Landscape evolution and climate in Madagascar: lavakization in the light of archive precipitation data

A.I. Szabó; A. Raveloson; B. Székely

doi:10.18172/cig.2646

Authors

A.I. Szabó Eötvös Loránd Univesity
A. Raveloson Department of Geophysics and Space Science, Eötvös University, Budapest
B. Székely Department of Geophysics and Space Science, Eötvös University, Budapest

DOI:

https://doi.org/10.18172/cig.2646

Keywords:

Madagascar, lavaka, gully, soil erosion, land degradation, climate.

Abstract

In Madagascar, soil erosion is significant even when it is compared to world averages. A resulting special geomorphic feature is a form of gully erosion known as lavaka that appears in the highlands of the country. Lavakization (the generation and development of these features) is due to rather unique multifactorial environmental conditions. Among many factors (geology, soil composition, human activities, etc.), the spatial and temporal distribution of precipitation is a key factor influencing the behaviour of lithology and the vegetation cover of the island. The inter-annual variability in precipitation seems to be responsible for the enhanced generation of small cracks that might eventually lead to the development of a gully. However, the way of the development of such gullies is unknown. To what extent the actual precipitation pattern contributes to the aforementioned phenomenon has not yet been studied in great detail.

This paper aims to analyze lavaka distribution with GIS methods and to study the relation between lavaka density and climatic conditions. Study areas have been designated throughout the country and lavakas have been identified using satellite imagery. Archive climate data of the study areas have been used to understand the influence of the weather on gully density. Data show that the spatial distribution of precipitation is connected to the appearance of lavakas to a given extent and its effect is further strengthened by the tropical cyclones. However, neither the amount of the precipitation, nor its variability alone can explain the high variation found in the spatial distribution of lavakas. Further multidisciplinary studies are necessary to draw conclusions about lavaka formation and to describe the process of lavaka development.

Downloads

Download data is not yet available.

References

Andriamampianina, N. 2006. L’érosion en lavaka: Processus et utilisation par les paysans d’Ampasimbe, Madagascar. In Efficacité de la gestion de l’eau et de la fertilité des sols en milieux semi-arides Roose, E. (ed.). AUF, EAC et IRD, Paris, pp. 256-261.

Bakoariniaina, L.N., Kusky, T., Raharimahefa, T. 2006. Disappearing Lake Alaotra: Monitoring catastrophic erosion, waterway silting, and land degradation hazards in Madagascar using Landsat imagery. Journal of African Earth Sciences 44, 241-252.

Besairie, H. 1946. Essai d’une carte des sols de Madagascar. Service des Mines de Madagascar, Madagascar.

Cerdà, A. 1998. The influence of aspect and vegetation on seasonal changes in erosion under rainfall simulation on a clay soil in Spain. Canadian Journal of Soil Science 78, 321-330.

CGIAR-CSI 2014. SRTM 90 m Database. Available at: http://srtm.csi.cgiar.org/Index.asp (last access: 12/11/2014).

Cornet, A. 1972. Carte bioclimatique de Madagascar. Service Cartographique de l’O.R.S.T.R.O.M, Madagascar.

Cox, R., Rakotondrazafy, M.A.F., Rakotondramazava, H.T. 2004. Geological versus human controls on lavaka formation and extreme erosion in Madagascar. In 2004 GSA Denver Annual Meeting, Geological Society of America, Denver, pp. 66-67.

Cox, R., Bierman, P., Jungers, M.C., Rakotondrazafy, A.F.M. 2009. Erosion rates and sediment sources in Madagascar inferred from 10Be analysis of lavaka, slope, and river sediment. The Journal of Geology 117 (4), 363-376.

Cox, R., Zenter, D.B., Rakotondrazafy, A., Rasoazanamparany, C.F. 2010. Shakedowns in Madagascar: Occurrence of lavakas (erosional gullies) associated with seismic activity. Geology 38 (2), 179-182.

Donque, G. 1972. The climatology of Madagascar In Biogeography and Ecology in Madagascar, R. Battistini, R. and Richard-Vindard, G. (eds.), Springer Netherlands, Monographiai Biologicae 21, 87-144.

Du Puy, D., Moat, J. 2003 Using geological substrate to identify and map primary vegetation types in Madagascar and the implications for planning biodiversity conservation. In The Natural History of Madagascar, Goodman S.M. and Benstead, J. (eds.), The University of Chicago Press, pp. 51-74.

Jury, M.R. 2003. The climate of Madagascar. In The Natural History of Madagascar, Goodman S.M. and Benstead, J. (eds.), The University of Chicago Press, pp. 75-87.

Lowry, R. 2015. VassarStats: Website for Statistical Computation. Mann-Whitney Test. Available at: http://vassarstats.net/index.html (last access: 05/02/2015).

Mietton, M., Cordier, S., Frechen, M., Dubar, M., Beiner, M., Andrianaivoarivony R. 2014. New insights into the age and formation of the Ankarokaroka lavaka and its associated sandy cover (NW Madagascar, Ankarafantsika natural reserve), Earth Surface Processes and Landforms 44, 1467-1477.

Mulder, H., Idoe, O. 2004. Lavaka the “hole” story: Analyses and design of an integrated biophysical and socio-economic ESWC management approach to the lavaka phenomenon in Madagascar. Wageningen University, Environmental Sciences, 121 pp.

NASA 2014. Tropical cyclones hitting Madagascar. Available at: http://earthobservatory.nasa.gov/ Natural Hazards (last access: 12/11/2014).

Nash, D.J., Pribyl, K., Klein, J., Endfield, G.H., Kniveton, D.R., Adamson, G.C.D. 2015. Tropical cyclone activity over Madagascar during the late nineteenth century, International Journal of Climatology (Early View on-line), DOI: 10.1002/joc.4204.

Nearing, M.A., Jetten, V., Baffaut., C., Cerdan, O.C.A., Hernandez, M., Le Bissonnais, Y., Nichols, M.H., Nunes, J.P., Renschler, C.S., Souchére, V., Van Oost, K. 2005. Modelling the response of soil erosion and runoff to change in precipitation and cover. Catena 61, 131-154.

NOAA, NCDC 2014. Climatic data. Available at: http://www7.ncdc.noaa.gov/CDO (last access: 12/11/2014).

Oldemann, L.R. 1988. Carte agroclimatologique de Madagascar. International Soil and Information Centre, The Netherlands.

ONE, 2008a. La pluviometrie moyenne de Madagascar. ONE, Madagascar.

ONE, 2008b. Classification des districts par rapports aux risques cycloniques. ONE, Madagascar.

Randriamanga, S., Bellan, M., Blasco, F. 2006. Application de la télédétection et d’un SIG á la typologie des lavakas sur lest hautes terres de Madagascar. Télédétection 6, 277-290.

Raveloson, A., Székely, B., Visnovitz, F., Udvardi, B., Szabó, Cs. 2013. Lavaka, the unusual gullies of Madagascar: A review on their formation and distribution. 6th International Symposium on Gully Erosion in a Changing World, Book of Abstract, Iaşi.

Raveloson, A., Ludván, B., Székely, B. 2014. Quantifying lavaka density and extension in relation with soil properties and topography (using high resolution satellite imagery and GIS). Geophysical Research Abstracts 16, EGU2014-754.

Riquier, J. 1955. Procédés de fixation d’une érosion en lavaka et de régénération d’un terrain extrêmement érodé. Mémoires de l’Institut Scientifique de Madagascar 6, 169-189.

Römkens, M.J.M., Helming, K., Prasad, S. 2001. Soil erosion under different rainfall intensities, surface roughness, and soil water regimes. Catena 46, 103-123.

Unruh, J., McConnell, B., Rodman, J. 2010. Environmental change and adaptation in degraded agro ecosystems: The case of highland Madagascar, Area 42 (3), 359-368.

Voarintsoa, N.R., Cox, R., Razanatseheno, M.M.O., Rakotondrazafy, A. 2012. Relation between bedrock geology, topography and lavaka distribution in Madagascar. South African Journal of Geology 115, 225-250.

Wells, N.A. 2003. Some Hypotheses on the Mesozoic and Cenozoic Paleoenvironmental History of Madagascar. In The Natural History of Madagascar S.M, Goodman and J. Benstead (eds.), The University of Chicago Press, pp. 16-34.

Wells, N.A., Andriamihaja, B. 1993. The initiation and growth of gullies in Madagascar: are humans to blame? Geomorphology 8 (1), 1-46.

Wells, N.A., Benjamin A., Solo Rakotovololona H.F. 1991. Patterns of development of lavaka, Madagascar’s unusual gullies. Earth Surface Processes and Landforms 16 (3), 189-206.

Zavada, M.S., Wang, Y., Rambolamanana, G., Raveloson, A., Razanatsoa, H. 2009. The significance of human induced and natural erosion features (lavakas) on the central highlands of Madagascar. Madagascar Conservation and Development 4, 120-127.