Yakima Training Center Research Articles

Validation of the Unit Stream Power Erosion and Deposition (USPED) Model at Yakima Training Center, Washington

During the last seventy years, numerous models have been developed to predict soil erosion; some models also predict concomitant sediment deposition. All have been proven inadequate and/or inaccurate in one respect or another. This paper discusses the application of the new-generation Unit Stream Power Erosion and Deposition (USPED) model at the US Army's Yakima Training Center (YTC), Washington. We incorporated a novel approach that compares model results with observed soil erosion and sediment deposition across the landscape in a spatially distributed fashion. The model results matched visually estimated values 90% of the time, providing an encouraging validation of the model. Historically, erosion models have been compared with sediment outflow from watersheds, providing no information regarding sources and sinks of erosion and deposition within watersheds. The USPED model is relatively simple to apply and the validation approach provides information in terms of the intensity and spatial distribution of soil erosion and sediment deposition that can be used to optimize the placement and size of soil erosion and sediment control efforts.

Fugitive Dust Emissions from Off-Road Vehicle Maneuvers on Military Training Lands

<abstract> <bold><sc>Abstract.</sc></bold> Off-road vehicle training can contribute to air quality degradation because of increased wind erosion as a result of soil disruption during high wind events. However, limited information exists regarding the impacts of off-road vehicle maneuvering on wind erosion potential of soils. This study was conducted to determine the effects of soil texture and intensity of training with off-road vehicles on fugitive dust emission potential due to wind erosion at military training installations. Multi-pass military vehicle trafficking experiments involving wheeled and tracked vehicles were conducted at three military training facilities (Fort Riley, Kansas; Fort Benning, Georgia; and Yakima Training Center, Washington) with different vegetative conditions and soil textures. The top 6 cm of soil was collected with minimum disturbance into trays and tested in a laboratory wind tunnel for dust emission potential. In wind tunnel testing, the amount of emitted dust was measured using a Grimm aerosol spectrometer. The dust emission potential due to wind erosion was significantly influenced by soil texture, vehicle type, and number of passes. For the light wheeled vehicle, total dust emissions (<20 μm) increased by 357% and 868% for 10 and 50 passes, respectively, from the undisturbed soil condition. For the tracked vehicle, an average increase in total dust emissions (<20μm) of 569% was observed between undisturbed soil and one pass, with no significant increase in emission potential beyond one pass. For the heavy wheeled vehicle, evaluated only at Yakima, emissions (<20 μm) increased by 2,108% and 5,276% for 10 and 20 passes, respectively, from the undisturbed soil condition. Soil texture also played an important role in dust emission potential. For all treatment effects with the light wheeled vehicle, there was a 1,396% increase in emissions (<20 μm) on loamy sand soil over silty clay loam soil.

Hydrologic and Erosion Models to Assess Land Use and Management Practices Affecting Soil Erosion

We developed a new, coupled, hydrologic-erosion model and a targeted field data-collection program to quantify hillslope soil erosion rates and sediment yield in semiarid regions. While the methodology has a wide range of actual and potential applications, we use military training activities as an example. The methodology is applied at the Yakima Training Center (YTC) in south central Washington, USA where most erosion and transport occurs during extreme events of short duration, often associated with rapid rain-induced snowmelt on frozen soil. The distributed hydrologic and soil erosion modeling system is used to simulate continuous water balance and soil thermal state throughout all seasons of the year. We estimated surface runoff and sediment yield for relatively undisturbed areas as well as from roads, firebreaks, and vehicle tracks associated with training activities at the study site. Field data were collected on over 100 hillslope profile transects across the YTC to parameterize, test, and evaluate the linked modeling system. We successfully validated the modeling system against several databases, upland sediment delivery to stream networks, and measured sediment yield from 12 sedimentation ponds within the YTC. The simulation results are superior to those from a currently used model, which help to illustrate applicability of the presented erosion prediction technology.

A GIS-Based Adaptive Management Decision Support System to Develop a Multi-Objective Framework: A Case Study Utilizing GIS Technologies and Physically-Based Models to Achieve Improved Decision Making for Site Management

ABSTRACT The notion of Adaptive Management (AM) allows for the realization and adjustment of management practices in response to elements of uncertainty. In terms of natural resource management, this will typically integrate monitoring, databases, simulation modeling, decision theory, and expert judgment to evaluate management alternatives and adapt them as necessary to continually improve the natural resource condition as defined by stakeholders. Natural resource management scenarios can often be expressed, viewed, and understood as a geospatial and temporal problem. The integration of Geographic Information System (GIS) technologies and physically-based models provide an effective state-of-the-art solution for deriving, understanding, and applying AM scenarios for land use and remediation. A recently developed GIS-based adaptive management decision support system is presented for the U.S. Department of Defense Yakima Training Center near Yakima, Washington.

A comparison of modeled and measured impacts of resource manipulations for control of Bromus tectorum in sagebrush steppe

The EDYS (ecological dynamics simulation) model was used to simulate vegetation growth resulting from different experimental treatments for Bromus tectorum control at Yakima Training Center, Washington. The treatments tested in the field for 4 years were seeding, sucrose application, and a combination of seeding and sucrose application. These treatments included burning to favor their implementation. A control plant community with no manipulations was also monitored in the study. The simulations of plant production were not significantly different from the observed field results in 90% of the comparisons, supporting the validity of the model. In long-term simulations, the population of B. tectorum ceased to dominate the plant community in about 12 years regardless of the treatments. Subsequently, the successional patterns were affected by the treatments. The control and sucrose treatments produced similar successional trends dominated mainly by shrubs ( Artemisia tridentata and Chrysothamnus nauseosus). In contrast, both seeding treatments, including the one with sucrose, produced successional trends dominated by grasses, which reflected the seed mix composition. Seeding had more lasting effects than sucrose application. However, the seeded species only started to dominate the seeded areas when the dominance of B. tectorum was reduced. The long-term simulations provided projections that were difficult to envision solely based on the results of the 4-year field experiment.

Modeling of terrain impact caused by tracked vehicles

Analytical models that can predict the terrain impact caused by tracked vehicles on a horizontal plane were developed and tested. The models included a disturbed width model and an impact severity model. Inputs of the terrain impact models included vehicle static properties, vehicle dynamic properties, and terrain properties. The tested vehicles included an M1A1 tank, an M577 Armored Personal Carrier (APC), and an M548 cargo carrier. The models were verified with field tests conducted in Yakima Training Center in Yakima, WA, Fort Riley, KS, and Camp Atterbury, Indiana. The average percentage errors of the disturbed width model for the M1A1, M577, and the M548 were 10.0%, 27.3%, and 8.5%, respectively. The average percentage errors of the impact severity model of the M1A1 and M577 were 25.0% and 21.4%, respectively.

GIS and Neural Network Method for Potential Road Identification

Global positioning system (GPS)-based vehicle tracking systems were used to track 20 vehicles involved in an 8-day field training exercise at Yakima Training Center, Washington. A 3-layer feed-forward artificial neural network (NN) with a backpropagation learning algorithm was developed to identify potential roads. The NN was trained using a subset of the GPS data that was supplemented with field observations that documented newly formed road segments resulting from concentrated vehicle traffic during the military training exercise. The NN was subsequently applied to the full vehicle movement data set to predict potential roads for the entire training exercise. Model predictions were validated using additional installation and site visit data. The first validation used the NN to identify the existing road network as represented in the Yakima Training Center GIS roads data layer. Next, the NN was used to predict emerging road networks that had not previously existed. The NN method accurately classified approximately 94% of the training data, 85% of the on-road movement data, and 78% of potential roads. The proposed NN method more accurately classified potential roads than the previously used multicriteria method, which was able to identify 10 out of 17 potential road segments across the entire training center.

English

A model of soil erosion and sediment transport on hillslopes is used to illustrate the role of process understanding in determining dominant processes as a function of spatial scale. Erosion and sediment yield from hillslopes are primarily determined by surface runoff, topography, vegetative canopy cover, ground surface cover, soil erodibility, and sediment properties. In areas where winter processes (snow, snowmelt, soil frost, etc.) are important, erosion and sediment yield also determined by these factors. The Hillslope Erosion Model (HEM) incorporates these factors in simulating erosion and sediment yield. The world's largest rainfall simulator database for arid and semiarid areas and data from small hillslope-scale watersheds are used to calibrate and validate the spatially distributed, processed-based HEM. Spatially distributed estimates of sediment transport and yield along hillslopes from the HEM are used with an understanding of dominant processes as a function of spatial scale as the scientific basis to determine stability of slopes at plot to hillslope scales. Interrill processes of raindrop splash and thin sheetflow transport are diffusive. Concentrated flow (rill erosion) processes are advective. Spatial loci of transition from diffusive to advective processes are inherently zones of landscape instability and channel formation. The HEM is used to define these areas of instability on hillslopes. Stability criteria for hillslopes are in turn used as criteria for geomorphic designs. Field data taken on a mine rehabilitation site in Queensland, Australia and at the Yakima Training Center in Washington State were used to extend the erosion model to disturbed site rehabilitation problems. These example applications from natural and designed slopes are used to illustrate model predictions and their applications in scaling and geomorphic designs.

Analysis of vehicle use patterns during field training exercises to identify potential roads

In October of 2001, global positioning system (GPS) – based vehicle tracking systems (VTS) were placed on 20 vehicles involved in an 8-day field training exercise at Yakima Training Center, Washington. Based on the GPS data, an analysis of the potential for identifying new roads was conducted. Analysis of vehicle use patterns within selected 25-m grids was utilized to identify new formed or previously unidentified roads in the training area. The factors used to determine the existence of these new roads were (1) if a vehicle actually passed through the grid, (2) the number of vehicles following the same trail segment, (3) if the vehicles passed on different days, (4) if the vehicles were in different troops, and (5) if the vehicles traveled in both directions. A site visit was conducted and confirmed the existence of new roads along segments that met all five criteria levels. Military road class 4 and 5 roads were identified at sites meeting all five criteria.

Effects of tank tracking on range grasses

The Department of Defense (DoD) must constantly balance its military mission and its commitment to stewardship on large tracks of federal land. These military training lands are some of the most intensely used land in the United States, and training requires that vegetation, primarily grasses, be as resilient as possible. The objectives of this study were to evaluate (i) plant establishment and (ii) the effect of light to heavy tank traffic that ranged from zero to four passes on range grasses at the Yakima Training Center, Yakima, Washington. Characteristics measured include the number of 10-cm gaps without plant materials in seeded rows of the target (sown) species, the biomass of the target species, and the percentages of bluegrass colonization, bare ground, and cheatgrass encroachment in tracked and untracked areas. Both stand establishment and the ability to produce rhizomes are associated with the ability to recover after training. The wildryes did not establish well and subsequently had more 10-cm gaps and lower yields than the other introduced species tested. Among the natives, Snake River wheatgrass and western wheatgrass exhibited the most resilience across the different tracking intensities. The largest decline in percentage target species was observed between the two- and four-pass treatments. After five years, cheatgrass was not able to encroach on Snake River wheatgrass, Siberian wheatgrass, and bluebunch wheatgrass plots. Tracking generally reduced the stand of the target species and increased the amount of bare ground.

Vehicle movement patterns and vegetative impacts during military training exercises

The operation of off-road vehicles during military training exercises can affect the environmental conditions of training lands by removing or disturbing vegetation. The use of global positioning systems (GPS)-based vehicle tracking systems can help to characterize the movement of vehicles during training exercises for the purpose of quantifying vegetative impacts. The combination of GPS positions of vehicles in the field during a training exercise, and geographic information system (GIS) maps of the training installation can provide information about vehicle-specific vegetation impacts of a training exercise, as related to vehicle locations, turning radius and velocity. Such relationships can be used to estimate off-road vegetation impacts. Twenty GPS-based vehicle tracking systems were installed on vehicles of the US Army 3rd Brigade 1/14 Cavalry to evaluate vegetation impacts during a 10 day reconnaissance training exercise at Yakima Training Center in Yakima, WA. The vehicle tracking systems were programmed to record the position of the vehicles every second. The resulting vehicle tracking data were analyzed for quantity of travel per day of the training activity, quantity of travel on and off roads, off-road vehicle dynamic properties turning radius and velocity, and off-road vegetation removed. The vehicles were in motion an average of 8.4% (approximately 2 h per day) of the training exercise time. The average distance traveled per day on roads was 33.5 km, and the average distance traveled per day off-roads was 7.7 km. On average, the vehicles spent 16% of their off-road traveling time at turning radii less than 20 m. Vegetation impacts were compared for different missions. The zone reconnaissance mission produced the highest vegetation impact per distance traveled.

Overwinter changes to near-surface bulk density, penetration resistance and infiltration rates in compacted soil

Previous studies at Yakima Training Center (YTC), in Washington State, suggest freeze-thaw (FT) cycles can ameliorate soil compacted by tracked military vehicles [J. Terramechanics 38 (2001) 133]. However, we know little about the short-term effects of soil freezing over a single winter. We measured bulk density (BD), soil penetration resistance (SPR), and steady-state runoff rates in soil newly tracked by an Abrams tank and in uncompacted soil, before and after a single winter at YTC. We similarly measured BD, SPR and saturated hydraulic conductivity ( k fs) in simulated tank tracks at another site near Lind Washington. Average BD was significantly greater in tank ruts at YTC and in simulated tracks at the Lind site than in uncompacted soil soon after tracking and did not change significantly during the winter of 1997–1998. Measurements of SPR were strongly influenced by soil moisture. When soil was moist or tracks were newly formed, SPR was significantly higher in tank ruts than in uncompacted soil from the surface to a depth of about 10–15 cm. The greatest average SPR in compacted soil was observed between 4 and 6 cm depth. We observed less difference in SPR between tank ruts and uncompacted soil near-surface at YTC as the time after trafficking increased. We observed highest SPR ratios (compacted rut:undisturbed) in fresh tracks near the surface, with lower ratios associated with increasing track age or soil depth, indicating that some recovery had occurred at YTC near-surface. However, we did not observe a similar over-winter change in SPR profiles at the Lind site. Rainfall simulator data from YTC showed higher steady-state runoff rates in tank ruts than over uncompacted soil both before and after winter. However, more time was required to reach steady-state flow in tank ruts and the proportion of runoff was slightly lower in May 1998 than in August 1997. At the Lind site, k fs was lower in newly compacted soil than in one-year old compacted soil or uncompacted soil. Our data suggest that indices of water infiltration such as steady-state runoff rates or k fs, are more sensitive indicators of soil recovery after compaction than are BD or SPR.

Soil compaction and over-winter changes to tracked-vehicle ruts, Yakima Training Center, Washington

We monitored two experimental areas at the Yakima Training Center (YTC) in central Washington to measure changes to M1A2 Abrams (M1) tank-rut surface geometry and in- and out-of-rut saturated hydraulic conductivity ( K fs), soil penetration resistance (SPR) and soil bulk density (BD). Profile-meter data show that rut cross-sectional profiles smoothed significantly and that turning ruts did so more than straight ruts. Rut edges were zones of erosion and sidewall bases were zones of deposition. K fs values were similar in and out of ruts formed on soil with 0–5% moisture by volume, but were lower in ruts formed on soil with about 15% water. Mean SPR was similar in and out of ruts from 0- to 5-cm depth, increased to 2 MPa outside ruts and 4 MPa inside ruts at 10- to 15-cm depth, and decreased by 10–38% outside ruts and by 39–48% inside ruts at the 30-cm depth. Soil BD was similar in and out of ruts from 0- to 2.5-cm depth, and below 2.5 cm, it was generally higher in ruts formed on moist soil with highest values between 10- and 20-cm depth. Conversely, BD in ruts formed on dry soil was similar to out-of-rut BD at all depths. This information is important for determining impacts of tank ruts on water infiltration and soil erosion and for modifying the Revised Universal Soil Loss Equation (RUSLE) and the Water Erosion Prediction Project (WEPP) models to more accurately predict soil losses on army training lands.

Nesting Habitat Selection by Sage Grouse in South-Central Washington

To characterize western sage grouse (Centrocercus urophasianus phaios Bonaparte) nesting habitat in sagebrush-steppe habitat in Washington, we initiated a study on the Yakima Training Center to determine nesting habitat characteristics and whether these characteristics differed between successful and depredated nests. Most nests (71%) were in big sagebrush (Artemesia tridentata Nutt.)/bunchgrass communities. Nest habitat was characterized by greater shrub cover, shrub height, vertical cover height, residual cover, and litter than at random locations. Successful 1-m2 nest sites within big sagebrush/bunchgrass in 1992 had less shrub cover (51%) and shrub height (64 cm) than depredated nest sites (70% and 90 cm, respectively). Successful 77-m2 nest areas in big sage-brush/bunchgrass in 1993 had more tall grass (greater than or equal to 18 cm) than depredated nest areas. Management that protects the big sage-brush/bunchgrass community is essential for maintaining nesting habitat for sage grouse.

Correlation of rangeland cover measures to satellite‐imagery‐derived vegetation indices

Abstract Using field data from the U.S. Army's land inventory and monitoring program, a study was conducted to examine the utility in estimating the quantity of vegetation cover with satellite imagery across a large and complex rangeland. The study area used for this investigation was the U.S. Army's Yakima Training Center in central Washington. The Land Condition‐Trend Analysis (LCTA) program at Yakima Training Center has 202 permanent plots located in a randomly stratified manner across the installation. The principle measures taken along the transects were canopy cover and ground cover. Landsat Thematic Mapper imagery collected in May and August of 1992 was used in the analyses. The satellite data coincided with the beginning and end of the field data collection period and were used to derive various vegetation indices including Ratio, TVI, SAVI, and MSAVI. Analysis of correlation of rangeland cover measures and satellite imagery derived vegetation indices were performed. Correlation between the vegeta...