Table 3.

Inter-correlations of PM_2.5 observations at all stations. R is the Pearson correlation coefficients, and D stands for the distance between every two stations, the unit is kilometers.

	R	1001	1002	1003	1004	1005	1006	1007	1008	1009	1010	1011	1012
D
1001		1	0.79	0.93	0.94	0.93	0.93	0.90	0.88	0.82	0.84	0.92	0.92
1002		47.38	1	0.83	0.84	0.83	0.85	0.85	0.85	0.89	0.94	0.85	0.85
1003		7.93	43.7	1	0.97	0.97	0.97	0.93	0.90	0.84	0.87	0.96	0.91
1004		4.78	47.87	4.86	1	0.97	0.96	0.93	0.90	0.84	0.88	0.95	0.91
1005		11.38	44.48	3.86	7.31	1	0.95	0.92	0.91	0.84	0.87	0.96	0.91
1006		5.78	41.61	6.65	7.52	10.44	1	0.95	0.91	0.85	0.89	0.97	0.94
1007		13.33	34.39	12.82	15.19	15.84	7.83	1	0.90	0.85	0.89	0.95	0.94
1008		37.85	41.24	29.92	34.12	26.82	34.77	34.89	1	0.90	0.87	0.92	0.89
1009		55.27	34.83	47.86	52.62	45.74	50.72	47.72	22.47	1	0.90	0.87	0.85
1010		39.10	8.38	35.76	39.77	36.82	33.34	26.03	37.47	35.95	1	0.89	0.90
1011		12.18	37.61	6.13	10.71	7.4	7.69	9.39	27.24	43.19	29.74	1	0.93
1012		14.88	42.14	19.94	19.28	23.76	13.32	11.96	46.58	59.54	33.92	19.67	1