@article{fdi:010073763,
  title = {{S}urface water monitoring in small water bodies : potential and limits of multi-sensor {L}andsat time series},
  author = {{O}gilvie, {A}ndrew and {B}elaud, {G}. and {M}assuel, {S}ylvain and {M}ulligan, {M}. and {L}e {G}oulven, {P}atrick and {C}alvez, {R}oger},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ydrometric monitoring of small water bodies (110 ha) remains rare, due to their limited size and large numbers, preventing accurate assessments of their agricultural potential or their cumulative influence in watershed hydrology. {L}andsat imagery has shown its potential to support mapping of small water bodies, but the influence of their limited surface areas, vegetation growth, and rapid flood dynamics on long-term surface water monitoring remains unquantified. {A} semi-automated method is developed here to assess and optimize the potential of multi-sensor {L}andsat time series to monitor surface water extent and mean water availability in these small water bodies. {E}xtensive hydrometric field data (1999-2014) for seven small reservoirs within the {M}erguellil catchment in central {T}unisia and {SPOT} imagery are used to calibrate the method and explore its limits. {T}he {M}odified {N}ormalised {D}ifference {W}ater {I}ndex ({MNDWI}) is shown out of six commonly used water detection indices to provide high overall accuracy and threshold stability during high and low floods, leading to a mean surface area error below 15 %. {A}pplied to 546 {L}andsat 5, 7, and 8 images over 19992014, the method reproduces surface water extent variations across small lakes with high skill ({R}-2 = 0.9) and a mean root mean square error ({RMSE}) of 9300m(2). {C}omparison with published global water datasets reveals a mean {RMSE} of 21 800m(2) (+ 134 %) on the same lakes and highlights the value of a tailored {MNDWI} approach to improve hydrological monitoring in small lakes and reduce omission errors of flooded vegetation. {T}he rise in relative errors due to the larger proportion and influence of mixed pixels restricts surface water monitoring below 3 ha with {L}andsat ({N}ormalised {RMSE} = 27 %). {I}nterferences from clouds and scan line corrector failure on {ETM}+ after 2003 also decrease the number of operational images by 51 %, reducing performance on lakes with rapid flood declines. {C}ombining {L}andsat observations with 10m pansharpened {S}entinel-2 imagery further reduces {RMSE} to 5200m(2), displaying the increased opportunities for surface water monitoring in small water bodies after 2015.},
  keywords = {{TUNISIE} ; {ZONE} {SEMIARIDE} ; {MERGUELLIL} {BASSIN} {VERSANT}},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {22},
  numero = {8},
  pages = {4349--4380},
  ISSN = {1027-5606},
  year = {2018},
  DOI = {10.5194/hess-22-4349-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010073763},
}