1. Aldine Professional Development Workshop: Navasota River Project

2. Purpose
There are both statewide & maps of the 7 counties in which the Navasota flows
Notice the context of the 7 counties in the overall statewide view for each parameter (i.e. precipitation, natural regions, etc.)

3. Geographic Location of Area of Interest
The Navasota River is a tributary of the Brazos River
Its headwaters (its beginning) are near Ft. Parker State Park outside of Groesbeck, Texas
The Navasota River ends when it flows into the Brazos River southeast of Navasota, Texas
It runs through 7 different counties:
Limestone
Robertson
Leon
Madison
Brazos
Grimes
Washington

5. Texas Natural Regions Texas has 11 different natural regions
Only 4 states have more than 10!
On the statewide map, the 7 counties are highlighted with an orange outline
Our 7 county study area encompasses 3 natural regions

8. Precipitation
Precipitation is the amount of water that falls from the sky, which includes rain, snow, hail, & sleet
Texas gets drier i.e. receives less precipitation the farther west you travel
Why is that?

11. Geology of Texas Texas is unique in terms of its geology
You can see rocks that span all of geologic time in different parts of the state
This is very cool for geologists!
Our study area consists mainly of Cenozoic sediments
Sorry, no dinosaur fossils – they came earlier in the Mesozoic

13. Questions: Statewide Maps
What is the relationship between geologic regions & natural regions?
What is the relationship between natural regions & precipitation?
What

14. Area of Interest
Let’s now focus on the 7 counties that comprise our study area
To get your bearings, we’ll first see a map where the towns are marked with different colored dots
Next we’ll see a map with the city limits outlined to gain a better understanding of large these towns are

17. Sampling Locations Let’s now focus on the sampling locations
The following map shows pink dots
Each of which is a sampling location

19. Watershed Map What exactly is a watershed?
“A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.” US EPA
This following map illustrates the Navasota River’s drainage
The United States Environmental Protection Agency “Surf Your Watershed” for the Navasota River:

21. Soil Type Map
GIS Data source:
USDA-NRCS

22. Questions: Relating Statewide to 7 county maps
The precipitation maps show an overall trend that the farther you go from the Gulf of Mexico, the drier it is.
On the statewide map, our counties are split between 2 regions while the 7 county map shows 5 regions.
Why is that?

23. Questions: 7 county study area maps
What is the relationship between natural regions & soil type?
Why are there lakes where the Navasota River flows?
On the soil type map, how can you tell where the river is?
What type of soil is that?
Brazos county’s eastern border is the Navasota river.
Why is there clay along the river, but almost nowhere else in the county?
Where did the clay come from?

24. Turbidity
Turbidity is a measure of the cloudiness or murkiness of water caused by suspended solids, and is an indicator of water quality.
How might the various parameters (precipitation, soil type, etc.) mentioned before affect turbidity in a river?
How would human interference affect the turbidity in a river?

25. About the Maps
All maps (excluding the geologic map) were created in ArcGIS by Jayme M. Foster
GIS data was downloaded for free from Texas Natural Resource Information System (TNRIS), United States Geologic Survey – National Hydrography Dataset (USGS-NHD), & United States Department of Agriculture Natural Resource Conservation Service (USDA-NRCS)
Soil type data is available on the web (no GIS necessary) for free from the USDA Web Soil Survey