Influence of Altitude on the Spatiotemporal Variations of Meteorological Droughts in Mountain Regions of the Free State Province, South Africa (1960–2013)

Abstract

The Standardized Precipitation Index (SPI) was computed for October to December (OND) and January to March (JFM) summer subseasons for Free State Province, South Africa, to assess the influence of altitude on drought severity and frequency. The observed spatiotemporal heterogeneity in the SPI variability revealed that factors governing drought interannual variability varied markedly within the region for the two subseasons. Strong correlations between = 0.76 and 0.93 across the clusters in both subseasons were observed. Significant shift in average SPI, towards the high during the OND subseason, was detected for the far western lowlying and central regions of the province around the 1990s. An ANOVA test revealed a significant relationship between drought severity and altitude during the OND subseason only. The impact of altitude is partly manifested in the strong relationship between meridional winds and SPI extremes. When the winds are largely northerly, Free State lies predominantly in the windward side of the Drakensberg Mountains but lies in the rain shadow when the winds are mostly southerly. The relationship between ENSO and SPI indicates stronger correlations for the early summer subseason than for the late summer subseason while overall presenting a diminishing intensity with height over the province.

Barriers Affecting Sustainable Agricultural Productivity of Smallholder Farmers in the Eastern Free State of South Africa

“…The study was conducted at Harrismith and Phuthaditjhaba, within the Maluti-a-Phofung municipality, located in the eastern parts of Thabo Mofutsanyana district in the Free State Province of South Africa (Figure 1). Free State is the third-largest province in the country, situated between latitudes 26.6 • S and 30.7 • S and between longitudes 24.3 • E and 29.8 • E [25,26]. According to Department of Agriculture, Forestry and Fisheries [25], the main economic activities contributing significantly towards the gross domestic product of the province are community service (24.7%), agriculture (20.1%), trade (10.7%) and mining (9.6%).…”

“…About 30% of the national maize production is produced in the Free State, thus contributing significantly to the agricultural economy of the country [6]. Most of the agricultural production in the province is under rainfed conditions, with less than 10% of the arable land being under irrigation [5,[26][27][28]. The climate in the Maluti-a-Phofung municipality is characterized by hot, humid summers and cold winters [29].…”

“…Therefore, eastern parts of Free State are highly suitable for dryland crop production compared to dry areas in the western and southern parts of the province [5]. Longer dry spells and droughts which often occur during summer months (December to February) are amongst the major agro-climatological hazards which affect agricultural production in Free State [26,31]. This makes soil-water conservation and efficient use of soil moisture very important for sustainable agricultural production in this region.…”

Factors Determining the Adoption of Strategies Used by Smallholder Farmers to Cope with Climate Variability in the Eastern Free State, South Africa

“…The study was carried out in the different villages of the Harrismith and Phuthaditjhaba towns that are located in the Maluti-a-Phofung municipality within the Thabo Mofutsanyana district in the eastern part of the Free State Province of South Africa (Figure 1). Free State is located between latitudes 26.6 • S and 30.7 • S and between longitudes 24.3 • E and 29.8 • E and is the third of the largest provinces in the country [35,36]. According to Moswetsi et al [37], it alone produces more than 30% of the total maize production in the country and most of its agricultural production (approximately 90%) is under rainfed cropping systems [35,36,38].…”

“…Free State is located between latitudes 26.6 • S and 30.7 • S and between longitudes 24.3 • E and 29.8 • E and is the third of the largest provinces in the country [35,36]. According to Moswetsi et al [37], it alone produces more than 30% of the total maize production in the country and most of its agricultural production (approximately 90%) is under rainfed cropping systems [35,36,38]. The Maluti-a-Phofung municipality has a subtropical highland climate with a mean annual air temperature of 17 • C and a mean annual rainfall ranging between 500 and 900 mm [38].…”