Laserfiche WebLink
<br />00840 <br /> <br />1.0 Inlroduclion <br /> <br />For the past two decades. monitoring and research teams in the physical. biological, and <br />cullural resource programs within the Glen Canyon Environmental Studies (GCES). and now the <br />Grand Canyon Monitoring and Research Center (GCMRC). havc been monitoring and modeling <br />the effects oflhe Glen Canyon darn flows on various ecological resources within the Colorado <br />River ecosystem (CRE). The overall objective of these programs is to determine 1I0w regimes <br />that maintain the rcsources al recenllevels, and possibly restore the resources to pre-dam <br />conditions. The research and monitoring has been performed mostly by ill situ measurements, <br />supplemented by annual airborne image data provided by the information technology (IT) <br />program. The image data that were acquired generally consisted of analog. stereo black,and- <br />white photography (color-infrared or CIR photography in particular locations) at II-cm spatial <br />resolution, These data were point-perspective (unrectified) without pointing or camera <br />information necessary to rectify (georeference) the data to make accurate maps or to perform <br />photogrammetry to derive accurate topography. Correct use of these image data by scientists <br />required a complex process to transform the distorted, point-perspective analog data into an <br />undistorted (rectified), map-projected digital form so that accurate information could be obtained <br />for any particular area. The complexity of the process did not encourage many scientists to use <br />the image data to its fullest potential or accuracy. Therefore. the approaches that were used by <br />GCMRC cooperators before the year 2000 were similar to approaches used by image scientists in <br />the early 1970's. <br /> <br />The GCMRC monitoring and research programs (i.e,. physical. biological, and cultural) <br />were reviewed by exlernal protocol evaluation panels (PEP) within the past few years (Wohl et <br />aI., 1999; Doelle et a!., 2000; Urquhart et a!., 2000; Anders et a!.. 2001; Jones et a!., 2001). In <br />general, these panels recommended thatlhese programs conduct more integrated, corridor-wide <br />monitoring in order to more accurately determine the effects of dam flow on ecosystem resources. <br />In addition, the Remote Sensing PEP for the IT Program (Berlin et a!., 1998) recommended thaI <br />more modcrn, advanced remote-sensing technologies be examined to provide bener data to the <br />research programs. These two factors prompted GCMRC to establish a remote-scnsing initiative <br />whose purpose was to determine the most appropriate remote sensing technologies and <br />approaches that could increase the capabilities and efficiencics of the research scientists in order <br />to help them perform more integrated, less-invasive, corridor-wide studies. The first step in that <br />initiative, which started in the fall of 2000, was a review of the types of ecological parameters <br />being monitored, the collection methods being used, the pl)'.cision required for each paramelcr, <br />and allemative remole-sensing and GIS approaches for such monitoring. The latter aspect <br />involved a review of published literature to determine technologies and approaches that produced <br />useful resulls for problems analogous to those faced by GCMRC. The L1Seful approaches were <br />reviewed in Davis (2002a), which also includes a table of over 100 operational airborne and <br />spacebome sensor systems Ihat lists relevant characteristics oflhe sensors. The scnsor table was <br />used to sclect appropriate sensors for consideration and possible cvaluation. based on Iheir <br />capabilities for meeting the requirements for a particular program parameter. Although the <br />review found that many resource parameters that are currently monitored could nol be adequately <br />approached using airborne remote-5ensing technology. these being mostly chemical <br />characteristics of water. the review also found an equal number of parameters Ihat might be <br />approached. if dala of Ihe correct type and format were collecled and provided to Ihe scientists. <br />During Ihis inilial fact-finding process, we found that the level of detail recorded by previous <br />airborne data collections was not being used during scientific analysis, despite initial claims by <br />scientists that they needed the high resolution provided by historical data. This initial review also <br /> <br />5 <br />