How to combine socioeconomic assessment and remote sensing methods to recover and group farm plots at risk of abandonment

Figures & data

Figure 1. Study area.

Figure 2. Methodological framework.

Table 1. Indicators and thresholds for the ‘traffic-light’ land use tool established by the expert panel.

Dimension	Indicator	Established Threshold	References
Social characteristics	Member’s age	≤70 years old	(Corbelle-Rico & Crecente-Maseda, 2014) (Terres et al., 2015)
Farm structure	Plot size	≥0.7 hectares	(Corbelle-Rico & Crecente-Maseda, 2014) (Terres et al., 2015)
Productive performance	Age of citrus crop	≤20 years old (planted after the year 2000)	(Ribal et al., 2017) (Corbelle-Rico & Crecente-Maseda, 2014) (Terres et al., 2015)
Commercial quality	The average quality of the last three seasons’ production	≤30% non-commercial quality	(Corbelle-Rico & Crecente-Maseda, 2014) (Terres et al., 2015) (Wilson, 2014)

Table 2. Classification of the socioeconomic characteristics of members and land plots.

	Social characteristics	Farm structure	Productive performance	Commercial quality
Red	X	X	X	X
Green	√	√	√	√
Amber	Different combinations; at least one X

√ means that a land plot is within the desirable limits; X means that a land plot fails to meet the desirable thresholds.

Figure 3. Workflow followed to classify the plots.

Table 3. References and equations of the spectral vegetation indices evaluated in this study.

Vegetation Index	Equation	Reference
Normalised Difference Vegetation Index	$NDVI=\frac{\left(NIR-R\right)}{\left(NIR+R\right)}$	Rouse et al. (1973)
Enhanced Vegetation Index	$EVI=2.5\frac{\left(NIR-R\right)}{\left(NIR+6R-7.5B+L\right)}$	Jiang et al. (2008)
Thiam’s Transformed Vegetation Index	$TTVI=\sqrt{\frac{\left(NIR-R\right)}{\left(NIR+R\right)}+0.5}$	Thiam (1998)
Soil-Adjusted Vegetation Index	$SAVI=\frac{\left(NIR-R\right)}{\left(NIR+R+L\right)}\left(1+L\right)$	Huete (1988)

Where: a) NIR is near infra-red, R is red, and B is blue spectral bands of Sentinel-2; b) L is a soil adjustment factor.

Figure 4. Categories of plots classified according to the type of land cover.Where: a) in production with large trees, b) in production with small trees, c) Not in production, d) Abandoned land.

Table 4. Confusion matrix (2×2).

		Predicted class
		Positive	Negative
Actual class	Positive	TP	FN	True positive rate (Sensitivity) TP/(TP + FN)
	Negative	FP	TN	True negative rate (Specificity) TN/(FP + TN)
		Positive Predicted Value (Precision): TP/(FP + TP)	Negative Predicted Value: TN/(TN + FN)	Accuracy (TP + TN)/(TP + FN + FP + TN)

Table 5. ‘Traffic-light’ results for the cooperative in the case study.

Groups and characteristics	Plots		Area
	Number	%	ha	%
Red	10	0.68	1.96	0.31
Green	130	8.83	207.18	32.79
Amber	1,332	90.49	422.67	66.90
Social characteristics	417	28.39	132.64	21.02
Farm structure	1,236	84.14	312.57	49.54
Productive performance	552	37.58	202.03	32.02
Commercial quality	30	2.04	7.85	1.24

Note: the number of plots in the amber group and their surface area may be greater than the total amber plots since a plot may have more than one problem.

Figure 5. Distribution of the plots of cooperative members according to the “traffic-light” approach.

Table 6. Obtained Confusion Matrix.

	Abandoned	Not in production	In production (Large trees)	In production (Small trees)	Classification error
Training set
Abandoned	222	9	15	16	0.1526718
Not in production	6	217	5	23	0.1354582
In production (large trees)	10	0	247	19	0.1050725
In production (Small trees)	17	12	14	230	0.1575092
Validation set
Abandoned	77	4	2	5	0.1250000
Not in production	4	74	1	4	0.1084337
In production (large trees)	7	4	71	3	0.1647059
In production (Small trees)	5	9	4	82	0.1800000

Figure 6. Random Forest results.

Table 7. Number of plots, surface area, and percentages of classification.

Classification	Plots		Area
	Number	%	ha	%
Abandoned	7,070	19	2,266	12
Not in production	3,620	10	1,596	9
In production (Large trees)	11,179	30	7,566	41
In production (Small trees)	14,054	38	6,171	33
Total	35,923		17,599

Figure 7. Map resulting from predicted model.

Figure 8. Potential JCM Initiatives.

Table 8. Main productive characteristics of JCM initiatives.

Areas	Abandoned plots outside the cooperative area		Red and amber Cooperative plots		Total plots
	Number	Area (ha)	Number	Area (ha)	Number	Area (ha)
1	114	29.84	13	2.97	127	32.81
2	95	21.49	25	7.31	120	28.8
3	50	17.43	22	6.88	72	24.31
4	56	11.88	5	1.11	61	12.99
5	75	20.07	13	4.78	88	24.85
6	87	17.94	45	12.23	132	30.17
7	9	7.59	1	0.24	10	7.83
8	44	7.35	8	1.37	52	8.72
9	81	11.9	17	2.25	98	14.15
10	7	5.71	1	0.39	8	6.1
11	29	5.66	4	0.92	33	6.58
TOTAL	647	156.86	154	40.45	801	197.31

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