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001			64442
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008			200602s2021 ne |||p|op||| 00| 0 eng d
022			_a0048-9697
024	8		_ahttps://doi.org/10.1016/j.scitotenv.2021.150483
040			_aMX-TxCIM
041			_aeng
100	1		_924358 _aBrosens, L.
245	1	0	_aUnder pressure : _crapid lavaka erosion and floodplain sedimentation in central Madagascar
260			_aAmsterdam (Netherlands) : _bElsevier, _c2021.
500			_aPeer review
500			_aOpen Access
520			_aLavaka (gullies) are often considered as the prime indication of a currently ongoing human-induced environmental crisis in Madagascar's highlands. Yet, lavaka are known to have existed long before human arrival and account for the majority of the long-term sediment input into the highland rivers and floodplains. The role of anthropogenic disturbances in their formation therefore remains highly debated and it is unclear whether lavaka erosion has recently increased. Here, we address these questions by evaluating the dynamics of lavaka in the Lake Alaotra region (central Madagascar). An overall birth to stabilization ratio of 6.1 indicates a rapid lavaka population growth over the period 1949–2010s. Using data on lavaka development we calculated a mean lavaka population age of 410 ± 40 years and estimate that the disequilibrium started at 870 ± 430 cal. BP. Floodplain sedimentation starts to increase around 1000 cal. BP and peaks over the last 400 years, thereby independently confirming this time frame of increased lavaka activity. Lavaka population dynamics modelling shows that a strong increase in environmental pressure over the last centuries is needed to attain current disequilibrium levels. A general drying of the climate since 950 cal. BP in combination with the introduction of cattle and growing human presence around 1000 cal. BP will likely have triggered the increase in lavaka erosion. However, the recent acceleration cannot be explained by climatic changes alone and seems to be linked to increased anthropogenic pressure on the environment. As such, we offer a fresh and quantitatively supported perspective on lavaka dynamics and human impact in central Madagascar, where our methodology can be used in other locations where similar questions on geomorphic equilibrium need to be answered.
546			_aText in English
650		7	_912272 _aLakes _2AGROVOC
650		7	_924359 _aGully erosion _2AGROVOC
650		7	_924360 _aFloodplains _2AGROVOC
651		7	_2AGROVOC _912307 _aMadagascar
700	1		_924361 _aBroothaerts, N.
700	1		_924362 _aCampforts, B.
700	1		_924363 _aJacobs, L.
700	1		_924364 _aRazanamahandry, V.F.
700	1		_924365 _avan Moerbeke, Q.
700	1		_924366 _aBouillon, S.
700	1		_924367 _aRazafimbelo, T.
700	1		_924368 _aRafolisy, T.
700	1		_924369 _aGovers, G.
773	0		_dAmsterdam (Netherlands) : Elsevier, 2021. _gv. 806, pt. 2, art. 2022 _tScience of the Total Environment _x0048-9697
856	4		_uhttps://doi.org/10.1016/j.scitotenv.2021.150483 _yClick here to access online
942			_2ddc _cJA _n0
999			_c64442 _d64434