@article{PAR00006578,
  title = {{M}odelling the hydrological behaviour of a coffee agroforestry basin in {C}osta {R}ica},
  author = {{G}omez-{D}elgado, {F}. and {R}oupsard, {O}. and le {M}aire, {G}. and {T}augourdeau, {S}. and {P}erez, {A}. and van {O}ijen, {M}. and {V}aast, {P}. and {R}apidel, {B}. and {H}armand, {J}. {M}. and {V}oltz, {M}arc and {B}onnefond, {J}. {M}. and {I}mbach, {P}. and {M}oussa, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he profitability of hydropower in {C}osta {R}ica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. {I}n order to foster the provision and payment for {H}ydrological {E}nvironmental {S}ervices ({HES}), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. {T}he present paper aims to study the water balance partitioning in a volcanic coffee agroforestry microbasin (1 km(2), steep slopes) in {C}osta {R}ica, as a first step towards evaluating sediment or contaminant loads. {T}he main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. {A} new {H}ydro-{SVAT} lumped model is proposed, that balances {SVAT} ({S}oil {V}egetation {A}tmosphere {T}ransfer) and basin-reservoir routines. {T}he purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. {T}he calibration of the model to perform streamflow yielded a {N}ash-{S}utcliffe ({NS}) coefficient equal to 0.89 for the year 2009, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration ({R}-2 = 0.79, energy balance closed independently), soil water content ({R}-2 = 0.35) and water table level ({R}-2 = 0.84). {E}ight months of data from 2010 were used to validate modelled streamflow, resulting in a {NS} = 0.75. {A}n uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. {I}t was observed that 64% of the incident rainfall {R} flowed out of the basin as streamflow and 25% as evapotranspiration, while the remaining 11% is probably explained by deep percolation, measurement errors and/or inter-annual changes in soil and aquifer water stocks. {T}he model indicated an interception loss equal to 4% of {R}, a surface runoff of 4% and an infiltration component of 92%. {T}he modelled streamflow was constituted by 87% of baseflow originating from the aquifer, 7% of subsurface non-saturated runoff and 6% of surface runoff. {G}iven the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable {HES}, such as a reduced superficial displacement- capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. {T}he proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare {HES} provision for different regions or management alternatives.},
  keywords = {},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {15},
  numero = {1},
  pages = {369--392},
  ISSN = {1027-5606},
  year = {2011},
  DOI = {10.5194/hess-15-369-2011},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00006578},
}