This edited volume comprises selected papers from the 7th IRSA International Conference, held at the University of Indonesia, 3-4 August 2005. The title of this book reflects the major theme of the meeting. Indeed, the theme is timely. Following the devastating December 2004 tsunami in Aceh, the steering committee of the IRSA conference decided to take the natural disaster as the main theme of the 2005 meeting. The major earthquake in March 2005 in Nias reconfirmed the decision. But still, the committee would also call for wider regional science topics. Hence is the sub-theme of the meeting. The natural disaster strikes not only the affected people of Aceh and Nias, but also regional scientists. Very few ever thought previously about the impact and redevelopment issues of the unexpected events. This is partly reflected in the relatively small number of papers submitted to the conference. However, we are grateful to those who responded to the call for papers of this conference, and some of the papers are included in this volume.