Time Series Analysis of Cedar Bayou

Transcription

1 Time Series Analysis of Cedar Bayou Mukesh Subedee James Gibeaut, Diana Del Angel Coastal & Marine Geospa<al Lab Harte Research Ins<tute for Gulf of Mexico Studies John C. Stennis Space Center, MS NGI Student Summit August 1 st, 2013

2 Mukesh Subedee 2 nd year Masters Student, GIS for Development and Environment (GISDE), Clark University MS Computer Science, University of Nebraska- Lincoln Research Interest: GIS and spa<al analysis Remote Sensing Web mapping

3 Dr. James Gibeaut Endowed Chair for Geospa<al Sciences, Harte Research Ins<tute for Gulf of Mexico Studies (HRI), Texas A&M University- Corpus Chris< Director, Coastal & Marine Geospa<al Lab, HRI Associate Professor of Geology, Texas A&M University- Corpus Chris< Exper<se: Coastal Morphodynamics GIS Modeling Effects of Sea level Rise

4 Project Overview Cedar Bayou a natural unstable pass that connects the Gulf of Mexico and Mesquite Bay Passage for migratory organisms Connec<on to Vinson Slough Back- island is rela<vely stable but beach zone is remarkably changed Status: open and closed regularly

5 Research Objec<ve Coast and Harbor Engineering (2005) approach: Dredge a straight Cedar Bayou connec<on to the Gulf, connec<on to Vinson Slough, and reconstruc<on of the submerged ebb shoal with dredged material Will Cedar Bayou stay open? Based on morphologic responses of the pass to past processes What happened in the past? Data Used: Aerial Imagery ( ) River discharge data ( ) Tropical Storm and Hurricane data ( ) Tide data ( ) Wave Hindcast data ( ) LiDAR and Historical Shoreline ( )

6 Tide and Wave Energy Morphology is constantly modified with the complex temporal and spa<al interac<ons of waves, <des, and longshore currents Tide dominated system Wave dominated system

7 Aerial Imagery

8 Throat Width Calcula<on Date Throat Width (meter) Observa=on Significant connec<on between CB and VS, single channel to the Gulf 4/22/ Separate channels from both CB and VS; CB and VS connected 9/1/ Channel move westward with CB and VS merged as a single channel to the Gulf 2/1/ Small channel between CB and VS, channel has further shijed towards VS 11/11/1979 CLOSED Closed by sand berm to prevent pollu<on from Ixtoc I oil spill (June 1979) 2/12/ No more sand berm, very small opening to the Gulf; small connec<on between CB and VS 11/5/ CB and VS s<ll connected but even smaller channel from VS than 1981, the island on the mouth of VS has increased and the pass has moved slightly westward than /6/ Increasing seashore mouth width, slightly wider channel to the Gulf than /6/ Dredged in June 1988 that shijed the pass toward CB and completely closed along VS, very small connec<on between CB and VS 12/10/ Throat width reduces even more with barely connec<on between CB and VS 3/18/ Almost no connec<on between CB and VS 2/7/2002 CLOSED Closed, although 300,000 cu yards dredged in 1995 and hurricane in Narrow channel and low water level, hurricane Claudeke in 2003 could have opened the channel Could be the result of hurricane Emily in 2005 as it looks like high <de event 4/28/2008 CLOSED Drainage channel can be seen 1/8/2009 CLOSED No channel at all 4/28/2010 CLOSED No channel

9 Tropical Storm and Hurricane Wide open to marginally open 1979 Marginally opened Closed Dredged

10 50000 Surface Water Discharge Mission River Daily Discharge Present (H 3 /s) Discharge /01/38 12/02/39 11/01/41 10/02/43 09/01/45 08/02/47 07/02/49 06/02/51 05/02/53 04/02/55 03/02/57 01/31/59 12/31/60 12/01/62 10/31/64 10/01/66 08/31/68 08/01/70 07/01/72 06/01/74 05/01/76 04/01/78 03/01/80 01/30/82 12/31/83 11/30/85 10/31/87 09/30/89 08/31/91 07/31/93 07/01/95 05/31/97 05/01/99 03/31/01 03/01/03 01/29/05 12/30/06 11/29/08 10/30/10 09/29/ Copano Creek Daily Discharge 1970 Present (H 3 /s) Discharge /24/69 3/8/71 7/20/72 12/2/73 4/16/75 8/28/76 1/10/78 5/25/79 10/6/80 2/18/82 7/3/83 11/14/84 3/29/86 8/11/87 12/23/88 5/7/90 9/19/91 1/31/93 6/15/94 10/28/95 3/11/97 7/24/98 12/6/99 4/19/01 9/1/02 1/14/04 5/28/05 10/10/06 2/22/08 7/6/09 11/18/10 4/1/12 8/14/13

11 Tide Effect Hourly observed water level: Maximum: m Minimum: m Datum: MSL

12 Tide Effect Gulf of Mexico seafront <de is described by hr semidiurnal and hr diurnal <de, and 13.6 day fortnightly cycle and semi- annual mode of <de. The slower, longer- period varia<ons (fortnightly and semi- annual <des) are likely to pass through the inlets but the shorter- period varia<ons are significantly Range of <de varies over filtered a out. period of 2 weeks Cyclic smoothed annual varia<on, exhibit 2 maxima (Fall & Spring) and 2 minima (Winter & Summer) When range is maximal: hr periodicity When range is minimal: hr periodicity The <de in the Gulf loses most of its energy as it passes through the inlets. S<lling well effect: inlet acts as a small port that connects a large oscilla<ng chamber of water to smaller chamber in co- oscilla<on.

13 Wave Hindcast Average wave height: : m : m No significant difference in wave height over <me

14 Shoreline Change Shoreline Change between 1860 and 2012 Shoreline Movement (m) 120 Landward Movement 0 Cedar Bayou Channel Seaward Movement

15 Conclusion For Cedar Bayou to remain open: Need of sufficient channel flow to remove sediments deposited in the channel by longshore drij From our observa<ons, The s<lling well effect reduces <dal energy when passing through the channel The fresh water discharge into the bay is not able to maintain the opening The occurrence of large hurricanes and dredging ac<vi<es have historically played a major role in the opening/closing of Cedar Bayou However, varia<ons in non- storm <de and wave energy are not strongly related to the opening/closing of Cedar Bayou

16 Conclusion Concerns regarding the project plan: Vinson Slough is only dredged to connect Cedar Bayou channel which would only connect Aransas Bay during high <de The claim that the ebb delta was present cannot be verified Need of jeqes and con<nuous maintenance dredging Environmental impacts

17 Use of Metadata It helps to find data, and also helps to answer many ques<ons about the dataset. Created metadata in progress NCDDC MERMAid: Slow, slow, slow!!

18 Skills Learned and Challenges Skills Learned Data acquisi<on LiDAR data usage on Shoreline Extrac<on Challenges Lack of Metadata Overwhelming amount of data Terrestrial laser scanning Real Time Kinema<c (RTK) data collec<on

19 Looking Back: Value of the An excep<onal opportunity Understanding barrier Island forma<on to other process informa<on Field observa<ons and data collec<on methods Diverse research group Internship

20 References Ward, George H. "Processes and trends of circula<on within the Corpus Chris< Bay na<onal estuary program study area." (1997). Ward, George H. "A <me line of Cedar Bayou." (2010). Shepsis, Vladimir, and Joshua Carter. "Cedar Bayou Inlet dynamics and engineering." Proc. Coastal Sediments 07 (2007). Wilkinson, Bruce H. "Matagorda Island, Texas: the evolu<on of a Gulf Coast barrier complex." Geological Society of America Bulle<n 86, no. 7 (1975): MORTON, ROBERTA, CG GROAT, and ACTING DIRECTOR. "Shoreline Changes on Matagorda Peninsula (Brown Cedar Cut To Pass Cavallo) An Analysis of Historical Changes of the Texas Gulf Shoreline." (1976). White, William, Calnan, Thomas, Tremblay, Thomas, Waldinger, and Rachel "Status and trends of estuarine marshes on barrier islands of the Central and Upper Texas Gulf Coast." 14 th Biennial Coastal Zone Conference (2005). Bermudez, Hugo E., Shepsis, Vladimir, and Carter, Josh. Restora<on of Cedar Bayou and Vinson Slough Phase 1. Coast & Harbor Engineering (2005).

21 Acknowledgements Dr. James Gibeaut, Mentor, Coastal & Marine Geospa<al Lab (CMGL), HRI Diana Del Angel, Costal Geoscien<st, CMGL JoAnn Moody, Internship Coordinator, NOAA- NGI Diversity Internship NOAA- NGI Diversity Internship Program CMGL Crew

22 Thank You!