@article{fdi:010061474,
  title = {{S}patial and temporal variations of overland flow during rainfall events and in relation to catchment conditions},
  author = {{O}rchard, {C}. {M}. and {L}orentz, {S}. {A}. and {J}ewitt, {G}. {P}. {W}. and {C}haplot, {V}incent},
  editor = {},
  language = {{ENG}},
  abstract = {{I}mproved knowledge on overland flow ({OF}) generation and its dynamics (i.e. spatial and temporal variations) is essential to understand catchment hydrology, a prerequisite for better water resources and soil management. {I}n this study, our main objective was to quantify the dynamics of {OF} during rainfall events and to assess its main factors of control. {T}he research study was undertaken in an agricultural 23-ha catchment of a communal pasture in {K}wa{Z}ulu-{N}atal ({S}outh {A}frica) experiencing {M}editerranean climate and with variations of soil, topography and vegetation conditions. {T}he dynamics of {OF} was evaluated during three rainfall seasons (2007 to 2010) by using 1x1-m(2) microplots (n=15) located at five landscape positions. {A}t each location, a microplot was equipped with an automatic tipping bucket linked to a logger to estimate the delay between the start of the rain and the start of {OF} [i.e. the time to runoff initiation ({TRI})]. {M}ultivariate analysis was applied to the total {OF} and {TRI} data and the information on selected environmental factors (rainfall characteristics; soil type; soil clay content, {C}lay; proportion of the soil surface covered by vegetation, {C}ov; proportion of the soil surface covered by crusting, {C}rust; mean slope gradient, {S}; soil bulk density, (b); soil water tension at different depths, {SWT}). {T}he average {OF} rate over the 3-year study period varied 2.3-fold across the catchment (from 15% footslope to 35% backslope), whereas the average {TRI} varied by a 10.6-fold factor (between 0.6min at bottomland and 6.4min at footslope). {TRI} temporal variations correlated the most with event duration (r=0.8) and cumulative amount of rainfall since the onset of the rainy season (r=-0.47), whereas {TRI} spatial variations were controlled the most by {C}rust (-0.97<r<-0.77). {U}ltimately, {TRI} spatial variations were modelled and mapped in an attempt to model {OF} dynamics over the entire microcatchment.},
  keywords = {environmental factors ; hydrological processes ; overland flow generation ; spatial and temporal variations ; {AFRIQUE} {DU} {SUD}},
  booktitle = {},
  journal = {{H}ydrological {P}rocesses},
  volume = {27},
  numero = {16},
  pages = {2325--2338},
  ISSN = {0885-6087},
  year = {2013},
  DOI = {10.1002/hyp.9217},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061474},
}