Hurricane Ike Impacts On Southeast Texas Wildland Fuels October 16 th 2008

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1 Hurricane Ike Impacts On Southeast Texas Wildland Fuels October 16 th 2008 Hurricane Ike made landfall near Galveston Texas as a category 2 hurricane during the early morning hours of September 13 th and tracked across the forestlands of east Texas before exiting the state near Texarkana during the evening hours of September 13 th as a tropical storm. The brief time that Ike spent in Texas will produce lasting impacts for the wildland firefighting community in portions of southeast Texas due to the results of wind damage to the timberlands of this region. The Southern Area Hurricane Ike assessment team produced the map below which shows the surface wind fields and track of Ike. The significant storm damage as it relates to wildland fire in timber fuel types seems to closely follow the surface wind bands that exceed 80mph. This would include portions of Liberty, Hardin, Polk, San Jacinto, and Montgomery Counties where timberland fuels can be found. Storm damage can be found in the timberlands of many east Texas counties but the significant damage that is discussed here is limited to the counties listed above.

2 The Texas Forest Service Forest Inventory team produced the timber damage assessment map shown here. This map was built using windspeed observations, aerial flights and over 275 ground plots. Below are the Inventory team s definitions for each timber damage category. 1. Scattered Light: Occasional downed tree or broken top; mainly in open areas such as pastures and residential areas; along roadways and edges of open areas such as ponds, lakes, pastures and cutovers. Damage is very scattered and barely noticeable from air. Slight possibility of a small patch of downed trees. Estimate less than 5% damage on all stand types in this area. 2. Light: Occasional small patch of scattered downed trees and broken tops occurring mainly in open canopy stands such as recently thinned timber and or open stands (low BA) of more mature timber. Noticeable damage but not significant: still very scattered. Estimate possibly 5%- 10% damage on stand types in this area. 3. Moderate: Widespread, noticeable damage but still patchy occurring in a scattered, sporadic pattern. Again occurring mainly in open canopy stands such as recently thinned timber and or open stands (low BA) of more mature timber. Occasional small to medium size areas of scattered downed trees and broken tops but still no total losses of stands in this area. Possible 10% - 50% damage on open canopy stands in this area; less than 25% damage on all other stands. SMZ s in this zone sustained significant damage, possibly up to 50%.

3 There are two modifications to the wildland timber fuels in southeast Texas that will have a significant impact on the occurrence frequency, intensity, and resistance to containment/control of wildland fires in this region for the next 12 months. The first modification is the tree blow down that has occurred in exposed or open stands of timber where the wind was able to penetrate and knock down the entire tree or break off at least the upper ½ of the tree. The heavy blow-down slows the construction of containment lines around the fire. It often takes multiple tractor plows to effectively construct containment line where there is heavy blow-down. Direct line construction is very difficult and avoiding twists and turns in the containment line is almost impossible. The result is that more resources are committed for a longer time for each fire. The downed canopies that now hold cured leaves or needles are sources for flare-ups and torching that will produce short range spotting. This short range spotting will cause loss of containment thus increasing the difficulty of control and increasing the amount of time and resources committed to each fire.

4 The second modification is the amount of debris that has been deposited on the forest floor and mixed in with the brush understory canopy. A month has passed since Ike s landfall. The leaf and needle debris has cured and now covers the forest floor like a red carpet. This Ike debris has increased the fuel bed depth, provided fuel continuity across the surface, increased the drying efficiency of the litter layer by laying down a loosely stacked layer of 1-hour dead fuel and increased the available ladder fuel by mixing in dead material with the understory brush canopies. Above are two pictures showing the Ike debris in thinned pine stands. The picture on the left above shows the Ike debris found in a mature pine plantation with a 4-6 foot brush understory. The picture on the right above shows the increased dead needle layer in a young, closed canopy pine plantation.

5 Debris piles will be a source of accidental ignitions. Unfortunately, most of the debris piles are located in and around rural home sites. The storm surge and associated saltwater intrusion from Ike carried much further inland than with previous storms. There is a possibility that our resources will be requested for fires occurring in non-traditional response areas due to the debris deposited by the storm surge and the vegetation kill from saltwater. The fuel types across the landscape of southeast Texas present many challenges to wildland firefighters and fire managers in any year that fuels dry enough to support ignition and spread of wildland fire. We saw the driest summer in recent history in 2000 which resulted in one of the most severe fire seasons for southeast Texas. Fuel dryness will certainly drive the severity of the fire activity in southeast Texas for the next 12 months. But it is my opinion that the wildland fuel modifications brought by Ike will increase the resultant fire severity by one adjective level on our fuel dryness index and fire danger rating. For example, if the adjective fire danger rating is forecasted as moderate for Liberty County, I believe firefighters will experience difficulty of control during suppression operations that they would normally associate with an adjective fire danger rating of high. We have already seen fire activity occurring with weather

6 conditions that would normally produce little if any activity. I think this can be attributed to the loosely stacked debris layer of 1-hour dead fuel that covers the forest floor. Because of the fuel modifications brought by Ike, it now takes less fuel drying and below normal fire weather thresholds to produce problematic fire behavior. To summarize: The Ike wildland fire impact area includes parts of Liberty, Hardin, Polk, San Jacinto, and Montgomery Counties which incurred the most significant damage to wildland timber fuels. The two fuel modifications that will impact fire suppression activities are the tree blow-down in open, exposed stands and the loosely stacked cured debris layer deposited on the forest floor. Difficulty of control during fire suppression operations will rank one adjective rating higher than indicated by NFDRS indices such as fire danger rating and fuel dryness. Fuel modifications will increase containment/control times and increase the number of resources required for each fire response. Brad Smith TFS Fire Analyst