@article{fdi:010068937,
  title = {{M}onitoring of the spatio-temporal dynamics of the floods in the {G}uayas watershed ({E}cuadorian {P}acific {C}oast) using global monitoring {ENVISAT} {ASAR} images and rainfall data},
  author = {{F}rappart, {F}. and {B}ourrel, {L}uc and {B}rodu, {N}. and {S}alazar, {X}. {R}. and {B}aup, {F}. and {D}arrozes, {J}. and {P}ombosa, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he floods are an annual phenomenon on the {P}acific {C}oast of {E}cuador and can become devastating during {E}l {N}ino years, especially in the {G}uayas watershed (32,300 km(2)), the largest drainage basin of the {S}outh {A}merican western side of the {A}ndes. {A}s limited information on flood extent in this basin is available, this study presents a monitoring of the spatio-temporal dynamics of floods in the {G}uayas {B}asin, between 2005 and 2008, using a change detection method applied to {ENVISAT} {ASAR} {G}lobal {M}onitoring {SAR} images acquired at a spatial resolution of 1 km. {T}he method is composed of three steps. {F}irst, a supervised classification was performed to identify pixels of open water present in the {G}uayas {B}asin. {T}hen, the separability of their radar signature from signatures of other classes was determined during the four dry seasons from 2005 to 2008. {I}n the end, standardized anomalies of backscattering coefficient were computed during the four wet seasons of the study period to detect changes between dry and wet seasons. {D}ifferent thresholds were tested to identify the flooded areas in the watershed using external information from the {D}artmouth {F}lood {O}bservatory. {A} value of -2.30 +/- 0.05 was found suitable to estimate the number of inundated pixels and limit the number of false detection (below 10%). {U}sing this threshold, monthly maps of inundation were estimated during the wet season ({D}ecember to {M}ay) from 2004 to 2008. {T}he most frequently inundated areas were found to be located along the {B}abahoyo {R}iver, a tributary in the east of the basin. {L}arge interannual variability in the flood extent is observed at the flood peak (from 50 to 580 km(2)), consistent with the rainfall in the {G}uayas watershed during the study period.},
  keywords = {flood ; {SAR} ; {ENVISAT} {ASAR} ; rainfall ; {G}uayas ; {E}cuadorian {P}acific slope ; {EQUATEUR} ; {GUAYAS} {BASSIN} {VERSANT}},
  booktitle = {},
  journal = {{W}ater},
  volume = {9},
  numero = {1},
  pages = {art. 12 [20 p.]},
  ISSN = {2073-4441},
  year = {2017},
  DOI = {10.3390/w9010012},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068937},
}