@inproceedings{fdi:010090485,
  title = {{T}ipping points in hydrology: observed regional regime shift and {S}ystem {D}ynamics modeling},
  author = {{W}endling, {V}alentin and {P}eugeot, {C}hristophe and {G}rippa, {M}. and {K}ergoat, {L}. and {M}ougin, {E}. and {H}iernaux, {P}. and {R}ouch{\'e}, {N}athalie and {P}anthou, {G}. and {R}ajot, {J}ean-{L}ouis and {P}ierre, {C}. and {M}ora, {O}. and {G}arcia-{M}ayor, {A}. and {B}a, {A}. and {L}awin, {E}. and {B}ouzou-{M}oussa, {I}. and {D}emarty, {J}{\'e}r{\^o}me and {E}tchanchu, {J}. and {H}ector, {B}asile and {G}alle, {S}ylvie and {L}ebel, {T}hierry and {T}ip{H}yc {P}rojetc},
  editor = {},
  language = {{ENG}},
  abstract = {{R}iver runoff and climate data existing from 1950 to present time in {W}est {A}frica are analyzed over a climatic gradient from the {S}ahel (semi-arid) to the {G}ulf of {G}uinea (humid). {T}he region experienced a severe drought in the 70s-90s, with strong impact on the vegetation, 


soils and populations. {W}e show that the hydrological regime in the {S}ahel has shifted: the runoff increased significantly between pre- and post-drought periods and is still increasing. {I}n the {G}uinean region, instead, no shift is observed. {T}his suggests that a tipping point could have been passed, triggered by climate and/or land use change. {I}n order to explore this hypothesis, we developed a {S}ystem {D}ynamics model representing feedbacks between soil, vegetation and flow connectivity of hillslopes, channels and aquifers. {M}odel runs were initialized in 1950 with maps of land use/land cover, and fed with observed rainfall (climate external forcing). {T}he modeling results accurately represent the observed evolution of the hydrological regime on the watersheds monitored since the 50s (ranging from 1 to 50000 km²).  {T}he model revealed that alternative stable states can exist for the climatic conditions of the study period. {F}rom the model runs, we showed that the drought triggered the crossing of a tipping point (rainfall threshold), which explains the regime shift. {W}e identified domains within the watersheds where tipping occurred at small scale, leading to larger scale shifts. {T}his result supports that tipping points exist in semi-arid systems where ecohydrology plays a major role. {T}his approach seems well suited to identify areas of high risk of irreversible hydrological regime shifts under different climate and land-use scenarios.},
  keywords = {{AFRIQUE} {DE} {L}'{OUEST} ; {SAHEL} ; {GUINEE}},
  numero = {},
  pages = {{EGU}22--5433 [2 ]},
  booktitle = {{EGU} {G}eneral {A}ssembly 2022},
  year = {2022},
  DOI = {10.5194/egusphere-egu22-5433},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090485},
}