3 – Climate Story

Johannesburg sits on a relatively flat region called the ‘Highveld’1 on the 4 Central plateau at an altitude of 1753m above mean sea level (Knight, 2018). It is surrounded by a protective line of the Great escarpment formed by geological upliftment of the continental crust. The city experiences a strong seasonal climate of wet-austral summers; from October to February and dry-short winters; June-August (Knight, 2018). The Cold Benguela current in the Atlantic Ocean regulates the temperature of Johannesburg below 30’ Celsius and in winters drops below freezing point causing frost (Daniel K. Irurah, 2010). The region receives an average of 235 sunshine hours a month and annual precipitation of 700-720 mm mostly in the summer months caused by the moisture-laden clouds coming from the Indian Ocean (Knight, 2018). The anti-cyclonic disturbances created by the Warm Agulhas current direct the wind towards the inland plateau, but the air masses are forced to condense passing over the Great escarpment, especially over the highlands of Lesotho (Knight, 2018). The regional topography of Johannesburg is significant because it is located on the continental drainage confluence of the Orange and Limpopo river basins fed by the Klip and Jukskei rivers that eventually flow into the Atlantic and Indian Oceans respectively (Knight, 2018). The subtropical highland climate characterized by a semi-arid environment is prone to droughts and floods (Daniel K. Irurah, 2010). The anthropogenic problems are exacerbated by the global increase in average temperatures, precipitation changes, and drought occurrences.

4 The word ‘veld’ in Afrikaans means field denotes the high-altitude grasslands elevated 1500m above mean sea-level.

FIG. 3.1 The city in nestled within Highveld, an inland portion of the central plateau

FIG. 3.2 Factors that influence the macro-climate of South Africa

PART 2 Peri-Urban Landscape

Water as Structuring Element

Origins: Soil, Minerals and Exploitation

Nature: Ecology & Habitat

Urban Fabric

Introduction

In his book the City of Extremes (2010), urbanist Marin J. Murray implores the subject of peripheral urbanization in greater Johannesburg. The author discusses the outcome of segregationist top-down apartheid planning and the slow decay of the historic downtown with business moving out to Sandton, Midrand, and Fourways. The spatial growth patterns and disjointed urban form of the greater Johannesburg metropolitan reflect the laissez-faire land-market operations (Murray, 2010). The wholesale restructuring and fragmentation of the city was facilitated by spatial dispersal of industrial, manufacturing and commercial activities overtaking unoccupied land and absorbing surrounding towns, and the intensive conglomeration of retail outlets, upscale shopping malls, and corporate offices (Murray, 2010). The peri-urban environments of Johannesburg lie on the periphery of the galactic megalopolis of fragmented settlements held together by a network of highways. Without the conventional boundaries or signposts, the city’s rapidly urbanizing peripheries expand and engulf existing cultivation and wetlands of the Klip River and Natalspruit.

As described by the urban geographer Pierce Lewis, Johannesburg resembles a city constituting a ‘galactic metropolis’: “where the residential sub-division, the shopping centres, the industrial parks seem to float in space, seen together, they resemble galaxy of stars and planets, held together by mutual gravitational attraction, but with large empty areas between clusters” (Lewis, 1983, p. 35).

There are several studies conducted about the city in relation to its colonial history (Cartwright, 1965) and settlement (Johannesburg. One Hundred Years, 1986), mining landscapes and apartheid policies (Mandy, 1984) that focus primarily on the political, socio-economic demographics, and social empowerment through land re-appropriation. Only a few studies and research have considered the relationship of the physical landscape and water to urbanism and development (Toffah, 2013; Knight 2018).

However, in retrospect, the following chapters decipher the peri-urban landscape character of the fragmented city and demonstrate the interdependency of water availability, soil structure, land occupation, and biodiversity. Later in chapter 8 of this volume, the impacts of climate crisis in Johannesburg are emphasized to formulate the thesis research question. The primary objective is to seek urban design mechanisms to redress the contemporary challenges of the city. Later in volumes 2 and 3, this is attempted using a set of design interventions to formulate and realise strategic urban design projects in the periurban fringes of Johannesburg (de Meulder, Shannon, & Loeckx, 2004).

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