景観評価に関する地理学的研究

わが国の湖沼を事例にして

抄録

Landscape evaluation is one of the main subjects in the field of geographical studies. Yet, little effort has been made in Japan to further study in the area of landscape evaluation and landscape characteristics. This study deals with 33 lakes in Japan as a sample, and aims to work out a model by which an appropriate evaluation of tourist resources can be obtained.
33 sample lakes are chosen with due consideration to their location, origin, size, horizontal and vertical distribution so that the samples are evenly distributed and regional bias is eliminated.
12 factors are set forth for evaluation of these samples: area, length of shore line, depth, transparency, shape, nutritive condition, origin, accessibility, existence of islands, surrounding scenery and other characteristics. Lake color, though an important factor, was only obtainable for half the samples. Therefore, we treated it as one factor among other “characteristics.”
Each of these 12 factors is standardized into three to five categories, and is applied to chosen samples, giving each lake a category score on each of these factors. A matrix chart is thus obtained of 33 lakes with category scores for 12 selected factors.
Ratings for 33 samples given by such specialists as limnologists and tourism planners are used to represent “general evaluation” as criterion variable. By analyzing the ratinge of 15 specialists for 33 lakes, we came to the conclusion that nine of them gave a fair and appropriate evaluation. Therefore, an arithmetical mean of the ratings given by nine specialists is used as a “ general evaluation.”
When we use the discriminat method of Qualification Theory I, 12 factors are too many to analyze as compared with the number of samples. Therefore, 12 factors are classified into three groups by the discriminant method of Qualification Theory III. Then, by stepwise regression analysis, 3 factors are left as key factors in evaluating the lake; namely, transparency, surrounding scenery and accessibility.
A category score of the factors thus chosen is obtained by calculating the relationship between the “general evaluation” and the 3 remaining factors, with the help of the method of Qualification Theory I. The range of these 3 factors are, respectively, 0.8744, 1.8544 and 0.8609. Its multiple regression coefficient is 0.8467, which proves that not much loss of information is caused when the number of factors decreased from twelve to three. The 3 remaining factors are very simple ones, easy to understand and to apply; transparency can be gauged by existing data. Accessibility can be gauged with topographical maps. Scenic quality of surrounding scenery is maintained by using sub-elements.
An objective, yet very simple, method of evaluation is thus established. We can safely say that this method is also applicable to any other tourist resources: mountains, plateau, rivers, etc.