Global Journal of Science Frontier Research, D: Agriculture and Veterinary, Volume 23 Issue 1

The world will be conquered by exacerbated cycles of drought due to global climatic changes. Shortages in rain-fed agriculture and crops’ yield will be caused, unless a restricted environmental policy is followed (FAO, 2020a). As global climatic changes have been blown, rises in the temperature and decreases in precipitation patterns would have attacked earth taking it from the fascinated greenish optimum conditions toward the terrible relative extremes yellow ones. Lots of environmental catastrophes will have threated the existence of mankind on planet earth due. Worldwide, the U.S. concurrent information system indicated a deteriorating climate situation. 47.81% of the U.S. and 57.06% of the lower 48 states were in a drought in the last week of February 2022. In addition, 200.6 million acres of crops in the U.S. were experiencing drought conditions, 93.1 million people in the U.S. and 91.8 million in the lower 48 states were affected by drought. 32 U.S. states were experiencing moderately worse drought at the latter week ( NIDIS, 2022). Sea level rises, temperature rises, storm surges, floods, and droughts are the main effects of global climatic changes. Moreover, climatic changes hold a series of interrelated side-effects to agriculture such as the deteriorated soil fertility, soil salinization, land degradation, shrunk crops’ yields, rise of the freshwater’s demand and decrease of the available water’s supply (Fig. 2a) (IPCC, 2013). The agricultural drought is determined by dividing the precipitation by evapotranspiration in order to characterize states of moisture’s regime. The conceptual definitions of drought focus on the physical processes involved in drought, such as the scarcity of precipitation (meteorological drought), regime in soil moisture (agricultural drought), lack of overland flow (hydrological drought) and shortage of municipal water (socioeconomic drought) (Hereher et al., 2022). Soil faces short periods of wetting cycles and long periods of drying ones now and again. The reason is the increase in soil evaporation due to the rising in air temperature and therefore increasing in plant transpiration (Schoups et al., 2010). Accordingly, the net capillary movement of soil water will have a much moving upward pull during the growing season which accelerates soil salinization. Hence, hydrological systems, especially soils, have been considered as sensitive elements to climatic changes (Hopmans et al., 2008). All countries receive drought waves but their frequency, severity and duration may vary from one to another and from region to region. The non-sustainable uses of natural resources, weather variability and climatic changes are the main factors responsible for the drought (Miyan, 2015). Most of the region WANA falls within the hyper-arid, arid and semi-arid zones (Fig.2). As the region is subject to frequent droughts, agriculture is a major and sensitive sector of the economy and consumes most of the water resources. The rain-fed crops are strongly affected by fluctuated precipitations to a degree of an extent that the era between 2000- 2010 is nominated as the decade of water scarcity (ASCAD, 2011). The total number of the people affected by the drought attack in WANA countries between 1970- 2009, is about 38.09 million (Abu Swaireh, 2009). Egypt (Hegazy, 2020), Mauritania, Sudan (Hamid and Eltayeb 2011), Syri a (ASCAD, 2011), and Comoros Islands are examples, not a survey. In the most dried year, a localized famine attacked parts from south Sudan (Hamid and Eltayeb, 2011). In the cropping season of 2009/2010, most of the world's croplands faced severe drought waves which 1 Year 2023 27 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( ) I. I ntroduction D The Modified Richard’s Equation for Assessing the Impact of Drought and Salinity in Arid and Semi-Arid Zones. Part Two: A Soil Hydraulic Capacitance