Designing Product Innovations in Agriculture:Remotely Measuring and Monitoring Agricultural RunoffAnnotated BibliographyPrepared for Professor Phil SealyCompiled by Annie BaumannDecember 1, 2010
Professor Sealy, As you and your colleagues have begun to embark on a new grant-funded researchventure at the University of Wisconsin Platteville Pioneer Farm, I have been honored to assistyou in your research needs. In an attempt to better use some of the grant monies, as well as tohelp your students develop critical skills to be used in industry-related careers, your team soughtto build a device that could remotely measure runoff water flow and head and remotely monitorthe quality of the water runoff in edge-of-field settings. Recognizing the need for a fairlythorough literature review of sampling and monitoring programs, you began a basic search usingthe resources available to you. However, after a few Google searches, you realized that anexpert searcher was needed to assist you in your research process. You explained to me yoursituation, and after a consultation you determined that it was necessary for you and your team tolearn about the ways and methods other people in your situation have remotely monitored andsampled agricultural runoff. After a brief interlude in which I began seeking articles to help you answer your researchquestion, we met again and rephrased your initial query. Rather than just finding researcharticles describing case studies in which a product was purchased for use in monitoring andsampling agricultural runoff, you wanted information about how the equipment was designedand built, providing, in a way, a series of possible blue prints for creating your own device. Because you initially started your research process doing a simple Google search, Ifocused on searching electronic databases that provide indexing and abstracting of scholarlyjournal articles. Nearly every academic institution provides free access to these resources, and a
quick search of your University’s library website affirmed that you have several good databasesat your disposal. Through my own university, the following databases proved most useful: GreenFILE Biological Abstracts AGRICOLAWithin these databases, I used the thesauri provided to match the terminology you provided inour consultations (ex. water, (farm) runoff, sampler, remote, agricultural) to controlledvocabulary (―Runoff/Analysis,‖ ―Runoff,‖ ―Sampling,‖ ―Equipment/Design‖). Most successful,I found, was searching with a combination of controlled vocabulary and keyword/naturallanguage terms. While the number of results returned in my searches was, at times, fairly scarce,from those provided I chose the most pertinent citations to give to you (see annotatedbibliography). After refining my searches and following many controlled-vocabulary- andcitation- leads, I carefully read through the abstracts of the articles returned from my searchesand chose only those that would answer an aspect of your research query. I recommend that you use the articles I have provided in the annotated bibliography as astarting point – if you find that a certain article or articles interests you, look at the article’sbibliography and search for the citations that interest you in your library’s electronic databases.Particularly, search in the natural sciences, agricultural, and environmental databases. While Ihad little success searching the engineering databases provided through my university’s Dialogsubscription, I noticed that your university provides access to a number of potentially fruitfulenvironmental engineering and civil engineering databases – you might try searching these. Asalways, please let me know if you require further assistance in your research or in future researchneeds. Once again, thank you for providing me with this opportunity. It has been a pleasureworking with you.
Annotated BibliographyBonilla, C.A., et al. "Instrumentation for Measuring Runoff, Sediment, and Chemical Losses from Agricultural Fields." Journal of Environmental Quality 35.1 (2006): 216- 223. Biological Abstracts. Web of Knowledge. Web. 17 Nov. 2010. This work describes a simple, passive sampling system for measuring runoff, sediment,and chemical losses from typical agricultural fields. The sampler consists of a 5 to 7 mwide runoff collector connected to a series of multislot divisors. These divisors split the flow intoaliquots, providing a continuous sampling during the runoff event. Divisors were located in awooden box below ground level. With an adequate pump, this system can operate in fields with aslope gradient as low as 2%, and can stay in the field during winter to record first snowmelt-generated runoff. A radio transmitter reports by telemetry the occurrence and magnitude ofany runoff event, and indicates when the system should be sampled and emptied. This articleincludes a description of the equipment, advantages, and disadvantages based on 2 yr ofoperation, and examples of data collected.Bonta, J.V., and F.B. Pierson. ―Design, Measurement, and Sampling with Drop-box Weirs.‖ Applied Engineering in Agriculture 19.6 (2003): 698-700. Agricola. EBSCO. Web. 1 Dec. 2010. Rangelands, surface mines, construction sites, unprotected and long slopes, gullies,eroding stream channels, and erosion plots will yield large sediment loads under high intensityrainfalls. Conventional flow-measuring devices can easily become clogged with sediment anddebris during a major runoff event, resulting in the loss of runoff and sediment records. Flowmeasurements can also be inaccurate using conventional flow-measuring devices in steepchannels. The drop-box weir (DBW) was developed to overcome many of the problemsencountered in sediment-laden flow measurement. The weir creates turbulence in a box thatentrains and passes sediment through the weir. It is not a well-known device, and it has not beenwidely used. Yet it is only one of two devices suitable for obtaining flow records with largesediment concentrations. It has utility for a range of watershed sizes from small erosion plots tolarge watersheds. Information on what is known about the design and operation of the DBW, andof sediment sampling approaches using the DBW, was compiled. Weir sizing, rating-curvedevelopment, and sampling strategies were presented to facilitate its use and to identify itslimitations. There are four known configurations of the DBW: the original weir with upper weirlips; a modification of the DBW for erosion plots (removal of upper weir lips); a modification ofthe DBW for small watersheds in steep and skewed channels (removal of upper weir lips and useof baffle); and a Korean version of the weir (larger chute opening to minimize blockage of trash– suitable for large and small watersheds). For each of the four configurations, rating tables andweir-sizing guidelines were summarized. Low-flow rating curves must be developed from field
data for individual weirs, but laboratory curves can be used for larger flow rates. Curve-fittingprocedures are outlined specifically for determining rating-curve equations where field data areobtained. Water samplers designed specifically for use with DBWs are described. Other designconsiderations are discussed for practical use of DBWs including measurement of stage,maintenance, and sediment traps. Research needs for hydraulic modeling and sediment samplingare presented.Bonta, J.V. "Water Sampler and Flow Measurement for Runoff Containing Large Sediment Particles."Transactions of the ASAE 42.1 (1999): 107-114. Agricola. EBSCO. Web. 17 Nov. 2010. A flow-measuring and composite water-sampler system was needed forsampling sediment-laden flaws containing large rock particles from strip-mine spoil erosionplots. The median percentage of soil particle sizes greater than 16 mm of the greater-than 2 mmfraction was 25%. A modified drop-box weir was used for measuring flows, and for providing awell-mixed water and sediment flow that could be sampled. A "diverter" composite sampler wasdesigned to divert the entire flow from a waste position to a sample position, and precluded theneed to subsample (split) the sampled flows. Indoor testing of the sampler showedthe sampler worked well with the modified drop-box weir. Field evaluation showedthe sampler and drop-box weir worked well under natural rainfall conditions.Recommendations for improvement in sampler and weir operation are given. Use ofthe sampler for other applications is also discussed.Bottcher, A.B., and L. Miller. "Flow Integrating Water Sampler for Remote Conditions." Applied Engineering in Agriculture 7.4 (1991): 400-403. Agricola. EBSCO. Web. 17 Nov. 2010. An inexpensive "paddle wheel" water sampler, to collect flow integrated water samplesunder its own power, was designed, constructed, and field tested for field plotsexhibiting low gradient or submerged conditions. The sampler collects a flow-proportionalcomposite sample using a helical tube attached to a paddle wheel rotating through the controlflume of the sampler. The helical sampling tube collects a sample volume proportional tothe water depth and delivers it to a composite sample bottle with each rotation. The rotationalrate is proportional to flow velocity, so the resulting composite sample is approximately flowintegrated. The sampler in both laboratory and field tests performed well over a wide range ofsubmerged conditions. However, submergence over 90% did reduce the sampling rate by about20%. Twenty-four "paddle wheel" samplers were used on high-water table field plots. Allsamplers functioned well for over a year during a recent field study.
Burcham, T.N., et al. "Distributed Data Acquisition System for Runoff Monitoring and Automated Water Sampler Control." Applied Engineering in Agriculture 14.6 (1998): 591-597. Agricola. EBSCO. Web. 17 Nov. 2010. A distributed data acquisition system (DDAS) was implemented to monitor stage andprovide automated water sampler control for eight runoff plots. The DDAS was composed of ahost-computer communicating (RS-485 serial protocol) with multiple remote-sensor-to-computer-interface (RSCI) modules via a single twisted-pair communication line. Control anddata storage routines were written in C++. Retrieved data are time-stamped and stored in a singleASCII file. The DDAS was capable of monitoring multiple weather parameter inputs and flumestage from eight runoff plots, while providing flow-weighted automated water sampler control.System reliability was good, but was detrimentally affected by electrical storms and nearbylightning strikes.Clark, Shirley E., Siu, Christina Y.S., and Pitt, Robert. ―Peristaltic Pump Autosamplers for Solids Measurement in Stormwater Runoff.‖ Water Environment Research 81.2 (2009): 192-200. Biological Abstracts. Web of Knowledge. Web. 17 Nov. 2010. Regulatory agencies approve automatic samplers containing peristaltic pumps as asample collection method for stormwater characterization and for treatment-device evaluation.Autosampler performance, as discussed in the limited available literature, can vary across theentire particle size range typically found in stormwater from different source areas and outfalls— reasonably consistent performance for particle sizes <250 μm, but much less consistency forparticles 250 μm. Therefore, a series of experiments was undertaken to quantify the upper rangeof consistent particle capture that may occur with sampling stormwater suspended sediment andparticulate-bound pollutants. These experiments, based on triplicate sampling at eachexperimental condition, found that peristaltic pump autosamplers commonly used in stormwatermonitoring could not repeatedly and effectively capture particles 250 μm from a simulatedstormwater whose particles have a specific gravity of 2.65. It was expected that the effective sizefor autosamplers would be correspondingly larger for particles having smaller specific gravities.The height of the sampler had no influence on particle recovery up to a height of 2.5 m, withslightly decreasing recoveries of large particles occurring at greater heights, as a result ofreduced sampler intake velocity. Therefore, to characterize the solids across the entire size rangeand specific gravities that may occur in stormwater runoff, autosamplers should be deployed inconjunction with bedload and floatables sampling.Cullum, R.F., et al. ―Shallow Groundwater and Surface Runoff Instrumentation for Small Watersheds.‖ Applied Engineering in Agriculture 8.4 (1992): 449-453. Agricola. EBSCO. Web. 1 Dec. 2010.
An acquisition system was constructed to sample and quantify surface runoff and shallowgroundwater. The main components of the system for shallow groundwater includedhydrologically isolated erosion plots with subsurface drains (installed via horizontal drilling),outlets into sumps, tipping buckets mounted under drain outlets, composite water samplers, and aseries of sampling piezometers ranging from 0.3- to 6.1-m (1- to 20-ft) depths positioned in onerow of each main plot. The main components of the system for surface runoff from standardizederosion plots cropped to corn were appropriately sized collectors, approaches, H-flumesequipped with portable liquid-level recorders, runoff splitters, dataloggers, and compositewater samplers. The dataloggers recorded rainfall and runoff every minute and groundwaterdischarge volume every 15 minutes during storm events. Water samplers were activated by thedataloggers when the cumulative discharge volumes equaled or exceeded a preset condition.Derived variables from surface runoff were incremental discharge rate, cumulative dischargevolume, sediment loads, and water quality. Groundwater incremental discharge and totaldischarge volumes were recorded and the composite of the weighted-discharge samples wereanalyzed for specific chemicals introduced as fertilizer or pesticides. Depth of free water withineach piezometer after major storm events was monitored to determine water movement in theroot and vadose zones.Dressing, S.A., et al. ―Water and Sediment Sampler for Plot and Field Studies.‖ Journal of Environmental Quality 16.1 (1987): 59. GreenFILE. EBSCO. Web. 1 Dec. 2010. The design and performance characteristics of a flush-type sampling device for plot andfield studies are described. The sampler is weld-constructed and requires excavation and waterconveyance for installation. It operates with no external power supply and collects consistently aknown fraction of water and sediment passing through it. In laboratory tests, the samplercollected 2.65% (number of data points (n) = 54, standard deviation (s) = 0.0040) of all waterpassing through it at average flow rates ranging from 18 to 196 L min/sup -1/. Sample volumesranged from 0.75 to 18.7 L. Correlation analysis showed that sampling percentage wasindependent of flow rate (n = 40, correlation coefficient = r = -0.04) over the range tested. Inother laboratory tests, 30 sampling runs with inflow rates and total sediment concentrationsranging from 35 to 182 L min/sup -1/ and 252 to 1410 mg L/sup -1/, respectively, showed thatthe ratios of waste to sample sediment concentrations were approximately one for total sediment(1.001), and for the sand (1.097), silt (1.008), and clay (1.020) fractions. Sand and clay ratioswere shown to be statistically independent of total sediment concentration, but silt (r = 0.30, n =30) and total sediment (r = 0.44, n = 30) ratios increased slightly with increasing totalconcentration. Monte Carlo simulation was performed to illustrate the suitability of the flush-sampler for field and plot runoff studies. Simulation results indicated that for runoff estimatesmeasurement error would exceed 10% with 33% probability for triplicate plots, but with only16% probability in five plot studies.
Fogle, A.W., and B.J. Barfield. ―A Low Head Loss Sampling Device for Monitoring Inflow to Natural Vegetated Filter Strips.‖ Transactions of the ASAE 36.3 (1993): 791-793. Agricola. EBSCO. Web. 1 Dec. 2010. A New Device was developed for use in sampling flows into natural vegetated filterstrips where minimal disruption of the flow onto the filter strip is desirable. The sample hasminimal head loss and allows sampling of flow from 4.57-m (15-ft) wide plots.Harmel, R.D., R.M. Slade, and K.W. King. "Automated Storm Water Sampling on Small Watersheds."Applied Engineering in Agriculture 19.6 (2003): 667-674. Agricola. EBSCO. Web. 17 Nov. 2010. Few guidelines are currently available to assist in designing appropriate automated stormwater sampling strategies for small watersheds. Therefore, guidance is needed to developstrategies that achieve an appropriate balance between accurate characterization of storm waterquality and loads and limitations of budget, equipment, and personnel. In this article, we explorethe important sampling strategy components (minimum flow threshold, sampling interval, anddiscrete versus composite sampling) and project -specific considerations (sampling goal,sampling and analysis resources, and watershed characteristics) based on personal experiencesand pertinent field and analytical studies. These components and considerations are important inachieving the balance between sampling goals and limitations because they determine how andwhen samples are taken and the potential sampling error. Several general recommendations aremade, including: setting low minimum flow thresholds, using flow-interval or variable time-interval sampling, and using composite sampling to limit the number of samples collected.Guidelines are presented to aid in selection of an appropriate sampling strategy based on user’sproject -specific considerations. Our experiences suggest these recommendations should allowimplementation of a successful sampling strategy for most small watershed sampling projectswith common sampling goals.Hsu, Y.S., et al. ―Capacitive Sensing Technique for Silt Suspended Sediment Concentration Monitoring.‖ International Journal of Sediment Research 25.2 (2010): 175-184. Biological Abstracts. Web of Science. Web. 1 Dec. 2010. Automated, real-time, and continuous techniques for monitoring suspended sedimentconcentration in rivers and reservoirs can play an important role in the improvement of thequantity and quality of sediment data, and are valuable to the management of water environment,water conservancy, hazard prevention, and water resources. Research in the monitoring
techniques has examined the possibility of using the characteristics of dielectric constants fordetecting soil moisture and concentration of air-water two-phase flow, based on the fact thatdielectric constants of sediment, air and water are different. A capacitance sensor was developedto monitor the silt suspended sediment concentration (SSSC) in a recent study, following theprinciple that as SSSC increases in the sediment-water mixture, the apparent dielectric constantof the water sample also increases and therefore the capacitance detected by the sensing systemalso increases. It is demonstrated that the variations in the concentration of silt sedimentcorrelates positively with the variations in observed capacitance in a linear fashion, andcorrelates negatively with voltage outputs but also in a linear fashion. The correlationcoefficients reached above 0.98. The overall errors in estimated concentrations range between0.26% and 2.91%. Elements in the capacitance sensor system such as the frequencies of thesignal generating system, areas of the electrode plates, and effects of sample temperature havealso been evaluated. The results illustrated that the capacitance sensor techniques can be appliedto monitoring SSSC automatically and continuously. Also, the range of SSSC in the experimentreached 200 kg/m(3); therefore, the application of this technique in practical SSSC monitoring isworthy of further research.Klik, A., W. Sokol, and F. Steindl. "Automated Erosion Wheel: A New Measuring Device for Field Erosion Plots." Journal of Soil & Water Conservation 59.3 (2004): 3. GreenFILE. EBSCO. Web. 18 Nov. 2010. For erosion experiments in the field where no electric power is available an automateddevice for runoff and soil loss measurements was developed. This equipment is designed forcontinuous runoff measurement from plots up to 60m2. The design is similar to a turning wheelwith a horizontal axle. The automated erosion wheel (AEW) consists of four equal sections eachone holding five liters (1.32 gal) resulting in a resolution for each tip of 0.08 mm (0.003 in) for60m2 plots. The automated erosion wheel is capable of measuring a maximum rate of 75L min-1(19.81 gal min-1). Each tip is monitored automatically in real time by a data acquisition system.Up to three automated erosion wheels can be connected to one data logger. The whole system ispowered by one solar panel. Soil-water-suspension is divided by an adapted multi-tube divisor.About 3.4% of the runoff is sampled in a plastic barrel for determination of sedimentconcentration and soil loss. At this stage no temporal distribution of sediment delivery can berecorded by the automated erosion wheel. After each erosive rain storm, collectors are emptiedand samples are taken to the lab for further analyses. With calibration of the tipping bucketsvolumes an accurate, time distributed runoff measurement is possible. The maximum error insediment concentration measurement is 1.1%. Therefore, the chosen multitube device is able tocollect representative runoff samples containing same sediment concentration as surface runoff.Each automated erosion wheel system is located in a shed. The automated erosion wheel hasbeen used at three locations in Austria since 1997.
Lecce, Scott A. "A Depth-Proportional Intake Device for Automatic Water." Journal of the American Water Resources Association 45.1 (2009): 272-277. Agricola. EBSCO. Web. 17 Nov. 2010. This paper describes the construction and testing of a device forpumping water samplers that collects suspended sediment samples by moving the intakevertically to keep it at the same proportion of flow depth. The device uses a simple sprocketmechanism that can be mounted vertically on the downstream side of culverts and bridge pilingsto protect against damage from floating debris during storms. Suspended sediment samplescollected from an urban stream with the depth-proportional device were compared with manualsamples taken with a depth-integrated sampler. Scatter in the relationship between pumped andmanual samples (R2 = 0.76) are probably explained by horizontal variability in concentrations,poor mixing associated with lateral sediment inputs from construction site erosion, thedownstream orientation of the intake, and the failure of the concentration at 60% of the flowdepth to match the average vertical concentration.Nabholz, J.V., G.R. Best, and D.A. Jr. Crossley. ―An Inexpensive Weir and Proportional Sampler for Miniature Watershed Ecosystems.‖ Water Resources Bulletin 20.4 (1984): 619-625. Agricola. EBSCO. Web. 1 Dec. 2010. A weir system with a proportional sampler for use on miniature watershed ecosystems isdescribed. Eight weir collection systems were evaluated for their ability to measure and sampleinputs and outputs of soil-island ecosystems which occur on granite outcrops. The proportion ofwater actually collected by the weir systems was generally less than the proportion the systemswere designed to sample, but adequate for supplying data needed for estimating elementalbudgets. The weir systems were not able to account for 25 to 50% of the variation in total waterpassing over the cutoff wall. Several ways of improving overall performance of the weir systemsare discussed.Ngandu, D.M., and K.R. Mankin. "Runoff Sampling System for Riparian Buffers." Applied Engineering in Agriculture 20.5 (2004): 593-598. Agricola. EBSCO. Web. 17 Nov. 2010. Riparian buffer system (RBS) effectiveness in reducing nonpoint source pollution fromsurface runoff can be evaluated by measuring constituent concentrations and flow volumesentering and exiting the system. This article describes the development and precision assessmentof a low-cost, low-maintenance surface runoff sampling system (ROSS) in measuring flowvolumes and collecting flow-weighted samples. The primary components of ROSS are a solarpanel, battery, pump with a float switch, and splitter assembly at a cost of $218 (2001). ROSS
delivers the runoff collected in a sump to a V-shaped splitter that separates successive fractionsof the total flow using six dividers. Eighteen ROSS units were subjected to lab and field tests toestablish calibration and quality control parameters and to determine the allowable maintenanceinterval. The results indicate ROSS units provide a reasonable precision over time, as indicatedby flow volumes being within a 95% confidence interval of expected values for 96% (divider#1), 100% (#2), 96% (#3), 89% (#4), 69% (#5), and 56% (#6) of the units. The mean measuredflow volumes by each divider in the lab and in the field were significantly different (alpha =0.05), suggesting calibration factors are best determined in the field. ROSS units provided runoffsamples with the same precision over a 3-month period, demonstrating an ability to maintaincalibration over time. The ROSS unit meets the needs of a low-cost, flow-weighted sampler withreasonable accuracy and ease of use and should facilitate more widespread field assessments ofRBS constituent-removal effectiveness.Pinson, W.T., et al. "Design and Evaluation of an Improved Flow Divider for Sampling Runoff Plots." Applied Engineering in Agriculture 20.4 (2004): 433-437. Agricola. EBSCO. Web. 17 Nov. 2010. An improved flow divider was designed to simplify and lower the cost of collectingrunoff data from research plots. The system was designed around commercially available andinexpensive 5-gal (19-L) plastic buckets with screw top lids. A precision cut sheet-metal divider"crown" is fastened to the lid, allowing it to be easily transferred between buckets. The dividercrown can be configured to handle various flow rates by specifying the number of flow divisions.Laboratory evaluation of the design indicated that the system divides runoff with accuracieswithin .5% over most of the flow range and within .15% at very low and very high flows. Theseresults are similar to those found for the more traditional flow divider designs. Adding sedimentto the inflow at three different flow rates yielded sediment division accuracies within 7%. Fivefield research projects have used the divider system with few problems. The average cost of thissystem is approximately US $500 per plot, in comparison to the US $3000 to $5000 it often coststo instrument a plot using standard equipment.Qu, L., et al. ―A Mechanic-electronic Sensor for Automatic Measurement of Sediment-laden Flow Rate from Erosion Runoff Plots.‖ Journal of Hydrology 342.1-2 (2007): 42-49. Scirus. Web. 1 Dec. 2010. Erosion and hillslope surface/subsurface hydrology studies are in need of temporalmeasurement of flow rates, where sediment-laden runoff normally presents. A newmethod/sensor capable of taking automatic measurements of sediment-laden runoff flow rates ispresented. Mechanical structures, hydraulic backgrounds and computational principles of thesuggested sensor are discussed in details. Theoretical-analysis of surface hydraulic formed the
basis for formulating a function for calibration of the sensor to clear water flow. A functionalrelationship was derived for adjustment of flow rates of sediment-laden water. Calibrationexperiments validated the hydraulic relationship between the flow rate of clear water and thesensor’s outputs. The adjustment function of flow rate produced highly accurate measurementsof sediment-laden runoff. Applications of the newly-developed flow senor to a laboratorywatershed exposed to rainfall evens of both constant and variable intensities demonstrate that thesensor is highly accurate and capable of taking continuous measurements of the transienthydrographic processes of runoff. The accuracy and reliability of the flow device with labor andtime saving advantages will be useful in hillslope hydrological monitoring for research and otherpurposes.Renard, K.G., C.E. Francher, and J.R. Simanton. ―Small Watershed Automatic Water Quality Sampler.‖ Proceedings of the Fourth Federal Interagency Sedimentation Conference: March 24-27, 1986, Las Vegas, Nevada / Subcommittee on Sedimentation, Interagency Advisory Committee on Water Data; Agricultural Research Service … [et al.]. Washington: U.S. G.P.O., 1986. Agricola. EBSCO. Web. 1 Dec. 2010.Salehi, F., A.R. Pesant, and R. Lagace. "Construction of a Year-round Operating Gauging Station for Sediment and Water Quality Measurements of Small Watersheds." Journal of Soil and Water Conservation 52.6 (1997): 431-436. Agricola. EBSCO. Web. 17 Nov. 2010.Sheridan, J.M., H.H. Henry, and R.R. Lowrance. "Surface Flow Sampler for Riparian Studies." Applied Engineering in Agriculture 12.2 (1996): 183-188. Agricola. EBSCO. Web. 17 Nov. 2010. A low-impact surface flow sampler was developed for riparian studies conducted in theCoastal Plain region of the southeastern United States. The device consists of two primarycomponents, a splitter and a collector, which were used for unattended samplingof surface flow in riparian buffer study areas. This low-cost device provides a composite eventsample at selected locations within experimental areas. The quantity of sample isadequate for laboratory analyses of dissolved and suspended constituents for both large andsmall flow events, and permits estimation of the volume of surface flow at the sampling location.Installation and operation of the device requires little disturbance to the riparian bufferground surface and vegetation, or to surface flow within experimental areas.Skarzynska, K., Polkowska, Z., Namiesnik, J., Przyjazny, A. ―Application of Different Sampling Procedures in Studies of Composition of Various Types of Runoff Waters – A Review.‖
Critical Reviews in Analytical Chemistry 37.2 (2007): 91-105. Biological Abstracts. Web of Knowledge. Web. 1 Dec. 2010. Runoff waters are one of the forms in which precipitation reaches the ground and surfacewaters. They are formed when rain or melting snow washes the surfaces of roofs, highways,agricultural areas or tree canopies. Pollutants present in runoff waters can constitute a potentialdanger to aquatic ecosystems. This paper reviews techniques and equipment for collecting runoffwater. It discusses storage and preparation of samples for analysis (errors made on the stage ofsampling, type of a sampled fraction-important step of analysis). This work presentsbibliographic information about a wide range of inorganic and organic compounds in variousform of runoff water (as a result of washing out pollutants from such surfaces as: highways,building roofs, and agricultural areas).Soultani, M., et al. "Measuring and Sampling Surface Runoff and Subsurface Drain Outflow Volume." Applied Engineering in Agriculture 9.5 (1993): 447-450. Agricola. EBSCO. Web. 17 Nov. 2010. An instrumentation system for automatically measuring and sampling surface runoff andsubsurface drain outflow from experimental plots was developed. Surface runoff and subsurfacedrain outflow were channeled to a central collection building where volumes were measured andrecorded by datalogger. The data stored in the datalogger were automatically transmitted to anIBM-compatible computer at Harrow Research Station every 24 h. Laboratory calibration andfield verification of the system showed excellent agreement between actual and measuredvolume. The digital output from the water-measuring device was used to activate a watersampler at selected volumes.Zhao, S.L., et al. ―Automated Water Sampling and Flow Measuring Devices for Runoff and Subsurface Drainage.‖ Journal of Soil & Water Conservation 56.4 (2001):2. GreenFILE. EBSCO. Web. 1 Dec. 2010. Inexpensive devices that characterize water flow rates as well as take samples eitherduring runoff or subsurface drainage are needed especially for developing countries where thecommercially available equipment may be cost prohibitive. Even in the developed countries,these devices could save considerable money especially if a large number of units are neededsuch as in replicated plot experiments. This paper describes the design, construction and testingof such devices for characterizing flow rates and also for collecting water samples from surfacetile inlets (runoff) and subsurface tile drains. For runoff, the tipping bucket device (about 4 L(1.06 gallon) per tip) sits on top of a sample holder. Flow rates, ranging from 1 to 116 L min-1(0.26 to 30.68 gallon min-1) are measured by recording the number of tips and time between twoconsecutive tips. The maximum error in flow measurement is 0.4%. Water samples are collectedby catching about 20 mL (0.68 oz) of flow every other tip (an equivalent to about 0.25% of the
total runoff) in a polyethylene bottle in the sample holder. The sample holder houses 20 bottles,19 are for sample collection. After a specific number of pre-programmed tips, the bottle isadvanced so that the next empty bottle is under the sampling port. The device can beprogrammed to catch volume distributed or time distributed samples. The subsurfacedrainage measuring and sampling device consists of a tipping bucket (410 ml (13.85 oz) per tip)and a tygon tube connected to the sampling port at the base of the tipping bucket. A smallfraction (3 ml (0.1 oz)) of the water collects in the tygon tube every other tip. The tube isemptied each day and the sample represents the daily composite drainage. A CR-10 data loggerprovides the electronic controls for automating the system.