Using Web Soil Survey: Soils lessons for PA Science classes

Transcription

1 Using Web Soil Survey: Soils lessons for PA Science classes Notes for the Instructor: This lesson was designed to serve two purposes. The main purpose of this lesson is for students to learn what information is available to them using the website, Web Soil Survey (WSS), and the basic steps they need to follow in order to access this information. The second purpose for this lesson is to have students learn some of properties of soil that would cause it to be classified as prime farmland or not. There are three basic steps a person must follow to use Web Soil Survey: 1. Defining the Area of Interest (the region that you want soil data on), 2. View and explore the soil data for the area of interest (AOI), and 3. Check Out with your data in the form of a custom soil report, a map, or exportable data that can be uploaded to a GIS software platform like ESRI s ArcView. To see a list of the Internet browsers that support WSS and the specific requirements that are needed to run WSS you can go to < This lesson is basically broken into two different parts with the first part having students go through a series of PowerPoint slides available on the WSS website and answer introductory questions as they do. The second part of this lesson walks students through the basic operation of using the Web Soil Survey website to find soil data for the predetermined location of the northern part of York County, Pennsylvania. Once students narrow their search to this area they will be directed to explore through several variables of soil data that are available for their area of interest. During this introductory activity students will be following step-by-step directions to guide them through the different levels and links available on Soil Web Survey. As they complete the steps in this instructions packet, there will be questions scattered throughout the lesson to track the successful completion of each segment and the acquisition of desired content knowledge.

2 Using Soil Web Survey: An introduction to accessing and interpreting soil data using the Internet. Purpose The purpose of this module is to give you provide you with a basic introduction to using the web site, Web Soil Survey (WSS), which was produced by the National Cooperative Soil Survey and is operated by the USDA s (United States Department of Agriculture) Natural Resources Conservation Service. The information that you will be generating throughout this module were previously only accessible through the use paper maps and other print media. To give you some perspective on why the Web Soil Survey was created, the paper copy of the 2003 soil survey for York County Pennsylvania is accessible as a.pdf file but is 372 pages in length (here is the link for print copies of PA soil surveys if you are curious: With the development of the WSS, this information is quickly and easily available. In addition to the speed and ease of the WSS, it is also customizable to meet whatever need you may have anywhere you have Internet access. The maps and soil data currently online represent about 95% of Nation s counties with a goal of 100% in the near future. In learning how to use the Web Soil Survey website in this module, you will also be learning about some of physical and chemical characteristics prime farmland soils have compared to other soil types. This module will be focusing on a region in the northern part of York County, Pennsylvania. If you are not familiar with this region, York County is situated in the Susquehanna River watershed of central Pennsylvania along the PA-MD border. As you work through the procedures outlined in this module, there will be one or more questions that you will to answer based on the information that is being displayed on your computer screen at that time. Your responses will be recorded on the Student Answer Sheet packet that is also being provided to you. Please note that the numbering sequence of these questions follows the order and placement of when you are being asked the questions in the procedure. This means that there could be times when you will be working for several steps without being asked any questions, yet it is very important that you follow the procedures as they are written to ensure that you are

3 looking at the exact data that you need to be. Skipping steps or working ahead of your procedures packet is the easiest way to get lost or confused, so please don t do it. Procedure Introduction to Web Soil Survey (WSS) Section A- Opening WSS and selecting an Area of Interest (AOI) A1. You will need to begin by opening a web browser of your choice and type in the following link into the address window that appears at the top of the screen < (to see a list of the browsers that support WSS and the specific requirements needed to run WSS you can go to < On this main page you will be able to find out a great deal of introduction information on what Web Soil Survey is, all of the different ways information can be acquired, and answers to other basic questions on using WSS. A2. Before we started with using the Web Soil Survey you need to understand some of the basic functions and tools that are available to you in the program. If you already know how to use common GIS programs, like ArcView, many of these tools will be familiar to you since WSS is basically a web-based GIS application. On this main page you will find a very useful tutorial that will give you a quick introduction to the basics of WSS. By clicking on the tab called How to use Web Soil Survey found under the I want help with section on the right hand side of the page, open this file now. When you click on this link a PowerPoint-like presentation will open in the form of.pdf pages that guide you through how WSS works. Skim through this presentation

4 to find the answers to the questions listed in your packet and to label the function of each icon shown on the Web Soil Survey toolbar. A3. Now that you have a basic understanding on how Web Soil Survey works, we are going to jump right into the data by clicking the big green button in the center of the screen that says Start WSS. A4. Once you click on this button a second browser page will open and give you a view that should look like the picture shown to the right. On this page you will be selecting a region of the country that will become known as the Area of Interest (AOI). When you select your AOI, you are telling the web site what part of the country you would like soil data on. Web Soil Survey limits the size of your AOI to a maximum of 10,000 acres of land, but that is over 15 square miles so that really shouldn t be a problem for you. Selecting and AOI B1. You will now need to select an area of land to be your Area Of Interest (AOI). There are many ways that you can search for your own specific area of interest based on what information you have or would need from WSS. To simplify this process you will conduct your search using the State and County option under the Quick Navigation tab. Click your mouse button where is says State, when you do this a drop-down menu will appear that will ask you to select a state that you want soil data for. You can scroll down to find Pennsylvania in the list or just start typing it out. Once you have the state selected the county window will change to show all of the counties in the Pennsylvania. Click on the window and scroll down to the very bottom to select York County. Now click on the View button in the upper right side of the picture on the previous page.

5 B2. Your map has now changed to a view of York County and the surrounding areas that include the Susquehanna River and the counties of Adams, Dauphin, Lancaster and Lebanon. You are now going to zoom-in on a part of northern York County to get a closer at the area. Make sure that the zoom-in tool is selected and find the two cities of Dillsburg and Wellsville towards the center of the map view. Put your cursor on the city of Dillsburg and click and drag a box that ends on the city of Wellsville, then release the mouse button. Your map view will now zoom-in on northern York County that should look like the picture to the right. The box with the dashed line is an example that you will use for the next step. Before you move on to select your area of interest (AOI), take a moment to look at how the land is being used by finding areas that look like farm fields and areas that are not farmland and record this answer on your student packet for step B2. To give you an idea of what you are looking at, farmland looks like a series of alternating bands of rectangles. Example Box for Step B3 B3. We are now at the point where we can create our AOI (area of interest). Change your tool bar to the define AOI by rectangle icon and make another box that is somewhat smaller than the box you did in step B2 between Dillsburg and Wellsville, see the example box in the picture above. If you see a window that says your AOI cannot be defined all you need to do is click on the close button and draw a slightly smaller box that you did before (remember that it must be less than 10,000 acres). Your AOI will be shown with a light blue colored box and horizontal lines running through it. On your answer sheet record the size of your AOI in units of acres and also from where the data

6 for your soil map is coming from. Now that we have an AOI selected, let s explore some of the data that can be found on WSS. Research on Your AOI C1. Once you have selected an AOI, there are new view options that are available for you to select from. To view the different soil types that are found in your AOI click on the Soil Map tab as shown. Your map now changes to a view that shows the boundaries of each soil type and the two or three letter abbreviation for its name. On the left-hand side of your screen you will find the Map unit legend that lists each abbreviation, defines what it stands for, how many acres of each type is found in your AOI, and finally what percentage of the total area that amount represents. On your answer sheet fill-in the data table that asks for the basic information on the top 5 most common soil types for your area of interest. C2. Notice that for each of the soil types listed in the legend the name looks just like a typical hyperlink does when you are on the Internet. By clicking on each soil name, a window will appear that describes the basic characteristics of that soil type. Scroll down the list and find the soil type called the Lehigh Channery Silt Loam, 3 to 8 percent slope; it has the abbreviation of LhC and should have a rather high percentage in your AOI. Click on the hyperlink to open a window called the Map Unit Description and answer the questions listed in your answer packet about this specific type of the Lehigh Channery Silt Loam. C3. Up to this point you have really just been learning how to navigate around the Web Soil Survey, now you are going to click on the tab called Soil Data Explorer, of the WSS. to really discover the power C4. We are going to start our examination of the soil properties in your AOI by looking at the ratings for the soil as farmland. Once you have switched to the Soil Data Explorer tab you will notice that the options on the left side of the screen have also changed.

7 Each of the tabs shown here are packed with background information on soil types and properties and also where you can learn about the specific properties of the soil in your AOI. Make sure that the Suitabilities and Limitations for Use tab is active (you will know this if it is colored dark red) and then click on the Land Classifications box as shown in the picture to the right. Once you click on the Land Classifications box you will notice that it has expanded to more options for you to pick from. We will be looking at the Farmland Classification for your AOI so click on that box and it will expand to show the options that you see in this picture. To get a better idea what this data will show you, click on the View Description button towards the top of the box and answer question C5 in you answer sheet based on the information in the description window. Once you have answered the question you can close that window by clicking on the X in the upper right-hand corner. C5. Now that you have an idea of the range of values you will be seeing, click on the View Rating button under Farmland Classification to see the ratings for the soil in your AOI. After a few seconds your soil map will now turn into one of three colors, red, light green, and dark green. Since there is not a legend provided to explain what each color is shown, you will need to determine the color scheme right now. Zoom in on the upper left-hand corner of your AOI to include the area shown in this picture: Once you zoom in to this view you will see that the soil types are now labeled with a three letter abbreviation called the map unit symbol. What you will need to do now is find the soil type listed in table on your answer sheet, determine what color that soil type is on the map, and then finally record what the rating is for that soil type. C6. Now that you have an idea what the different colors on your map represent, click on the Zoom to AOI extent button on the toolbar (it s the small globe that says AOI below it)

8 to return you map to view that shows the entire AOI. Now you should estimate the percentage of your AOI that would be defined as each of the three farmland classifications and put those estimates in the table for question C6 in your student answer sheet. (Make sure that your answers add up to 100% when you are finished) C7. Now select three examples of each farmland rating (9 soil types in total and don t include water or urban land) to become the group that you will be studying for the remainder of this section of the module. For question C7 on you answer sheet, fill-in your soil selections along with the area and percentage of the AOI for each soil type. It is suggested that you try to select soil types which represent the high three percentages for each farmland classification group so you can get a better representation of the soil in your AOI. Record the Map Unit Symbol, Map Unit name, Acres in AOI, and Percentage of AOI on you data table. When finished with this step you will only have the first 5 columns on the table completed, we will do the rest over the next few steps. C8. We will now try to determine some factors that could cause one soil type to be considered prime farmland, while another nearby soil types are not. To do this you will need to find out more information about the nine soil types that you have listed by looking at a few more characteristics in the Soil Data Explorer. Let s start with the Soil Taxonomy Classification information which can be found on the bottom tab in the Land Classification group that the Farmland information was in. Just as you did before, click on the title, Soil Taxonomy Classification and then View Rating. Now your map will change into a new color scheme to represent the specific classification of each of soil types in your AOI. If you think back to lessons that you may have had in a Biology or Life Science class over the years, when you are taking about taxonomy groupings you are looking at the way things can be grouped together based on their common properties. You may have previously learned that the scientific name of an organism comes from the last two taxonomical listings for that organism, the genus and species (example: Homo sapiens for modern humans). Use the summary table below the map on your screen to fill-in the next column on your data table from step C8. You will need to find the same nine soil types that you selected from before and list their soil

9 taxonomy classifications. If you would like further information on what these different taxonomical groupings represent, you can read through the Keys to Soil Taxonomy document provided with this module, otherwise you can move onto the next step. C9. We will now look at the Representative Slope for each of the 9 soil types in our study. For this you will need change the active tab to the Soil Properties and Qualities tab as shown by clicking it. Now scroll down and click on the Soil Qualities and Features listing to open even more options. Under this listing you will be looking at both the Representative Slope and the Hydrologic Soil Group. We will start with the Representative Slope, which is the second listing from the bottom of this section. When you click on this listing a set of view options will open for you to select from, we will simply go with the default setting so don t change any of the options here. All you will need to do is click the View Rating button as you did before with the Taxonomy Ratings. If at any time you get a BAF Map Service Error message saying that the map cannot be drawn simply click on the close button in the lower right of that window and then click the View Rating button again. For some reason this seems to work on the second attempt. As before, find the listing for each soil type and record the classification on your table from step C8, since you have the same AOI for every step the specific rating for each characteristic is the only thing in each table that changes. The number that you are recording here is a measurement of the average slope of the land for this soil map unit. Remember from math class that slope is defined as the change in the vertical distance (the rise or y-axis) divided by the change in the horizontal distance (the run or x-axis). Since these numbers are shown as a percentage you can assume that the change in horizontal distance is 100 feet and the change is vertical distance is the value that is given for each soil map unit. Once you have recorded your data for the nine soil types, answer the summary question for step C9 and then move onto the next step.

10 C10. The next factor that you will need to consider when thinking about farmland classification is something called the Hydrologic Soil Group. This data listing can be found in the Soil Qualities and Features group a few listings above the Representative Slope values that you just recorded on the previous step. When you click on this listing another view options screen will appear. We will again accept the default settings for our view, but before you click on the View Ratings button, it is important to understand what the values that you will be recording are actually showing. Directly beside the View Rating button you see another button called View Description,, click on this button and read the description for what the Hydrologic Soil Group values represent. Now summarize what you have read in the space provided in your answer packet for step C10. Once you have written your summary, click on the View Rating button, find your nine soil types, and record the values for each. C11. We will now shift our attention to some of the soil s physical properties that may affect its farmland rating. We will begin with a factor called, Liquid Limit. Reduce the size of the Soil Qualities and Features tab by clicking on it and then click on the Soil Physical Properties tab to open the different data options here. In addition to the Liquid Limit variable, we will be examining the Percent Clay and Organic Matter variables found in this section. About halfway down the listings for Physical Properties you will find the Liquid Limit. Just as before, click on this listing and read the View Description window so you get an idea of what this data is showing you. Summarize your reading on the

11 space provided to you for Step C11 and then proceed to step C12. C12. Now you have summarized what the Liquid Limit variable is showing, you will need to tell the WSS one more thing about the exact data that you would like. The WSS database can tell you the liquid limit for a wide range of soil depths for basically any area. To keep things simple, find the options shown in this picture and click on the Surface Layer button as shown here. Once you have that selected, you can once again click on the View Ratings button and record the values for your nine soil types. C13. The final two factors that we will need to consider is the percentages of organic matter and clay particles found in each of your nine soils. You will see each of these listings under the Soil Physical Properties section. Start with the listing for Percent Clay for this step. Once you find it click on this listing a box will open that will ask you to select the view options for the layer. You will once again need to tell WSS for what depth you want information on. To keep our data as consistent as possible you should select the surface layer just as you did before for the Liquid Limit and then click on the View Ratings Button. Find your 9 soil types and fill-in the next column in the data table. To better understand what these ratings are telling you, click on the View Description button and read the information in the window that opens. Summarize what you have read in the window by writing a few sentences in the space provided to you on the answer sheet for step C13 on Percent Clay. C14. This step is basically a repeat of stet C13 only now you will be viewing data on the percentage of Organic Matter in the soil of your AOI. Make sure that you read the description window for this variable and write a summary on your answer sheet. Also, don t forget that you select surface layer under the options before you click on the view ratings button. Once you have recorded your values in the table you can proceed onto the summary and conclusions section of this module, well done!

12 Summary and Conclusions D1. You have now gone to great lengths to uncover a vast amount of information about the soil properties in the northern part of York County, PA. In your research you found that about half of the soil in this area is considered to be either prime farmland or farmland of statewide importance, while other soil types are not prime farmland. Keep in mind that even though you have gathered quite a bit of information about the soil characteristics in your area of interest, the data that you have on your table represents only a very small amount of the information available to you on WSS. Before answering the summary questions, take a few minutes to review your data table and reflect on any patterns that you may have noticed in the maps that were being generated throughout this module. You may then turn to the Summary and Conclusions section of your answer packet and begin work on the summary questions. D2. (OPTIONAL) Once you have answered all of your questions on your student answer packet you can actually create your own Soil Survey Report based on your personalized Area of Interest that you created at the beginning of this module. If your teacher does not want you to complete this step go to step D3 now. The soil survey report that you create here will be generated in the form of a.pdf file that you can save or print, just be advised that it will be quite lengthy (somewhere around 50 pages or more) and printing it would be time consuming and costly. To create your soil survey all you need to do is click on the tab that runs across the top of your window called Shopping Cart :. When you click on this tab a new button will appear in the upper right hand corner of the screen below these tabs that says, Check Out. Click on this button and then select the Get It Now option on the next window and click OK. Now the WSS will begin to write the customized soil survey for your AOI. Your soil survey will include descriptions of each soil type found in your AOI along with any other information that you may selected to add to the shopping cart as you were working on the module. If you did not select anything for your shopping cart while you were working you can go back to any of the steps in the C section of your procedure to repeat your work. Once you have the data

13 that you want simply click on the Add to Shopping Cart button towards the top of your screen and this data will be added into your custom soil report. D3. You are now finished with the introduction to Web Soil Survey module. Close the soil survey window the same way you would close any other standard web browser screen and thank you for all of your hard work in this module.