What Brings More People to Parks? Open Space Environment and Visitation in Tokyo The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:37925656 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA What Brings More People to Parks? Open Space Environment and Visitation in Tokyo Jihoon Song October 2018 A dissertation presented in partial fulfillment of the requirements for the degree of Doctor of Design in the subject of Urban Planning, Design, and Environmental Studies Department of Urban Planning and Design Graduate School of Design, Harvard University Cambridge, Massachusetts © 2018 by Jihoon Song All rights reserved. iii Dissertation Advisors: Professor Peter G. Rowe, Ann Forsyth, and S. V. Subramanian Author: Jihoon Song Abstract In dense urban settings, efficient use of land is a crucial issue. Especially, urban parks take a large amount of space in high land value areas. Creating an attractive park environment for current and future visitors has the potential to increase the benefits provided by parks to surrounding communities as well as individual park visitors (Dramstad, Tveit, Fjellstad, & Fry, 2006; Roberts, McEachan, Margary, Conner, & Kellar, 2016; Whyte, 1980). This study provides models to predict the number of annual visitors to parks, and identifies the associations between park visitations and environmental factors in parks with a specific focus on medium sized neighborhood parks. The main research questions that this study addresses include the followings. Are the proportions of specific land covers (tree, water, and building) associated with visitation volumes after removing the effects from park land size and demographic variables? If so, what are the characteristics and magnitudes of the associations? This study uses neighborhood parks in Tokyo, Japan as its samples. Among more than 5,000 official urban parks in the 23 central wards of Tokyo, 185 medium-sized parks between 1ha and 10ha were selected. The annual visitation to parks was estimated through cell-phone GPS records. This GPS processing method effectively estimates visitation to medium sized parks that oftentimes are impossible to acquire. Through this application, this study exemplifies how newly emerging industry scale data can contribute to understanding of everyday activities of people that can aid more efficient planning and design (Calabrese, Diao, Di Lorenzo, Ferreira, & Ratti, 2013; Girardin, Vaccari, Gerber, Biderman, & Ratti, 2009). iv Dissertation Advisors: Professor Peter G. Rowe, Ann Forsyth, and S. V. Subramanian Author: Jihoon Song This study investigates the research questions through both OLS and multi-level models. First, a baseline model with three most probable factors - park size, surrounding population, and building footprint - were carefully established. The associations between land cover variables and visitation volumes were estimated on top of the baseline model. To enable a more robust conclusion, several sensitivity tests were conducted. The final baseline model found to have a very high fit (R2=0.8628), and the estimation remained robust when multi-level modeling was introduced. When several models were tested, the quadratic relationship between visitation and tree cover percentage appeared clearly and consistently. Although less clear than tree cover percentage, there was a positive association between visitation and water cover percentage in an acceptable significance. Also, the magnitude and certainty of the association between visitation and tree cover percentage remained almost same after water cover was added to the model. This study found there is an approximate optimal value of tree cover, which is 45%. When tree cover percentage increases from 10% to 30%, the number of visitors is likely to go up by 21,696 people yearly and 59 people daily. When tree cover percentage increases from 60% to 80%, the number of visitors is likely to decrease by 22,124 people yearly and 61 people daily. As for water cover, 10% increase in water cover percentage is likely to be related with 14,168 more visitors per year and 39 more visitors per day. The magnitudes of these associations are considerable, even when compared to the baseline factors. For example, 1ha increase in park land area is associated with an increase of 15,527 visitors yearly. These results, although not strictly causal, suggest that design or environmental quality variables in parks are important in attracting more people to parks. Careful design of parks v Dissertation Advisors: Professor Peter G. Rowe, Ann Forsyth, and S. V. Subramanian Author: Jihoon Song with appropriate amount of diverse environmental elements may be more effective than creating large parks in terms of benefitting individuals and community. Furthermore, considering the high land values of large cities such as Tokyo, these findings can help the government with cost-effective park planning. iii TABLE OF CONTENTS ABSTRACT III LIST OF FIGURES VI LIST OF TABLES IX CHAPTER 1 INTRODUCTION 1 1.1 Overarching Research Goals 1 1.2 Dissertation Organization and Main Findings 5 1.3 Contributions 8 Measurement 8 Model 11 Contents 13 Area-specific contribution 16 CHAPTER 2 LITERATURE REVIEW 18 2.1 Observing People in Open Spaces: Urban Planners and Designers’ Findings 22 2.2 Psychological Studies on Landscape Preference and Their Application to Landscape Metrics 25 Psychological studies on landscape preference 25 Linking landscape preference to landscape metrics 28 2.3 Analytic Models for Open Space Visitation 33 2.4 Measurement of Open Space Environment and Visitation 41 Open space physical environment field audit data 43 Open space physical environment GIS-based data 45 Open space visitation field audit data 47 Open space visitation GIS-based data 48 CHAPTER 3 RESEARCH SITE AND DATA 51 3.1 Current Status of Urban Open Spaces in Tokyo 51 iv 3.2 A Brief History of Tokyo Park Planning: Shaping the Current Spatial Patterns 61 3.3 Estimating the Relative Volume of Visitors: Cell Phone GPS data 83 3.4 Statistical and GIS Data on Open Spaces 90 Data gathering efforts 90 Kouen-chosho (Public Open Space Report) 90 Public open space GIS 91 Green land cover GIS 91 Zmap TOWN II Digital Housing Data for the buildings and waterbodies 92 Field audit: The Japanese version Public Open Space Tool (POST) 92 CHAPTER 4 DEVELOPMENT AND RELIABILITY OF POST JAPAN 94 4.1 Research Goals and Questions 94 4.2 Development of the Tool 95 Original POST 95 Translation, adaptation, and retranslation 97 Training of field auditors 109 Actual audit schedule 109 4.3 Sample Selection and Analysis Methods 110 Sample selection 110 Analysis methods: Simple agreement percentage and Cohen’s Kappa 112 4.4 Reliability Results and Finalization of POST JAPAN 113 CHAPTER 5 DEVELOPMENT AND VALIDATION OF ‘CONVENIENCE OF USE’ SCORES FOR OPEN SPACES 126 5.1 Research Goals and Questions 126 5.2 Definition of ‘Convenience of Use’ 127 5.3 Sample Selection and Analysis Methods 127 Sample selection 127 Analysis methods 128 5.4 Internal Structure and Score Composition 129 Internal structure 130 IRT result and correlation with the weighted score 136 5.5 Relationship with Size 141 CHAPTER 6 OPEN SPACE ENVIRONMENT AND VISITATION 148 v 6.1 Research Goals and Questions 148 6.2 Sample Selection and Analysis Methods 149 Sample selection 149 Analysis methods 153 6.3 Building a Baseline Model 155 6.4 Individual Elements 166 Tree land cover 166 Water cover 169 The convenience scores - amenities 171 Final model interpretation for individual elements 174 6.5 Spatial Composition and Configuration 176 CHAPTER 7 CONCLUSION 181 BIBLIOGRAPHY 186 APPENDICES 197 Appendix A: POST JAPAN (in Japanese) 197 Appendix B: POST JAPAN Audit Manual used for the training of the assistant (in Japanese) 203 vi List of Figures FIGURE 1-1 JOAN LORENTZ PARK IN FRONT OF CAMBRIDGE PUBLIC LIBRARY, MA ................................................................................................................................................. 1 FIGURE 1-2 CONCEPTUAL RELATIONSHIP BETWEEN OPEN SPACE VISITATION AND RELATED FACTORS ............................................................................................................ 3 FIGURE 3-1 AREA PROPORTION BY CATEGORY (SOURCE: CALCULATED BASED ON TOKYO METROPOLITAN GOVERNMENT (2014)) ....................................................... 57 FIGURE 3-2 SPATIAL DISTRIBUTION OF PARKS IN THE 23 SPECIAL WARDS............. 57 FIGURE 3-3 NUMBER OF PARKS BY SIZE AND CATEGORY (SOURCE: CALCULATED BASED ON TOKYO METROPOLITAN GOVERNMENT (2014)) .................................. 58 FIGURE 3-4 COMPARISON OF URBAN PARKS BETWEEN TOKYO 23 WARDS AND SEOUL (SOURCE: CALCULATED BASED ON BUREAU OF GREEN CITY ; TOKYO METROPOLITAN GOVERNMENT (2014)) ...................................................................... 61 FIGURE 3-5 HIBIYA PARK WITH KASUMIGASEKI HIGH-REISE BUILDINGS ............... 64 FIGURE 3-6 PARK PLAN OF THE IMPERIAL CAPITAL RECONSTRUCTION PLAN (1923): SHOWS LARGE PARKS AND BOULEVARDS CONNECTING THEM............ 67 FIGURE 3-7 GREEN SPACE CLASSIFICATION SYSTEM BY THE TOKYO REGIONAL GREEN SPACE COUNCIL .................................................................................................. 69