INTRODUCTION TO WATER RESOURCES

Introduction to Water Resources



Introduction

More than 70 percent of the Earth's surface is covered with water, the majority of which is salt water in the oceans and seas. Despite this seeming overabundance, only a small portion of this water is suitable for drinking. Merely 3 percent of all water, according to author Gary Null, is freshwater, which is the only type safe for human consumption.

Less than 3 percent of water is available for human consumption because of the chemical fouling of so much freshwater sources with substances that render their water unfit for human consumption. The resulting pollution has rendered regions all over the world with far less access to clean water supplies than just 50 years ago. In 1994, 54 percent of Africa's population did not have access to clean water, along with 20 percent of the people in Latin America and the Caribbean. The vast majority in Asia—over 80 percent of its population—also do not have access to clean drinking water. Overall, more than a billion, mostly poor people lack clean drinking water supplies. That is close to one-sixth of the population of the Earth. Although the poor suffer the most from increasing water scarcity because they cannot afford to develop new sources, developed industrial countries such as the United States are also feeling its effects (Leopald, 1997).

Discussion

Water Resources

Water belongs to the category of “depletable natural resources”; at the same time, it is also considered one of the “renewable resources.” There are three basic groups of resources for meeting water needs:

Atmospheric precipitation and deposits

Underground waters at deep water-bearing layers (with no direct recharge of surface waters)

Surface waters (river runoff comprising surface and shallow ground runoff) (Biswas, 1997)

The Geography of Surface Water

The majority of surface water found in the oceans (97.2%) and is saline. Oceans are the largest input to the global hydrology cycle, where 320,000 cubic kilometers evaporates from their surfaces each year. The world's oceans are highly influential on climate patterns, as these massive water bodies act as a sink for solar energy. Oceanic water circulation moves warm water away from the equator, while cold water forced toward lower latitudes. These massive transfers of energy drive global temperature and precipitation patterns and explain a great deal about climate and biogeography. For example, the cold current flowing adjacent to the western edge of South America produces air and is a factor in ...