Spatiotemporal Variations of Drought in the Arid Region of Northwestern China during 1950–2012

Table 5

Analysis of the catastrophe points of the SPI, SPEI, and SC-PDSI.

Study area	SPI				SPEI				SC-PDSI
	M-K		Pettitt		M-K		Pettitt		M-K		Pettitt
I	1987	−/+	1987	−/+	1984	−/+	1984	−/+	1987	−/+	1987	−/+
II	1993	−/+	1987	−/+	1987	−/+	1987	−/+	1987	−/+	1987	−/+
III	1981	−/+	1987	−/+	1980	−/+	1987	−/+	1977	−/+	1987	−/+
IV	1978	−/+	1972	−/+	1976	−/+	1972	−/+	1978	−/+	2002	−/+
V	1985	+/−	1985	+/−	1985	+/−	1985	+/−	1990	+/−	1967	+/−
VI	1982	+/−	1982	+/−	1981	+/−	1982	+/−	1972	+/−	1980	+/−
ARNC	1987	−/+	1987	−/+	1980	−/+	1987	−/+	1983	−/+	1987	−/+