6. Examples of accomplishments of the NAEW

The outdoor laboratory of the NAEW has historically addressed the challenges of emerging national issues and addressing stakeholder's needs. Over 500 reports and peer-reviewed publications originated from NAEW research. The NAEW was a world-class facility and examples of accomplishments of the NAEW are [2]:

Crop rotations: The early record of runoff measurements (first ~28 years) documented the benefits of rotating crops and planting on the contour to reduce erosion in agricultural fields in the hill lands of Appalachia.

No-till/Conservation tillage: No-till farming reduces (and can essentially eliminate) soil losses and runoff (Figure 12). The USDA funds a national farm program and recommends the no-till practice for improving agricultural lands as a best practice. The NAEW was the first facility in the world to evaluate the water quality benefits of no-till on a watershed basis with experiments beginning in 1964 and continuing through 2011 [8]. The practice allows more frequent harvesting of high value crops, produces yields that are the same or greater than with conventional tillage (especially during droughts), increases soil-carbon storage (resulting in larger soil moisture for crops), and reduces energy needs. The environmental benefits of other types of conservation tillage have also been investigated [9–12].

5. Data

12 Hydrology of Artificial and Controlled Experiments

hard copy to electronic form.

in the hill lands of Appalachia.

The basic data types collected include runoff, precipitation, weather, and water-quality data. Tables listing details of runoff, precipitation, lysimeter, weather, land-management, and other data are listed in [3] through about 2009 and are not repeated here. Due to specific project, financial, and personnel constraints during NAEW history, data for some watersheds such as runoff, precipitation and other data were not obtained for the entire 79-year period of monitoring. ARS operation of the NAEW ceased in late 2011, however, data collection continued from seven watersheds as part of a grant-funded project through Dec 2015 when all monitoring operations were discontinued. Through 2015, approximately 2125 station years of runoff

At the time of this writing, the NAEW data are being reviewed, corrected, and uniformly formatted from variety of original formats. The location for the data on the internet is yet to be determined. As part of the NAEW data-review process, a GIS of the NAEW has been developed documenting locations of runoff, precipitation, weather stations, etc. GIS will become part of the NAEW data base posted on the web site. The list of NAEW publications will also be posted.

Even though data collection has ceased, the database is valuable for further investigations of hydrology and water quality. Watershed modeling, in particular, can be studied at large (LMC —scaling, spatial parameterization of watershed models, and hydrology) and small scales (small watersheds—watershed modeling, hydrology, and water quality). The long precipitation and runoff records are valuable because they have experienced a wide array of weather conditions, even during a period of trending climate. Other precipitation, infiltration, soil moisture, ground water, and soil characterization data bases have not been analyzed and are available in hard copy form in the NAEW files. These data would have to be converted from

The outdoor laboratory of the NAEW has historically addressed the challenges of emerging national issues and addressing stakeholder's needs. Over 500 reports and peer-reviewed publications originated from NAEW research. The NAEW was a world-class facility and

Crop rotations: The early record of runoff measurements (first ~28 years) documented the benefits of rotating crops and planting on the contour to reduce erosion in agricultural fields

No-till/Conservation tillage: No-till farming reduces (and can essentially eliminate) soil losses and runoff (Figure 12). The USDA funds a national farm program and recommends the no-till practice for improving agricultural lands as a best practice. The NAEW was the first facility in the world to evaluate the water quality benefits of no-till on a watershed basis with experiments beginning in 1964 and continuing through 2011 [8]. The practice allows more frequent

data and 1126 station years of precipitation data were collected.

6. Examples of accomplishments of the NAEW

examples of accomplishments of the NAEW are [2]:

Grazing: The NAEW developed environmental recommendations for pasture fertilizer application rates based on nitrogen [13, 14], sources of nitrogen fertility for pastures [15], and overwintering practices on grazing lands [16].

Management-Intensive Grazing (MIG): The NAEW management-intensive grazing (MIG) project investigated the water-resource benefits of frequent rotation of livestock between small paddocks in a pasture for organic and non-organic production, and included impacts on surface and subsurface water quality, animal health, and changes in plant species [17]. Potential benefits of MIG to the producer include extended grazing season, less cost, and more leisure time.

Nutrient movement in stormflow vs. baseflow: Major transport of nutrients can occur in both baseflow and stormflow from mixed agricultural watersheds [18].

Preferential movement of water in soil: Fundamental knowledge from NAEW experiments on the fate of infiltrated water and chemicals in the subsurface through preferred pathways (e.g., earthworm burrows and cracks) has been used by scientists worldwide and in the development of a macropore component of a watershed model [19–21]. Additionally, guidance was developed on manure application in tiled fields [22, 23].

Evaluation of best management practices: A method was published to estimate the variability of chemical concentrations in runoff when there are few water samples and a history of runoff using duration curves [24].

Pesticide transport: Research on herbicide concentrations for weed control on watersheds showed that concentrations in runoff can reach levels of concern, particularly in the first few events after application, and that by reducing application rates by replacing herbicides with short half-life types, concentrations can be reduced [25–27].

Figure 12. Original no-till experiments on steeply sloping experimental watershed.

Climate change: Climate was changing starting in about 1980 at the NAEW. Several studies of precipitation showed that underlying runoff parameters in the "curve number" method of estimating runoff were changing as extreme precipitation events were increasing in magnitude, and that air temperature was trending upward [28]. Watershed data were used for modeling watersheds for climate change impacts [29].

sampler, drip-flow meter and sampler, hydraulic studies of the drop-box weir, adaptation of the Coshocton Wheel for the drop-box weir [39], natural-precipitation infiltrometer, worm-

Experimental Watersheds at Coshocton, Ohio, USA: Experiences and Establishing New Experimental Watersheds

http://dx.doi.org/10.5772/intechopen.73596

15

Filter sock performance: Coshocton data showed that there were limits to use of on-field control of pesticides on watersheds. Netting in the form of tubes filled with materials that can adsorb pesticides and nutrients from surface runoff have been studied and published. The results are useful for contractors that use filter socks in controlling chemical and sediment water quality

Paper mill byproducts: In collaboration with the State of Ohio and the paper industry, NAEW studies on use of paper-mill sludge (waste product) applied to surface mines showed that the State's upper limit of land application rate was environmentally acceptable [42]. This provided paper mills a cheaper, more environmental beneficial, alternative to landfill disposal, and at the same time provide a good source material for revegetating and controlling erosion when

Carbon sequestration: The long-term nature of the management practices on the small watersheds including continuous no-till corn with over 40 years of runoff records have enabled numerous investigations into the impact of land management on carbon sequestration (Figure 13). Sediment-bound carbon losses from various conservation tillage practices and organic carbon

Surface mining and reclamation: A landmark study on effects of coal mining and reclamation on surface and ground water in three watersheds (~16 ha) showed the temporary and permanent effects of this drastic land disturbance (Figure 11). Watersheds were monitored before, during, and after mining and reclamation. Monitoring could not have been possible without the use of the drop-box weir [7] due to the large sediment-laden flows from areas such as shown in Figure 5. Runoff potential increased (large curve number) to a near constant after reclamation regardless of original geology, and erosion can be controlled to near pre-mine levels with the right reclamation practice [45–47]. The results have been used in court cases and in regulations.

Figure 13. Soil carbon increases in soil planted to continuous no-till corn (bottom right) compared with soil from

burrow infiltrometer, and rainfall simulator for macropore studies.

from construction sites and farm fields [40, 41].

losses in subsurface flow were also measured [43, 44].

reclaiming surface mines.

conventionally tilled soil (upper left).

Organic agriculture: The NAEW investigated the organic-agriculture component of a large nationwide study on the effect of climate on corn production (data still being analyzed). Other organic-related research included comparing impacts of continuous and MIG as they underwent transition to organic agriculture.

Precipitation modeling: Several studies on modeling short-time increment precipitation data (of the order of minutes) for modeling purposes have been completed. Studies on parameterization, data quality, seasonal variation, times between storms, climate change, etc., support a model that generates independent storms of any duration [30, 31].

Ground-water recharge: The Glugla method for estimating ground-water recharge was verified by using the NAEW lysimeters [32]. This method is used nationwide in Germany.

Evapotranspiration (ET): Lysimeter data have been useful for investigating ET losses under different management practices. The Glugla method also estimates long-term ET losses. The lysimeters were used in modeling the ET component for verifying the engineering design procedure for alternate and cheaper landfill covers [33].

Watershed modeling: Models of some small watersheds allowed the evaluation of climate change and runoff, and the adequacy of a model-parameterization procedure [34]. NAEW data are currently being used to nationally update a runoff-estimation procedure used worldwide ("curve number" model).

Biofuel removal: It was documented that removal of large amounts of crop residue for ethanol production can negate many soil and water-quality benefits of long-term no till [35, 36].

Urbanization: It was shown that a low level of imperviousness, either close to or far from a stream channel, on a 3-ha watershed had no effect on runoff. It was also shown that minor surface disturbances can increase runoff potential, but that the land surface can recover, using grazing a surrogate for urban land surface disturbance [37].

Winter application of manure: Data from large runoff plots of various sizes and treatments, and experimental watersheds were used to provide guidance for applying manure during the winter [38].

Pathogens from manure applications: The winter-manure application project provided an opportunity to add another dimension to NAEW research—pathogens. The data were used to provide pathogen guidance for winter application of manure.

Instrumentation: NAEW scientists developed and adapted many hydrological and waterquality instruments required for specific research objectives and not commonly available commercially. Examples are the Coshocton Wheel water sampler (invented in ~1945 and used worldwide in remote areas), Coshocton Vane water sampler, large sediment particle runoff sampler, drip-flow meter and sampler, hydraulic studies of the drop-box weir, adaptation of the Coshocton Wheel for the drop-box weir [39], natural-precipitation infiltrometer, wormburrow infiltrometer, and rainfall simulator for macropore studies.

Climate change: Climate was changing starting in about 1980 at the NAEW. Several studies of precipitation showed that underlying runoff parameters in the "curve number" method of estimating runoff were changing as extreme precipitation events were increasing in magnitude, and that air temperature was trending upward [28]. Watershed data were used for

Organic agriculture: The NAEW investigated the organic-agriculture component of a large nationwide study on the effect of climate on corn production (data still being analyzed). Other organic-related research included comparing impacts of continuous and MIG as they

Precipitation modeling: Several studies on modeling short-time increment precipitation data (of the order of minutes) for modeling purposes have been completed. Studies on parameterization, data quality, seasonal variation, times between storms, climate change, etc., support a

Ground-water recharge: The Glugla method for estimating ground-water recharge was verified

Evapotranspiration (ET): Lysimeter data have been useful for investigating ET losses under different management practices. The Glugla method also estimates long-term ET losses. The lysimeters were used in modeling the ET component for verifying the engineering design

Watershed modeling: Models of some small watersheds allowed the evaluation of climate change and runoff, and the adequacy of a model-parameterization procedure [34]. NAEW data are currently being used to nationally update a runoff-estimation procedure used world-

Biofuel removal: It was documented that removal of large amounts of crop residue for ethanol production can negate many soil and water-quality benefits of long-term no till [35, 36].

Urbanization: It was shown that a low level of imperviousness, either close to or far from a stream channel, on a 3-ha watershed had no effect on runoff. It was also shown that minor surface disturbances can increase runoff potential, but that the land surface can recover, using

Winter application of manure: Data from large runoff plots of various sizes and treatments, and experimental watersheds were used to provide guidance for applying manure during the

Pathogens from manure applications: The winter-manure application project provided an opportunity to add another dimension to NAEW research—pathogens. The data were used to

Instrumentation: NAEW scientists developed and adapted many hydrological and waterquality instruments required for specific research objectives and not commonly available commercially. Examples are the Coshocton Wheel water sampler (invented in ~1945 and used worldwide in remote areas), Coshocton Vane water sampler, large sediment particle runoff

by using the NAEW lysimeters [32]. This method is used nationwide in Germany.

modeling watersheds for climate change impacts [29].

model that generates independent storms of any duration [30, 31].

procedure for alternate and cheaper landfill covers [33].

grazing a surrogate for urban land surface disturbance [37].

provide pathogen guidance for winter application of manure.

wide ("curve number" model).

winter [38].

underwent transition to organic agriculture.

14 Hydrology of Artificial and Controlled Experiments

Filter sock performance: Coshocton data showed that there were limits to use of on-field control of pesticides on watersheds. Netting in the form of tubes filled with materials that can adsorb pesticides and nutrients from surface runoff have been studied and published. The results are useful for contractors that use filter socks in controlling chemical and sediment water quality from construction sites and farm fields [40, 41].

Paper mill byproducts: In collaboration with the State of Ohio and the paper industry, NAEW studies on use of paper-mill sludge (waste product) applied to surface mines showed that the State's upper limit of land application rate was environmentally acceptable [42]. This provided paper mills a cheaper, more environmental beneficial, alternative to landfill disposal, and at the same time provide a good source material for revegetating and controlling erosion when reclaiming surface mines.

Carbon sequestration: The long-term nature of the management practices on the small watersheds including continuous no-till corn with over 40 years of runoff records have enabled numerous investigations into the impact of land management on carbon sequestration (Figure 13). Sediment-bound carbon losses from various conservation tillage practices and organic carbon losses in subsurface flow were also measured [43, 44].

Surface mining and reclamation: A landmark study on effects of coal mining and reclamation on surface and ground water in three watersheds (~16 ha) showed the temporary and permanent effects of this drastic land disturbance (Figure 11). Watersheds were monitored before, during, and after mining and reclamation. Monitoring could not have been possible without the use of the drop-box weir [7] due to the large sediment-laden flows from areas such as shown in Figure 5. Runoff potential increased (large curve number) to a near constant after reclamation regardless of original geology, and erosion can be controlled to near pre-mine levels with the right reclamation practice [45–47]. The results have been used in court cases and in regulations.

Figure 13. Soil carbon increases in soil planted to continuous no-till corn (bottom right) compared with soil from conventionally tilled soil (upper left).

Landfills: Lysimeter data validated an engineering design model for a new type of landfill cover that utilized the ET processes in the soil to minimize water percolating to ground water [33].

3. Monitoring a large experimental watershed requires sufficient funding to sustain scientists, support staff, and experimental resources. The value of experimental watersheds is that they can provide an uninterrupted record of runoff, water quality, etc., spanning years, with dry years producing insufficient numbers of runoff events and longer periods of runoff records may be required. Furthermore, watershed-science research can be considered long-term and high risk because experiments are subject to weather extremes (e.g., droughts and other project factors that are affected by the weather). It is expensive to maintain such a record, and continuous funding must be maintained—temporary grants will interrupt long-term records after the grant period is completed, and a sufficient record of runoff may

Experimental Watersheds at Coshocton, Ohio, USA: Experiences and Establishing New Experimental Watersheds

http://dx.doi.org/10.5772/intechopen.73596

17

4. It can be difficult to exploit characteristics unique to a site (e.g., at the NAEW—understanding and quantifying interflow, nonuniform runoff generation, etc.) because of funding and a wide range of expertise needed. At the NAEW, some of these features were

5. Figure 7 shows the wide variety of watershed behaviors for three experimental watersheds in different physiographic and climatological regions of the USA [49, 50] and generally describes how runoff is generated on landscapes. It is apparent from Figure 7 that the unglaciated NAEW area will follow a convex-upward curve where smaller overland flow areas do not support baseflow (annual runoff is small). For larger areas, however, baseflow is increasing as incising stream channels drain water from intersected water tables, and the curve approaches an apparent constant. For arid areas (Tombstone, AZ), runoff decreases with area in a log-log manner due to channel transmission losses and isolated storms. For the location at Reisel, TX, the response is nearly flat due to its climate and soil conditions leading to a more uniform generation of runoff. The reader is referred to [49] for more particulars of Figure 7. If a network of experimental watersheds is developed, a plot of data in a similar manner may lead to a general characterization of watershed sites under

6. Site specificity of experimental watersheds must be expected. Soil and geology are important factors that can affect different responses of two similarly treated small adjacent watersheds subjected to similar precipitation and weather drivers. This variability affects project results, numbers of watersheds needed for experiments, and highlights the need for watershed modeling to extrapolate field data to ungauged areas. Furthermore, the history of an individual watershed is known and quantified with permanently monitored sites. Some watersheds may still be responding to prior treatments when a new treatment is initiated. In the case of new watersheds, the effects of prior treatments may be unknown,

7. Seasonal air temperatures and percent of snow in a precipitation record are important for seasonal runoff generation mechanisms that can affect water quality also. At the NAEW, lower winter air temperatures did not always insure frozen soil, and sometimes frozen soil occurred intermittently. Consequently, latitude and climate are important to consider.

consideration, and may help differentiate proposed sites.

yet they may affect interpretations of the data.

not be recorded.

not fully exploited.

Other research: Other research conducted at the NAEW (not exhaustive list) were projects related to water quality of spent foundry sand, dairy wastes, and nursery operations. Frozen soil, rain gauges, soil moisture, soil characterization, etc., have also been topics.

Emerging issues: A significant advantage of the NAEW facility is its long-term data base and the permanent monitoring infrastructure. It has been used for many investigations which were never imagined at the outset. Examples are placement of impervious structures for urbanization studies, evapotranspiration landfill caps, macropore investigations, advanced modeling, organic agriculture, climate change, ground-water recharge studies, spent foundry sand, nursery operations, dairy wastes, filter socks, carbon sequestration, pathogens and estrogens in runoff [48], biofuels, surface mining and reclamation, paper mill sludge, and long-term waterquality response times in natural systems.
