Rainfall variability, soils and land use changes in the Ethiopian highlands

Type Thesis or Dissertation - Doctoral Thesis
Title Rainfall variability, soils and land use changes in the Ethiopian highlands
Author(s)
Publication (Day/Month/Year) 2013
URL https://gupea.ub.gu.se/bitstream/2077/33656/9/gupea_2077_33656_9.pdf
Abstract
Most farmers in the Ethiopian highlands are dependent on rain-fed agriculture. The
indigenous cereal tef is the most important crop for the farmers in the highlands. The central
highland is an environmentally fragile area and a marginal area of Ethiopia with a recurring
problem for the farmers to sustain an adequate agricultural production.
The objectives of this thesis are; to analyse the rainfall change and rainfall variability in time
and space and its impact on farmers’ potential to cultivate during the short rainy season Belg;
to analyse the status of soil parameters and its consequences for farmers’ food production and;
to analyse land-use changes and its consequences for the farmers dependent on agriculture.
The geographical focus is on the central highlands and especially South Wollo. The rainfall
analysis is based on daily rainfall data from 13 stations and covers the time period 1964-2012.
Land use and land cover changes were analysed by interpretation of black and white aerial
photographs from 1958 and colour satellite images from 2003 and 2013. All soil samples
used in the study were analysed according to standard methods. In addition interviews with
farmers and field observations were done during six different field campaigns between 1999
and 2012.
The results reveal a decline in the total Belg rainfall since the 1980´s in the central highlands.
The total amounts of rainfall during the long rainy season, called Kiremt, have increased
during the same time period. An increase in the rainfall variability over time is also found.
The increased rainfall variability is also found when comparing two adjacent places only 30
km apart. It is also found that the synchronicity of rainfall between the two adjacent stations is
very low during Belg, but higher during Kiremt season. A rainfall model for tef cultivation is
developed and used as a tool to analyse the impact of rainfall changes on tef cultivation. The
model suggests that during the time period 1963-1982 and 1984-2003 farmers were able to
have a potential tef harvest every second year during both these twenty-year periods. The
model also shows that the possibilities to grow tef at Combolcha after 1996 has become more
difficult and the possibilities to grow tef during the Belg season are very limited today

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