3 Land Area Change in Coastal Louisiana from 1932 to 2010 By Brady R. Couvillion, John A. Barras, Gregory D. Steyer, William Sleavin, Michelle Fischer, Holly Beck, Nadine Trahan, Brad Griffin, and David Heckman Pamphlet to accompany Scientific Investigations Map 3164 U.S. Department of the Interior U.S. Geological Survey i Land Area Change in Coastal Louisiana from 1932 to 2010 Pamphlet to accompany Scientific Investigations Map 3164 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2011 This and other USGS information products are available at http://store.usgs.gov/ U.S. Geological Survey Box 25286, Denver Federal Center Denver, CO 80225 To learn about the USGS and its information products visit http://www.usgs.gov/ 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Couvillion, B.R.; Barras, J.A.; Steyer, G.D.; Sleavin, William; Fischer, Michelle; Beck, Holly; Trahan, Nadine; Griffin, Brad; and Heckman, David, 2011, Land area change in coastal Louisiana from 1932 to 2010: U.S. Geological Survey Scientific Investigations Map 3164, scale 1:265,000, 12 p. pamphlet. iii Contents Abstract ..........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Methodology ..................................................................................................................................................1 Land Area Changes ......................................................................................................................................4 Land Change Trends .....................................................................................................................................5 Discussion and Conclusions .......................................................................................................................5 References ...................................................................................................................................................12 Figures 1. Map of the study area in coastal Louisiana ............................................................................3 2. Land area in coastal Louisiana, 1932 to 2010 ...........................................................................4 3. Persistent land loss and land gain in coastal Louisiana by period and by basin for 1932–2010 ..........................................................................................................8 4. Persistent land loss and land gain coastwide across Louisiana by period for 1932–2010 ....................................................................................................................9 5. Linear regressions of land area change trends coastwide across Louisiana, 1985–2010 .................................................................................................................10 6. Linear regressions of land area change trends in coastal Louisiana by hydrologic basin, 1985–2010 ...................................................................................................11 Tables 1. Land area in coastal Louisiana by basin, 1932–2010 ..............................................................2 2. Water levels at selected gages on the date of acquisition for imagery used in the land area estimates ................................................................................................5 3. Persistent land loss and land gain in coastal Louisiana by basin, 1932–2010 ...................6 EXPLANATION EXPLANATION 1932–56 land gain1 1932–561932–56 land landloss 2gain1 Background1932–56 imagery land loss 2 Background imagery EXPLANATION (inside modified Coastal Zone Boundary)(inside modified Coastal Zone Boundary) 1,4 2,4 1,4 EXPLANATION2,4 1932–56 land gain1 1932–561956–73 land land loss gain2 Background1956–731956–73 imagery land landloss gain 1956–73 land loss 5 1 5 2 Background imagery 1,4 (inside modified Coastal Zone2,4 Boundary)1,4 Developed 2,41932–56 land gainDeveloped 1932–56 land loss 1956–73 land gain1,4 1956–731973–75 land land loss gain2,4 1973–751973–75 land landloss gain 1973–75 land loss (inside modified Coastal Zone Boundary) 5 1,4 5 2,4 1,4 5 2,4 1,4 Uplands 2,41956–73 land gainUplands 1956–73 land loss 1,4 1975–77 land gain2,4 Developed1975–771975–77 land landloss gain 1975–77 land loss 1973–75 land gain 1973–75 land loss 5 5 1,4 5 2,4 Developed 1,4 5 2,4 1,4 Persistent forested wetland2,41973–75 land gainPersistent forested1973–75 wetland land loss 1,4 1977–85 land gain2,4 Uplands1977–851977–85 land landloss gain 1977–85 land loss 1975–77 land gain 1975–77 land loss 5 5 1,4 5 2,4 Uplands 1 2 1 5 Persistent wetland 21975–77 land gainPersistent wetland1975–77 land loss 1977–85 land gain1,4 1977–851985–88 land land loss gain2,4 Persistent1985–881985–88 forested land landloss wetland gain 1985–88 land loss 1,4 2,4 Persistent forested wetland5 1 5 2 1 Persistent water 21977–85 land gainPersistent water 1977–85 land loss 1 1988–90 land gain2 Persistent1988–901988–90 wetland land landloss gain 1988–90 land loss 1985–88 land gain 1985–88 land loss 5 1 2 Persistent wetland 1990–95 land gain1 1990–95 land 2gain1 21985–88 land gain 1985–88 land loss 1988–90 land gain1 1988–90 land loss2 Persistent1990–95 water land loss Background1990–95 imagery land loss Background imagery 1 2 Persistent water 1 2 1 21988–90 land gain 1988–90 land loss EXPLANATION 1 EXPLANATION1995–98 land gain 1995–98 land gain 1995–98 land loss (outside modified Coastal Zone Boundary) 1990–95 land gain 1990–95 land loss2 1995–98EXPLANATION land loss (outside modified Coastal Zone Boundary) Background imagery 1 5 2 1 2 1 1 Background imagery 2 2 1 Background imagery5 21990–95 land gain 1 1998–99 land gain 1998–99 land gain Developed Developed 1990–95 land loss 1995–981932–56 land land gain gain 1995–981932–561932–56 land land loss landloss2 gain (outside modified1998–991932–561932–56 landCoastal land loss land loss Zone gain Boundary1 ) 1998–991932–56 land land loss loss2 Background imagery Background imagery (inside modified Coastal Zone Boundary)(inside modified Coastal Zone Boundary) 1 2 1,4 2,4 1,41 2,42 1 5 1995–982 land(inside gain modified5 Coastal1995–98 Zone landBoundary) loss (outside modified Coastal Zone Boundary) 1 1999–2002 land gain 1999–20025 land gain Uplands Uplands 1998–991956–73 land land gain gain 1998–991956–731956–73 land land loss landloss2 gain Developed1999–20021956–731956–73 land land land loss loss gain1,4 1999–20021956–73 land land loss loss2,4 1 2 5 1 5 1 5 5 5 Developed 1,4 2,4 1,4 Developed5 2 2,4 Developed 2 1998–99 land gainPersistent forested5 1998–99 wetland land loss 1973–75 land gain 1 1973–752002–41973–75 land land landloss gain gain2 Uplands2002–41973–752002–4 land land landloss loss gain 1,4 Persistent2002–4 forested land loss wetland2,4 Developed 1999–2002 land gain 1999–2002 land loss 1973–75 land gain 1973–75 land loss 5 5 5 1 2 1,4 2,4 1 1,4 2 2,4 1 5 2 1999–2002 land gain 5 Uplands 1 2004–6 land gain Uplands2004–62004–6 land landloss gain 5 PersistentUplands2004–6 wetland land loss Persistent5 wetland1999–2002 land loss 2002–41975–77 land land gain gain 1975–771975–77 land landloss2 gain Persistent1975–77 forested land loss wetland1,4 2,4 Uplands 2002–4 land loss 1975–77 land gain 1975–77 land loss 1 5 1 2 1 5 2 5 2 Persistent forested wetland 1 1,4 2006–8 land gain2,4 1,4 Persistent2006–82006–8 land forested landloss5 gainwetland2,4 PersistentPersistent2006–8 water landforested loss wetland2002–4 land gainPersistent water 2002–4 land5 loss 2004–61977–85 land land gain gain 2004–61977–851977–85 land land loss landloss2 gain Persistent1977–85 wetland land loss 1,4 2,4 Persistent forested wetland 1977–85 land gain 1977–85 land loss 1 2 5 1,3 52,3 1,3 5 2,32004–6 land gain 2004–6 land loss Persistent wetland 1 1 2008–9 land gain2 2 1 Persistent2008–92008–9 landwetland landloss gain2 Persistent2008–9 wetlandland loss 5 2006–81985–88 land land gain gain 1985–881985–88 land landloss gain Persistent1985–88 water land loss 1 2 Persistent wetland 2006–8 land loss 1985–88 land gain 1985–88 land loss 1 1,3 2,3 1,3 2006–82,3 land gain 2006–8 land loss2 Persistent water 1,3 1 2009–10 new land2 1 Persistent2009–102009–10 water new newwater land2 BasinPersistent2009–10 boundary water new water Basin boundary 2008–91988–90 land land gain gain 2008–91988–901988–90 land land loss landloss2,3 gain 1988–90 land loss 1 2 Persistent water 1988–90 land gain 1988–90 land loss 1,3 2,3 1Gain is determined by the last date a particular pixel transitioned from water to land1Gain and is remained determined land by throughout the last date the a period particular of observation. pixel transitioned from water to land and remained land throughout the period2008–9 of observation. land gain 1,31 2 2,3 1 2 2008–9 land loss 2009–101990–95 new land land gain 2 2009–101990–951990–95 new land water landloss gain Basin2Loss1990–95 is boundary determined by