Tag Archive for: Houston Advanced Research Center

How fast are we replacing forests and wetlands with concrete?

We all know that concrete is impervious and that it increases both the amount and speed of runoff, which contributes to flooding. But how fast are we losing wetlands, forest and prairie to development? Does anyone really know? The folks at the Houston Advanced Research Center (HARC) in The Woodlands have attempted to quantify the answer.

You can see their findings in a presentation called Houston-Galveston & Southeast Texas Land Cover Change. This interactive presentation/tool allows you to zoom into individual watersheds or examine data regionally.

“Green infrastructure such as forests, prairies, and wetlands,” they say, “can capture and slow the release of rainfall. When preserved and integrated with engineered retention systems, this can help alleviate runoff issues.”

Concrete Details from Montgomery and Northern Harris Counties

The presentation consists of a series of interactive maps that lets you explore the world immediately around you. It begins with measurements of the extent of “imperviousness.” Then it goes into a series of maps that show the rate of change in the amount of upland forests, wetlands and developed areas over the last 20 years throughout the region and state. Below, some examples from the Lake Houston/Montgomery County Area.

In 2001, the Lake Houston Area was 10-20% impervious. Most of Montgomery County was less than 10. Compare this to…

By 2011, imperviousness in the Lake Houston area had not changed much. But look at the large finger extending up into Montgomery County along the San Jacinto West Fork.

This map shows the loss of wetlands between 1996 and 2010. The deep orange color shows the greatest loss of wetlands. Note the dramatic changes upstream of Lake Houston along the West Fork, Spring Creek and Cypress Creek. The East Fork, Peach Creek and Caney Creek watersheds show loss also.

This map shows loss of forests upstream of Lake Houston between 1996 and 2010. Again, the deep orange color shows the greatest loss. Note the similar pattern to loss of wetlands. According to the US Forest Service, a single large tree can soak up 100 gallons of water a day.

HARC ends with a discussion of future development by showing the Montgomery County Thoroughfare Plan (circa 2016) and how it would impact important eco-systems.

The Montgomery County Thoroughfare Plan as of 2016. The orange areas show planned additions. Note the density of additions in the Spring, Porter, New Caney and Splendora areas.

Montgomery County is the second fastest growing county in the region (3% per year) after Fort Bend County (3.1%).

Unchecked Upstream Development can Cause Downstream Flooding

HARC’s data underscores the need for a regional approach to watershed development and the strict enforcement of flood plain regulations. We need look no farther than the west side of Houston, in areas like Meyerland and Bellaire, to see the impact of encroachment on flood plains.

Posted by Bob Rehak on November 11, 2018

439 Days since Hurricane Harvey



Houston Advanced Research Center Pre-/Post Harvey Mapping Tool

A novel GIS mapping tool developed by the Houston Advanced Research Center (HARC) now makes it easy to see how Hurricane Harvey changed the San Jacinto River.

This novel, 4-pane mapping tool allows users to view pre- and post- Hurricane Harvey images in natural and infrared colors.

The four panels make it very helpful when looking at how river and stream channels changed before and after the storm. Zooming and scrolling in the upper-left pane automatically zooms and scrolls the other panes to match, so all four images remain in perfect register.

Hurricane Harvey brought more than 50 inches of rain in a single week to a region that normally receives 45 inches of rainfall in a year. This amount of rainfall in such a short period of time brought widespread flooding and destruction of property throughout the Houston-Galveston region. This mapping tool lets you easily see it.

The natural color images make it easy to see changes in the river. The infrared images make it easy to see changes in vegetation. This link provides an overview of how to interpret the colors in infrared images.

Seven Areas of Interest

Here are several striking images that jumped out at me as I scrolled around the Humble/Kingwood Area.

Note how the channel under the US59 Bridge seems to have shifted north.

Note the massive sand deposition along the banks of the river between 59 and Forest Cove.

Note the huge extension of the sand bar that blocked the drainage ditch coming out of River Grove Park.

Note the massive enlargement of the mouth bar between Kings Point and Atascocita Point.

Note the enlargement of the sand bars blocking the East Fork at East End Park.

Note the destruction in Forest Cove along Marina Drive.

Note the blockage in the river south of Kingwood County Club that altered the entire channel.

Explore for Yourself

Explore other areas, perhaps closer to your home, by visiting this link: Effects of Hurricane Harvey: Pre & Post Regional Aerial Imagery.

The before imagery has resolution down to one meter. The after imagery has resolution down to one foot.  What does that mean? If you left a shoe in your driveway when the plane was flying over, you could see it in the image.

My only wish is that the site had a ruler tool for measuring distance. But overall, this is an outstanding and valuable tool.

HARC is a research hub providing independent analysis on energy, air, and water issues to people seeking scientific answers. They are focused on “building a sustainable future that helps people thrive and nature flourish.”

Posted on November 10, 2018

438 Days after Hurricane Harvey