Drought is one of the current natural disasters significantly affecting different regions on small and large scales. Drought creates environmental, economic, and social issues in the affected regions. Among the various disasters known in the world, drought is termed a natural disaster. Although, different definitions have been made of the drought (McMahon and Arenas, 1982). During drought, a lack of moisture normally causes a serious hydrological imbalance. Due to this condition, drinking water is usually used for precipitation, which has serious implications for humans and the earth. Due to water deficiency, the affected areas also suffer dry weather and long-lasting water scarcity. According to Hagman et al. (1984), drought is more common than any other disaster globally. Droughts are the most complex of all-natural disasters that have affected humans, but drought's least understood nature has been described (Beran and Rodier, 1985). In a specific period and under specific circumstances, the area's decrease in water availability is termed drought. Drought has been affecting various regions of the world every year (Hisdal and Tallaksen, 2003).
With the emergence of drought as a result of the lack of rainfall, the water, and water resources, which were the source of life, decreased in the region, and accordingly, it might harm agricultural productivity. In this condition, some issues might arise under the phenomena of the agricultural and hydrological drought, which occurred because of Libya's meteorological drought at a time when Libya suffered a dry period. These are certain agricultural sectors, which is one of Libya's most essential sectors, that had suffered a downfall due to the agricultural drought. Similarly, the products cultivated by the farmers, considered to be the most basic elements of this sector, are generally dependent on the climate. Therefore, a decrease in rainfall usually causes problems such as a decrease in the yield of the products and the inability to meet the country's food needs (Öztürk et al., 2002).
Considering the severity, duration, and effects of the drought, there are certain drought types, including meteorological-, agricultural-, hydrological-, and socioeconomic droughts (Wilhite and Glantz, 1985). Meteorological drought is expressed depending on the degree and duration of drought. Depending on the rainfall data, it is the first type of drought that we come across. Since its effect depends on the rainfall, the rainfall period constitutes a normal level in that drought type. It is evaluated in seasonal, water-year, or annual time scales (Şen, 2009). Agricultural drought is examined as a result of a shortage of rainfall due to meteorological drought and deterioration of soil water. The water demand of a plant depends on that plant's biological properties along with the growth or stages of the physical and biological properties of the soil (Wilhite, 2000). Hydrological droughts mean a lack of water in the hydrological system. It was a type of drought that manifested itself at unusually low levels in rivers, lakes, reservoirs, and groundwater (Van Loon, 2015). The socioeconomic drought had occurred as a result of linking the supply and demand of some economic goods or services with meteorological, hydrological, and agricultural drought factors. Therefore, drought usually happens due to an increase in demand for supply goods and a decrease in climate factors (Van Loon, 2015).
Drought is a hidden natural hazard that involves complex climatic systems and has significant environmental and social consequences. Due to the current state of catastrophic climatic occurrences, there has been an increase in interest in drought consequences and monitoring in recent years. Drought events have an impact on many of the GEOSS (Global Earth Observation System of Systems) Societal Benefit Areas (SBAs). Drought has created a link between various fields, including agriculture sustainability, food security, ecosystem functions and services, biodiversity, carbon stocks, water resources, and wildfires, to name a few. According to the IPCC's 5th Assessment Report, a drop in precipitation, coupled with increasing temperatures associated with drought occurrences, is expected, particularly in the Mediterranean Basin, resulting in lower water availability for natural and agricultural systems and human requirements. Hence this study aims to determine the longest drought period in the study area. The main concern is to find one of the driest years of all the stations and to find the years with high drought rates. For the purpose of this study, located in the Great Man-Made River region, meteorological drought analysis will be conducted for five monitoring stations in Northern Libya. For the drought analysis using DrinC software of the Great Man-Made River region for 1-, 3-, 6-, and 12-months, Standardized Precipitation Index (SPI) and Reconnaissance Drought Index (RDI) values are conducted and discussed.