NU Water-Related Research in Sandhills WMA

The list below shows water-related research being conducted within your WMA or that affects your WMA. They are sorted by water topic, then by primary contact's last name.

Displaying 23 records found for Sandhills WMA


Topic
Project's Primary Contact Information
Name van Donk, Simon
Unit West Central Research and Extension Center
Email simon.vandonk@unl.edu
Phone 308-696-6709
Web Page http://westcentral.unl.edu/web/westcentral/svandonk
Project Information
Title Site-specific management of heterogeneous fields
Other(s) Richard Ferguson, Department of Agronomy & Horticulture, rferguson1@unl.edu; Tim Shaver, West Central Research & Extension Center, tim.shaver@unl.edu 
Description

Variable rate technology (e.g., for irrigation, fertilization, seeding) has developed rapidly, enabling agricultural producers to practice site-specific management on heterogeneous fields. However, knowledge is lacking on how to implement site-specific management; the variable rate technology is available to producers, but knowledge is needed on where, when, and how much water and/or nutrients to apply. A research project was started in 2011, studying the interactions of landscape position (topography), soil type, irrigation and nitrogen.

Impact:Producers will be able to better implement site-specific management on heterogeneous fields benefitting their economic bottom line as well as the environment.

Project Support John Deere
Project Website
Report
Current Status Continuing
Topic Climate
Project's Primary Contact Information
Name Shulski, Martha
Unit High Plains Regional Climate Center
Email mshulski3@unl.edu
Phone 402-472-6711
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=474
Project Information
Title High Plains Regional Climate Center - Monitoring Stations
Description

As the demand for water grows, it is important to have reliable information for various assessments, such as drought, fire, and water development. In an effort to understand the surface hydrology and the water and energy interactions at the surface, scientists with the High Plains Regional Climate Center have installed a series of monitoring stations that collect temperature, humidity, solar radiation, windspeed and direction, soil temperature, precipitation and soil moisture data. These stations take hourly and daily data which can be used to calculate evapotranspiration and water balance terms. Monitoring equipment is located near Higgins Ranch, Sparks, Merritt, Ainsworth, New Port, Barta, Gudmundsens, Halsey, and Merna.

Volunteers supplement these stations by using rain gauges to monitor precipitation; volunteers enter their data online as part of the Nebraska Rainfall Assessment and Information Network (NeRAIN). In total volunteers from 40 states contribute precipitation data to the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS). The CoCoRaHS network has been incorporated into the Applied Climate Information System (ACIS), which allows resource managers, researchers, and decision-makers to better access data.

Project Support National Climatic Data Center
Project Website http://hprcc.unl.edu
Report
Current Status Continuing
Topic Extension
Project's Primary Contact Information
Name Hergert, Gary
Unit Panhandle Research and Extension Center
Email ghergert1@unl.edu
Phone 308-632-1372
Web Page http://www.panhandle.unl.edu/personnel/personnel_hergert.htm
Project Information
Title Improving Nitrogen Management for White Wheat
Description

Winter wheat, long a mainstay of dryland agriculture in the Panhandle, is being grown on a growing number of irrigated fields because it will grow under limited irrigation and wheat prices have risen to cover irrigation costs. Nonetheless, limited irrigation and increasing fertilizer prices mean producers need to sharpen their management skills. Research is proving that soil testing, timing fertilizer applications and managing application rates are all very important to growing winter wheat.

Preliminary data from this research shows top yields come when one third of the fertilizer is applied in the fall and two-thirds at boot stage. Maximum yields have been produced when the amount of residual nitrogen in the top four feet of soil, along with the applied fertilizer, totals 200-210 pounds of nitrogen per acre. Top nitrogen rates to maximize yield have not been higher than 100 pounds per acre, which is lower than commonly used to produce high yields. These recommendations for white wheat should also apply to hard red wheat.

Project Support Nebraska Wheat Board
Project Website
Report
Current Status Underway
Topic Extension
Project's Primary Contact Information
Name Kranz, Bill
Unit Northeast Research and Extension Center
Email wkranz1@unl.edu
Phone 402-584-3857
Web Page http://bse.unl.edu/web/bse/wkranz1
Project Information
Title Demonstration Projects and Field Tours
Other(s) Charles Shapiro, Northeast Research and Extension Center, cshapiro1@unl.edu. 
Description

A project associated with using beef manure compost on sandy soils is being conducted near Pierce and Plainview as a means of improving soil quality, using a beef production by-product in crop production and reducing commercial fertilizer application. The data collected at these two sites has been presented by Charles Shapiro at several educational meetings across northeast Nebraska. The project shows a slight improvement is some parameters, but the cost of transportation reduces the quantity of compost that can be transported and so the effect on soil physical properties is minimal, although soil phosphorus levels are increasing.

Near Pierce a project funded by the Lower Elkhorn Natural Resources District aims to demonstrate the impact of reducing season long water application by 10% on corn yield. At this site the farmer uses a computer control panel to speed up or slow down his center pivot automatically to apply 10% less or 10% more than his normal application, respectively. Nitrogen is being applied at three different rates to demonstrate the adequacy of the UNL Calculation Procedure.

Near Brunswick a project funded by the Upper Elkhorn Natural Resources District aims to develop improved nitrogen credit following soybeans in a corn-soybean rotation. Six nitrogen treatments and 6 different cropping sequences have been imposed to determine the nitrogen credit from soybeans on sandy soils. This project will run through the 2008 growing season. To date data suggests lower nitrogen credits on the sands than the silt loam soils in eastern Nebraska.

Project Support Lower Elkhorn Natural Resources District, Upper Elkhorn Natural Resources District
Project Website
Report
Current Status Continuous
Topic Extension
Project's Primary Contact Information
Name Kranz, Bill
Unit Northeast Research and Extension Center
Email wkranz1@unl.edu
Phone 402-475-3857
Web Page
Project Information
Title Northeast Research and Extension Center - Haskell Agricultural Laboratory
Other(s) Charles Shapiro, Northeast Research and Extension Center, cshapiro1@unl.edu; Dave Shelton, Northeast Research and Extension Center, dshelton2@unl.edu; Sue Lackey, Conservation and Survey, slackey1@unl.edu; Terry Mader, Haskell Ag. Lab, tmader1@unl.edu 
Description

The role of the faculty and staff in this unit is to prevent or solve problems using research based information. Faculty and staff subscribe to the notion that their programs should be high quality, ecologically sound, economically viable, socially responsible and scientifically appropriate. Learning experiences can be customized to meet the needs of a wide range of business, commodity, or governmental organizations based upon the many subject matter disciplines represented. As part of the University of Nebraska, the Northeast Center faculty and staff consider themselves to be the front door to the University in northeast Nebraska. Through well targeted training backgrounds and continuous updating via the internet and other telecommunications technologies, faculty and staff have the most current information available to help their clientele.

The Haskell Ag. Lab is a University of Nebraska research farm located 1.5 miles east of the Dixon County Fairgrounds in Concord. This 320 acre farm was donated to the University of Nebraska by the C.D. Haskell family of Laurel in 1956. A number of demonstrations and projects are going on at the Haskell Ag. Lab, including a riparian buffer strip demonstration and a study to evaluate the effect of irrigation on soybean aphid population dynamics. Other studies focus on:

Subsurface Drip Irrigation: In the spring of 2007 a new subsurface drip irrigation system was installed on a 4 acre portion of the farm with sandy loam soils. The initial objective of the research is to collect field data to document crop water use rates for new corn varieties. Specifically, the work will concentrate on varieties that have different drought resistance ratings to improve the accuracy of the information provided to producers via the High Plains Regional Climate Center. In 2007, two varieties were planted and five irrigation treatments were imposed ranging from dryland to full irrigation. The data will also be used to develop improved local crop production functions for use in the Water Optimizer spreadsheet.

Hormones in Livestock Waste: This project will evaluate the fate of both naturally occurring and synthetic hormones that are associated with solid waste harvested from beef cattle feeding facilities. The research involves: 1) tracking the fate of hormonal compounds from the feedlot into surface run-off that would make its way into a liquid storage lagoon; 2) establishing stockpiled and composted sources of the solid manure removed from the feedlot; and 3) applying stockpiled and composted manure to cropland areas under different tillage systems and native grasses. Once the manure is applied the runoff potential will be evaluated using a rainfall simulator. Research will then focus on whether plants that could be a source of food for wildlife and/or domestic animals take up the hormones. (More information about this project is available; see projects listed under Dan Snow.)

Project Support Varies according to program and project - for more information see http://nerec.unl.edu/ Hormone Project funded by the U.S. Environmental Protection Agency
Project Website http://nerec.unl.edu/
Report
Current Status Continuous
Topic Groundwater
Project's Primary Contact Information
Name Kranz, Bill
Unit Northeast Research and Extension Center
Email wkranz1@unl.edu
Phone 402-584-3857
Web Page http://bse.unl.edu/web/bse/wkranz1
Project Information
Title Demonstrate Improved Irrigation Scheduling and Nitrogen Management Practices
Other(s) Charles Shapiro, Agronomy and Horticulture, cshapiro1@unl.edu; Steve Melvin, Extension, smelvin1@unl.edu; Denny Bauer, dbauer1@unl.edu; Ralph Kulm, rkulm1@unl.edu. 
Description This three-year project demonstrates improved irrigation scheduling and nitrogen management practices. At the research site near Springview, soil water sensors, tipping bucket rain gauges and an ETgage have been installed. Sprinkler packages were changed to apply 10% more water or 10% less water than the farmer normally applies. Soil water sensors and tipping bucket rain gauges document the water applied; chlorophyll meter readings, plant samples, and hand picked yields are collected during the summer.
Project Support Bureau of Reclamation, Nebraska Environmental Trust
Project Website
Report
Current Status Continuing
Topic Groundwater
Project's Primary Contact Information
Name Swinehart, James B.
Unit School of Natural Resources
Email jswinehart1@unl.edu
Phone 402-472-7529
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=487
Project Information
Title Geology and Groundwater Supplies of Box Butte County, Nebraska
Other(s) Vernon L. Souders (project lead, retired); Frank A. Smith (retired), fsmith1@unl.edu 
Description

This report describes the relationship between the geology and the groundwater supplies in Box Butte County. It also evaluates the aquifers with respect to waterbearing characteristics and groundwater in storage. It further describes recharge to and discharge from the aquifers, outlines the movement of groundwater in the county, and summarizes the changes in groundwater storage that have occurred since the advent of irrigation in the county. Brief descriptions of the topography and drainage are included. An evaluation of climatic data for Box Butte County and the Nebraska Panhandle is incorporated into this report and several observations are made about climate in relation to groundwater and the irrigation requirements of crops. Brief mention is made of the soils and agricultural activity in the county.

The report estimates that to date (1975-1976) the amount of groundwater in storage has decreased 2-3% since 1938 and perhaps 1/2 of this decrease has occurred since 1964. The most serious water level declines were immediately north of Alliance in an area where the groundwater resource is large. This area had the highest concentration of irrigation wells and is also the oldest irrigated part of the county.

The report explicitly does not answer the question, "How long will the water supply last?" Rather the authors make the point that economic considerations and social attitudes are just as important as the characteristics of local groundwater supplies in answering that question.

Project Support Upper Niobrara White Natural Resources District, U.S. Geological Survey
Project Website
Report WSP-47.pdf
Current Status Test Holes Drilled Fall 1975-Spring 1976, Report Published 1980. An electronic copy of the report is available above; A hard copy is available via Nebraska Maps and More
Topic Hydrology
Project's Primary Contact Information
Name Ayers, Jerry
Unit School of Natural Resources
Email jayers1@unl.edu
Phone 402-472-0996
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=5
Project Information
Title Box Butte County / Niobrara River Numerical Groundwater Flow Model Studies
Description

The main objective of these studies was to determine the effect, if any, of large-scale regional pumping on the base flow of the Niobrara River. One study involved the construction and implementation of a groundwater-flow model for Box Butte County and the surrounding region to simulate hydrogeologic and hydraulic conditions, including groundwater extraction by large-capacity wells. The other study focused on the upper reaches of the Niobrara River to obtain estimates of stream-bed hydraulic conductivity (i.e., the ease with which water can move through pore spaces or fractures in the stream-bed) to be used as input to the modeling effort.

The groundwater-flow model was calibrated to predevelopment by primarily adjusting recharge flux through a trial-and-error process until a reasonable fit was obtained to the observed water table configuration of 1938. Once calibrated to predevelopment heads, transient simulations (i.e., simulations taking into account real-life conditions, thus modeling potential real-life changes in the basin), were run to model the change in heads due to pumping for the time period between 1938 and 2005. Results from these simulations were compared with observed heads for available years. After satisfactory results were obtained from the transient simulations, two additional scenarios were tested. These were simulations where all wells were turned off and where only those wells in Box Butte County and its proximity were active. The computer program ZONEBUDGET, which computes the water budget for user-defined zones, was run coincident with all simulations. Both head and water budget computation results were then used to determine the effect of pumping on the base flow the Niobrara River.

Based on model results, reductions in the base flow of the Niobrara River is due primarily to localized pumping effects, rather than from groundwater extraction on a regional scale. A comparison of simulated outflow values for selected reaches of the Niobrara River indicates that 1) flow characteristics in the uppermost part of the basin did not change greatly over the period of pumping indicating that base flow is not significantly reduced by large-scale pumping, 2) significant changes in base flow appear to have occurred after about 1960 in the middle and lower reaches, 3) the maximum change in flow for the middle reach due to all wells pumping is 19.6% and only 4.4% for Box Butte wells, with both maximum reductions occurring at the end of the 2005 pumping season, 4) the maximum change in flow for the lower reach is about 24.4% for all wells and only 2.5% for Box Butte wells, again, both occur at the end of the 2005 pumping season. Overall, the Niobrara River appears to be a gaining stream along most of its flow path, with the exception of the uppermost part of the basin.

The conclusion is that the affects of large-scale regional pumping appears to not impact base flow in the Niobrara River to any significant degree. Rather, localized pumping, especially where irrigation wells are situated near the river, reduces base flow on the order of 20% to 25%. For the most part, the Niobrara River valley is somewhat isolated from the extensive pumping taking place in Box Butte County. The upper reach is sufficiently distant from the pumping center that the cone of depression has little effect on the water table. Much of the middle reach transects units of the White River group that are considered to be nearly impermeable, and thus, provide a hydrogeologic barrier, preventing the northward expansion of the cone of depression. Pumping along the lower reach of the Niobrara River has a much greater influence on base flow reduction simply due to the proximity of the extraction wells to the river.

Project Support Nebraska Department of Natural Resources
Project Website http://www.dnr.state.ne.us/Publications_Studies/Box-Butte_ModelProjectCompletionReport.pdf
Report
Current Status Completed
Topic Hydrology
Project's Primary Contact Information
Name Chen, Xun-Hong
Unit School of Natural Resources
Email xchen2@unl.edu
Phone 402-472-0772
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=19
Project Information
Title Hydrologic Connections in the Elkhorn River Basin
Other(s) Sue Lackey, Conservation and Survey, slackey1@unl.edu 
Description This project involves investigating the hydrologic connections between streams and the adjacent aquifer systems in the Elkhorn River Basin. Researchers have used a Geoprobe direct-push technique, in-situ permeameter tests, and a thermal camera to collect data in this basin. Research has been conducted in Taylor Creek (west of the City of Madison), in Maple Creek, and two sites in the Elkhorn River near Norfolk and Meadow Grove. Ultimately this data will be used for integrated management of surface and groundwater resources.
Project Support Nebraska Department of Natural Resources, Upper Elkhorn Natural Resources District, Lower Elkhorn Natural Resources District
Project Website
Report
Current Status Continuous
Pic 1 Project Image
Pic Caption 1 This image shows our work in the Elkhorn River near Meadow Grove and in Taylor Creek. 
Pic 2 Project Image 2
Pic Caption 2 Direct-push techniques used by UNL researchers for study of stream-aquifer connections in Madison County, Nebraska. 
Topic Hydrology
Project's Primary Contact Information
Name Lenters, John
Unit School of Natural Resources
Email jlenters2@unl.edu
Phone 402-472-9044
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=743
Project Information
Title On Basin Residence Time and Annual Hydrology: Development of Annual Hydrology Model of the Sandhills Rivers
Other(s) Erkan Istanbulluoglu, University of Washington, erkani@u.washington.edu; Durelle Scott, Virginia Tech, dscott@vt.edu; Tiejun Wang, University of Washington-Seattle, tjwang@u.washington.edu 
Description

Simple models of annual and mean annual basin runoff and evapotranspration, such as the one proposed by Budyko, are useful for investigating the relationship between river flow and climate, and planning water storage structures in basins where long term streamflow measurements are not available. Such models are often based on the assumption that annual precipitation is in balance with annual runoff and evapotranspiration, and change in water storage of the basin is negligible. In basins where groundwater is the dominant source of streamflow this assumption hardly holds.

In this study first we develop a technique to investigate groundwater residence time to identify time scales over which a simple model of mean annual runoff can be meaningfully used. The model is applied in the Niobrara and Loup Rivers. Second we develop an annual hydrology model by solving the rate of change in basin storage. The runoff component of the model is based on the well-known linear reservoir model and a parameterization to characterize runoff on saturated areas. River water storages and streamflow diverted for irrigation are included as inputs in the model. The model explained as high as 80% of the annual variability of runoff in the Niobrara River at the Sparks gage. The model underscores the importance of saturation overland flow in the basin. Finally we used the model to investigate climate change scenarios, including extreme dry and wet conditions, as well as scenarios for the Medieval Warm Period during which Sandhills were destabilized as suggested by geological evidence.

Project presentation at the 2008 Water Colloquium

Project Support National Science Foundation
Project Website
Report Lenters_Groundwater.pdf
Current Status Published "On the role of groundwater and soil texture in the regional water balance: An investigation of the Nebraska Sand Hills", USA, Water Resour. Res., 45, W10413, doi:10.1029/2009WR007733.
Topic Hydrology
Project's Primary Contact Information
Name Pederson, Darryll
Unit Earth and Atmospheric Sciences
Email dpederson2@unl.edu
Phone 402-472-7563
Web Page http://eas.unl.edu/people/faculty_page.php?lastname=Pederson&firstname=Darryll&type=REG
Project Information
Title Waterfalls on the Niobrara River's Spring-fed Tributaries
Description The waterfalls on the spring-fed tributaries of the Niobrara River downstream from Valentine, Nebraska are unique in that the waterfalls are convex downstream. Groundwater discharge on either side of the waterfalls has led to significant weathering because of freeze/thaw cycles in the winter and wet/dry cycles in the summer. The water falling over the face of the falls protects them from the two weathering processes. Because the weathering rates on either side are higher than the erosion rates from falling water, the face of the falls is convex downstream. Similar waterfall face morphology occurs on the Island of Kauai where the main weathering processes are driven by vegetation and the presence of water.
Project Support National Park Service through the Great Plains Cooperative Ecosystem Studies Unit
Project Website http://snr.unl.edu/gpcesu/Project_library.htm
Report Waterfalls_Abstract.pdf
Current Status Completed
Topic Hydrology
Project's Primary Contact Information
Name Wang, Tiejun
Unit School of Natural Resources
Email tiejunwang215@yahoo.com
Phone
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=945
Project Information
Title Niobrara River Flow Variability
Other(s) Erkan Istanbulluoglu, University of Washington, erkani@u.washington.edu 
Description This project develops a database for hydrological and climatological variables within the Niobrara River basin so that researchers may study flow variability in the Niobrara River and its historical changes. Analysis includes all existing and discontinued streamflow gages within the system. Surface water diversion data are also collected to relate to changes in the flow discharge. Annual water yield of the river is studied at Sparks and Verdel gages. A lumped annual water yield model is developed to identify the natural variables that control runoff. The model uses annual runoff as forcing variable, as well as water diversions as outflux from the system. The model is currently being extended to monthly time scales.
Project Support Nebraska Game and Parks Commission, National Park Service
Project Website
Report
Current Status Underway
Topic Recreation
Project's Primary Contact Information
Name Laing, Kim (Graduate Student)
Unit School of Natural Resources
Email kmeuhe1@unl.edu
Phone n/a
Web Page
Project Information
Title Assess Extent of Disturbance by Canoeists in Tributaries to the Niobrara National Scenic River
Other(s) Kyle Hoagland, School of Natural Resources, khoagland1@unl.edu 
Description

The Niobrara is a rich and unique ecosystem. Because it is relatively swift and shallow along this reach, the Niobrara is also a popular locale for tens of thousands of canoeists each year. Frequent bottom trampling and bank destabilization can result in a variety of short and long-term changes, including bottom substrate degradation, higher levels of drift including premature drift of aquatic larvae, increased turbidity and sedimentation, and the elimination of sensitive species.

The overall goal of this project is to assess the extent of disturbance by canoeists in tributaries to the Niobrara National Scenic River and its overall impact on stream ecosystem health. This assessment will be used to evaluate resource management practices in these unique habitats, while also serving as a basis for future comparisons to assess habitat degradation.

Ten tributaries, located along the south side of the Niobrara River, were sampled each month May through September. The tributaries were divided into five streams that were potentially impacted from visitors, located upstream, and five streams that were known to have no visitors. A mini-surber sampler was used to collect invertebrates from upstream sections of the tributaries (above the waterfalls with no visitors) and from downstream sections, below the waterfalls. Current velocity, depth, width, and distance from the edge of the tributary were recorded at each location. Water temperature, pH and conductivity were measured and a water sample taken to measure total nitrogen, total phosphorus and turbidity. In June, July and August visitor information was collected by volunteers at each potentially impacted tributary. Each volunteer counted the number of times the tributary was disturbed. This information, along with daily visitor use collected by Fort Niobrara, U.S. Fish and Wildlife Service, was used to calculate the amount of disturbance occurring at each location.

Project Support n/a
Project Website
Report
Current Status Completed
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Awada, Tala
Unit School of Natural Resources
Email tawada2@unl.edu
Phone 402-472-8483
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=4
Project Information
Title Soil Moisture Use by Grasses and Trees in the Sandhills
Other(s) Kathleen Eggemeyer, Texas State University, keggemeyer@txstate.edu; Ed Harvey, School of Natural Resources, feharvey1@unl.edu; David Wedin, School of Natural Resources, dwedin1@unl.edu; Xinhua Zhou, School of Natural Resources, xzhou2@unl.edu; C. William Zanner, University of Minnesota, bzanner@umn.edu 
Description

The Sandhills are well known as Nebraska's grassland region. The continued presence of relatively shallow-rooted grasses in the Sandhills have contributed to making this region a major recharge zone for the High Plains Aquifer. Unfortunately, trees are encroaching on the Sandhills, potentially threatening the region's recharge capacity.

This study was conducted in the Nebraska National Forest at Halsey (located in Blaine and Thomas counties). Researchers established a network of soil moisture monitoring sites to observe how relatively shallow-rooted grasses (i.e., little bluestem and switchgrass) and deep-rooted trees (i.e., ponderosa pine and eastern red cedar) deplete soil moisture at depths up to 10 feet. The study confirmed that both grasses use mostly shallow soil water. Deeper switchgrass roots may serve as an important survival mechanism for the plant during drought, but overall switchgrass's deep roots contribute only a small fraction to the plant's total water uptake.

On the other hand, the study showed that both trees "exhibited significant plasticity in sources of water uptake." During winter both trees drew soil water from below 0.9 m depth and in spring from the upper soil profile (0.05 - 0.5 m). During the growing season (May-August), the pine drew water mostly from the upper and mid soil profiles (0.05 - 0.5 and 0.5-0.9 m). The cedar gradually moved from the upper to the mid soil profile, thus being less responsive to precipitation but taking advantage of available soil moisture.

Overall the study showed that ponderosa pines and eastern red cedars have been able to encroach into the Sandhills because the trees "acquired water outside of the growing season, competed for shallow water with grasses during spring and early summer, and depended on water drawn from deeper in the soil profile during drought."

For more information about this topic, see David Wedin's presentation, "Was Weaver Wrong? Rooting Depths and Soil Moisture Depletion in the Nebraska Sandhills".

Project Support McIntire Stennis Forest Research Funds - USDA, Interdisciplinary Research Grant, ARD-University of Nebraska-Lincoln, Center for Great Plains Studies, UNL Water Sciences Lab, US Forest Service
Project Website
Report Awada_Sandhills.pdf
Current Status Published in Tree Physiology 29:157-169
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Billesbach, Dave
Unit Biological Systems Engineering
Email dbillesbach1@unl.edu
Phone 402-472-7961
Web Page http://bse.unl.edu/faculty/Billesbach.shtml
Project Information
Title Effects of Precipitation and Groundwater on Grassland Productivity in the Nebraska Sand Hills
Other(s) Tim Arkebauer, Agronomy and Horticulture, tarkebauer1@unl.edu 
Description

In the Sand Hills the depth to groundwater greatly affects the types and amounts of grasses that grow there, suggesting a strong linkage between groundwater, precipitation, and grass productivity. Wet meadows are where the water rable is usually less than a meter below the surface and make up about 10% of the Sand Hills land area. Dry valleys are where the water table never intersects the land surface and usually lies several meters below; dry valleys also make up about 10% of the Sand Hills land area. Except for lakes and wetlands (about 2% of the land area), the rest of the Sand Hills is dunal uplands where the water table is many meters below the surface.

It has long been assumed that the Sand Hills are a recharge zone for the underlying aquifer and that local precipitation more than accounts for the water usage of surface vegetation. This research measures how much water enters the Sand Hills ecosystem (via precipitation) and how much water leaves the land surface - the Sand Hills surface water balance. Research shows that Sand Hills surface water is lost primarily through evapotranspiration, or surface water evaporation and plant transpiration, with the relative size of each varying greatly depending on the time of year and other factors, such as drought. Research also shows that: 1) the most water is transferred to the atmosphere from wet meadows, followed by dry valleys and dunal uplands; 2) the close proximity to the aquifer acts as a buffer to both wet meadows and dry valleys, but not to dunal uplands; and 3) groundwater buffering is most affected by regional rather than local precipitation events. The long-term goal of this project is to study and better understand the relationship between water and the vegetative land cover (carbon).

Project Support n/a
Project Website
Report Billesbach_SandHills_Water.pdf
Current Status Continuing
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Efting, Aris
Unit School of Natural Resources
Email aefting@unl.edu
Phone 402-472-3471
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=226
Project Information
Title Determining Toxic Algal Bloom Frequency in Nebraska Lakes
Description Research has been conducted in the Sandhills to determine whether or not there has been an increase in toxic algal blooms. Four different lakes were cored to identify the lakes' history of toxic algal blooms and determine whether there is an increase in toxin concentrations post 1950.
Project Support Layman Fund
Project Website
Report
Current Status Underway
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Hu, Qi (Steve)
Unit School of Natural Resources
Email qhu2@unl.edu
Phone 402-472-6642
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=54
Project Information
Title The Missing Term in Surface Water Balance in the Great Plains
Other(s) Jinsheng You, School of Natural Resources, jyou2@unl.edu 
Description

It has been recognized that the surface water budget derived from the NCEP-NCAR Reanalysis and other existing climatic datasets is not in balance in the Great Plains region. This imbalance is shown by large surface evaporation which cannot be supported by source terms in the budget equation. This large surface evaporation is always appearing in calculations from the surface and soil moisture conditions specified in those datasets. This imbalance poses serious uncertainties to diagnostic and modeling studies of energy and carbon balances and to our understanding of atmospheric/climatic processes in this region. An effort aiming at identifying sources causing the water budget imbalance has been underway and some preliminary results have been obtained. A main source of the imbalance arises from the calculation of the surface evaporation. It was found that the surface and soil water specified in those datasets (developed from integrations of both observations and model simulations) is biased because of inaccurate descriptions of the soil properties, particularly the sandy soils in the Nebraska Sand Hills. A revised model with more accurate descriptions of the soils and soil hydrology in the Sand Hills has produced a balance surface water budget in the Sand Hills.

Project presentation at the 2008 Water Colloquium

Project Support Department of Commerce - National Oceanic and Atmospheric Administration (NOAA)
Project Website
Report
Current Status
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Hubbard, Kenneth
Unit High Plains Regional Climate Center
Email khubbard1@unl.edu
Phone 402-472-8294
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=55
Project Information
Title Assessment of Soil Moisture Dynamics of the Nebraska Sandhills Using Long-Term Measurements and a Hydrology Model
Other(s) Venkataramana Sridhar; David Wedin, School of Natural Resources, dwedin1@unl.edu 
Description Soil moisture, evapotranspiration, and other major water balance components were investigated for six Nebraska Sandhills locations during a 6 year period (1998-2004) using a hydrological model. Annual precipitation in the study period ranged from 330 to 580 mm. Soil moisture was measured continuously at 10, 25, 50, and 100 cm depth at each site. Model estimates of surface (0-30 cm), subsurface (30-91 cm), and root zone (0-122 cm) soil moisture were generally well correlated with observed soil moisture. The correlations were poorest for the surface layer, where soil moisture values fluctuated sharply, and best for the root zone as a whole. Modeled annual estimates of evapotranspiration and drainage beneath the rooting zone showed large differences between sites and between years. Despite the Sandhills' relatively homogeneous vegetation and soils, the high spatiotemporal variability of major water balance components suggest an active interaction among various hydrological processes in response to precipitation in this semiarid region.
Project Support National Science Foundation, High Plains Regional Climate Center
Project Website
Report Hubbard06.pdf
Current Status Published in Journal of Irrigation and Drainage Engineering, September/October 2006, 463-473
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Loope, David
Unit Earth and Atmospheric Sciences
Email dloope1@unl.edu
Phone 402-472-2647
Web Page http://eas.unl.edu/people/faculty_page.php?lastname=Loope&firstname=David&type=REG
Project Information
Title Large Wind Shift on the Great Plains During the Medieval Warm Period
Other(s) Venkataramana Sridhar; James Swinehart, School of Natural Resources, jswinehart1@unl.edu; Joseph Mason, University of Wisconsin, Madison, mason@geography.wisc.edu; Robert Oglesby, School of Natural Resources, roglesby2@unl.edu; Clinton Rowe, Geosciences, crowe1@unl.edu 
Description Spring-Summer winds from the south move moist air from the Gulf of Mexico to the Great Plains. Growing season rainfall sustains prairie grasses that keep large dunes in the Nebraska Sandhills immobile. Longitudinal dunes built during the Medieval Warm Period (800-100 yBP) record the last major period of sand mobility. These dunes are oriented NW-SE and are composed of cross-strata with bi-polar dip directions. The trend and structure of these dunes directly record a prolonged drought that was initiated and sustained by a historically unprecedented shift of Spring-Summer atmospheric circulation over the Plains: southerly flow of moist air was replaced by dry southwesterly flow.
Project Support National Science Foundation
Project Website
Report Loope Wind Shift.pdf
Current Status Published in Science November 2007 318:1284-1286
Topic Sandhills Studies and Modeling
Project's Primary Contact Information
Name Wedin, Dave
Unit School of Natural Resources
Email dwedin1@unl.edu
Phone 402-472-9608
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=128
Project Information
Title Sand Hills Biocomplexity Project
Other(s) Vitaly Zlotnik, Department of Geosciences, vzlotnik1@unl.edu. 
Description

The Sand Hills, the largest sand dune area in the Western Hemisphere, is now stabalized by native grasses. This was not always the case. The Sand Hills have mobilized several times over the last 10,550 years. Major droughts destabilized significant portions of the Sand Hills as recently as 1000 years ago. The stability of the Sand Hills affects not only hundreds of cattle ranches, but also the recharge of the High Plains Aquifer. Of the total groundwater stored in this vast aquifer, 65% occurs in Nebraska and over half of that lies under the Sand Hills. The groundwater connection is obvious throughout the region. Due to the high water table, interdunal valleys in portions of the Sand Hills contain extensive complexes of lakes, wetlands, and naturally sub-irrigated wet meadows, which together cover over 10% of the landscape.

The Sand Hills Biocomplexity Project is a major federal project led by Professor Wedin. The project is aimed at testing whether:

  1. Evapotranspiration (ET) from wet valleys buffers the impacts of short-term drought on upland grasslands through local climate feedbacks. (resistance stability)
  2. When wetlands go dry, the combined effect of lost upland grass cover and lost wetland ET creates a desertification feedback that amplifies drought impacts.
  3. Since subregions of the Sand Hills differ in their extent of interdunal wetlands, subregions respond differently to paleo and historic droughts, thus enabling landowners to prepare for future droughts.
  4. Increased groundwater recharge when dunes are bare hastens the rise of groundwater levels, which, together with the rapid recovery of warm season grasses, restabilizes the dunes. (resilience stability)

The project's Grassland Destabilization Experiment (GDEX) is studying what happens to a Sand Hills dune when the vegetation dies. Researchers have created 10 circular plots at the Barta Brothers Ranch, each 120 meters in diameter, and used herbicide to kill all the vegetation on several of them. The plots are kept clear of vegetation, so that information on vegetation coverage, root mass, soil organic matter, and sand movement may be monitored and recorded to determine the stability of the plots. Results indicate that the Sand Hills may be more stable than previously thought; that is, ersosion is just starting to occur were vegetation was killed two years ago. Additional studies are needed to determine what happens when sand dunes become mobile.

As a part of this project, Professor Vitaly Zlotnik carries out research on groundwater recharge, hydraulic properties of the dune cover, and the climate change effects on groundwater recharge.

Project Support National Science Foundation
Project Website http://sandhills-biocomplexity.unl.edu/
Report
Current Status n/a
Topic Water Quality
Project's Primary Contact Information
Name Kolok, Alan
Unit Biology, UNO
Email akolok@mail.unomaha.edu
Phone 402-554-3545
Web Page http://www.unomaha.edu/envirotox/whoiam.php
Project Information
Title The Watershed as A Conceptual Framework for the Study of Environmental and Human Health
Other(s) Cheryl L. Beseler, Department of Environmental, Agricultural and Occupational Health, UNMC, cbeseler@unmc.edu; Xun-Hong Chen, School of Natural Resources, xchen2@unl.edu; Patrick J. Shea, School of Natural Resources, pshea1@unl.edu 
Description

The watershed provides a physical basis for establishing linkages between aquatic contaminants, environmental health and human health. Current attempts to establish such linkages are limited by environmental and epidemiological constraints. Environmental limitations include difficulties in characterizing the temporal and spatial dynamics of agricultural runoff, in fully understanding the degradation and metabolism of these compounds in the environment, and in understanding complex mixtures. Epidemiological limitations include difficulties associated with the organization of risk factor data and uncertainty about which measurable endpoints are most appropriate for an agricultural setting. Nevertheless, the adoption of the watershed concept can alleviate some of these difficulties. From an environmental perspective, the watershed concept helps identify differences in land use and application of agrichemicals at a level of resolution relevant to human health outcomes. From an epidemiological perspective, the watershed concept places data into a construct with environmental relevance. This project uses the Elkhorn River watershed as a case study to show how the watershed can provide a conceptual framework for studies in environmental and human health.

Environmental sampling is necessary for evaluating exposure to hormone disrupting chemicals (HDCs); however, sampling is not systematic in time or space, nor does it represent the time frame necessary to adequately link it to human disease outcomes. Although data from municipal sources are available and reliable, countless private drinking water wells go untested and unmonitored. These wells may be in areas vulnerable to concentrated reservoirs of contaminants due to the soil type, infiltration rate, runoff potential, organic matter and erodibility coupled with land use in the region and the chemical properties of the contaminants introduced into the environment. The lack of a defined boundary and introduction of exposure heterogeneity is one of the primary reasons why associations to health outcomes cannot be shown in environmental epidemiological studies.

The use of the watershed provides a natural boundary and the potential within this boundary to obtain denominator data. Based on the characteristics of the watershed combined with sampling data, shared exposures can be identified and intermediate hypotheses tested using sentinel markers of exposure in fish and humans. Lastly, comparable groups identified in other watersheds with similar characteristics but different surrounding land uses can be used to replicate findings.

Project Support Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center
Project Website
Report Kolok_Watershed.pdf
Current Status Published in Environmental Health Insights 2009 3:1-10
Topic Water Quality
Project's Primary Contact Information
Name Kolok, Alan
Unit Biology, UNO
Email akolok@mail.unomaha.edu
Phone 402-554-3545
Web Page http://www.unomaha.edu/envirotox/whoiam.php
Project Information
Title Occurrence and biological effect of exogenous steroids in the Elkhorn River, Nebraska
Other(s) Daniel D. Snow, School of Natural Resources, dsnow1@unl.edu; Satomi Kohno, Department of Zoology, University of Florida, kohno@ufl.edu; Marlo K. Sellin, Department of Biology, UNO, msellin@mail.unomaha.edu; Louis J. Guillette Jr., Department of Zoology, University of Florida, ljg@ufl.edu 
Description

Recent studies of surface waters in North America, Japan and Europe have reported the presence of steroidogenic agents as contaminants. This study had three objectives:

  1. to determine if steroidogenic compounds are present in the Elkhorn River,
  2. to determine if sediments collected from the Elkhorn River can act as a source of steroidogenic compounds to aquatic organisms, and
  3. to determine if site-specific biological effects are apparent in the hepatic gene expression of fathead minnows.

Evidence was obtained using three approaches:

  1. deployment of polar organic chemical integrative samplers (POCIS),
  2. deployment of caged fathead minnows, and
  3. a laboratory experiment in which POCIS and fish were exposed to sediments from the deployment sites.

Deployment sites included: the Elkhorn River immediately downstream from a Nebraska wastewater treatment plant, two waterways (Fisher Creek and Sand Creek) likely to be impacted by runoff from cattle feeding operations, and a reference site unlikely to be impacted by waste water inputs. The POCIS extracts were analyzed for a number of natural steroids and metabolites, as well as four different synthetic steroids: ethinylestradiol, zearalonol, 17-trenbolone and melengestrol acetate. Estrogenic and androgenic metabolites, as well as progesterone and trace levels of melengestrol acetate were detected in POCIS deployed at each site. POCIS deployed in tanks containing field sediments from the four sites did not accumulate the synthetic steroids except for ethinylestradiol, which was detected in the aquarium containing sediments collected near the wastewater treatment plant. Fish deployed in Sand Creek and at the wastewater treatment plant experienced significantly elevated levels of gene expression for two genes (StAR and P450scc) relative to those deployed in Fisher Creek. Fish exposed to the sediments collected from Sand Creek had significantly higher levels of hepatic StAR and P450scc gene expression than did fish exposed to sediments from the two other field sites, as well as the no-sediment control tank.

In conclusion:

  1. detectable levels of steroidogenic compounds were detected in passive samplers deployed in the Elkhorn River,
  2. sediments do not appear to be a significant source for steroidogenic compounds, and
  3. site-specific differences were found in mRNA expression among the different treatment groups of fish; however, a functional explanation for these differences is not readily forthcoming.
Project Support Nebraska Game and Parks Commission, U.S. Geological Survey's Section 104b Program as administered by the UNL Water Center, US Environmental Protection Agency Greater Opportunities Fellowship, Dr. Daniel Villeneuve, US Environmental Protection Agency
Project Website
Report Kolok_Elkhorn.pdf
Current Status Published in Science of the Total Environment 2007 388:104-115
Topic Wildlife
Project's Primary Contact Information
Name Pegg, Mark
Unit School of Natural Resources
Email mpegg2@unl.edu
Phone 402-472-6824
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=739
Project Information
Title Habitat Usage of Missouri River Paddlefish Project
Description Sediment from the Niobrara River has created a delta area near the headwaters of Lewis and Clark Lake, the reservoir formed by Gavins Point Dam on the Missouri River. This sediment aggregation has reduced reservoir volume and threatens to fill the reservoir; therefore, restoration of reservoir capacity has been proposed by means of high-velocity water releases from upstream mainstem dams. Biologists, however, have reported that this delta area may serve as spawning grounds for native fishes like paddlefish, and may provide suitable spawning habitat for federally endangered pallid sturgeon. This situation has created a unique paradox where information is needed to provide insight into fulfilling both the river management needs and biological needs in the Missouri River. This project will use paddlefish telemetry to study spawning success.

Click here to read Brenda Pracheil's dissertation on Paddlefish populations

Project Support Nebraska Environmental Trust
Project Website
Report Pracheil et al_Fisheries_2012.pdf
Current Status Completed
Location

Sandhills WMA

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