PREDICTING MODELS OF OPENNESS AND COMPLEXITY IN RIVER LANDSCAPE BY PHYSICAL CHARACTERISTICS BASED ON CG PICTURES FROM GIS DATA

―A study on Up・PHe・PSe synthesis evaluation system of river landscape Part 4―

Abstract

1 Introduction

In order to help us understanding river landscape better and create value as urban river landscape resources, we need more objective and quantitative cognition. Therefore the purpose of this study is to construct a multi-level evaluation system that predict the physical evaluation of a river landscape by the city planning indexes around the river and then predict the psychological evaluation of the river landscape by the physical indexes.

2 Outline of the study

As a result of a factor analysis of psychological evaluations in the previous study, it was also confirmed that four factors predicted satisfaction, which was an overall psychological evaluation. In two of these factors, it was not sufficient in the prediction by the physical indexes. Therefore, the purpose of this paper was to create new physical indexes that can explain these two, “Openness” and “Complexity”.

3 Method of the study

We conducted two preliminary experiments and a main experiment of psychological evaluation about the river landscape. At first, preliminary experiment 1 was conducted to identify factors related to the “Openness” and “Complexity” of river landscape images. In addition, 65 CG pictures were created that are expected to show variable evaluations related to these factors, and preliminary experiment 2 was conducted to reduce the number of CG pictures from 65 to 45. Based on the above results, we conducted the main experiment and confirmed the usefulness of the new physical indexes by considering the relationship between psychological and physical evaluation.

4 Conclusion　　　　Major findings are as follow:

1) From the results of preliminary experiment 1, it was confirmed that various factors have an influence on “Openness” and “Complexity”, unlike “Green-visibility” and “Constructivenss”. Therefore, it was shown that it is necessary to pay attention not only to the amount of simple elements in the landscape images but also to the positional relationship such as arrangement, density, and overlapping, as factors of “Openness” and “Complexity”.

2) Assuming that one image is composed of multiple images, the new physical indexes obtained by disassembling the image enabled us to grasp more detailed physical evaluation, and understand the features at each point. In particular, the physical evaluation concerned with “the Buildings forming 1st Line-of-Sight Area” was confirmed to be related to the various psychological evaluation items.

3) According to the results of multiple regression analysis, we obtained high multiple correlation coefficients in "Sense of openness" and “Sense of complexity" explained by the new physical indexes. And the proposal of new physical indexes led to the construction of a more precise predictive model.

 

In the future, we will explore ways to further improve the accuracy of psychological evaluation prediction models. Furthermore, we will examine the relationship between physical evaluation and urban planning indexes in order to construct the multi-level evaluation system.