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<br />(II t, . <br />0110068 <br /> <br />1790 <br /> <br />BROW,.. AND DANIEL: LANDSCAPE AESTHETICS OF RIPARIAN ENVIRONMENTS <br /> <br />about 9% of the recreational trips, while less than 1% were <br />for floating in a raft or kayak. The most popular activities <br />were sightseeing, picnicking, and hiking, in that order. We <br />have no information about the Tucson respondents' famil- <br />iarity with rivers in the Rocky Mountains, but it is safe to <br />assume that only the rare observer was familiar with the <br />Poudre River. <br />Group-to-group reliability [Ebel, 1951] is of primary inter- <br />est in this study because it focuses on group mean prefer- <br />ences, rather than individual observer differences. Group-to- <br />group reliability indicates the expected correlation between <br />panels of the same size as the sample panel, drawn from the <br />same population. The reliability coefficients were 0.81 (n = <br />27). 0.87 (n = 32), and 0.89 (n = 26) for the three Tucson <br />pbOIO sets and 0.91 (n = 34),0.91 (n = 43), and 0.94 (n = 37) <br />for the three Fort Collins sets. These reliability coefficients <br />indicate substantial agreement among observer groups about <br />the relative scenic beauty of the scenes but somewhat more <br />agreement in Fort Collins than Tucson. The coefficients are <br />similar to those we have obtained for scenic beauty ratings of <br />forest scenes [Brown and Daniel, 1987]. <br />The correlations across photo sets of SBEs for the base- <br />line scenes, which were common to all observer groups, <br />provide another indication of the level to which the groups <br />agreed about the relative scenic beauty of the scenes. <br />Correlations among the three Tucson scene sets are 0.85, <br />0.86, and 0.87, and the three correlations for the Fort Collins <br />scene sets are 0,83, 0.87. and 0.87, These baseline correla- <br />tions are similar to those for forest scenes obtained from <br />groups viewing color slides [Daniel el aI., 1989]. . <br />Paired-comparison experiment. Eight views for which <br />relatively good photographic representations were available <br />for four different flow categories were chosen for presenta- <br />tion to observers in pairs, each pair showing the same view <br />at two different flow levels. The flow categories and rheir <br />nominal flow levels were low (152 cfs (4.30 ml/s)), medium <br />low (479 or 715 cf, (13.6 or 20.: mJ/s)). medium high (1202 <br />cfs (34.04 mJ/s)), and high (2304 or 2642 cfs (65.24 or 74.81 <br />m lIs)). All six possible pairs of the four flow categories were <br />shown for each of the eight views, requiring 48 paired <br />comparisons. Further, to lessen the flow-oriented focus <br />somewhat, 28 additional pairs of different views at the same <br />flow level (medium low) were randomly interspersed among <br />the same-view pairs. for a total of 76 comparisons. <br />The pairs of scenes were shown to two Tucson student <br />observer groups, of 15 and 19 participants, for 12 s each on <br />a pair of monitors placed side by side. The general introduc- <br />tion to observers about the purpose of the study was the <br />same as that for the rating experiments, but the specific <br />instructions were quite different. Observers were instructed <br />to "decide which of the two scenes is more attractive." <br />They were further informed that, for many of the compari- <br />sons, <br /> <br />you will see essentially the same river scene on both screens. <br />This is because these areas were filmed al several different <br />times during the past summer. One of our concerns in this <br />research is whether the scenic quality of river areas changes <br />with the sea~ons; and even during (he course of one summer <br />there are subtle variations In such variables as the flow rate of <br />the river. the amount of sun-ounding vegetation. and the color <br />of the vegetation that might influence perceplions of scenic <br />quality, <br /> <br />Thus the instructions tended to soften the emphasis on flow <br />level by mentioning vegetation differences as well. <br />Each group of observers' preferences was scaled to Z <br />scores according to Thurstone's law of comparative judg_ <br />ment, as outlined by Torgerson [1958] and reviewed by Hull <br />et al. [1984]. This is a common scaling procedure for paired <br />comparisons and has been used extensively in other scenic <br />quality studies [e.g., Buhyoff and Leuschner, 1978; Buhyoff <br />and Wellman, t980]. The resulting Z scores provide an <br />interval scale of preference. The Z scores of the two ob- <br />server groups were averaged, and the averages were multi- <br />plied by 100 to eliminate decimal~, making them similar in <br />magnitude to SBEs. These adjusted Z scores are called <br />paired-comparison estimates (PCEs) herein. <br /> <br />RELATIONSHIP OF FLOW TO SCENIC BEAUTY <br /> <br />Plots of SHE versus flow for the two rating experiments <br />show a wide range in scenic beauty among scenes at any <br />given flow level, reflecring the large differences in vegeta- <br />tion, topography. view perspective. depth of view. weather, <br />and other features among the scenes. However. within all <br />that diversity, a concave relationship is noticeable, as scenic <br />beauty initially incr-eases with flow and then decreases as <br />flow continues to increase. Similarly, a plot of PCE from the <br />paired-comparison experiment verses flow for the eight <br />views each shown at four flow levels shows a wide range in <br />scenic beauty across the sites at a given flow level, but a <br />concave relationship of scenic beauty to flow is evident. <br />Furthermore, the concave relationship is somewhat more <br />pronounced than it is for the rating experiments, which is <br />expected given the greater emphasis on flow in the paired- <br />comparison format and the omission of the scenes showing <br />the most cloudy weather. <br />As discussed above, flow rate was estimated from USGS <br />records. Numerous other variables were estimated by visual <br />inspection of the Video scenes. These variables. listed in <br />Table 2, include characteristics such as percent of the scenes <br />in rock, sky, and water, distance of the view, color of the <br />water, distance ofthe camera from the stream channel, and <br />color trueness of the photography. Four observers indepen. <br />dently estimated each variable. and the mean of their judg- <br />ments was computed. The reliability coefficients for these <br />means ranged from 0.47 to 0.98, with a median of 0.91, <br />indicating generally good relative agreement among the four <br />observers. The lowest reliability coefficient was for the <br />percent of the scene showing ex.posed river bed (BED, Table <br />2), which tended to be a very small percentage of rhe scene <br />and thus difficult to precisely estimate. The nex.t lowest <br />coefficient was 0.72 for photographic lighting accuracy <br />(PHOTOL), which is a relmively subjective variable. <br />The relationship of flow to scenic beauty was assessed by <br />regressing the scenic beauty measure on variables represent- <br />ing scene features, using slepwise least squares. Because <br />plots indicated a concave relationship of scenic beauty to <br />flow, flow was represented by simple and squared terms in <br />the regressions. Other independent variables were included, <br />as described in Table 2. Separate models were produced for <br />the three experiments. <br />The regression models of each experiment included both <br />flow terms and supported Litton's (1984) hypothesis that <br />scenic beaulY of streams is diminished at both very low and <br />abnormally high flow levels, SSE reached a maximum 3t <br /> <br /> <br />N" <br /> <br />Indepe:J <br />FLO <br />SOIt <br /> <br />VEG <br /> <br />ROC <br /> <br />SKY <br />WAl <br />BED <br /> <br />VIE' <br /> <br />sou <br /> <br />WIN <br />WID <br /> <br />WC( <br /> <br />L1G' <br /> <br />PHC <br /> <br />PHC <br /> <br />HDJ <br /> <br />VDI <br /> <br />-All <br />sequer <br /> <br />1092 <br />06,3\ <br />maxir <br />value <br />of flo <br />rating <br />exper <br />about <br />mJ/s) <br />nic b~ <br />reach <br />All <br />error <br />beaul <br />thai t <br />equal <br />dUre. <br />Th <br />perio <br />prefe <br />betw <br />klos <br />ftow~ <br />reSer <br />read' <br />0, <br /> <br />