Figure 1.
Topography of the Beijing–Tianjin–Hebei Region (BTHR) in China, showing the meteorological stations used in this study.
Figure 1.
Topography of the Beijing–Tianjin–Hebei Region (BTHR) in China, showing the meteorological stations used in this study.
Figure 2.
A land cover map of the Beijing–Tianjin–Hebei Region in China (derived from Moderate-Resolution Imaging Spectroradiometer data (2017)).
Figure 2.
A land cover map of the Beijing–Tianjin–Hebei Region in China (derived from Moderate-Resolution Imaging Spectroradiometer data (2017)).
Figure 3.
Region-averaging time series for indices indicating the intensity of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The straight red line represents the linear trend line for 1959–2018. NB (Nota Bene): SDII, the annual average daily precipitation on wet days; RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation; R95P, the annual total precipitation when daily precipitation was >the 95th percentile of daily precipitation; and R99P, the annual total precipitation when daily precipitation was >the 99th percentile of daily precipitation.
Figure 3.
Region-averaging time series for indices indicating the intensity of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The straight red line represents the linear trend line for 1959–2018. NB (Nota Bene): SDII, the annual average daily precipitation on wet days; RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation; R95P, the annual total precipitation when daily precipitation was >the 95th percentile of daily precipitation; and R99P, the annual total precipitation when daily precipitation was >the 99th percentile of daily precipitation.
Figure 4.
Region-averaging time series for indices indicating the frequency and duration of extreme precipitation events in the Beijing–Tianjin–Hebei region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: R10mm, the annual count of days when daily precipitation was >10 mm; R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm; and CWD, the maximum number of consecutive wet days.
Figure 4.
Region-averaging time series for indices indicating the frequency and duration of extreme precipitation events in the Beijing–Tianjin–Hebei region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: R10mm, the annual count of days when daily precipitation was >10 mm; R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm; and CWD, the maximum number of consecutive wet days.
Figure 5.
Spatial distributions of trends in indices representing the intensity of extreme precipitation events at the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: SDII, the annual average daily precipitation on wet days; RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation; R95P, the annual total precipitation when daily precipitation was >the 95th percentile of daily precipitation; and R99P, the annual total precipitation when daily precipitation was >the 99th percentile of daily precipitation.
Figure 5.
Spatial distributions of trends in indices representing the intensity of extreme precipitation events at the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: SDII, the annual average daily precipitation on wet days; RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation; R95P, the annual total precipitation when daily precipitation was >the 95th percentile of daily precipitation; and R99P, the annual total precipitation when daily precipitation was >the 99th percentile of daily precipitation.
Figure 6.
Spatial distributions of trends in indices representing the frequency and duration of extreme precipitation events for the meteorological stations in the Beijing–Tianjin–Hebei region from 1959 to 2018. NB: R10mm, the annual count of days when daily precipitation was >10 mm; R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm; and CWD, the maximum number of consecutive wet days.
Figure 6.
Spatial distributions of trends in indices representing the frequency and duration of extreme precipitation events for the meteorological stations in the Beijing–Tianjin–Hebei region from 1959 to 2018. NB: R10mm, the annual count of days when daily precipitation was >10 mm; R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm; and CWD, the maximum number of consecutive wet days.
Figure 7.
Region-averaging time series for indices indicating extreme hot weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: TMAX, the maximum temperature; TX90P, the annual count of days when TMAX was >the 90th percentile; SU25, the annual count of days when TMAX was >25 °C; and TR20, the annual count of days when the daily minimum temperature was >20 °C.
Figure 7.
Region-averaging time series for indices indicating extreme hot weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: TMAX, the maximum temperature; TX90P, the annual count of days when TMAX was >the 90th percentile; SU25, the annual count of days when TMAX was >25 °C; and TR20, the annual count of days when the daily minimum temperature was >20 °C.
Figure 8.
Region-averaging time series for indices indicating extreme cold weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: TMIN, the annual minimum temperature; TN10P, the annual count of days when TMIN was <the 10th percentile; FD0, the annual count of days when TMAX was <0 °C; and ID0, the annual count of days when TMIN was <0 °C.
Figure 8.
Region-averaging time series for indices indicating extreme cold weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018. The red straight line represents the linear trend line for 1959–2018. NB: TMIN, the annual minimum temperature; TN10P, the annual count of days when TMIN was <the 10th percentile; FD0, the annual count of days when TMAX was <0 °C; and ID0, the annual count of days when TMIN was <0 °C.
Figure 9.
Spatial distributions of trends in indices representing hot weather extreme events for the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: TMAX, the maximum temperature; TX90P, the annual count of days when TMAX was >the 90th percentile; SU25, the annual count of days when TMAX was >25 °C; and TR20, the annual count of days when the daily minimum temperature was >20 °C.
Figure 9.
Spatial distributions of trends in indices representing hot weather extreme events for the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: TMAX, the maximum temperature; TX90P, the annual count of days when TMAX was >the 90th percentile; SU25, the annual count of days when TMAX was >25 °C; and TR20, the annual count of days when the daily minimum temperature was >20 °C.
Figure 10.
Spatial distributions of trends in indices representing cold weather extreme events for the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: TMIN, the annual minimum temperature; TN10P, the annual count of days when TMIN was <the 10th percentile; FD0, the annual count of days when TMAX was <0 °C; and ID0, the annual count of days when TMIN was <0 °C.
Figure 10.
Spatial distributions of trends in indices representing cold weather extreme events for the meteorological stations in the Beijing–Tianjin–Hebei Region from 1959 to 2018. NB: TMIN, the annual minimum temperature; TN10P, the annual count of days when TMIN was <the 10th percentile; FD0, the annual count of days when TMAX was <0 °C; and ID0, the annual count of days when TMIN was <0 °C.
Figure 11.
Spatial distributions of significant trends in indices representing the intensity of extreme precipitation events derived from ground measurement data from meteorological stations and satellite measurement data from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Climatology Project (GPCP) for the Beijing–Tianjin–Hebei region from 1998 to 2018. NB: RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation.
Figure 11.
Spatial distributions of significant trends in indices representing the intensity of extreme precipitation events derived from ground measurement data from meteorological stations and satellite measurement data from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Climatology Project (GPCP) for the Beijing–Tianjin–Hebei region from 1998 to 2018. NB: RX1DAY, the annual maximum daily precipitation; RX5DAY, the annual maximum consecutive five-day precipitation.
Figure 12.
Spatial distributions of significant trends in indices representing the frequency of extreme precipitation events derived from ground measurement data from meteorological stations and satellite measurement data from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Climatology Project (GPCP) for the Beijing–Tianjin–Hebei Region from 1998 to 2018. NB: R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm.
Figure 12.
Spatial distributions of significant trends in indices representing the frequency of extreme precipitation events derived from ground measurement data from meteorological stations and satellite measurement data from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Climatology Project (GPCP) for the Beijing–Tianjin–Hebei Region from 1998 to 2018. NB: R20mm, the annual count of days when daily precipitation was >20 mm; R50mm, the annual count of days when daily precipitation was >50 mm.
Table 1.
Definitions of the extreme precipitation event indices used in this study.
Table 1.
Definitions of the extreme precipitation event indices used in this study.
Index | Category | Definition | Units |
---|
SDII | intensity | annual average daily precipitation on wet days | mm |
RX1DAY | intensity | annual maximum daily precipitation | mm |
RX5DAY | intensity | annual maximum consecutive 5-day precipitation | mm |
R95P | intensity | annual total precipitation when daily precipitation >the 95th percentile of daily precipitation in the 60-year period | mm |
R99P | intensity | annual total precipitation when daily precipitation >the 99th percentile of daily precipitation in the 60-year period | mm |
R10mm | frequency | annual count of days when daily precipitation >10mm | days |
R20mm | frequency | annual count of days when daily precipitation >20mm | days |
R50mm | frequency | annual count of days when daily precipitation >50mm | days |
CWD | duration | maximum number of consecutive wet days | days |
Table 2.
Definitions of the extreme temperature event indices used in this study.
Table 2.
Definitions of the extreme temperature event indices used in this study.
Index | Category | Definition | Units |
---|
TMAX | hot weather | annual daily maximum temperature | °C |
TX90P | hot weather | annual count of days when TMAX >the 90th percentile of daily TMAX in the 60-year period | days |
SU25 | hot weather | annual count of days when TMAX >25 °C | days |
TR20 | hot weather | annual count of days when TMIN >20 °C | days |
TMIN | cold weather | annual minimum temperature | °C |
TN10P | cold weather | annual count of days when TMIN <the 10th percentile of daily TMIN in the 60-year period | days |
FD0 | cold weather | annual count of days when TMIN <0 °C | days |
ID0 | cold weather | annual count of days when TMAX <0 °C | days |
Table 3.
The trends of five indices indicating the intensity of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Table 3.
The trends of five indices indicating the intensity of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Index | Average Value | Trend | Significant or Not |
---|
SDII | 11.1mm | −0.086 mm/decade | No |
RX1DAY | 74.1 mm | −2.650 mm/decade | Yes |
RX5DAY | 110.7 mm | −4.544 mm/decade | Yes |
R95P | 161.3 mm | −8.645 mm/decade | Yes |
R99P | 132.1 mm | −5.896 mm/decade | Yes |
Table 4.
The detected trends of four indices indicating the frequency and duration of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Table 4.
The detected trends of four indices indicating the frequency and duration of extreme precipitation events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Index | Average Value | Trend | Significant or Not |
---|
R10mm | 15.10 days | −0.130 days/decade | No |
R20mm | 7.25 days | −0.149 days/decade | No |
R50mm | 1.46 days | −0.103 days/decade | Yes |
CWD | 3.97 days | −0.076 days/decade | Yes |
Table 5.
The trends of the four indices indicating extreme hot weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Table 5.
The trends of the four indices indicating extreme hot weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Index | Average Value | Trend | Significant or Not |
---|
TMAX | 16.93 °C | 0.198 °C/decade | Yes |
TX90P | 10.04 days | 1.000 days/decade | Yes |
SU25 | 121.61 days | 2.373 days/decade | Yes |
TR20 | 48.24 days | 2.820 days/decade | Yes |
Table 6.
The detected trends of four indices indicating extreme cold weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Table 6.
The detected trends of four indices indicating extreme cold weather events in the Beijing–Tianjin–Hebei Region from 1959 to 2018.
Index | Average Value | Trend | Significant or Not |
---|
TMIN | 5.44 °C | 0.383 °C/decade | Yes |
TN10P | 10.08 days | −2.070 days/decade | Yes |
FD0 | 132.41 days | −3.193 days/decade | Yes |
ID0 | 33.23 days | −1.614 days/decade | Yes |