Freshwater is one of the most essential natural resources for sustaining life, supporting ecosystems, and enabling socio-economic development. Despite covering about 71 percent of the Earth's surface, water is largely saline, with only about 2.5 percent classified as freshwater. Of this small fraction, nearly 68.7 percent is locked in glaciers and ice caps, 30.1 percent is stored as groundwater, and less than 1.2 percent is available in surface water bodies such as rivers, lakes, and wetlands. This limited and unevenly distributed resource forms the foundation of all terrestrial ecosystems and human civilizations. The global distribution of freshwater is influenced by climatic, geological, and topographical factors, resulting in significant regional disparities that shape the environmental, economic, and political realities of societies across the world. The availability of freshwater varies widely between regions. South America, particularly the Amazon Basin, holds the largest share of global freshwater resources, with countries like Brazil possessing almost 12 percent of the world’s renewable freshwater supply. The Congo River Basin in Central Africa also accounts for a substantial portion of the global total. North America benefits from large freshwater systems such as the Great Lakes, the Mississippi River, and vast groundwater aquifers, while parts of Asia, including the Himalayan region, contain massive reserves of glacial meltwater feeding major rivers like the Ganges, Brahmaputra, Yangtze, and Mekong. In contrast, the Middle East, North Africa, and parts of Central Asia are characterized by extreme water scarcity, with annual renewable freshwater availability often falling below 500 cubic meters per person—a level defined as absolute water scarcity. Australia, despite being a developed nation, also faces acute spatial and temporal variability in freshwater distribution due to its arid climate and irregular rainfall patterns. The uneven distribution of freshwater is further compounded by temporal variability, as precipitation patterns fluctuate with seasonal and climatic changes. Monsoon-dependent regions, such as South Asia, receive the bulk of their rainfall during a few months of the year, leading to alternating periods of flooding and drought. In contrast, polar and subpolar regions store vast quantities of freshwater in frozen form, making it inaccessible for human use. Climate change is intensifying these imbalances by altering hydrological cycles, accelerating glacial melt, shifting precipitation zones, and increasing the frequency of extreme weather events. As a result, regions already vulnerable to water stress face greater challenges in maintaining sustainable