Groundwater has long been an object of intense scrutiny. Only recently have methods become available that permit ecologists, hydrologists, and environmental scientists to assess the biotic and abiotic status of these all-important aquifers. - The dynamics of water movement through complex subterranean ecosystems - The biological organization and the factors that constrain these ecosystems - Alluvial and karst ecosystem functions - Contamination, management, and remediation

This book encompasses the characterisation of meteorological drought by the newly invented index called “SPI – Standardised Precipitation index” approved by World Meteorological Organization (WMO) in June 2011. It is a simple index with precipitation as the only parameter and can be computed for different scales (1-3-6-12-24 months) and compared across regions with different climatic zones. The author has depicted graphs with regard to trends, onset, end, magnitude with dates of occurrence of droughts over a period of 102 years with regard to rainfall and temperature with the aid of SPI and SPEI, for Anantapur District of Andhra Pradesh, India. To characterise the agricultural drought, climatological water balance was carried for a period of 30 years for the data. In this book a composite index called “Indian drought monitor” with ten indicators and indices has been developed for releasing drought information weekly considering and incorporating review from a group of climatologists, extension agents and others across the nation. This will lead the country economically forward.