NU Water-Related Research in McPherson County

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

Displaying 16 records found for McPherson County


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 Crop Water Use
Project's Primary Contact Information
Name van Donk, Simon
Unit West Central Research and Extension Center
Email svandonk2@unl.edu
Phone 308-696-6709
Web Page http://westcentral.unl.edu/web/westcentral/svandonk
Project Information
Title Determining the effect of the amount and timing of irrigation on corn production, using subsurface drip irrigation (SDI)
Description

It is important to learn how to grow crops with limited amounts of water and to determine crop water use with SDI. In 2007 a field study with corn was initiated that will be continued in 2008 and 2009. The treatments are:

  • Rainfed (no irrigation)
  • 0.50 ET (meet 50% of evapotranspiration requirements) throughout the season
  • 0.75 ET throughout the season
  • 1.00 ET throughout the season
  • no irrigation at first, 1.00 ET during 2 weeks around tasseling, then no more irrigation after that
  • 0.50 ET at first, 1.00 ET during 2 weeks around tasseling, then 0.50 ET after that
  • 0.50 ET at first, 1.00 ET during 3 weeks around tasseling, then 0.50 ET after that
  • 0.50 ET at first, 1.00 ET during 4 weeks around tasseling, then 0.50 ET after that
  • 0.75 ET at first, 1.00 ET during 4 weeks around tasseling, then 0.75 ET after that

Using SDI may not only increase water use efficiency, but also nutrient use efficiency when applying nutrients through the SDI system. This study was conducted at WCREC to assess the effect of different in-season nitrogen (N) application (via SDI) timings on corn production and residual soil nitrate-nitrogen (NO3-N). We evaluated the effect of three N application timing methods at two N application rates (UNL recommended rate and the UNL rate minus 20%) on corn grain, biomass yield, and end-of-study distribution of residual soil NO3-N.

In 2006, there were no significant differences in corn grain yields between the two N application rates. In 2007, the grain yield under the UNL recommended N rate was significantly higher (3.0 bu/ac) than under the UNL-minus-20% N rate. In both years, grain yield and biomass production for the N application timing treatments were not significantly different. The lack of response to different N application timing treatments indicates that there is flexibility in N application timing for corn production under SDI. This two-year field study was published in Soil Science.

Impact: This study helps us better understand the most appropriate times to apply N with SDI (underground fertigation). If applied at inappropriate times, nitrates are not used by the crop and may leach into groundwater. If N use is minimized, the producer's cost can be minimized.

Project Support n/a
Project Website
Report SDI_Corn_Yield.pdf
Current Status Completed
Topic Extension
Project's Primary Contact Information
Name van Donk, Simon
Unit West Central Research and Extension Center
Email svandonk2@unl.edu
Phone 308-696-6709
Web Page http://westcentral.unl.edu/web/westcentral/svandonk
Project Information
Title West Central Research and Extension Center - Gudmundsen Sandhills Laboratory
Other(s) Jim Goeke, West Central Research and Extension Center, jgoeke1@unl.edu 
Description

The University of Nebraska West Central Research and Extension Center is a research and extension facility of the University of Nebraska Institute of Agriculture and Natural Resources (IANR). It serves as the site for field-based research and extension involving faculty and graduate students in eight IANR departments. West Central consists of approximately 1,800 acres of which 1,100 acres are in pasture with the remaining in dryland and irrigated cropping systems. West Central delivers research-based education and information to citizens throughout the state. Extension specialists and educators are committed to excellence, conducting educational programs customized to meet the needs of Nebraskans. These educational programs, delivered via a variety of methods, are offered through federal, state and county partnership arrangements and provide research-based information and other educational resources to the 20-county West Central district and beyond.

The Gudmundsen Sandhills Laboratory (GSL), a 13,000 acre working ranch in the Nebraska Sandhills, is also part of West Central. GSL is situated over a relatively small portion of the High Plains Aquifer where saturated thickness exceeds 1000 feet. GSL also features a valley with a live stream, a drained valley with wet meadows, an adjacent lake, dry valleys, and many dune types so that literally all the surface and groundwater locales in the Sandhills are represented and available for research. In 2004 a U.S. Climate Reference Network station was established at GSL to provide future long-term observations of temperature and precipitation accurate enough to detect present and future climate change.

Project Support Varies according to program and project - for more information see http://www.westcentral.unl.edu
Project Website http://westcentral.unl.edu/web/gudmundsen/
Report
Current Status Continuous
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 Invasive Species
Project's Primary Contact Information
Name Narumalani, Sunil
Unit School of Natural Resources
Email snarumalani1@unl.edu
Phone 402-472-9842
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=85
Project Information
Title Predicting Potential Occurrence and Spread of Invasive Plant Species along the North Platte River, Nebraska
Other(s) Justin D. Hoffman; Deepak R. Mishra, University of New Orleans, dmishra@uno.edu; Paul Merani; Robert G. Wilson, Panhandle Research and Extension Center, rwilson1@unl.edu 
Description

Riparian habitats are important components of an ecosystem; however, their hydrology combined with anthropogenic effects facilitates the establishment and spread of invasive plant species. Researchers used a maximum-entropy predictive habitat model, MAXENT, to predict the distributions of five invasive plant species (Canada thistle, musk thistle, Russian olive, phragmites, and saltcedar) along the North Platte River in Nebraska. Projections for each species were highly accurate. Researchers studied a 1-mile wide buffer on either side of the North Platte River channel from the Wyoming-Nebraska state line to approximately 3.2 km west of North Platte. Field work was conducted in September 2005, March 2006, and May 2007.

Researchers found different distribution patterns among the species. Russian olive and thistles closely resembled each other in extent and variable contribution. While conducting field work, researchers repeatedly documented thistles below Russian olives or in close proximity. In addition, both species were commonly documented at varying distances from the river. Conversely, researchers found phragmites and saltcedar to have a more restricted potential distribution. Saltcedar was common throughout most of the study area except in the extreme eastern parts. The eastern edge of the study area approaches the distribution limit of saltcedar in Nebraska (Kaul et al. 2006; Wilson and Knezevic 2006). Phragmites was common in the eastern parts of the study area; however, there was low to no probability of phragmites occurrence in the west. Potential suitable habitat diminished just west of Lake MaConaughy, suggesting researchers have identified the western distributional limit of phragmites on the North Platte River and in Nebraska.

Variable contribution among all species was similar, with elevation and distance from river as the two most important variables for all species. The most probable underlying variable explaining the significance of distance from river is soil moisture. In most cases soil moisture will decrease as distance from river increases. Although soil moisture may be more directly responsible for the observed plant distributions, this variable is not easily estimated over large areas, unlike distance from river. There was a large disparity of elevation in the study area. The importance of elevation may be the result of the locations of the survey sites, underlying mechanistic variables, or both. Collection sites occurred at the elevational extremes. For Russian olive, thistle, and saltcedar, the lack of presence data at median elevations most likely caused MAXENT to weight that variable higher than others. The predictive model of phragmites also determined elevation to be the most important variable. Unlike the other species, no phragmites was documented at the western site. It is possible that phragmites can not survive at higher elevations because of colder temperatures found at these sites. However, Saltonstall (2002) found invasive haplotypes of phragmites occurring at high elevations in Wyoming and Utah, which does not support the previous hypothesis. A more likely explanation is that phragmities is in the process of expanding its range westward on the North Platte River and has not had enough time to disperse to the western parts of the river.

The results of this study have management implications for these species along the North Platte River, as well as other river ecosystems. For example, the variables used in this study resulted in excellent predictions of the distributions of invasive plants. As mentioned above, some of these variables (i.e., elevation and distance from river) may have underlying mechanistic factors that are more accurate measures of plant distributions. However, one of the utilities of the current approach is that these variables are easy to access and generate in a geographic information systems environment and useful predictions can be derived, which is not the case for some of their potential underlying factors. Also, predictive modeling shows limited areas of suitable habitat in the western parts of the North Platte River, primarily along the river channel. Researchers suggest that extensive monitoring be conducted in these areas to identify any populations that may occur there. Identification and control of these populations will significantly slow or stop the westward spread of phragmites. Also, any populations of phragmites that occur in the west should be relatively small and isolated making control of these populations more feasible. Similarly, abundances of saltcedar decreased in the eastern parts of the North Platte River. As with phragmites in the west, a control strategy should be used for saltcedar while populations are small and manageable. In addition, both species were found to occur close to the river bed, thus by monitoring the riverbanks and sandbars, the majority of populations could be identified within a very limited search area. Russian olive and thistles occur throughout the study area. Researchers suggest that control of these species should take place in areas with high probability of occurrence to prevent establishment of monotypic stands of each species.

Project Support U.S. Department of Agriculture - Animal and Plant Health Inspection Service
Project Website
Report Narumalani_Invasive.pdf
Current Status Published in Invasive Plant Science and Management 2008 1:359-367
Topic Invasive Species
Project's Primary Contact Information
Name Narumalani, Sunil
Unit School of Natural Resources
Email snarumalani1@unl.edu
Phone 402-472-9842
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=85
Project Information
Title Detecting and Mapping Four Invasive Species along the Floodplain of North Platte River, Nebraska
Other(s) Deepak R. Mishra, University of New Orleans, dmishra@uno.edu; Robert G. Wilson, Panhandle Research and Extension Center, rwilson1@unl.edu; Patrick Reece, Panhandle Research and Extension Center, preece1@unl.edu; Ann Kohler 
Description

This research focused on the dominant invasive plant species in Nebraska, including saltcedar, Russian olive, Canada thistle, and musk thistle. Once established, these invasive species can have several harmful effects, such as increasing (1) soil salinity, which reduces productivity of native plants and results in the loss of natural habitat (Pimentel et al. 2000); (2) soil water consumption to such an extent that it can dry up streams and reduce water levels of rivers and lakes (Friederici 1995); (3) risk of wildfires during summer (Brooks et al. 2004); and (4) chances of flooding during high-intensity rainfall by impeding stream flow (Zavaleta 2000).

The study area was a corridor approximately 1.6 km wide and 257 km long located along the North Platte River starting at the Wyoming/Nebraska border and ending at Kingsley Dam on Lake McConaughy. The elevation ranges from 1,244 m above sea level at the Wyoming/Nebraska state line to 943 m, in an area below Kingsley Dam. The Platte River is generally considered to be a braided river with a network of small channels separated by large and small islands and sandbars. It has been noted that historically the banks of the Platte River were rarely covered with trees but instead with grasses and sedges (Farrar 1983; Kuzelka et al. 1993). Some of the islands were wooded, and willows (Salix exigua) and cottonwood (Populus deltoids) trees were observed. In the 1930s, Russian olive was introduced into the region for conservation plantings. It has rapidly spread along the Platte River, replacing willows and cottonwoods. More recently, saltcedar has also invaded the study area from the west and, along with Russian olive, occupies riverbanks, sandbars, and islands. Saltcedar seedlings are tolerant of shade and thrive in a variety of soil and moisture conditions, but especially saline soils.

When examined from a comprehensive perspective for the entire study area (22 flight lines) from the Nebraska/Wyoming Border to Kingsley Dam, invasive plants covered an area of 139,632 ha, of which 1,965 hectares (2% of the total area) were identified as saltcedar and 1,478 hectares (1.1% of the total area) as Russian olive. The three mixed classes occupied approximately 5% of the total area. These numbers indicate the severity of invasion of nonnative species along the North Platte River. Nonnative species such as saltcedar have been known to consume large quantities of water, and because western Nebraska is frequently affected by drought, mapping and monitoring their spread along the river corridor can aid in the implementation of biological, mechanical, chemical, or some combination of these control mechanisms to minimize the effects on water resources.

Effective control and management of an invasive species begins with its detection and inventory. The ability to detect invasive plants with the use of remotely sensed data has improved with new sensors, enhanced technology (e.g., hyperspectral), and innovative image processing techniques. However, datasets that have the highest likelihood of detecting invasive plants come with high fiscal and technical considerations. When compared with low-resolution multispectral data, airborne hyperspectral data is most appropriate for detecting subtle changes in the reflectance properties of various vegetation species present in the landscape (Narumalani et al. 2006).

Project Support n/a
Project Website http://snr.unl.edu/invasives/file/northplatte_sunil_deepak.ppt
Report Narumalani_Platte.pdf
Current Status Published in Weed Technology 2009 23:99-107
Topic Production Agriculture
Project's Primary Contact Information
Name Supalla, Raymond
Unit Agricultural Economics
Email rsupalla1@unl.edu
Phone 402-472-1792
Web Page http://agecon.unl.edu/supalla
Project Information
Title Economic and State Budget Cost of Reducing the Consumptive Use of Irrigation Water in the Platte and the Republican Basins
Other(s) Brian McMullen, Agricultural Economics, bmcmullen2@unl.edu 
Description

The terms of the Cooperative Agreement for the Platte Basin and the Supreme Court settlement decision for the Republican Basin both require that Nebraska reduce its consumptive use of irrigation water. This analysis evaluated the economic and the budgetary costs of meeting these requirements. Both the on-farm and off-farm costs were evaluated for both land retirement and water allocation programs, implemented in several different ways, over three alternative time periods, 10, 25 and 50 years.

The on-farm economic costs were defined as the change in net farm income associated with less irrigation. Off-farm economic costs were defined as the statewide change in household income resulting from changes in irrigation, as the effects ripple through the Nebraska economy. Budgetary costs were defined as the cost to the state budget (taxpayers) of policies which compensate irrigators for reducing consumptive use are implemented. Statewide economic costs were found to be lower for land retirement than for allocation programs, assuming the same total change in consumptive use. Total budgetary costs depended primarily on: where the irrigation reductions occurred (proximity to river); on how long the program was continued (number of years), and on whether irrigation was reduced voluntarily with incentives, or by regulation, or by some combination of regulation and incentives. It was found that policy makers could minimize the cost of reducing consumptive use from irrigation and augmenting stream flow by purchasing rather than leasing irrigation rights, by using a regulatory rather than a willing seller incentive approach, and by reducing irrigation at locations close to the river.

More on this research in a UNL Agricultural Economics working paper

Project Support n/a
Project Website
Report
Current Status Completed
Topic Property Values
Project's Primary Contact Information
Name Shultz, Steve
Unit UNO Real Estate Research Center
Email sshultz@mail.unomaha.edu
Phone 402-554-2810
Web Page http://cba.unomaha.edu/dir/HomePageBio.cfm?id=347
Project Information
Title Ongoing UNO/UNL Research on the Determinants of Agricultural Land Values: How Irrigation Contributes to Land Values in Western and Central Nebraska
Other(s) Nick Schmitz, UNO Real Estate Research Center 
Description

Hedonic (mass appraisal) land valuation models were estimated in the Republican and Platte watersheds of Central and Western Nebraska. These models are based on assumption that the buyers and sellers of agricultural land are able to accurately assess the value of irrigation when negotiating sale contract prices, and that irrigation equipment can be distinguished from land and irrigation values. Alternative models were estimated using various combinations of explanatory variables (all measured at the parcel level of analysis). These include: soil productivity measures, topography precipitation, parcel size, cropping patterns, topography, aquifer thickness, well pumping capacity, distances to elevators and towns, and irrigation systems.

The location of all agricultural land sales statewide (2000-2007) and estimated irrigation values in the Platte and Republican Watersheds were identified. Preliminary mass appraisal model results were summarized in tables and the locations of retired irrigation parcels in the Republican Watershed (as part of a 2006 NE DNR and USDA Pilot Program) were identified. The value of irrigated cropland is on average $615/acre (this is the value of irrigated cropland only and does not include the value dryland corners within pivot systems). As well, there are numerous areas and site-specific parcels within the watershed with both lower and higher irrigation values. In fact, we have calculated irrigation values for all of the natural resource districts in the Republican watershed: they range from $488/acre to $948/acre. These estimates are still considered 'preliminary' and may be subject to revision. These irrigation values also do not account for premiums above and beyond marginal market values that farmers and landowners will likely require to willingly participate in future irrigation retirement programs.

More on this research in a journal of the Western Agricultural Economics Association

Project Support U.S. Department of Agriculture Water and Watershed Program
Project Website
Report
Current Status Complete (up to 2007)
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 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