By Dave Gosselin and Duane Mohlman
Students will become familiar with the distribution of geology, soils, groundwater, topography and geography in Nebraska.
Students will be able to determine these general characteristics for their own areas.
The two most valuable natural resources that Nebraska has are its soils and groundwater. Groundwater provides the majority of the drinking water in Nebraska. Nebraska is also well known for its agricultural production that relies heavily on its productive soils. The type of soils (e.g., clayey versus sandy) in an area also influences the amount of water that can infiltrate through the root zone and into the subsurface where it may eventually be added to the groundwater supply. The topographic characteristics of an area also influence the occurrence and use of both groundwater and soils. Where slopes are steep water runs off carrying soil with it. In contrast, where slopes are flat water has an opportunity to infiltrate, and soils have an opportunity to become more well developed and potentially more productive. The topography, groundwater and soil types are directly related to the geology of an area. The geology of an area describes the types of materials and their distribution at the surface and in the subsurface. For example, the block diagram of geology shows the distribution of sedimentary rocks in Nebraska. Overlying these rocks are highly variable sediments that cover a large portion of the state. These sediments consist of sand, gravel, silt, and clay. Processes related to water, wind and ice acting upon these sediments and underlying sedimentary rocks have carved and built the present land surface. The following pages from The Groundwater Atlas of Nebraska provide an overview of the soils, groundwater, and topography in the context of Nebraska's geologic framework.
- Nebraska State Highway Map
- Colored Pencils, Markers or Crayons
- Review background material on each of the maps.
- Hand out a copy of maps and color it in by number. Working in groups of four is optional.
- Answer study guide questions.
- The Groundwater Atlas of Nebraska, 1986, Resource Atlas No. 4, Conservation and Survey Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln.
- Geology, Geologic Time, and Nebraska, 1993, Marvin P. Carlson, Educational Circular No. 10, Conservation and Survey Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln.
Suggested Study Guide Questions
Locate your town or school on the Nebraska State Highway Map. What is the dominant soil association and what are its general characteristics?
What topographic region are you in and what are its characteristics?
What groundwater region are you in? What type of geologic material is groundwater obtained from? Is groundwater easy or difficult to find? What is the age of the materials from which you obtain groundwater (e.g., Quaternary, Tertiary, etc.)? What does this correspond to in millions of years (look at Water Bearing Properties of Major rock units--see enclosed)? Find out what type of geologic material your water supply at home and school comes from.
You have been selected by the governor to become the director of a new state-wide agency responsible for managing the state's soil and groundwater resources. Because you are new to the state, you take two trips shortly after you arrive in Nebraska. Your first trip takes you along Nebraska State Highway 2 between Grand Island in Hall County to Crawford in Dawes County. During your trip, what soil associations, groundwater regions, and topographic regions will you cross over? What is the dominant groundwater region?
On your second trip you are driving along Interstate 80 and head north on Nebraska State Highway 15 from Seward to Hartington in Cedar County. As in the previous questions describe the soil associations, groundwater regions, and topographic regions you will cross over. What is the dominant groundwater region?
You meet with governor and he wants you to describe your trips. Highlight the differences in the soils, topography and groundwater occurrence along the two routes. He then asks you to give him one primary reason for these differences. How do you reply?
Next, he asks you to come up with one plan to manage the soil and groundwater resources of the state. You respond to him by saying that this would not be a good approach to managing the state's resources. Why?