. 2017 Dec 13;12(12):e0188687. doi: 10.1371/journal.pone.0188687

Table 3. Internal models of RSDMS.

Category	Index name	Formula	Reference
Inversion models of surface parameters	NDVI [40]	NDVI = (ρ_NIR − ρ_Red)/(ρ_NIR + ρ_Red)	Deering, 1978
	ATI [41]	ATI = (1 − Albedo)/(T_max − T_min)	Tian and Yang, 1992
	NDWI [42]	NDWI = (ρ_Green − ρ_NIR)/(ρ_Green + ρ_NIR)	McFeeters, 1996
	MNDWI [43]	MNDWI = (ρ_Green – ρ_MIR)/(ρ_Green + ρ_MIR)	Xu, 2006
Drought monitoring models	VSWI [44]	VSWI = 100 × NDVI/T_s	Carlson et al., 1994
	VCI [45]	$V C I = \frac{N D V I - N D V I_{\min}}{N D V I_{\max} - N D V I_{\min}} \times 100$	Kogan, 1995
	TVDI [23]	TVDI = (T_s − T_s,min)/(T_s,max − T_s,min)	Sandholt et al., 2002
	SIWSI [46]	$S I W S I = \frac{ρ_{S W I R} - ρ_{N I R}}{ρ_{S W I R} + ρ_{N I R}}$	Fensholt et al., 2003
	PDI [24]	$P D I = \frac{1}{\sqrt{M^{2} + 1}} (ρ_{Re d} + M ρ_{N I R})$	Zhan et al., 2007
	MPDI [47]	$M P D I = \frac{ρ_{Re d} + M ρ_{N I R} - f_{v} (ρ_{Re d} + M ρ_{N I R, v})}{(1 - f_{v}) \sqrt{M^{2} + 1}}$	Ghulam et al., 2007a
	VCADI [47]	$V C A D I = \frac{A_{N D V I} - A_{\min N D V I}}{A_{\max N D V I} - A_{\min N D V I}}$	Ghulam et al., 2007a
	SPSI [25]	$S P S I = \frac{1}{\sqrt{M^{2} + 1}} (ρ_{S W I R} + M ρ_{N I R})$	Ghulam et al., 2007b
	NPDI [48]	$N P D I = \frac{1}{\sqrt{M^{2} + 1}} (R_{s} + M R_{d})$	Feng et al., 2011