Table 3.

Conditional probability of SPI and SPEI (Cp (SPI) and Cp (SPEI)) in different geomorphic types in Sichuan province in different periods and time scales.

Physiognomy	Period	Cp (SPI)				Cp (SPEI)
		1	3	6	12	1	3	6	12
Plateau	1961–1970	0.33	0.58	0.75	/	0.29	0.66	0.94	/
	1971–1980	0.41	0.33	0.49	0.43	0.45	0.53	0.51	0.56
	1981–1990	0.82	0.25	0.66	/	0.83	0.84	0.33	/
	1991–2000	0.95	0.25	0.33	/	0.54	0.33	0.25	/
	2001–2010	0.14	0.28	0.44	0.11	0.95	0.55	0.66	0.87
	2011–2019	0.44	0.33	0.5	/	0.95	0.98	0.96	/
Mountainous	1961–1970	0.64	0.82	0.75	0.78	0.98	0.93	0.92	0.95
	1971–1980	0.51	0.81	0.82	0.95	0.33	0.75	0.97	0.93
	1981–1990	0.56	0.86	0.72	0.22	0.71	0.66	0.73	0.25
	1991–2000	0.71	0.75	0.57	/	0.71	0.97	0.55	/
	2001–2010	0.29	0.63	0.63	0.92	0.83	0.98	0.87	0.98
	2011–2019	0.59	0.64	0.76	0.97	0.91	0.9	0.91	0.99
Hill	1961–1970	0.55	0.8	0.92	/	0.67	0.81	0.95	/
	1971–1980	0.53	0.61	0.93	/	0.68	0.66	0.56	/
	1981–1990	0.62	0.54	/	/	0.71	0.59	/	/
	1991–2000	0.58	0.69	0.63	0.92	0.64	0.95	0.78	0.96
	2001–2010	0.57	0.7	0.64	0.92	0.89	0.95	0.96	0.96
	2011–2019	0.64	0.62	0.43	/	0.98	0.83	0.67	/
Plain	1961–1970	0.44	0.85	0.91	/	0.57	0.95	0.83	/
	1971–1980	0.83	0.75	0.57	0.33	0.95	0.75	0.67	0.95
	1981–1990	0.44	0.75	/	0.89	0.95	0.95	/	0.96
	1991–2000	0.93	0.74	0.86	/	0.87	0.78	0.87	/
	2001–2010	0.67	0.69	0.76	0.92	0.91	0.95	0.91	0.95
	2011–2019	0.67	0.43	0.55	/	0.8	0.75	0.95	/

(‘/’ means that there is no drought, so the conditional probability cannot be calculated).