Abstract
Remote sensing technology enables detecting, acquiring, and recording certain information about objects and locations from distances relative to their geographic locations. Airborne Lidar bathymetry (ALB) is an active, non-imaging, remote sensing technology for measuring the depths of shallow and relatively transparent water bodies using light beams from an airborne platform. In this study, we acquired Lidar datasets using near-infrared and visible (green) wavelength with the Leica Airborne Hydrography AB Chiroptera-I system over the Devils River basin of southwestern Texas. Devils River is a highly groundwater-dependent stream that flows 150 km from source springs to Lake Amistad on the lower Rio Grande. To improve spatially distributed stream bathymetry in aquatic habitats of species of state and federal conservation interest, we conducted supplementary water-depth observations using other remote sensing technologies integrated with the airborne Lidar datasets. Ground penetrating radar (GPR) mapped the river bottom where vegetation impeded other active sensors in attaining depth measurements. We confirmed the accuracy of bathymetric Lidar datasets with a differential global positioning system (GPS) and compared the findings to sonar and GPR measurements. The study revealed that seamless bathymetric and geomorphic mapping of karst environments in complex settings (e.g., aquatic vegetation, entrained air bubbles, riparian zone obstructions) require the integration of a variety of terrestrial and remotely operated survey methods. We apply this approach to Devils River of Texas. However, the methods are applicable to similar streams globally.
Highlights
Remote sensing technology uses active or passive propagated signals to enable remote acquisition of information about objects
The findings of this study are expected to contribute to the ongoing investigation of airborne light detection and ranging (Lidar) bathymetry quality-control aspects applicable to karstic riverine environments with varying environmental and morphological conditions
We computed the theoretical Dmax = 2.72 m by Dolan Falls (L6), where sonar readings indicated a depth of 5.77 m and Lidar beams were attenuated at a depth of 2.65 m
Summary
Remote sensing technology uses active or passive propagated signals (e.g., light pulses, electromagnetic radiation) to enable remote acquisition of information about objects. With the advent of recent survey technologies, researchers have access to autonomous unmanned surface (USV) and aerial vehicles (UAV), sophisticated GPS/INS positioning, dual and multibeam sonars, submerged spectrometers, and Lidar fluorosensors to measure depth, water transparency, bottom properties, and environmental conditions that impact inherent optical properties (IOP). With conservation and research partners to develop and execute a multidisciplinary research program to collect the scientific evidence needed to inform management of D. diaboli and several other species of interest to state and federal conservation efforts This includes data collection to support development of a robust two-dimensional hydraulic fish habitat model, enabling resource managers understand the declines in spring flow and surface water discharges that affect habitats for imperiled fish and mussel species. In-stream stage and temperature measurements were acquired to quantify spring inputs and identify seasonal trends in thermal regime affecting target species [26]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
