Water Environment in South Asia: An Introduction

South Asia covers an area of nearly 4.78 million km2 and extends from near the Equator to 38°26′N and 60°34′E–97°25′E. It is surrounded by (from west to east) Western Asia, Central Asia, Eastern Asia, and Southeast Asia. The subregion comprises eight countries: Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. The physiography is dominated by the Himalayan Mountains, which form a physical and cultural barrier separating the subregion from China. The subregion is home to a variety of geographical features such as glaciers, rainforests, valleys, deserts, and grasslands. Two major rivers flow out of the Himalayas: the Ganges, which flows across northern India into Bangladesh, and the Indus, which flows across Pakistan. Home to the highest mountains and largest mangrove forests in the world, lush jungles, the tenth-largest desert on Earth, deep river valleys, and many other unique landscape features, this subregion boasts a most diverse assortment of geographic features