Optimizing community green roof spaces in high-density cities: a K-modes clustering algorithm based analysis of resident preferences and spatial configuration

Figures & data

Figure 1. Green roofs cases integrated with spatial functions.

Figure 2. Map of 6 survey sites in 6 blocks in Hangzhou.

Table

Career	%	Monthly Income	%	Family Members	%
Self-employed	9.3	Less than 700	25.3	Solitude	19.9
Workers	3.3	700–1400	41.5	Cohabitation	19.0
Company employees	18.9	1400–2800	16.7	Two generations	35.3
Services	1.1	2800–4200	7.8	Three generations	23.2
Managers	7.3	>4200	8.7	Others	2.6
Students	17.9
Institutional Staff	6.4
Professionals	17.3
Freelancers	9.2
Retirees	9.3

*The unit for respondent Monthly Income is USD. The officially pegged exchange rate is USD1.00 = CNY7.14.

Table 1. Distribution of respondent characteristics.

Gender	%	Age	%	Education level	%
Male	46.9	14–24	20.7	Junior high school and below	5.6
Female	53.1	25–40	38.6	Senior school Degree	23.8
		41–55	28.2	Associate Degree	11.3
		56–70	9.4	Bachelor’s Degree	31.9
		>70	3.0	Master’s Degree or above	27.5

Table 2. Distribution of respondent acceptance level about green roofs.

Exercise Frequency	%	Types of Roof	%	Willingness to Participate	%
Never go	23.4	Empty Roof	6.7	Very willing	33.9
1 time a week	13.5	Lawn Roof	8.0	Willing	43.8
2–3 times a week	28.1	Garden Roof	85.6	Neutral	17.7
4–5 times a week	16.9			Unwilling	3.7
Everyday	18.1			Very unwilling	0.9

Table 3. Respondent preference degree to roof functional forms.

Spaces Classification	1-2points		3-4points		5-6points		7-8points		9-10points		Average
	N	%	N	%	N	%	N	%	N	%
Landscape Leisure Space (LLS)											7.67
Plant Viewing	15	2.2	19	2.7	106	15.2	249	35.6	310	44.3	8.03
Relaxation & Leisure	22	3.2	19	2.7	103	14.7	244	34.9	311	44.5	7.94
Landscape Sculpture	44	6.3	61	8.7	164	23.5	200	28.6	230	32.9	7.05
Agricultural Production Space (APS)											6.45
Crop Growing & Picking	69	9.9	73	10.4	177	25.3	197	28.2	183	26.2	6.53
Crop Bazaar & Sharing	77	11.0	90	12.9	209	29.9	207	29.6	116	16.6	6.07
Nature Education	48	6.9	59	8.4	191	27.3	230	32.9	171	24.5	6.74
Ecological Low-Carbon Space (ELS)											6.69
Rainwater Collection	38	5.4	69	9.9	147	21.0	203	29.0	242	34.6	7.13
Waste separation	90	12.9	94	13.5	161	23.0	167	23.9	187	26.8	6.28
Solar Power	58	8.3	59	8.4	196	28.0	211	30.2	175	25.0	6.66
Activity Gathering Space (AGS)											6.65
Salon & Party	48	6.9	80	11.4	182	26.0	206	29.5	183	26.2	6.67
Sport & Fitness	51	7.3	66	9.4	187	26.8	237	33.9	158	22.6	6.64
Festival & Event	59	8.4	63	9.0	182	26.0	230	32.9	165	23.6	6.63

Figure 3. Elbow method graph.

Table 4. Cluster centers of 16 clusters from K-modes clustering.

Cluster	N	Gender	Age	Education	Monthly Income	Family Numbers	Times of Activities	MHD
01	111	F	25–40	Bachelor’s Degree	700–1400	Two generations	2–3 times a week	3
02	72	M	14–24	Senior school Degree	Less than 700	Three generations	Never go	3
03	80	F	41–55	Senior school Degree	Less than 700	Two generations	4–5 times a week	2
04	45	F	41–55	Master’s Degree and above	700–1400	Three generations	Everyday	2
05	66	M	41–55	Senior school Degree	700–1400	Two generations	2–3 times a week	3
06	65	F	25–40	Master’s Degree and above	1400–2800	Solitude	Never go	2
07	56	M	25–40	Master’s Degree and above	700–1400	Cohabitation	4–5 times a week	2
08	32	F	14–24	Bachelor’s Degree	Less than 700	Solitude	Everyday	2
09	33	M	41–55	Bachelor’s Degree	1400–2800	Three generations	2–3 times a week	2
10	27	F	56–70	Associate Degree	700–1400	Cohabitation	Everyday	2
11	29	F	25–40	Bachelor’s Degree	700–1400	Cohabitation	Never go	1
12	28	F	25–40	Master’s Degree and above	Less than 700	Two generations	Everyday	1
13	11	F	25–40	Bachelor’s Degree	Less than 700	Three generations	Never go	1
14	13	F	41–55	Bachelor’s Degree	700–1400	Solitude	4–5 times a week	1
15	11	F	14–24	Master’s Degree and above	700–1400	Solitude	2–3 times a week	1
16	20	F	41–55	Bachelor’s Degree	1400–2800	Two generations	Never go	1

*The unit for respondent Monthly Income is USD. The officially pegged exchange rate is USD1.00 = CNY7.14.

Figure 4. 16 clusters respondents spatial preference ranking and classification.

Figure 5. Respondent social demographic characteristics radar chart.

Figure 6. “1+X” green roofs spatial function configuration.