Spatio-temporal Dynamics of Spartina alterniflora in Tianjin-Hebei Coastal Area

Fig. 2. Interannual distribution of Hebei coastal Spartina alterniflora

Fig. 3. Interannual distribution of Spartina alterniflora rice in Tianjin Binhai New District

Fig. 4. Transfer in and out of Spartina alterniflora and other land cover types in Tianjin-Hebei coastal area from 2000 to 2022

Fig. 5. Change map of centroid of Spartina alterniflora in Tianjin-Hebei coastal area from 2000 to 2022

Fig. 6. Standard deviation ellipse of Spartina alterniflora in Tianjin-Hebei coastal area from 2000 to 2022

Table 1. Table 1Distribution of Spartina alterniflora in various coastal areas of Tianjin-Hebei from 2000 to 2022

Table 1. Table 1Distribution of Spartina alterniflora in various coastal areas of Tianjin-Hebei from 2000 to 2022

主要分布区域		年份面积/hm²
主要分布区域		2000年	2005年	2010年	2015年	2020年	2022年
唐山市	曹妃甸区						3.26
	滦南县				3.24
	丰南区				6.39	45.91	43.78
天津	滨海新区	9.18	53.74	122.05	425.88	195.32	249.74
沧州市	黄骅市	0.90	7.65	3.81	15.93	56.39	128.84
	总计	10.08	61.39	125.86	451.44	297.62	425.62

Table 2. Table 2Changes of expansion intensity and speed index of Spartina alterniflora

Table 2. Table 2Changes of expansion intensity and speed index of Spartina alterniflora

主要分布区域		Q/%					S/(hm²/a)
主要分布区域		2000~2005	2005~2010	2010~2015	2015~2020	2020~2022	2000~2005	2005~2010	2010~2015	2015~2020	2020~2022
唐山市	曹妃甸区										1.63
	滦南县				-20				0.65	-0.65
	丰南区				124	-2			1.25	7.90	-1.07
天津	滨海新区	97	25	50	-11	14	8.91	13.66	60.77	-46.11	27.21
沧州市	黄骅市	150	-10	64	51	64	1.35	-0.77	2.42	8.09	36.23
	总计	102	21	52	-7	22	10.26	12.89	65.12	-30.76	64.00

Table 3. Table 3Parameter values of the standard deviation ellipse of the variation of Alternaria Spartina alterniflora in each period

Table 3. Table 3Parameter values of the standard deviation ellipse of the variation of Alternaria Spartina alterniflora in each period

年份	Shape_Length/km	Shape_Area/km²	CenterX/km	CenterY/km	XStdDist/km	YStdDist/km	Rotation/°	Oblateness
2000	194.45	15.95	560.90	4307.99	0.27	19.01	17.31	0.99
2005	286.68	40.02	559.40	4302.80	0.45	28.06	22.53	0.98
2010	322.78	603.29	1078.57	4319.06	5.71	33.61	10.50	0.83
2015	391.06	1856.86	560.94	4297.59	13.64	43.33	19.59	0.69
2020	206.94	2385.15	565.81	4303.33	16.57	45.83	20.22	0.64
2022	214.78	2470.47	563.44	4289.83	16.37	48.05	17.76	0.66

Table 4. Table 4Fractal dimension of Spartina alterniflora in various regions of the Tianjin-Hebei coastal area