Modelling Tsunami Effects on Mangrove Ecosystems and the Role They Play in Saving Lives and Properties

Arizona State University, Scottsdale AZ

Investigators

Abstract

Mangrove forests play an important role in stabilizing shorelines and in providing important ecological and societal goods and services including wildlife habitat, firewood, and timber, but mangrove forests are declining at an alarming rate. Some observers have posited that mangroves act as bio-shield to protect people and property from natural disasters, such as tsunamis and hurricanes. The loss and degradation of mangroves may make coastal regions more vulnerable to tsunamis and hurricanes, thereby leading to the loss of hundreds of thousands of lives and billions of dollars. When the highly destructive Indian Ocean tsunami hit India's southern state of Tamil Nadu in December 2004, some areas with dense mangroves suffered fewer human casualties and less damage than areas without mangroves. It is also believed that loss of coastal vegetation along the Mississippi delta contributed to the enormous devastation from hurricane Katrina in 2005. Although many scientists have emphasized the importance and role of mangrove forests in saving lives and property, only sparse data exist to support this claim, and the protective function of mangroves has never been scientifically and systematically investigated. The long-term goal of this research project is to explore if mangrove forests play a role in saving lives and property from natural disasters like tsunamis and hurricanes. To achieve this goal, the investigators will conduct field surveys in tsunami-hit areas in South and Southeast Asia and collect remotely sensed data and other ancillary data. These data will be used to develop a number of indices using pre-classification change-detection techniques that represent property damages in urban areas due to a natural disaster, identify the mangrove ecosystem and its surrounding land-use and land-cover types using object-oriented approaches (in contrast with supervised decision-tree classification methods), and employ multiple-endmember spectral-mixture analysis to characterize the density of mangroves. As a more cost and labor-effective and time-efficient alternative, the damage indices developed in this study using remote sensing and geographic information system technologies offer the potential for effectively and extensively use for many resource management and applications. The assessment techniques, indices or composites developed in the proposed plan will have a significant impact on disaster management and planning, because all hazard mitigation, planning, and preparedness programs need to begin with an understanding of risk and potential impacts through an estimation of the number of people and structures that would be affected by a disaster event. The comparison and classification approaches employed in this project will be useful for any level of application. Results and findings from this proposed research plan and the biophysical and socioeconomic data collected during this project will serve as a solid foundation to achieve the long-term goal of determining whether mangrove forests play an important role in saving lives and property. This line of research promises socially beneficial contributions related to reducing the vulnerability of coastal cities in relation to natural disasters and to natural resource management. It also promises to make methodological innovations in geographic information science.