Spatiotemporal dynamics of coastal aquaculture and driving force analysis in Southeastern China

Figures & data

Figure 1. Study area

Figure 2. Procedures of Ningde coastal region land use and land cover classification

Table 1. Description of landscape metrics

Landscape index	Formula
NP	NP = ni; n-Number of patch
PD	PD = N/A; N-Number of patch; A-Total area
LPI	LPI = Max (a1, … an)/A × 100; ai-patch area i; A-Total area
CONTAG	$\mathrm{C}\mathrm{O}\mathrm{N}\mathrm{T}\mathrm{A}\mathrm{G}=\left[1+\frac{{\sum }_{\mathrm{i}=1}^{\mathrm{m}}{\sum }_{\mathrm{k}=1}^{\mathrm{m}}\left[\left({\mathrm{P}}_{\mathrm{i}}\right)\left(\frac{{\mathrm{g}}_{\mathrm{i}\mathrm{k}}}{{\sum }_{\mathrm{k}=1}^{\mathrm{m}}{\mathrm{g}}_{\mathrm{i}\mathrm{k}}}\right)\right]\left[ln({\mathrm{P}}_{\mathrm{i}})\left(\frac{{\mathrm{g}}_{\mathrm{i}\mathrm{k}}}{{\sum }_{\mathrm{k}=1}^{\mathrm{m}}{\mathrm{g}}_{\mathrm{i}\mathrm{k}}}\right)\right]}{2ln\left(\mathrm{m}\right)}\right]\times 100$; pi-The percentage of the area occupied by the type of patch; gik-The number of type I patch adjacent to class k plaques; m-Total number of patch types in the landscape
PAFRAC	$\mathrm{P}\mathrm{A}\mathrm{F}\mathrm{R}\mathrm{A}\mathrm{C}=\frac{\frac{2}{\left[{\mathrm{n}}_{\mathrm{i}\mathrm{j}}{\sum }_{\mathrm{j}=1}^{\mathrm{n}}\left(\mathrm{l}\mathrm{n}{\mathrm{p}}_{\mathrm{i}\mathrm{j}}-ln{\mathrm{a}}_{\mathrm{i}\mathrm{j}}\right)\right]-\left[\left({\sum }_{\mathrm{j}=1}^{\mathrm{n}}{\mathrm{p}}_{\mathrm{i}\mathrm{j}}\right)\left({\sum }_{\mathrm{j}=1}^{\mathrm{n}}{\mathrm{a}}_{\mathrm{i}\mathrm{j}}\right)\right]}}{\left({\mathrm{n}}_{\mathrm{i}}{\sum }_{\mathrm{j}=1}^{\mathrm{n}}ln{\mathrm{p}}_{\mathrm{i}\mathrm{j}}^2\right)-{\left({\sum }_{\mathrm{j}=1}^{\mathrm{n}}ln{\mathrm{p}}_{\mathrm{i}\mathrm{j}}\right)}^2}$; aij-patch area; Pij-patch perimeter; ni-patch number.
$\mathrm{D}\mathrm{I}\mathrm{V}\mathrm{I}\mathrm{S}\mathrm{I}\mathrm{O}\mathrm{N}$	$\mathrm{D}\mathrm{I}\mathrm{V}\mathrm{I}\mathrm{S}\mathrm{I}\mathrm{O}\mathrm{N}=\left[1-\sum _{j=1}^n{\left(\frac{a_{ij}}{A}\right)}^2\right]$; aij-Patch area; A-Total area
SHDI	$\mathrm{S}\mathrm{H}\mathrm{D}\mathrm{I}=-\sum _{\mathrm{i}=1}^{\mathrm{m}}\left({\mathrm{p}}_{\mathrm{i}}\mathrm{l}\mathrm{n}{\mathrm{p}}_{\mathrm{i}}\right)$; Pi-Proportion of land occupied by patch type i; m-Number of patch types present in the landscape

Table 2. Dynamics of landscape changes during 2003–2010 and 2010–2016

Time Interval	Indicator	Ecosystem Types
		CA	CL	BL	FL	WB	WL	OL
2003–2010	K/%	0.29	6.43	−5.89	−4.03	0.02	0.36	3.17
	CA/%	0.08	2.02	−1.46	−1.60	0.07	0.89	0.00
	LCI	1.53
2010–2016	K/%	0.66	4.00	−4.74	−1.64	−0.52	0.31	1.52
	CA/%	0.16	1.56	−0.59	−0.40	−1.46	0.68	0.00
	LCI	1.21

Notes: CA: Coastal aquaculture; CL: constructed land; BL: bare land; FL: farmland; WB: waterbody; WL: woodland; OL: other land.

Figure 3. Land use/cover of the Ningde coastal region in 2003 (left), 2010 (middle), and 2016 (right)

Figure 4. Types of coastal aquaculture in Ningde coastal region between 2003 and 2016. Razor clam: in blue color; farmland pond: in green color, and artificial shrimp pond: in red color

Figure 5. Transfer flows of different land use types between 2003–2010 and 2010–2016. See details in Appendices F and G

Table 3. Landscape pattern metrics of the coastal aquaculture area and the entire Ningde coastal region

Place	Indicator	2003	2010	2016
Coastal aquaculture area	NP	2269	3369	3690
	PD	0.99	1.48	1.62
	LPI	0.08	0.04	0.05
	PAFRAC	1.31	1.22	1.46
Ningde coastal region	NP	31,403	63,801	80,692
	PD	13.75	27.93	35.47
	DIVISION	0.80	0.81	0.89
	SHDI	1.27	1.24	1.25
	PAFRAC	1.23	1.30	1.31
	CONTAG	65.15	65.15	64.94

Table 4. Descriptive statistics of variables used in the regression model

Independent variable	Growth model			Attenuation model
	Mean (S.D.)	Mean (S.D.)
Initial coastal aquaculture area in 2003 (ha)	6.832(16.195)		10.724(19.573)
Distance to initial road in 2003 (m)	5.027(1.125)		4.984(1.042)
Distance to initial coastal aquaculture area in 2003 (m)	5.221(1.146)		-
Distance to newly-built port (m)	7.490(0.983)		-
Distance to initial coastline in 2003 (m)	−2.533(4.475)		-
Distance to newly-built factory (m)	-		7.660(1.222)
Distance to newly-built road (m)	-		6.595(1.904)

Notes: The distance variables used in the models are in the natural log form. For the distance to the coastal line in 2003, negative values indicated the direction to the land, and positive values indicated the direction to the sea.

Table 5. Coefficients of factors that are associated with coastal aquaculture area changes

Variable	Growth model		Attenuation model
	Unstandardized coefficient (SE)	Standardized coefficient (SE)	Unstandardized coefficient (SE)	Standardized coefficient (SE)
Initial coastal aquaculture area in 2003	0.290* (0.115)	0.570*** (0.027)	0.364*** (0.072)	0.677*** (0.134)
Distance to initial road in 2003 (log)	10,431.690** (2998.761)	0.142*** (0.028)	10,529.580*** (2251.809)	0.104*** (0.022)
Distance to initial coastal aquaculture in 2003 (log)	14,068*** (3585.648)	0.194*** (0.027)	-	-
Distance to newly-built port (log)	7023.016*** (1628.327)	0.083** (0.026)	-	-
Distance to initial coastline in 2003 (log)	4044.739*** (579.363)	0.218*** (0.029)	-	-
Distance to newly-built factory (log)	-	-	−14,529.370*** (2615.052)	−0.169*** (0.030)
Distance to newly-built road (log)	-	-	−7225.955*** (1940.229)	−0.131*** (0.035)
Intercept	146,004.400*** (20,106.330)	3.790E-9 (0.026)	112,921.500*** (31,230.640)	1.620E-9 (0.026)

Notes: *p < 0.05, **p < 0.01, ***p < 0.001. The growth model: N = 829, R² = 0.449. The attenuation model: N = 582, R² = 0.596. Variance inflation factors were tested to be < 5 in all models (see Appendices H and I).