@article{fdi:010046326,
  title = {{A}ssessment of {D}igital {E}levation {M}odel ({DEM}) aggregation methods for hydrological modeling : {L}ake {C}had basin, {A}frica},
  author = {{L}e {C}oz, {M}athieu and {D}elclaux, {F}ran{\c{c}}ois and {G}enthon, {P}ierre and {F}avreau, {G}uillaume},
  editor = {},
  language = {{ENG}},
  abstract = {{D}igital {E}levation {M}odels ({DEM}s) are used to compute the hydro-geomorphological variables required by distributed hydrological models. {H}owever, the resolution of the most precise {DEM}s is too fine to run these models over regional watersheds. {DEM}s therefore need to be aggregated to coarser resolutions, affecting both the representation of the land surface and the hydrological simulations. {I}n the present paper, six algorithms (mean, median, mode, nearest neighbour, maximum and minimum) are used to aggregate the {S}huttle {R}adar {T}opography {M}ission ({SRTM}) {DEM} from 3 ' (90 m) to 5' (10 km) in order to simulate the water balance of the {L}ake {C}had basin (2.5 {M}km(2)). {E}ach of these methods is assessed with respect to selected hydro-geomorphological properties that influence {T}errestrial {H}ydrology {M}odel with {B}iogeochemistry ({THMB}) simulations, namely the drainage network, the {L}ake {C}had bottom topography and the floodplain extent. {T}he results show that mean and median methods produce a smoother representation of the topography. {T}his smoothing involves the removing of the depressions governing the floodplain dynamics (floodplain area<5000 km(2)) but it eliminates the spikes and wells responsible for deviations regarding the drainage network. {B}y contrast, using other aggregation methods, a rougher relief representation enables the simulation of a higher floodplain area (>14,000 km(2) with the maximum or nearest neighbour) but results in anomalies concerning the drainage network. {A}n aggregation procedure based on a variographic analysis of the {SRTM} data is therefore suggested. {T}his consists of preliminary filtering of the 3 ' {DEM} in order to smooth spikes and wells, then resampling to 5' via the nearest neighbour method so as to preserve the representation of depressions. {W}ith the resulting {DEM}, the drainage network, the {L}ake {C}had bathymetric curves and the simulated floodplain hydrology are consistent with the observations (3% underestimation for simulated evaporation volumes).},
  keywords = {{D}igital {E}levation {M}odel ; {A}ggregation ; {SRTM} ; {H}ydrological model ; {THMB} ; {L}ake {C}had},
  booktitle = {},
  journal = {{C}omputers and {G}eosciences},
  volume = {35},
  numero = {8},
  pages = {1661--1670},
  ISSN = {0098-3004},
  year = {2009},
  DOI = {10.1016/j.cageo.2008.07.009},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046326},
}