This project examines whether two innovative technologies-lidar (LIght Detection and Ranging) and EM (electromagnetic induction) can be used to improve the accuracy of wetlands mapping that has historically been based chiefly on analysis of aerial photographs. Recognition of the importance of monitoring the status and trends of coastal wetlands has increased in recent decades because of our new awareness of the critical role wetlands play in the transitional aquatic-terrestrial environment and our increasing alarm at the rapid change in wetlands resulting from the rise in relative sea level. In this pilot study on Mustang Island, we will demonstrate a rapid and accurate wetland-mapping approach that will complement existing efforts in traditional aerial photographic analysis. This project will be exploiting (1) the known strong relationship between elevation and marsh type by comparing a lidar-derived digital elevation model of Mustang Island with existing wetlands maps and detailed vegetation transects, and (2) another known strong relationship between soil and water salinity and marsh type by collecting and comparing EM-derived conductivity data with elevation and vegetation type along the same detailed island transects.