Future Implications of Desert Malaria in Global Elimination Campaign

Abstract

AbstractDeserts, covering nearly 33% of the earth’s land area (approximately 33.7 million square kilometres) and inhabited by over 500 million people, are found in every continent and are, therefore, truly global in representation. These are located on both sides of the equator in the northern and the southern hemisphere (Goudie and Wilkinson 1977). Deserts such as Saharan and Chilean-Peruvian deserts have hyperaridity, followed by the Arabian, East African, Gobi, Australian and South African Deserts, whereas Thar and North American deserts have lower aridity. Both cold and hot deserts have arid environments with varying degrees of aridity index. A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life which though less diverse are, nevertheless, unique and rich in rare and endemic species despite being often subject to vulnerability to extinction and environmental degradation (Thornthwaite 1948; Louw and Seely, 1982; UNEP 2002; FAO 2019; Sher et al. 2004; Ezcurra et al. 2006). The scanty, erratic and variable precipitation/rainfall is the basis of chronic shortage of available moisture/water for plants/animals resulting from an imbalance between precipitation and evapotranspiration. This situation is exacerbated by considerable variability in the timing of rainfall, influenced often by the El Nino and La Nina phenomena in the Pacific Ocean, low atmospheric humidity, high daytime temperatures and winds such as that in case of the Thar Desert (Bouma and van der Kaay 1994, 1995). The Thar Desert environment is so dry that it supports only extremely sparse vegetation; trees are usually absent, and, under normal climatic conditions, shrubs or herbaceous plants provide only very incomplete ground cover such as the ‘Khejri’ tree (Prosopis cineraria) in the vast expanse of the desert. A hot desert and its boundaries are varyingly defined either climatologically in context with arid and hyperarid areas or biologically as the ecoregions wherein plants and animals are adapted to optimally survive in arid environments or physiologically where exist humongous extensions of bare and contiguous soil with scarcely vegetated cover. Overlaying the areas defined by each of the three criteria yields a composite definition of global deserts (Fig. 24.1).