{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T14:09:52Z","timestamp":1777126192714,"version":"3.51.4"},"reference-count":50,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2020,7,22]],"date-time":"2020-07-22T00:00:00Z","timestamp":1595376000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Coastal wetlands are productive ecosystems driven by highly dynamic hydrological processes such as tides and river discharge, which operate at daily to seasonal timescales, respectively. The scientific community has been calling for landscape-scale measurements of hydrological variables that could help understand the flow of water and transport of sediment across coastal wetlands. While in situ water level gauge data have enabled significant advances, they are limited in coverage and largely unavailable in many parts of the world. In preparation for the NISAR mission, we investigate the use of spaceborne Interferometric Synthetic Aperture Radar (InSAR) observations of phase and coherence at L-band for landscape-scale monitoring of water level change and vegetation cover in coastal wetlands across seasons. We use L-band SAR images acquired by ALOS\/PALSAR from 2007 to 2011 to study the impact of seasonal changes in vegetation cover on InSAR sensitivity to water level change in the wetlands of the Atchafalaya basin located in coastal Louisiana, USA. Seasonal variations are observed in the interferometric coherence (   \u03b3   ) time-series over wetlands, with higher coherence during the winter and lower coherence during the summer. We show with InSAR time-series that coherence is inversely correlated with Normalized Difference Vegetation Index (NDVI). Our analysis of polarimetric scattering mechanisms demonstrates that double-bounce is the dominant mechanism in swamps while its weakness in marshes hinders estimation of water level changes. In swamps, water level change maps derived from InSAR are highly correlated (r2 = 0.83) with in situ data from the Coastwide Reference Monitoring System (CRMS). From October to December, we observed that the water level may be below wetland elevation and thus not inundating wetlands significantly. Our analysis shows that water level can only be retrieved when both images used for InSAR are acquired when wetlands are inundated. The L-band derived-maps of water level change show large scale gradients originating from the Gulf Intracoastal Waterway rather than the main delta trunk channel, confirming its significant role as a source of hydrologic connectivity across these coastal wetlands. These results indicate that NISAR, with its InSAR observations every 12 days, will provide the measurements necessary to reveal large scale hydrodynamic processes that occur in swamps across seasons.<\/jats:p>","DOI":"10.3390\/rs12152351","type":"journal-article","created":{"date-parts":[[2020,7,23]],"date-time":"2020-07-23T11:26:01Z","timestamp":1595503561000},"page":"2351","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Monitoring Water Level Change and Seasonal Vegetation Change in the Coastal Wetlands of Louisiana Using L-Band Time-Series"],"prefix":"10.3390","volume":"12","author":[{"given":"Tien-Hao","family":"Liao","sequence":"first","affiliation":[{"name":"Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9442-4562","authenticated-orcid":false,"given":"Marc","family":"Simard","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4298-4127","authenticated-orcid":false,"given":"Michael","family":"Denbina","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael P.","family":"Lamb","sequence":"additional","affiliation":[{"name":"Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,22]]},"reference":[{"key":"ref_1","unstructured":"United States, Environmental Protection Agency, Office of Wetlands and Watersheds (1995). America\u2019s Wetlands: Our Vital Link between Land and Water."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1038\/ngeo629","article-title":"Sinking deltas due to human activities","volume":"2","author":"Syvitski","year":"2009","journal-title":"Nat. Geosci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1038\/516031a","article-title":"Climate change: Protect the world\u2019s deltas","volume":"516","author":"Giosan","year":"2014","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1007\/s11625-016-0374-4","article-title":"Co-evolution of wetland landscapes, flooding, and human settlement in the Mississippi River Delta Plain","volume":"11","author":"Twilley","year":"2016","journal-title":"Sustain. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1007\/s11625-008-0043-3","article-title":"Deltas at risk","volume":"3","author":"Syvitski","year":"2008","journal-title":"Sustain. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Couvillion, B.R., Barras, J.A., Steyer, G.D., Sleavin, W., Fischer, M., Beck, H., Trahan, N., Griffin, B., and Heckman, D. (2011). Land Area Change in Coastal Louisiana from 1932 to 2010, Scientific Investigations Map 3164, scale 1:265,000.","DOI":"10.3133\/sim3164"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/s13157-016-0744-9","article-title":"Spatial Configuration Trends in Coastal Louisiana from 1985 to 2010","volume":"36","author":"Couvillion","year":"2016","journal-title":"Wetlands"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Sasser, C.E., Visser, J., Mouton, E., Linscombe, J., and Hartley, S.B. (2014). Vegetation Types in Coastal Louisiana in 2013, Scientific Investigations Map 3290, 1 sheet, scale 1:550,000.","DOI":"10.3133\/sim3290"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1023\/A:1021368722681","article-title":"A Proposed Coast-Wide Reference Monitoring System for Evaluating Wetland Restoration Trajectories in Louisiana","volume":"81","author":"Steyer","year":"2003","journal-title":"Environ. Monit. Assess."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.ecss.2019.04.020","article-title":"Drivers and impacts of water level fluctuations in the Mississippi River delta: Implications for delta restoration","volume":"224","author":"Hiatt","year":"2019","journal-title":"Estuar. Coast. Shelf Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2167","DOI":"10.1109\/TGRS.2008.917271","article-title":"Radarsat-1 and ERS InSAR Analysis Over Southeastern Coastal Louisiana: Implications for Mapping Water-Level Changes Beneath Swamp Forests","volume":"46","author":"Lu","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.1080\/01431169008955095","article-title":"Radar detection of flooding beneath the forest canopy: A review","volume":"11","author":"Hess","year":"1990","journal-title":"Int. J. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Cloude, S.R. (2010). Polarisation: Applications in Remote Sensing, Oxford U. Press.","DOI":"10.1093\/acprof:oso\/9780199569731.001.0001"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1016\/j.rse.2007.06.008","article-title":"Space-based detection of wetlands\u2019 surface water level changes from L-band SAR interferometry","volume":"112","author":"Wdowinski","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1080\/07038992.2018.1477680","article-title":"Wetland Water Level Monitoring Using Interferometric Synthetic Aperture Radar (InSAR): A Review","volume":"44","author":"Mohammadimanesh","year":"2018","journal-title":"Can. J. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1355","DOI":"10.1109\/LGRS.2013.2293492","article-title":"Multitemporal Multitrack Monitoring of Wetland Water Levels in the Florida Everglades Using ALOS PALSAR Data With Interferometric Processing","volume":"11","author":"Hong","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Oliver-Cabrera, T., and Wdowinski, S. (2016). InSAR-Based Mapping of Tidal Inundation Extent and Amplitude in Louisiana Coastal Wetlands. Remote Sens., 8.","DOI":"10.3390\/rs8050393"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Brisco, B., Ahern, F., Murnaghan, K., White, L., Canisus, F., and Lancaster, P. (2017). Seasonal Change in Wetland Coherence as an Aid to Wetland Monitoring. Remote Sens., 9.","DOI":"10.3390\/rs9020158"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1029\/2005EO140002","article-title":"C-band radar observes water level change in swamp forests","volume":"86","author":"Lu","year":"2005","journal-title":"Eos Trans. Am. Geophys. Union"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5210","DOI":"10.1109\/TGRS.2012.2231418","article-title":"Interferometric Coherence Analysis of the Everglades Wetlands, South Florida","volume":"51","author":"Kim","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","unstructured":"Jet Propulsion Laboratory (2019). NASA-ISRO SAR (NISAR) Mission Science Users\u2019 Handbook."},{"key":"ref_22","unstructured":"Rosen, P.A., Gurrola, E.M., Sacco, G.F., and Zebker, H. (2012, January 23\u201326). The InSAR scientific computing environment. Proceedings of the EUSAR 2012, 9th European Conference on Synthetic Aperture Radar, Nuremberg, Germany."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2356","DOI":"10.1016\/j.rse.2009.06.014","article-title":"Integrated analysis of PALSAR\/Radarsat-1 InSAR and ENVISAT altimeter data for mapping of absolute water level changes in Louisiana wetlands","volume":"113","author":"Kim","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Homer, C.G., Fry, J.A., and Barnes, C. (2012). The National Land Cover Database.","DOI":"10.3133\/fs20123020"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Steyer, G.D. (2010). Coastwide Reference Monitoring System (CRMS).","DOI":"10.3133\/fs20103018"},{"key":"ref_26","unstructured":"Google (2020, June 20). (n.d.) [Google Maps, Wax Lake, LA]. Available online: https:\/\/goo.gl\/maps\/UeX3XBQESjck1dmG8."},{"key":"ref_27","unstructured":"Coastal Protection and Restoration Authority (CPRA) of Louisiana (2017, February 02). 2007\u20132011. Coastwide Reference Monitoring System-Wetlands Monitoring Data. Retrieved from Coastal Information Management System (CIMS) Database, Available online: http:\/\/cims.coastal.louisiana.gov."},{"key":"ref_28","unstructured":"Dataset: U.S. Geological Survey (2016). USGS NED 1\/3 arc-second n30w091 1 \u00d7 1 degree ArcGrid 2016."},{"key":"ref_29","unstructured":"Dataset: U.S. Geological Survey (2016). USGS NED 1\/3 arc-second n30w092 1 \u00d7 1 degree ArcGrid 2016."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Archuleta, C.-A.M., Constance, E.W., Arundel, S.T., Lowe, A.J., Mantey, K.S., and Phillips, L.A. (2017). The National Map Seamless Digital Elevation Model Specifications, Chapter 9.","DOI":"10.3133\/tm11B9"},{"key":"ref_31","unstructured":"ALOS PALSAR (2018, October 19). L1.0 2007\u20132011. Accessed through ASF DAAC. Available online: http:\/\/www.asf.alaska.edu."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2436","DOI":"10.1016\/j.rse.2010.05.019","article-title":"Multi-temporal monitoring of wetland water levels in the Florida Everglades using interferometric synthetic aperture radar (InSAR)","volume":"114","author":"Hong","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1038\/35004560","article-title":"Interferometric radar measurements of water level changes on the Amazon flood plain","volume":"404","author":"Alsdorf","year":"2000","journal-title":"Nature"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"41672","DOI":"10.1038\/srep41672","article-title":"Uncertainties in the Shuttle Radar Topography Mission (SRTM) Heights: Insights from the Indian Himalaya and Peninsula","volume":"7","author":"Mukul","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_35","unstructured":"(2020, July 21). The Western North America InSAR (WInSAR) Consortium. Available online: https:\/\/winsar.unavco.org\/."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1109\/5.838084","article-title":"Synthetic aperture radar interferometry","volume":"88","author":"Rosen","year":"2000","journal-title":"Proc. IEEE"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1109\/JSTARS.2017.2761338","article-title":"An Assessment of Temporal Decorrelation Compensation Methods for Forest Canopy Height Estimation Using Airborne L-Band Same-Day Repeat-Pass Polarimetric SAR Interferometry","volume":"11","author":"Simard","year":"2018","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1109\/TGRS.2014.2333814","article-title":"Temporal Decorrelation in L-, C-, and X-band Satellite Radar Interferometry for Pasture on Drained Peat Soils","volume":"53","author":"Morishita","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1364\/JOSAA.18.000338","article-title":"Two-dimensional phase unwrapping with use of statistical models for cost functions in nonlinear optimization","volume":"18","author":"Chen","year":"2001","journal-title":"J. Opt. Soc. Am. A"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3452","DOI":"10.1109\/TGRS.2010.2076285","article-title":"Model-Based Decomposition of Polarimetric SAR Covariance Matrices Constrained for Nonnegative Eigenvalues","volume":"49","author":"Arii","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Pottier, E., Ferro-Famil, L., Allain, S., Cloude, S., Hajnsek, I., Papathanassiou, K., Moreira, A., Williams, M., Minchella, A., and LaValle, M. (2009, January 12\u201317). Overview of the PolSARpro V4.0 software: The open source toolbox for polarimetric and interferometric polarimetric SAR data processing. Proceedings of the 2009 IEEE International Geoscience and Remote Sensing Symposium, Cape Town, South Africa.","DOI":"10.1109\/IGARSS.2009.5417532"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/0034-4257(79)90013-0","article-title":"Red and photographic infrared linear combinations for monitoring vegetation","volume":"8","author":"Tucker","year":"1979","journal-title":"Remote Sens. Environ."},{"key":"ref_43","unstructured":"Didan, K. (2015). MOD13Q1 MODIS\/Terra Vegetation Indices 16-Day L3 Global 250m SIN Grid V006."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.isprsjprs.2018.05.009","article-title":"Multi-temporal, multi-frequency, and multi-polarization coherence and SAR backscatter analysis of wetlands","volume":"142","author":"Mohammadimanesh","year":"2018","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"42","DOI":"10.3390\/rs5010042","article-title":"Using InSAR Coherence to Map Stand Age in a Boreal Forest","volume":"5","author":"Pinto","year":"2012","journal-title":"Remote Sens."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"975","DOI":"10.3390\/rs4040975","article-title":"An Empirical Assessment of Temporal Decorrelation Using the Uninhabited Aerial Vehicle Synthetic Aperture Radar over Forested Landscapes","volume":"4","author":"Simard","year":"2012","journal-title":"Remote Sens."},{"key":"ref_47","unstructured":"Google (2020, June 20). (n.d.) [Google Maps, Belle Isle, LA]. Available online: https:\/\/goo.gl\/maps\/MHwYjwsjNCUrrA5U6."},{"key":"ref_48","unstructured":"Google (2020, June 20). (n.d.) [Google Maps, Lake Palourde St, Franklin, LA]. Available online: https:\/\/goo.gl\/maps\/xJZxmJXsWmuVUuvw7."},{"key":"ref_49","unstructured":"Google (2020, June 20). (n.d.) [Google Maps, Mobil Oil Ln Franklin, LA]. Available online: https:\/\/goo.gl\/maps\/oPhRwhL7c7MFS8pU6."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Swarzenski, C.M. (2003). Surface-water hydrology of the Gulf Intracoastal Waterway in South-Central Louisiana, 1996\u201399.","DOI":"10.3133\/pp1672"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/15\/2351\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:50:44Z","timestamp":1760176244000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/15\/2351"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,7,22]]},"references-count":50,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2020,8]]}},"alternative-id":["rs12152351"],"URL":"https:\/\/doi.org\/10.3390\/rs12152351","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,7,22]]}}}