This book contains contributions written by leading experts in karstology, karst hydrogeology and closely related fields. Achievements in karst research by three authors who have been awarded the annual prize of the IAH Karst Commission, are included. The main focus of this book is to learn about the important and complex aquifer system. The book consists of four main subjects: 1. Management of transboundary karst aquifers; 2. Karst aquifer characterization and monitoring; 3. Water flow in karst: from vadose to discharge zone; and 4. Engineering, sustainable use and protection of water in karst.