Houston Ship Channel
About Houston Ship Channel |
Storm Surge History |
|
The Houston Ship Channel is part of the Port of Houston which is one of the largest ports in the US and serves the metropolitan city of Houston. It was dredged in the 19th century to accommodate larger ships and after the 1900 Galveston Hurricane this inland port became the leading port in Texas.
|
Infographics
This histogram provides the maximum water levels of the 59 recorded storm tide events at Pensacola since 1890. The events are ordered from the highest water level (Rank = 1) to lowest (Rank = 59). These events are not placed in chronological order. All data are detrended to remove the influence of relative sea level rise, so they represent water levels above an Annually-Adjusted Mean Sea Level (AAMSL).
This time series provides maximum water levels from 59 recorded storm tide events at Pensacola since 1890. These events are ordered chronologically from oldest (left) to newest (right). The numerous low-magnitude events in recent decades are influenced by both climate and data availability. All data are converted to NAVD88 datum, however, the data are intentionally not detrended, so the influence of relative sea level rise is included. SLR trend taken from NOAA tide gauge at Pensacola.
Graph of the four most severe storm surge events at Pensacola, as well as the amount of water (6.50 feet) needed for a 2019 storm to reach FEMA's BFE, considering the annual Mean Sea Level (MSL).
Statistics/ Return Period
Storm tide return levels graph for Pensacola. This graph uses a log-linear regression plot based on observed data from 1890-2018 (129 years). The graph uses the Weiboll Plotting Position Formula, whereby the probability of an extreme event occurring is Rank/ (n+1), where "n" is the number of years in the data record. These data have been detrended to remove the influence of sea level rise and all data are plotted relative to Annually Adjusted Mean Sea Level (AAMSL). The regression line represents the line of best fit and indicates return levels (y-axis) for various return periods (x-axis).
Return Period |
Storm Tide Level (Feet above AAMSL) |
500-year |
12.63 |
200-year |
10.77 |
100-year |
9.37 |
50-year |
7.97 |
25-year |
6.57 |
10-year |
4.71 |
Extreme water levels above Annually-Adjusted Mean Sea Level (AAMSL) with long-term sea level rise removed. The correct way to interpret these levels is as follows: Based on a log-linear regression of observed data from 1890-2018, storm tide levels at Pensacola should equal or exceed 9.37 ft every 100 years, on average, above the annually-adjusted MSL. According to the regression equation, the 1906 Hurricane's 9.97-ft storm tide was a 135-year event and Hurricane Ivan's (2004) 9.71-foot storm tide was a 118-year event.
Sea Level Rise and Future Extreme Water Levels
Long-term SLR graph for Pensacola, Florida. The long-term rate of SLR is 0.76 feet/century.
Source: https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8779770.
Source: https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8779770.
Graph of SLR scenarios for Pensacola, Florida, from NOAA et al. (2017). The CorpsClimate web-tool developed by the U.S. Army Corps of Engineers provided this graph. Data revised July 18, 2017. Available on the Web at: http://corpsclimate.us/ccaceslcurves.cfm.
Table of SLR scenarios for Pensacola, Florida, from CorpsClimate web-tool developed by U.S. Army Corps of Engineers.
Data from this table revised July 18, 2017. Available on the Web at: http://corpsclimate.us/ccaceslcurves.cfm.
Data from this table revised July 18, 2017. Available on the Web at: http://corpsclimate.us/ccaceslcurves.cfm.
Year |
100-Year Flood Intermediate SLR |
100-Year Flood Intermediate-High SLR |
2000 |
9.73 |
9.73 |
2020 |
10.19 |
10.32 |
2040 |
10.71 |
11.04 |
2060 |
11.44 |
12.19 |
2080 |
12.32 |
13.63 |
2100 |
13.37 |
15.57 |
This table provides future 100-year water levels above NAVD88 datum. These numbers are calculated by adding four values: 1) The 100-year storm tide listed in the Statistics/ Return Period section- measured in feet above AAMSL; 2) An adjustment from MSL to NAVD88, which involved adding 0.30 ft to all water levels for Pensacola; 3) A conversion from water levels in 1992 (the mean year of the Present Epoch for Pensacola tide gauge data) to 2000, based on a long-term SLR rate of 0.76 ft/ century, which meant adding 0.06 ft; 4) Sea-Level rise projections from NOAA (2017), shown in the Future SLR Graph and Table above.
Extreme water level predictions for the 100-year coastal flood event at Pensacola. All of these projected values pertain to water levels for the "100-year storm" (1% annual chance) in the future. This analysis assumes stationarity in the flood level above the Annually Adjusted Mean Sea Level (AAMSL), so the increase in values are completely due to sea-level rise. According to this graph, there is a 1% chance that water levels will equal or exceed 12.19 feet in the year 2060, according to the intermediate-high SLR projection. These values do not account for wave action in velocity zones.
Data Sources
|
Tide Gauge Site: Morgans Point, Barbours Cut, TX 8770613
Operation: National Ocean Service (NOS) Coordinates: Lat: 29.68167 Lon: -94.985 6-Min Water Level Data December 31, 1995 - August 27, 1996 January 5, 1997 - Present Hourly Water Level Data March 17, 1993 - August 27, 1996 January 5, 1997 - Present The NOAA tide gauge at Morgans Point provides verified hourly data since 1993 and verified 6-min data since 1995. |
|
Houston Ship Channel's high water marks come from a small geographic area near the city's waterfront. This tightly-clustered area provides a highly homogenous dataset that represents flood risk on the inside of Galveston Bay. The data-selection circle includes the waterfront of Laporte and Baytown, as well as the NOAA tide gauge at Morgan's Point. This tide gauge provides a center point for the circle and is located at the following coordinates: lat: 29.681667, lon: -94.985.
Missing Data
We have identified five hurricanes/ tropical storms since 1900 that may have generated storm tides exceeding 4 ft (1.22 m) near Houston Ship Channel area, but a literature review does not yet provide data. These maps are provided by Unisys Corporation
Storm Surge Multimedia
Note: All of these pics/ video were taken from HSC/LaPorte area
Hurricane Harvey (2017)
Hurricane Ike (2008)
Hurricane Rita (2005)
Hurricane Alicia (1983)
Brownwood subdivision in Baytown was a beautiful place to live, but its vulnerability to coastal flooding was its downfall. Sea-level rise and subsidence enabled salt-water flooding to occur with increasing frequency through the 1960s and 1970s. In 1983, Hurricane Alicia produced a large surge that destroyed much of the area, causing hundreds of homes to be abandoned. Note: Around 1:30-1:40 into the video a man says he moved into a home that he later learned flooded in Carla in 1961.
Hurricane Carla (1961)
Galveston Hurricane (1915)
