Detecting Variation Trends of Temperature and Precipitation for the Dadu River Basin, China

Table 2

Definitions of temperature and precipitation extreme indices used in the present study.

Index	Index name	Definitions	Units
Temperature
FD0	Frost days	Annual count when TN (daily minimum) < 0°C	d
SU25	Summer days	Annual count when TX (daily maximum) > 25°C	d
TXn	Minimum	Monthly minimum value of daily maximum temperature	°C
TXx	Maximum	Monthly maximum value of daily maximum temperature	°C
TNn	Minimum	Monthly minimum value of daily minimum temperature	°C
TNx	Maximum	Monthly maximum value of daily minimum temperature	°C
TX90p	Warm days	Percentage of days when TX > 90th percentile	d
TX10p	Cool days	Percentage of days when TX < 10th percentile	d
TN90p	Warm nights	Percentage of days when TN > 90th percentile	d
TN10p	Cool nights	Percentage of days when TN < 10th percentile	d
Precipitation
CDD	Consecutive dry days	Maximum number of consecutive dry days of a year. The dry day is defined as the day with precipitation < 1 mm	d
CWD	Consecutive wet days	Maximum number of consecutive wet days of a year. The wet day is defined as the day with precipitation ≥ 1 mm	d
RX1	Max 1-day precipitation amount	Maximum 1-day precipitation	mm
RX5	Max 5-day precipitation amount	Maximum consecutive 5-day precipitation	mm
R10	Heavy precipitation days	Annual number of days with daily precipitation ≥ 10 mm	d
R20	Very heavy precipitation days	Annual number of days with daily precipitation ≥ 20 mm	d
R95p	Very wet days	Annual total precipitation when daily precipitation ≥ the 95th percentile threshold. The 95th percentile threshold is calculated based on the precipitation series of all wet days at each station	mm
R99p	Extremely wet days	Annual total precipitation when daily precipitation ≥ the 99th percentile threshold. The 99th percentile threshold is calculated based on the precipitation series of all wet days at each station	mm
NWD	Number of wet days	Number of wet days in a year. The wet day is defined as the day with precipitation ≥ 1 mm	d
SDII	Simple daily intensity index	Annual total precipitation divided by the number of wet days in the year	mm/d