Establish GIS for the TW Daniel Experimental Forest (TWDEF) Field   Area and Export GIS Map to the Google Earth

 

 

 

 

 

CEE 6440, GIS in Water Resources

 Term Project

  Fall 2006

 

 

 

 

 

 

 

 

 

 

 

Vinod Mahat

 

Department of Civil and Environment Engineering

Utah State University

 

1      Introduction

Water is a scarce commodity and the drought is the recurring problem in the Western US. In many basins 80% of useable water comes from mountain snow pack that varies dramatically year to year. The increasing population demands and spatial discontinuity between water source and consumption necessitate the proper planning and management of water supplies. Drought management project, Utah has been trying to address the key areas that can improve the drought prediction and management in the west. Experts and scientists from many different fields have been involved in this project and working hard to make the project succeed. As a research student in hydrology, I am taking care of the hydrology part of this project and would be working soon on the snow model to improve the water supply forecasting for this semi-arid climate.

 

For many years, the TWDEF field area has been a research site for university students, hydrologists or ecologists; and substantial investment in instrumentations has been made to this area to conduct the different field experiments. My research area is also based on this TWDEF field area.  Since GIS is a useful tool to provide the systematic way to link the data with the geospatial feature, my idea, for the term project, is to connect this experimental forest with all available information to the GIS and attach it to the Google earth so that the information available in the Google Earth would be beneficial not only to me but also to all the researchers interested in the TWDEF research field in the future. 

 

1.1    Objective

 

To establish a connection of the all information, regarding the different instruments with available data of the TWFDEF to the GIS and to export this information to the Google Earth.

 

1.2    Plans

 

Collection and analysis of DEM

Collection of hydrological data

Delineation of the extent of the TWDEF area

Collection of the information regarding the infrastructures, instrumentation and other important information

Preparation of the site, location and regional map for the TWDEF

Export map and data information to the Google earth.

 

2      Study Area

The TW Daniel Experimental Forest, the research site for diverse set of investigation, comprises the area approximately 0.25 km2 at an elevation of approximately 2700 m. It lies 41.860 North and 111.500 West, which is about 30 km North –East from the Logan. The TW Daniel Experimental Forest is the canopy of the watershed that contributes to the Logan River and Bear Lake.

 

The average annual precipitation around the TWDEF region is about 950 mm where the 80% is snow, and the expected maximum depth of snow during winter is 5.00 m high. Average mean monthly low temperature is -100C and highest mean monthly temperature is 14.50C. A mosaic of forest and range vegetation communities representing the vegetation communities typical of Utah’s montane ecosystems occurs at TWDEF. Forested communities include aspen forest and conifer forest dominated by Engelmann spruce and subalpine fir. Non-forested range communities include open meadows consisting of a mixture of grasses and forbs, and areas dominated by sagebrush.

 

 

3      Data Collection

Most of the data are collected from the different sources, e.g. from different people involved in this research project; and few of the data are collected by myself too from visiting the research site. The geographical spatially explicit data like digital elevation model (DEM), land cover (NLDC), hydrography (streams) required for this project are downloaded from the USGS site. Then the gathered data are analyzed and converted into the simple information map easily understandable to everybody by using the GIS tool and that map is exported into the kml file to link the TWDEF information to the Google Earth.

 

Data collected from Internet

  • DEM
  • National Hydrography data set
  • DOQ (Digital Orthophoto quadrangles)
  • Topographic map
  • County’s boundaries, information about the access road etc.

 

Data collected from other different sources

  • GPS data for the location of site, position of the weather instruments etc.
  • Data for the boundary of the area
  • GPS data for the road inside the boundary
  • Data for the position of the cables
  • GPS data for the position of the other structures e.g. cabin, old precipitation station etc.
  • Weather data recorded by the instruments

 

Table 1 shows the Coordinates of the instruments (in UTM 1983, 12 zones coordinate system) that are set up in four vegetation type area in the TWDEF site.

     Table-1

Weather Station

 ID

Easting

Northing

 A-1

457696

4635088

A-2

457836

4634947

A-3

457864

4634845

G-1

457614

4635049

G-2

457719

4634947

G-3

457741

4634918

S-1

457613

4634976

S-2

457824

4634920

S-3

457848

4634913

C-1

457943

4634870

C-2

457928

4634976

C-3

457995

4634836

 

            where,

            A= Aspen Area

            G= Grass Area

            S= shrub Area

            C= Conifer Area

 

4      Data analysis and Map Preparation

Of the two types of data I have collected, the first type of data which exhibits the geo-spatial reference for the TWDEF site is used for different kinds of surface analysis. The second type of data, the GPS data, is used to create the information map of the TWDEF site showing the position of the instruments and other structures on the DEM based surface.

4.1    Creating a New Features

All the GPS data collected have been used to prepare map. Since the data are in point form, the necessary work to be carried out to prepare map is to convert the points into the lines and polygons shape. As the instrument stations are represented by points in map, no extra work is required but to represent the area covered by site, points should be converted into polygon and similarly to represent the cable length, access road etc. the points should be converted into line shape file. Along with the GPS data I also had the data of lines and polygons created by using the GPS data. But, I was very anxious about creating the new features as I did not have opportunity to create these kinds of features in GIS in my life. I created the new features using the GPS points. One of the examples, which shows how the TWDEF boundary has been created, is presented here.

 

In Arc Catalog, a new feature class ‘New polygon’ is created in a feature data set inside a Geodatabase. While creating this new feature class the default configuration for the data storage is used, however the geometry is defined by clicking on the polygon shape in Geometry Type and the spatial reference is defined by the geographic coordinate system since our GPS data for the boundary is in geographic coordinate system.

 

Now, the ‘New Polygon’ feature class is created.

 

 

 

Then, the ArcCatalog is closed and the Arc map is opened.  The GPS data for the boundary of the TWDEF, which is in the CSV format (Fence.csv), has been added to the GIS map. By this way, the data table is added to the GIS map. To show the data on the map, Add XY data under Tools menu is hit and the data is assigned to spatial reference. In this case geographic spatial reference is assigned to our data as the data are originally in this coordinate system. These steps in GIS create a new events file Fence.csv Events and this events file creates the data points in the GIS map. Still the Fence.csv Events is not a shape file; we need to export the data from this Events file to get the shape file. So these data are exported and given name ‘fence’, which is the point shape file in GIS map. Thus the Point shape file is created in GIS map.

 

 

Creating the Point shape file (fence) for the TWDEF Perimeter

 

 

 

After creating the point shape file, effort is made to create the polygon boundary of the TWDEF site. To do this, the New Polygon feature class is added to the map and the start editing button is clicked on the Editor tool bar to activate the editor toolbar. After selecting the start editing in Editor tool bar, Task and Target box will be active and the Task is assigned for Create New Feature and Target is assigned for New Polygon. Then the new polygon is created by clicking over the each of the points obtained from the GPS measurement by using the sketch tool from the Editor Tool bar. Still the Polygon thus created in not a shape file. It is converted into a polygon shape file by exporting the data and giving a spatial reference, and also giving a new name. In our case, the polygon has been exported and given the name ‘TWDEF Perimeter’ which is the boundary area of the TWDEF site.

 

Some tools used to create the new polygon feature

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


                                  New Polygon building process.

 

 

After completing the polygon boundary other information are also converted into different features (point or line features) by using the same technique. And all these features are put together with DEM, topographic map or Digital Orthophoto quadrangles (DOQ) to give a good overview of the TWDEF site.

 

                          Cable Duct map of TWDEF built over Topographic map

 

4.2    Surface analysis

The DEM which has been used for the various surface analyses has the resolution 30x30 m grid. Contour maps, elevation map, hillshade map have been prepared by using the DEM. Some of the important maps are also presented in this report. The elevation map created by DEM shows that the TWDEF Site has higher elevation at east site and lower at the west and the GPS records also the show the same thing.  Most of the Conifer Instruments are situated at the lower level. This information could be helpful to some extent for the analysis in the future.

 

 

 

 

4.3    Vegetation analysis

Since the vegetation information is very much useful for a hydrological analysis, it is a good idea to put some analysis about the vegetation on the Google Earth map. Being occupied in a small area the TWDEF site could not have the vegetation information from the internet or from any of the national or Federal sources. It is very difficult to get the vegetation information on that scale. GPS could work on delineating the different types of vegetation inside the TWEDF boundary area, but collecting the information about the short vegetation hiding inside the snow was difficult. However based on the knowledge of site visit, photographs, DOQ and especially with the consultation of people regularly working on the field, a vegetation map has been prepared using the GIS tools. Certainly, to some extent, this map would be helpful. The vegetation map shows that more than half of the area is covered by conifer, and the remaining area is almost equally covered by other three vegetation types.

 

 

 

 

5      Exporting Map to Kml

I have just been able to export a single layer from GIS to kml file. Among three features class that I created, I could either export point feature or line feature; or the polygon feature. So I decided to export the point shape file to represent the TWDEF Experimental Forest site in Google Earth and link that site to the available information that I have. It would have been nicer if I had been able to export the entire information map directly to the Google earth map. In this case, we could have seen all information about the TWDEF site as we see the streets and building of the big city in the Google Earth. This is the one way of linking the TWDEF information with the Google Earth. The other way I choosed is to build detail information map in one layer and export it to the kml file.

5.1    Kml

Before exporting file in to Kml, let's talk little bit about kml. KML (Keyhole Markup Language) is an XML-based language for managing three-dimensional geospatial data in the program Google Earth, Google Maps and Google Mobile. (The word Keyhole is an earlier name for the software that became Google Earth. The company that produced it was bought by Google.)

 

The KML file specifies a set of features (placemarks, images, polygons, 3D models, textual descriptions, etc.) for display in Google Earth, Maps and Mobile. Each place always has a longitude and a latitude. Other data can make the view more specific, such as tilt, heading, altitude, which together define a "camera view". KML shares some of the same structural grammar as GML[1]. Some KML information cannot be viewed in Google Maps or Mobile [2]

 

KML files are very often distributed as KMZ files, which are zipped KML files with a .kmz

extension. When a KMZ file is unzipped, a single "doc.kml" is found along with any overlay and icon images referenced in the KML. To export the GIS data into kml file the "Export to KML" tool should be installed which is freely available at http://earth.google.com/download-earth.html.

5.2    Linking Google Earth to the TWDEF Site

Let’s convert the TWDEF site to the kml file from GIS shapefile and save it in the website. In my case I have converted the TWDEF site into kml and saved it as TWDEFSITE.kml. Along with the kml file all the available information (map information, hydrological data etc.) are put in this server so that all these information linked to the Google Earth could be seen from any places in the internet. We can also link the TWDEFSITE to other place like linking it in Google Earth Location of TWDEF SITE. So, by clicking the any of above two links we can open the TWDEF SITE on Google.

 

                                                         

                       The TWDEF location map shown in the Google Earth

 

 

But this link only gives the information about the location of the site. To add the other information just follow the following instruction.

After opening the TWDEF SITE (location point) in the Google Earth, right click on the TWDEF SITE on Google and click the properties, a pop window appears where we can copy and paste the following code.

 

p> <img width =528 height=408

src="http://Ceefs2.cee.usu.edu/giswr/mahat/sitemap.jpg"</p><p></p>

 

Similarly the other information can be linked by using the following codes.

<a  href=http://Ceefs2.cee.usu.edu/giswr/mahat/cablemap.jpg>cable map</a>

<a  href=http://Ceefs2.cee.usu.edu/giswr/mahat/Location.jpg>Location map</a>

<a href="http://ceefs2.cee.usu.edu/giswr/mahat/Weather Instrument.jpg">Weather Station</a>

<a  href=http://Ceefs2.cee.usu.edu/giswr/mahat/Aspen-2.xls>weather data</a>

<a  href=http://Ceefs2.cee.usu.edu/giswr/mahat/vegetationmap.jpg>Vegetation map</a>

<a  href=http://Ceefs2.cee.usu.edu/giswr/mahat/elevationmap.jpg>Elevation map</a>

 

The first two codes links the site map to the TWDEF location in the Google Earth and the remaining codes links the different information to the sitemap in the Google Earth.

 

How to write these codes?

 

To write these codes into the kml file just write click on the kml file and open it in WordPad. We will see a window with the tons of code inside it. It seems a big knowledge of programming is required to understand the code. But we don’t need to understand all these stuff. All we need to do it just to replace the code inside the square brackets in the window by our codes as I have done below. That’s all.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Now the site map, which shows the geographical location, boundary area of site, instrument station location etc., has been linked to Google earth. By clicking on the TWDEF SITE file name on the left side of the Google Earth, we can have all these information of site from the Google Earth. But this must not be the all information, at the bottom of the site map we can see the various links to the TWDEF information e.g. links to the location map, weather data, vegetation information etc. by clicking on that we can have the more information about the data that are put in the server.

 

 

Site map linked to the Google Earth

 

 

 

Suppose, if we click the weather data link on the site map, we can get the weather data information that are recorded by the instrument. Below we can see the linked data recorded by the one of the instrument set in the Aspen vegetation type. The table shows the data recorded in every hour in the month of October in 2006. We can see the data of soil temperature at different level, net radiation, precipitation, relative humidity etc.

 

 

 

Weather data linked to the Google Earth

 

 

 

 

Site Photograph linked to the Google Earth

 

 

The steps above described to link the data with Google earth is one of the two methods. There is another easy way to link the information to the Google Earth. In this method, all we have to do is write click on the TWDEF location point (icon) on the Google Earth and click the properties button. Clicking properties button there appears mini window where we can paste the same codes. These codes connect the information to the Google. The difference between two methods is, in first method we have to click on the file name on the right side of the Google Earth but in the second method we can click on the TWDEF icon on the centre of the Google Earth.  We should not forget to save the file at the end.

 

 

 

5.1    Map building using one feature class and exporting it to kml

As I mentioned earlier in this report, it has been difficult to export a whole map into a kml file. Kml can accept only a layer, a single layer. Since our map is result of mixed features (layers) of points, lines and polygons. So, in my capacity, it has almost been impossible to export the whole map into Google earth. But after a long time, I came up with an idea to build the map putting all information in one layer and export it into Google Earth. Eventually I decided to choose the line shape file and created it to represent all information in map. This feature is converted into shape file, given spatial reference, and a new name called ‘TWDEF MAP’. After that it is exported to the kml file and viewed in the Google Earth. Look at the TWDEF map on Google Earth .

 

 

 

TWDEF Map on Google Earth

 

The resolution of Google Earth on the TWDEF Site area is not so good. So we can not view the Google Earth surface very well. Let’s check out our map on the good resolution area how it does look like. See the map below, we can visualize the open area, forest area, nearby road etc. Probably an experienced person can even distinguish the vegetation type which could be very useful for the hydrological analysis. So without being on the site one can have sense of all topographical, geographical and other information with the help of Google Earth map as if he has been to site many times. See the TWDEF map in high resolution.

 

 

 

The TWDEF Map on high resolution

 

6      Conclusion

I hope that this term project provides the some of the information to the students and researchers interested in the TWDEF site. They can have some knowledge about TWDEF in the Google Earth after this information is permanently put in the server.

 

7      Acknowledgement

I would like  to thank Professor Dr. Tarbotan for his guidance and regular feed back to complete the term project; and also thanks to Kim at my department and Justin for providing the information about the TWDEF site.