Ikuo Towhata

Towhata and coauthors draw on their decades of research and innovation to describe an inexpensive and easy to interpret early warning system for rainfall-induced landslides. This system will enable readers to identify slope collapses before they happen and act to prevent economic and human losses. Readers will gain an understanding of existing slope monitoring technologies and their applications and advantages and disadvantages. They will also understand the need for early warning systems for rapid landslides that are caused by heavy rainfall. Because such landslides are increasing in frequency because of a climate-change-related increase in short-term but heavy rainfall, the authors first review the current context before explaining the importance of field monitoring for their continuing professional career development. The authors describe their technology, which is based on an inexpensive tiltmeter sensor and can detect landslides several hours prior to their onset. It is important that the authors present ample cases in which their technology was able to foresee imminent landslides. This description is supported by in-depth comparisons with other methodologies, field tests, and case studies. Finally, existing problems are introduced and future research directions are presented. This information will enable readers to implement their own system to identify slopes at imminent risk of collapse following rainfall events so that they may take appropriate action to prevent economic damage and loss of life. This book is an indispensable guide for practitioners in both public and private sectors who are responsible for the implementation of slope monitoring and landslide early warning systems. Postgraduate students who specialize in the mitigation of natural disasters and effects of global climate change will also benefit from the discussions of differing available technologies and case studies.

This book is a product of my long-term activities in both education and research. Its publication was made possible by a financial support supplied by the Ministry of Education, Culture, Sports, Science and Technology. As for education, I was told for the first time in 1985 to teach soil dynamics in Asian Institute of Technology in Bangkok, Thailand. I collected experimental and field findings from many publications and made a small series of handouts. Since computer technologies were not well advanced in mid 80s, the handouts were products of cut-and-paste in the physical sense. Many pages were even handwritten. Afterwards, I started to teach the same subject in 1995 at University of Tokyo. Since then I have added more information from field investigation and laboratory tests as well as analyses. It has become possible to put all in an electronic media that makes teaching easier. Readers can find that this book includes Japanese writing among English text. This is because I use this text for teaching in Tokyo. The main aim of this book is a collection of data which is useful in understanding the state-of-art technology and its application to new topics. Understanding the fundamental issues is important because practice makes use of many assumptions, hypotheses, and way of thinking. It has been my policy to show reasons why practice employs those ideas by showing experimental and field backgrounds. This idea does not change even today.

This book is a product of my long-term activities in both education and research. Its publication was made possible by a financial support supplied by the Ministry of Education, Culture, Sports, Science and Technology. As for education, I was told for the first time in 1985 to teach soil dynamics in Asian Institute of Technology in Bangkok, Thailand. I collected experimental and field findings from many publications and made a small series of handouts. Since computer technologies were not well advanced in mid 80s, the handouts were products of cut-and-paste in the physical sense. Many pages were even handwritten. Afterwards, I started to teach the same subject in 1995 at University of Tokyo. Since then I have added more information from field investigation and laboratory tests as well as analyses. It has become possible to put all in an electronic media that makes teaching easier. Readers can find that this book includes Japanese writing among English text. This is because I use this text for teaching in Tokyo. The main aim of this book is a collection of data which is useful in understanding the state-of-art technology and its application to new topics. Understanding the fundamental issues is important because practice makes use of many assumptions, hypotheses, and way of thinking. It has been my policy to show reasons why practice employs those ideas by showing experimental and field backgrounds. This idea does not change even today.