
The time and remarks column is used for recording the time that flow readings begin and end, WSL's are taken and stream gages are read. Remarks include notes on stream substrate, the presence of hydraulic controls and any other pertinent observations.
[ Up to CONTENTS ]
d. Transect substrate
While defining transect topography, the rodman must also describe transect substrate and cover characteristics. Record the different substrates and covers for the transect using the tape as a guide while traversing the stream with the rod. The typical substrate characteristics are sand (SA), terrestrial vegetation (TV), gravel (GR), cobble (COB), and boulder (BOL). The usual cover types are overhanging vegetation (OHV), undercut banks (UCB), woody debris (WD) and instream cover (ISC) like undercut bedrock or boulders.
[ Up to CONTENTS ]
e. Water surface elevation survey
The WSL is measured for each transect ( see Table 8 ). Hold the survey rod so the base just touches the water and call "TOUCH". This informs the person on the level to take the survey reading. Take several WSL readings across the transect and circle the best representatives, or note the readings to omit, or average all of the readings.
The rod must be held level to obtain accurate readings with the instrument. A rod level must be used to keep the rod perpendicular to the water surface. Try to read the rod accurately but quickly; holding the rod true for a long period of time is difficult.
[ Up to TABLES ]
| Table 8. Layout of data book page with nail and transect water surface elevation survey readings from site visit. | |||||
|---|---|---|---|---|---|
| Page 5 | |||||
| Deep River
Below Randleman Dam near lift station |
Date: | Time in: | |||
| (Initials of field personnel) | Time out: | ||||
| LOC | BS | HI | FS | Elev | Time/Remark |
| N1 | 1.34 |
101.34 | 100.0 | 10:42 | |
| WSL1 | |||||
| RB | 101.34 | 6.5 | 94.84 | ||
| MID | 6.5 | 94.84 | |||
| LB | 6.48 | 94.86 | 11:00 | ||
[ Up to CONTENTS ]
f. Tying benchmarks
The objective of tying benchmarks, or nails, together is to determine the elevation of the second benchmark using the known elevation of the first benchmark ( see Figure 6 ). The preferable setup is to locate the survey instrument an equal distance from the backsight and foresight. No shots should be taken greater than 200 feet.
If you need to determine the elevation of a third benchmark with the known elevation of N2, the survey instrument is moved between N2 and N3; N2, therefore, becomes the BS and N3 would be the FS.
[ Up to FIGURES ]
| Figure 6. Relating elevation of one benchmark, nail one (N1), to a second benchmark, nail two (N2). |
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[ Up to CONTENTS ]
g. Turning points and loop closure
A turning point (TP) is required when the distance is too great between nails for an accurate reading. The primary considerations for selecting a turning point are that it must be between the two benchmarks, preferably an equal distance from both, and must be easily sighted with the survey instrument. The best turning point is a permanent structure with a distinct feature, such as a boulder with a sharp point or a bolt on a water pipeline or dam. A wooden stake driven securely into the ground can serve as a turning point if no permanent structures exist. Do not remove temporary turning points until the survey is completed ( see Figures 7 and 8 ).
[ Up to FIGURES ]
| Figure 7. Using a turning point between two distant nails. |
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(Elevation of N2 + BS on N2) - FS on TP1 = Elevation of TP1
(move level)
Elevation of N3 = (Elevation of TP1 + BS on TP1) - FS on N3
(Elevation of N3 + BS on N3) - FS on TP2 = Elevation of TP2
[ See Figure 8 below ]
(move level)
(Elevation of TP2 + BS on TP2) - FS on TP3 = Elevation of TP3
(move level)
Elevation of N4 = (Elevation of TP3 + BS on TP3) - FS on N4
[ Up to FIGURES ]
| Figure 8. Relating four nails with three turning points. |
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Closing a loop checks for survey errors by reversing the direction of the survey from the last benchmark back to the first benchmark. To close a loop, move the survey instrument a few feet from the last setup, relevel, and resight N4 and the turning point. Remember that BS is now FS and FS is now BS. Continue to resight nails and turning points and relevel the instrument until the first nail is reached.
When the loop is closed, confirm that the elevations of the nails remained constant. Some error is acceptable during the survey. The following equation provides the acceptable limit of error.
| Maximum error of closure = 0.05 x (length of loop in miles)0.5 |
[ Up to CONTENTS ]
h. Stage at zero flow
Another important piece of information for each transect is the stage at zero flow (SZF). This is the WSL that would occur at a discharge of 0.0 cubic feet per second (cfs). The SZF is influenced by downstream controls. A control is any channel feature which holds back water and raises upstream WSL's. This feature can be thought of as the lip of the bathtub. Examples of controls are dams, weirs, fallen logs, riffles, and ledges. Habitats which have a downstream control are pools and some deep runs. These do not dewater completely at a discharge of zero. The water will only drop as low as the lowest point on the downstream control. Riffles and swift runs have no downstream control however, and would dry completely if all of the water were allowed to drain from the channel.
No effort is required to find the SZF for transects without a downstream control. For these transects, the SZF is simply the lowest point on the transect. For pools, a survey is required to determine the SZF by measuring the elevation of the lowest point on the downstream control. Identifying the downstream control is easiest at low flows. The SZF elevation at the downstream control must be relative to the elevation of the transects affected by the downstream control. Figure 9 illustrates the concept of the SZF.
[ Up to FIGURES ]
| Figure 9. Stage at zero flow (SZF) for pool with downstream control. |
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[ Up to CONTENTS ]
C. Discharge measurements
1. Price AA and pygmy flow meter operation
( Refer to the instruction manual for operation of electromagnetic sensor velocity meter. )
- Remove flow meter from carrying case.
- Slide flow meter onto flow rod peg and tighten meter screw to secure meter to rod.
- Make sure flow meter is positioned so screw is parallel to flow rod.
- If the flow meter is a mechanical ("cat whisker") design, attach the rod wire behind the flow meter nut and tighten; attach the wire to the upper nut for slow velocity water, one beep per revolution, or the lower nut for high velocity water, one beep per five revolutions. If the meter is a fiber optic design, remove the protective caps from the meter chamber and relay cable and connect them with the burred sleeve. Check that a rubber washer separates the drum and cable; else, the cable may impede the free spin of the meter.
- Loosen the traveling ring completely so the bucket wheel spins freely. To prevent damage to the internal mechanism, do not use the bucket wheel to loosen or tighten the traveling ring.
- If the flow meter is a mechanical design, remove the cap on the flow meter and check that the gears are oiled. If not, put in a drop or two and replace the cap.
- If water is fast or turbulent, assemble fins and insert fin peg into rod sleeve and tighten screw.
- Attach revolution counting device (headphones, beeper box, digitizer, fiber optic) to flow meter rod or cable.
- Check that the counting device functions properly. If there is a signal relay problem, check: the "cat whisker" connection; the phone jack on the rod; the relay cable connections; the battery in the headphones; the internal battery; or connections in the beeper box. If the meter is a fiber optic design, check the calibration of the data recorder by setting the selector switch to calibration, press start/stop button, press and hold either AA or pygmy button, depending on meter in use, and press and release reset button. The calibration number for the AA and pygmy are 920 and 2036, respectively. If the calibration number requires adjustment, remove the appropriate protective screw at the base of the data recorder and adjust recessed screw with screw driver.
- Check that the bucket wheel spins freely for the appropriate amount of time.
- Check bucket wheel pivot free play. The directions for adjustment are on the metal plate located in the flow meter carrying case.
- The button on the flow rod when pushed allows the flow meter and measuring rod to move up and down freely.
- The stationary rod on the flow rod is marked in tenths of a foot increments and measures the true water depth. The adjustable rod on the flow rod has one foot marks and, with the numbers on the handle at the top of the rod, are used for setting the flow meter 0.6 times the true water column depth ( see Figures 10 and 11 ).
[ Up to FIGURES ]
| Figure 10. Rod setting for whole number depths. | Figure 11. Rod setting for fractional number depths. |
|---|---|
| If the rod is sitting in two feet of water, the "2" on the rod should line up with the "0" on the handle. | If the rod is sitting in 1.5 feet of water, the correct setting would have the "1" on the rod aligned with the tick mark representing "5" on the handle. |
 |
 |
- Two flow measurements are required if the vertical to be measured exceeds 2.5 feet. Meter position is 0.2 times the true depth of the water column (true depth x 0.5 = 1st rod setting) and 0.8 times the true depth of the water column (true depth x 2 = 2nd rod setting). For example, in water 3 feet deep the correct settings would be "1" aligned with "5" for the first setting and "6" aligned with "0" for the second setting ( see Figures 12 and 13 ).
[ Up to FIGURES ]
| Figure 12. First Setting @ Depth > 2.5 feet | Figure 13. Second Setting @ Depth > 2.5 feet |
|---|---|
| Depth x 2 = Setting
Example: 3 x 2 = 6 |
Depth x 0.5 = Setting
Example: 3 x 0.5 = 1.5 |
 |
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2. Transect selection
- Water should be moving quickly, but not turbulent, to turn flow meter cups steadily.
- Try to minimize double measurements by selecting depths 2.5 feet or less.
- Search for the most uniform cross section available--depths and velocities not varying much.
- Current should be perpendicular to the tape for entire width. Avoid swirls, bends, and eddies.
- If none of the cross sections are suitable for discharges, it may be necessary to locate a transect off site just for measuring discharge. If no such cross section is available, then it is preferable to measure discharge at more than one cross section and average the results.
- When a transect is selected, place a stake in the ground on both sides of the stream and string a tape measure between them.
The tape measure should be above the water to avoid immersion but close enough for easy reading. The tape MUST be perpendicular to the direction of the current.
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3. Placement and number of velocity measurements
- Divide width of water by 20. This will give an approximate distance between each reading. For example, a stream 60 feet wide would have velocity readings spaced no more than three feet apart.
- Readings will need to be taken closer together where there are significant changes in depth or velocity.
- Select more points to make a smooth, gradual transition between adjacent points in areas of abrupt changes in stream bottom elevation. More flow measurements will help avoid erroneous discharge calculations.
- Measuring discharges in deep pools is accomplished with a canoe anchored across the bow and stern with ropes secured to each stream bank.
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4. Data collection
- Q's and WSL's must be measured during steady flow conditions.
- Place a staff gage near the transect at the water's edge to monitor fluctuations of the water surface elevation.
- From one edge of the stream, record: the distance at the edge, depth (0), revolutions (1), and time (1).
- Move out to first selected distance and record distance. Submerge flow meter, record depth and set depth on rod.
- Face the flow meter bucket wheel upstream and stand to the side of the flow meter to prevent interference with the flow.
- When using the cat-whisker contact with headphones, listen for beeps to confirm that the equipment is working. Start the stopwatch at THE END of a beep. Count the beeps for at least 40 seconds. If the beep falls on 40 seconds, stop the watch at the end of that beep. If the beep is after 40 seconds, stop the watch at THE END of a beep that falls on one of the "magic numbers." The magic numbers are 1, 3, 5, 7, 10, 15, 20, 25, 30, 40, 50, 60, and 80. These number help to quickly calculate the velocity from the meter rating tables.
- For a wetted perimeter study, one Q calculation will suffice for the study site. For an Instream Flow Incremental Methodology (IFIM) study, flow measurements are required at each transect.
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5. Data entry
- Record the data in the data book as shown in Table 9 . This is the proper page set up when collecting Q data at a transect.
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| Table 9. Layout of data sheet for flow data collected on transect. | ||||
|---|---|---|---|---|
| Q | Deep River | Cobble bend | Date: | Time In: |
| T3 | D/S of riffle | Time Out: | ||
| Distance | Depth | Rev | Time | Notes |
| WS edge 18 | 0 | 1 | 1 | |
| 19.2 | 0.5 | 5 | 51 | |
| 20.5 | 0.6 | 0 | 40 | Behind rock |
| 22.0 | 0.6 | 15 | 43 | |
| -- et cetera -- | ||||
| WS edge 81.5 | 0 | 1 | 1 | |
- The first and last entries are for the water surface edge. The distances are recorded from the tape, but depth, revolutions, and time have dummy variables of 0, 1, and 1, respectively. When there is no flow, you still record distance, depth, a revolution value of zero, and a time value of 40 seconds.
- Some exposed areas may be present on a transect. The distance must be recorded for each additional water surface edge. Remember to record these distances on the data page. Beginning and ending times are important to record so the water surface elevations and staff gage readings can be referenced to the discharge.
- Staff gage readings at the beginning and end should be recorded with Q information or on a separate sheet.
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6. Photographic documentation
Photographic documentation of transects will help locate the transects on subsequent visits, provide insight during analysis and may help answer questions during meetings or negotiations. Photographs should be taken of all transects at all flows when data is collected. Photographs should be taken using slide film. Photographs of the transects with the measuring tape in place will help view the transect, and will help relocate the headpin and tailpin. Establish a photolog in the data book during the first visit, and use the log on subsequent visits to duplicate the photographs. See Table 10 for an example of a photolog.
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| Table 10. Layout of data book photograph log for transects. | ||||
|---|---|---|---|---|
| PHOTOLOG | Page 7 | |||
| Photo Number by Date | Description | |||
| 2/18/99 | 3/7/99 | (Date3) | ||
| #1 | #17 | Across T1 from RB/US, vertical | ||
| #2 | #18 | Upstream from mid-T1, horizontal | ||
| #3 | #19 | Downstream from mid-T1, horizontal | ||
| #4 | #20 | Across T2 from LB/US, vertical | ||
| #5 | #21 | Looking US @ T2 from 50 feet DS | ||
| #6 | #22 | Across T3 from LB/US & 5 feet US, vertical | ||
| -- et cetera -- | ||||
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7. Subsequent data sets
Three different data sets are collected at a site. Each data set is collected at a different water level. The low, medium and high flow data will help reveal the POI, which is discussed in Data Analysis. Important information on these three data sets is helpful if kept together on the same page ( see Table 11 ).
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| Table 11. Layout of summary data sheet for three site visits. | ||||||
|---|---|---|---|---|---|---|
| Name: Dutch Buffalo Creek | ||||||
| 7Q10 = 1.0 cfs, MAF = 46.4 cfs, DA = 45.1 mi2 | ||||||
| 8/28/85 | 10/9/85 | 11/13/85 | ||||
| Q = 52.2 cfs | Q = 2.1 cfs | Q = 14.4 cfs | ||||
| Tr | Nail | WSEL1 | WSEL2 | WSEL3 | SZF | SRC |
| 1 | 100.00 | 97.81 | 96.00 | 97.27 | 95.54 | 0.14 |
| 2 | 100.44 | 97.80 | 97.03 Mid | 97.32 Mid | 96.45 | 0.19 |
| 96.96 LB | 97.32 LB | |||||
| 3 | 99.30l | 98.89 | 98.32 | 98.61 | 97.88 | 0.29 |
| Gage @ 1.61 = 37.4 cfs | @ .87 = 2.6 cfs | @ 1.24 = 12.6 cfs | ||||
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D. Before leaving the site
- Make sure to resurvey nail before moving survey level.
- Check that there are times in and out for each transect.
- Staff gage readings are recorded with time of readings.
- WSL's are taken and the best WSL's are indicated.
- Compare WSL's to previous data sets to detect obvious errors.
- If nails are tied, compare WSL's to upstream or downstream transects to detect obvious errors. Does the water flow downhill?
- Check that WSL's are consistently higher or lower compared to previous data sets, and that they vary proportionally. The WSL's will vary according to the type of transect.
- Check end of day (EOD) WSL or staff gage reading to determine total change in water elevation and flow during data collection.
- If time allows, calculate approximate Q and compare to WSL's and previous data sets to detect obvious errors.
- Check that all necessary nails are tied and that SZF's have been determined for transects with downstream controls.
- Have questions based on preliminary analysis of data from previous visits been addressed, such as, what is the value of specific habitat on a transect and should the value of that habitat dictate flow recommendations?
- Check that all photographs have been taken and noted.
- Account for all gear.
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III. DATA PROCESSING
A. First Data Set
1. Discharge calculation
Use the Q-CALC program with Price AA meter measurements, the QPYG program for pygmy meter measurements and the QNEW program for velocity data. If time and revolution data is collected at transects requiring both types of meters, then run the input data file with the Q-CALC and QPYG programs, cut and paste into a new file the correct point velocity calculations and total the cell velocities to get the correct discharge. Remember, water surface edge should be indicated with a zero depth and dummy values of one for both revolution and time. For example:
2 0 1 1 (distance, depth, revolutions, time)
Also, remember to enter double measurements separately where the transect depth exceeds 2.5 ft. A depth of 3 feet, for example, would be entered as follows:
6 3 31 40 (distance, depth, revolutions, time)
6 3 35 40 (distance, depth, revolutions, time)
Build the input files using a text editor. It is a good practice to save the file with the letter Q preceding the site abbreviation, but you must save with a .DAT extension. For example, a data file for the Eno River would be QENO.DAT.
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2. Creating transect *.DAT files
Using a text editor, create a separate *.DAT file for each transect. The following is an example of the process for inputting data and running the wetted perimeter program, WP. (Create a directory, if one does not already exist, on your drive to store *.DAT files.)
First (title) line of new file: River site name, Transect #
Second line of new file: # of points, height of instrument, 0.1
Third line of new file: Distance Foresight
( Continue to add new lines until the end of the data set. )
When data input is complete, save the file in the correct directory:
> SAVE \directory\filename.DAT NOTABS
Check to see that file was successfully saved
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3. Running wetted perimeter program
> WETTED
INPUT FILE NAME :
> filename.DAT
OUTPUT FILE NAME :
> filename.OUT
DEPTH CALCULATION ? (Y or N)
> N
Program should be running
STOP - Program Terminated
To check output:
> SCAN or LIST filename
> filename.OUT
Use PgUp and PgDn keys to view *.OUT file
Press ESC to exit to DOS and repeat procedure with the other transects.
Print a hard copy of the output file.
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4. Plotting wetted perimeter output
Use the available spreadsheet software to import and plot the transect cross section (X versus Y) and wetted perimeter (wetted perimeter versus elevation) data. To make an informative graph: add titles and axis labels, specify size and placement, specify grid, tick marks, line and marker style. This will not be necessary if templates exist.
Once you have a suitable style, save it as a template which can be used for importing data for the remaining transects. There should be separate templates for X vs. Y and WP vs. ELEV graphs. Save each graph in the proper directory before creating the next.
The type of plot to specify is XY. Transect distance (X) and transect elevation (Y) are the top most columns in the *.OUT file. The first column of data is the range for transect distance (X). Repeat the procedure to set the Y range. Adjust the ranges for the axes to incorporate all of the data, to use the page economically, and to make the plot easily comprehensible.
Create the titles for the plot. The first title should be the stream name and transect number. The second title indicates the type of plot, distance versus elevation. The X axis label should be "DISTANCE (FT)," and the Y axis label should be "ELEVATION (FT)".
Once the plot looks right, save the file. It is a good idea to save the worksheet for any future editing.
For convenience, create the wetted perimeter versus elevation graph next. The procedure should be the same as that used for the X vs. Y plot. Graph wetted perimeter on the X axis and elevation on the Y axis. Wetted perimeter is in column D at the bottom of the *.OUT file. Elevation is in column A at the bottom of the *.OUT file. Adjust the ranges for the axes to incorporate all of the data, to use the page economically, and to make the plot easily comprehensible.
Create the titles for the plot. The first title should be the stream name and transect number. The second title indicates the type of plot, wetted perimeter versus elevation. The X axis label should be "WETTED PERIMETER (FT)," and the Y axis label should be "ELEVATION (FT)".
Once the plot looks right, save the file. It is a good idea to save the worksheet for any future editing.
After the graphs for this transect are completed and saved, repeat the procedure for the rest of the transects. When all transects are finished for the study site, print the plots.
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5. Determine further data needs
After calculating the discharge, compare it to the hydrologic records researched for this site. Also, select preliminary POI's at each transect prior to collecting subsequent data sets. This initial analysis will help identify what range of the stage versus discharge relationship needs to be bracketed and better defined, and help guide the selection of discharges that need to be collected on subsequent visits. It may also point out the need to check certain areas of particular transects to evaluate their habitat value. For example, "Is that part of transect 2 between 10 and 17 feet an expendable sandbar or a valuable spawning bed?" A full description of POI selection is in the Data Analysis section.
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B. Subsequent Data Sets
1. Discharge calculation
Run new Q's as before using Q-CALC, QPYG or QNEW.
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2. Stage versus discharge curves
The stage versus discharge curves can be plotted as the best fit straight line on log/log graph paper, or by using drafting curves to get the best fit curve of points on arithmetic graph paper. The latter approach is preferable since the straight line relationship may not hold at low flow conditions. Plot the SZF points, if known, for each transect on a graph with WSL on the Y axis and discharge on the X axis. Next, plot the remaining transect data sets collected at various flows and elevations. Photocopy the plots after the points are graphed. Photocopying is helpful in case the curve does not come out quite right and saves time in replotting the points. With the points plotted correctly, use drafting curves to draw a stage discharge curve that best fits at least the plotted points above the SZF. To finish the curve, another drafting curve may be required to connect the SZF points to the rest of the plot. Make sure that the curve is smooth and there are no sharp or drastic changes. Follow a curve fitting approach to come as close as possible to all points. For example, if there are four points on a plot, a "best fit" curve would miss two points by a narrow margin rather than intersect three points and miss the fourth by a wide margin--unless you have a reason to doubt the accuracy of the fourth point.
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IV. DATA ANALYSIS
A. Straight Wetted Perimeter
Straight wetted perimeter analysis can be done manually or with a computer spreadsheet. The manual version is discussed first.
1. Manual analysis
The number for each transect of a study is written in the Transect column.
The Elevation column holds the water surface elevation that creates the most dramatic increase in the amount of stream habitat. This water elevation is the POI (point of inflection) in the relationship between wetted perimeter and water elevation. This information is found in the *.OUT file. It should be determined to the nearest 0.01 foot. It is helpful to graph this relationship. The Delta WP column in the *.OUT file is also a good indicator of the POI. Look for the elevation where the change in wetted perimeter drops off significantly. If there is no obvious POI, or if it is at a very low flow, the 7Q10 water elevation is used as the default for the transect. Transects across pool habitat typically default to the 7Q10 elevation.
Sometimes there will be more than one POI, or no POI or a gradual drop-off in Delta WP that is more like a range of inflection. If the cross section is not a pool, where the elevation would default to the 7Q10, the investigator must use professional judgment to determine what water level is needed to adequately maintain aquatic habitat. Two pieces of information are useful here. The first is substrate data collected in the field at each point on the cross section. This can be used to determine what portions of the channel need to be inundated and how deeply. For example, is that broad flat area which results in a point of inflection an important gravel spawning bed, or is it a bedrock slab? The other important factor in selecting the water elevation is the discharge at that elevation. Is the flow below the 7Q10, or too high or within the range of reasonable flows?
If selecting a water elevation is difficult for a particular cross section, perform the calculations more than once, using different water elevations to see what effect various elevations have on the overall recommendation for the site.
Developing a good water surface elevation versus discharge relationship for each cross section is very important to assure validity of the wetted perimeter analysis. There should be at least three water surface elevation versus discharge data points for each cross section. Preferably, these points should be spread over a range that encompasses the water elevation selected for each cross section. A fairly low flow data point is often needed to bracket the elevation at the 7Q10 flow.
The confidence of accurately predicting a POI is increased by interpolating between two data points rather than extrapolating out from a data point. Interpolate to determine WP if the elevation selected is between two elevations in the *.OUT file table. For example, the table may list water elevations of 96.00 and 96.10 with WP's of 10 and 20, respectfully. A water elevation of 96.05 would, therefore, have a WP of 15.
Discharge' (Q'n) is 0.8 times (or 80 percent) the discharge (Qn) selected for a particular cross section.
Elevation' is the water elevation at a discharge equal to Q'n. Elevation' is obtained by reading the stage discharge curve constructed for each cross section using the corresponding Q'n. The curve should be read to the nearest 0.01 foot.
Wetted perimeter' (WP') is the amount of wetted perimeter at elevation'. It is determined from the *.OUT file table and should be calculated by interpolation if necessary.
The sensitivity coefficient (SC) weighs each cross section according to how much wetted perimeter is lost if the discharge is reduced. The lower the sensitivity, the lower the SC and the less weight the cross section is given in calculating the overall recommended flow. The coefficient should be determined to four decimal places. The SC total needs not, and usually does not, equal one. The inequality is handled algebraically when the overall discharge is calculated on the work sheet. The sensitivity coefficient is determined using the following equation:
SC = ( WP - WP' ) / WP
The representative stream coefficient (RSC) weights the cross sections to determine the amount of the stream segment represented by each cross section. The sum of the coefficients for all cross sections must equal one. Each RSC should be calculated to four decimal places. To calculate the RSC, measure the lengths of the stream associated with each cross section and divide by the total length of the study site. We refer to this approach as habitat mapping. Depending on how the site was set up, these lengths may be the distances of the habitat upstream and downstream of each cross section that is similar to the cross section. Alternatively, there may be scattered portions of a diverse stream which are all represented by a particular cross section. The total length of these scattered pieces divided by the site total yields the RSC. If a very long stream segment is being studied, or, if there are physical difficulties with actually measuring stream lengths, we may use other approaches. These include measuring from the side of the stream or from roads which closely follow the stream. Notes, photos, videos, maps, and recollections may be used to assign percentage weights to each cross section following reconnaissance of the stream. The total of these weights must equal one.
The composite factor (CF) is obtained for each cross section by multiplying the SC by the RSC. Calculate the CF to four decimal places. The CF is part of the algebraic process for properly weighting each cross section to calculate the overall recommended flow.
Multiplying the composite factor by the selected discharge (CF x Qn) provides a weighting factor for each cross section based on the amount and value of the habitat represented by each cross section in relation to its discharge.
The final recommended total flow for the site (Qt) in cubic feet per second is calculated using the following equation:
Qt = ( CF x Qn ) / ( CF )
When the final recommended total flow for the site has been calculated, review the effect of this flow on each cross section. Determine each cross section's water elevation at the final recommended total flow using the stage versus discharge curves. How does the cross section appear at this water elevation? What depths of water are provided? Are any areas of valuable habitat dewatered?
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2. Computer analysis
The wetted perimeter computer spreadsheet, STRAITWP.123, is a Lotus 1-2-3 program that should be stored in a directory named "wetted". The columns "Transect #", "Elev @ POI", "Transect Length", "Q", "Elev'", "Pre-Step", and "Post-Step" are completed by the programmer while the remaining columns are generated with equations.
The "Pre-Step Elevation" column contains the elevation on the line, in the wetted perimeter *.OUT file table, above the elevation from the "Elev @ POI" column. The "Pre-Step WP" contains the wetted perimeter value that corresponds to the elevation in the "Pre-Step Elev" column. The "Post-Step WP" column contains the wetted perimeter value, from the wetted perimeter *.OUT file table, that corresponds to the elevation on the line below the "Pre-Step Elev" value.
The "Pre-Step Elev'", "Pre-Step WP'", and "Post-Step WP'" columns are completed using the same procedure except that the values from the "Elev'" column are used as the point of reference.
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B. Incremental Wetted Perimeter
Before beginning, make sure that directory for study site exists on the hard drive, format a blank computer disk, have hard (printed) copies of all *.OUT files (wetted perimeter output files) on hand, and have stage versus discharge curves for all transects.
1. Completing spreadsheet
Access spreadsheet software and retrieve spreadsheet. When the spreadsheet is retrieved, cursor to B25 (WP Table), and import and parse the desired *.OUT file. Examine the data table for missing data or errors. Column A is a lag column and should have the same values as column B only displaced one row. If there are any missing values in column A, copy the equation for computing column A into the spaces which have missing values.
Set the ranges for Table and LTable. Table consists of all columns excluding Column A. Repeat for LTable which consists of all columns excluding the first row. When setting Table and LTable ranges, it is important to check for garbage remaining from previous *.OUT files. Check for garbage by comparing the screen with the hard copy. Delete any extraneous data and recalculate.
Access the Total WP range, cursor to cell I2 and type site name. Cursor to cell I3 and enter transect number. Cursor to cell I6 and enter habitat length. Cursor to cell H11 and type the first stage value. Repeat for remaining values. Cursor to cell I11 and type the first discharge (Q) value. Repeat for remaining values.
If Wetted Perimeter or Total Area columns show errors or missing values, the equations for these calculations must be copied down as previously described. The equations in the hidden columns L, M, N, and O must also be copied down. Rehide columns L, M, N, and O after equations are copied down.
When transect is complete, copy from range H1 through K1 through bottom of data and paste into Summary range (cell T1) for first transect. Subsequent transects are moved in the same manner but are moved past the last transect in the Summary Table leaving a blank column between each.
Return to WP Table range (cell B25) and repeat the procedure for the next transect. Check for garbage after transferring data, especially when short transects follow long transects.
When the transfer of all transect data is complete, modify Q6 for total number of transects.
Modify the equation for calculating Total Area in Column Q. This equation is the summation of the Total Area from each individual transect in the Summary Table. Scan through the Summary Table and write down the letters for these columns. Cursor to Q11 and modify this equation using appropriate column letters followed by 11. Press enter. Copy the equation to the bottom of the table. The equation for calculating Mean Perimeter in column R will not need to be modified but may need to be copied down the table.
Save the file on the hard drive and on the blank, formatted disk.
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2. Plotting output
Once the incremental wetted perimeter spreadsheet is finished and saved, the next step is to plot total area versus discharge for each transect and the entire site.
The type of graph to specify is XY. The range for X should contain the flows of interest. Move the cursor to the top of one of these columns and highlight to the end. The A range is the TOTAL AREA (ft2) column and is different for each transect. Highlight the appropriate column that coincides with the transect of interest.
The main title should indicate the site name. The second title should be "TOTAL AREA (ft2) -vs- DISCHARGE". Label the X axis as "DISCHARGE (cfs)". Label the Y axis as "TOTAL AREA (ft2)". Displaying the grid helps to read the plot. Adjust the ranges for the axes to incorporate all of the data, to use the page economically, and to make the plot easily comprehensible.
If the graph is not correct, make the necessary changes. Check that the titles and labels are correct. When the graph is acceptable, save the file. A good idea is to save the worksheet for any future editing. Also, saving the material as a template will allow the importation of new data without duplicating unnecessary changes on remaining transects.
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C. Statistical Programs
Habitat time series: GAGETABL, other HISARS or SAS programs.
Make changes such as job name, station identification number, period of record, titles, drainage area ratio. The following lines require modification in GAGETABL:
Line #1 - job name
Line #9 - station identification number
Lines #34, 35, 36 - titles.
Line #26 through #33 provide entry information.
If you need to save something, make a copy of the original under a different name before you start, edit the duplicate and save changes. Otherwise, the changes made will be saved and the master copy of the program will be altered.
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V. REFERENCES
Bovee, K.D. (unpublished manuscript). Data collection procedures for the physical habitat simulation system. National Ecology Research Center. National Biological Survey. Fort Collins, Colorado. 159 pp.
Harrelson, C.C., C.L. Rawlins, and J.P. Potyondy. 1994. Stream channel reference sites: an illustrated guide to field technique. Gen. Tech. Rep. RM-245. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 61 pp.
Meikle, R.L. 1983. Drainage areas of selected sites on streams in North Carolina. Open-file report 83-211. United States Department of Interior Geological Survey. 163 pp.
Trihey, E.W. and D.L. Wegner. 1981. Field data collection procedures for use with the Physical Habitat Simulation System of the Instream Flow Group. Cooperative Instream Flow Service Group, Internal Publication. Fort Collins, Colorado. 151 pp.