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<br />00838 <br /> <br />Executive Summary <br /> <br />In mid-2000, the Grand Canyon Monitoring and Research Center (GCMRC) <br />began a remote-sensing initiative to evaluate all remote-sensing technologies and <br />methods that had potential for providing improved data (capability) for its various <br />programs that monitor the Colorado River ecosystem (CRE). The primary objective of <br />the initiative was to detennine the most cost-effective data collection protocols for <br />GCMRC programs that (I) provide the accuracies required for currently measured <br />parameters, (2) provide additional parameters for ecological monitoring, (3) reduce <br />environmental impact by being less invasive (han current methods, and (4) expand <br />geographic extent of current ground approaches. The initial phase of the remote-sensing <br />initiative detennined the types of sampling parameters and their required accuracies for <br />monitoring. This infonnation was used to detennine the most appropriate sensors for <br />evaluation, The initiative evaluated 2S different data collections over a three-year period; <br />many more remote-sensing instruments were considered, but were not evaluated because <br />they could not meet the basic requirements on spatial resolution, wavelength, positional <br />accuracy, or elevation accuracy. It was hoped that the evaluations would lead to a <br />minimum set of technologies that would satislY many program requirements. The results <br />from all of our evaluations are reviewed in this report and are briefly summarized in the <br />following paragraphs. <br /> <br />Of the three research and monitoring programs (biological, physical, and cultural) <br />within GCMRC, the cultural resources program presented the most difficult set of <br />requirements on remote-sensing data due to the small size and obscuration of its <br />resources. For example, very small, individual ethnobotanical stands require very high <br />resolution imagery for monitoring, which is extremely expensive to acquire. Although <br />__ lai-get.ca1Tl~len~es, provide image higher resolution at higher flight altitudes, the flight <br />altitude would still,be relatively low to obtain 3.cm imagery and would require expensive <br />- HelicopTer flights' and expensive mobilization costs. Another example are mineral <br />.resources within. rock walls, which are obscured from aerial view and therefore cannot be <br />approached using airborne remote-sensing data: Cultural resources that were evaluated <br />with 'remote-sensing technologies consisted of: (I) camping sites and beaches; (2) <br />archaeological structures; (3) natural springs; and (4) arroyos and their effects of check <br />dams and archaeological structures. Of these resources, remote-sensing approaches <br />proved useful for mapping camping sites and beaches. The compositelbeach map <br />produced in this evaluation includes more sediment sires than can reasonably be mapped <br />by ground surveys, is a more rapid and more accurate method for change detection, and <br />was produced at a fraction of the time and expense of the traditional ground surveys. Our <br />evaluations for archeological structures and natural springs showed that (I) daytime <br />thennal infrared (TIR) and 6-II-cm resolution visible imagery do not provide sufficient <br />resolution or thennal differences to unambiguously identify or detennine changes of the <br />resources, and (2) although imagery at 3-cm resolution could only produce elevation <br />accuracies near 20 cm, which is below the accuracies required to detect small changes in <br />arroyos, the data do provide catchment-scale topography that allows geomorphic <br />modeling of the potential effects of rainfall on arroyo development and on down-slope <br />structure modification. With respect to the detection of archaeological structures and <br /> <br />~ <br /> <br />2 <br />