Paleohydrology of Lake Nhaucati (southern Mozambique),c. 400 AD to present
2008 (English)In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 40, 1127-1141 p.Article in journal (Refereed) Published
This paper investigates the correlations between lake level change, rainfall variability and general atmospheric forcing in southern Africa. The analysis of fossil diatom assemblages in a sediment sequence from the small, rain-fed Lake Nhaucati, southern Mozambique, is presented and discussed in relation to regional palaeoclimate data. The accumulation of organic sediments in Lake Nhaucati began 1,600 years ago when the lake level was rising. Lithology and pollen suggest a low stand at 800 AD, which correlates with other climate proxies from the summer rainfall region of southern Africa. The diatom assemblage suggests that lake levels were high between 900 and 1300 AD, with shorter low stands at c.1100 and 1200 AD. The period after 1400 AD was marked by a slow rate of accumulation and consequently a low temporal resolution. The correlation with other climate proxies in the summer rainfall region, written sources, and pollen data suggests repeated droughts corresponding to the Little Ice Age, though the driest periods may have caused complete desiccation of the lake. Higher lake levels are suggested after 1800 AD, though written sources suggest droughts in the beginning of the twentieth century. The analysis shows a good correlation with palaeoclimate data from the summer rainfall region and confirms the presence of an antiphase relationship between the summer rainfall region of southern Africa and the bi-modal rainfall region of east tropical Africa. It also supports the general hypothesis that variation in the intensity of the Inter Tropical Convergence Zone is the main agent modulating rainfall over southern and eastern Africa on centennial timescales.
Place, publisher, year, edition, pages
Dordrecht: Kluwer , 2008. Vol. 40, 1127-1141 p.
Diatom analysis, Lake level change, Climate change, Rainfall variability, Climatic forcing
IdentifiersURN: urn:nbn:se:uu:diva-119231DOI: 10.1007/s10933-008-9218-2OAI: oai:DiVA.org:uu-119231DiVA: diva2:299883