Open AccessTemporal rainfall trend analysis in different agro-ecological regions of southern Africa
Author(s) -
W. Mupangwa,
R Makanza,
Lovemore Chipindu,
Mokhele Edmond Moeletsi,
Siyabusa Mkuhlani,
Feyera M. Liben,
Isaiah Nyagumbo,
Munyaradzi Mutenje
Publication year - 2021
Publication title -
water s.a./water sa
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.389
H-Index - 59
eISSN - 1816-7950
pISSN - 0378-4738
DOI - 10.17159/wsa/2021.v47.i4.3844
Subject(s) - arid , environmental science , growing season , agriculture , seasonality , trend analysis , geography , climatology , hydrology (agriculture) , agronomy , ecology , biology , mathematics , geology , statistics , geotechnical engineering , archaeology
Rainfall is a major driver of food production in rainfed smallholder farming systems. This study was conducted to assess linear trends in (i) different daily rainfall amounts ( 40 mm∙day-1), and (ii) monthly and seasonal rainfall amounts. Drought was determined using the rainfall variability index. Daily rainfall data were derived from 18 meteorological stations in southern Africa. Daily rainfall was dominated by 40 mm day-1 category. Semi-arid location experienced increasing trends in <5 and 5–10 mm∙day-1 events. A significant linear trend in seasonal rainfall occurred at two locations with decreasing rainfall (1.24 and 3 mm∙season-1). A 3 mm∙season-1 decrease in seasonal rainfall was experienced under semi-arid conditions. There were no apparent linear trends in monthly and seasonal rainfall at 15 of the 18 locations studied. Drought frequencies varied with location and were 50% or higher during the November–March growing season. Rainfall trends were location and agro-ecology specific, but most of the locations studied did not experience significant changes between the 1900s and 2000s.