Dataset DOI: 10.5061/dryad.g4f4qrg2r

Description of the data and file structure

• Each file named in the format Fig.XXX* provides the data used to generate the corresponding Fig. XXX in the manuscript.

• For example, the file Fig1A.nc contains the data used in Fig. 1A. If the data consist only of time series or site locations, they are provided in .xlsx format.

• If the data include two-dimensional meteorological fields or other gridded variables, they are provided in .nc (NetCDF) format to facilitate access and analysis.

Please refer to the file names for correspondence with the figures in the manuscript.

Files and variables

File: Fig1A.nc

Description: 

• Purpose:
  This NetCDF file provides the gridded typhoon-occurrence probability field in modern times (1950–2021) and the archaeological site coordinates used to generate Fig. 1A, which maps spatial patterns of typhoon exposure and overlays site locations in the Central Plains and Chengdu Plain.

Variables and definitions:

• Typhoon_occurrence_probability (unit: %) — A 2-D field representing the typhoon occurrence probability during 1950–2021.

• XLONG (unit: degrees) and XLAT (unit: degrees) — 2-D longitude/latitude arrays defining the geographic grid for the probability field.

• Archeological_site_in_Central_Plains_lon/lat — Longitude/latitude (degrees) of archaeological sites in the Central Plains.

• Archeological_site_in_Chengdu_Plain_lon/lat — Longitude/latitude (degrees) of archaeological sites in the Chengdu Plain.

File: Fig1B.xlsx

Description: 

• Purpose:
  This Excel file provides the time-series data used to generate Fig. 1B, which compares (i) population-size changes in the Central Plains (represented by the reconstructed SPD) with normalized northward typhoon activity (upper panel), and (ii) archaeological site numbers in the Chengdu Plain with westward typhoon activity (lower panel), as described in the manuscript.

File structure (worksheets and variables):

Sheet: SCP_CP_all

• Year (BP) — years before present corresponding to SPD in Central Plains of China

• SPD in Central Plains of China — reconstructed summed probability distribution (SPD; dimensionless), used as a population-size proxy in Fig. 1B (upper panel)

Sheet: Remains_Chengdu_Plain

• Year (BP) — years before present corresponding to Archeological site number

• Archeological site number — number of archaeological sites in the Chengdu Plain (unit: count), used in Fig. 1B (lower panel)

Sheet: Typhoon_northward_normalize

• Year (BP) — years before present corresponding to Normalized northward typhoon activity

• Normalized northward typhoon activity — dimensionless normalized index representing northward typhoon activity reconstructed from paleo-typhoon proxies

• Average normalized northward typhoon activity (1850-1950) — reference-period mean value used to plot the dashed average line for northward typhoon activity in Fig. 1B (1850-1950 CE)

Sheet: Ave_Nor_TY(1850-1950)

• Average Normalized westward typhoon activity (1850-1950) — reference-period mean value used to plot the dashed average line for westward typhoon activity in Fig. 1B (1850–1950 CE)

• Third-party data notice (CC0 compliance):
  The Normalized westward typhoon activity in this study was computed by normalizing a raw westward typhoon activity time series derived from Fig. 5(a) of Li, P., Li, M., Gan, H., & Xia, Z. (2021). A preliminary study on sediment records of possible typhoon in the northern South China Sea during the past 6500 yr. The Holocene, 31, 1221–1228; this third-party time series is not redistributed in this Dryad package because Dryad requires CC0, and readers should obtain it from the original publication and cite Li et al. (2021). Only the reference-period mean for 1850–1950 CE is provided here for plotting the dashed line in Fig. 1B.

File: Fig2C.xlsx

Description: 

• Purpose:
  This Excel file contains the quantitative reconstructions used to generate Fig. 2C, showing temporal variations in the (upcoming) rain pieces ratio (RR) and the (upcoming) heavy rain pieces ratio (HRR) inferred from oracle bone scripts for the Central Plains. These reconstructed ratios are compared in the manuscript with paleo-typhoon activity records from southwestern Japan and South Korea, to show the impact of northward typhoon on the Central Plains of China.

Worksheet: Rainfall record(Fig.2C)

Variables and definitions:

• Time range (BP) — Time bin in years before present corresponding to each oracle bone script phase used in Fig. 2C.

• Rainfall record ratio (%) — Percentage of oracle bone script pieces within each time bin that record (upcoming) rainfall.

• Heavy rainfall record ratio (%) — Percentage of oracle bone script pieces within each time bin that record (upcoming) heavy rainfall.

• Third-party data notice (CC0 compliance):
  The typhoon-activity series for southwestern Japan (KI) and South Korea (YR) shown in Fig. 2C are based on previously published materials and are not redistributed in this Dryad package because Dryad requires CC0. Readers should obtain the original materials from the original publications and cite:

Woodruff, J. D., Donnelly, J. P., & Okusu, A. (2009). Exploring typhoon variability over the mid-to-late Holocene: evidence of extreme coastal flooding from Kamikoshiki, Japan. Quaternary Science Reviews, 28, 1774–1785 (see Fig. 7).

Lim, J., Lee, J.-Y., Hong, S.-S., & Kim, J.-Y. (2013). Late Holocene flooding records from the floodplain deposits of the Yugu River, South Korea. Geomorphology, 180–181, 109–119 (see Fig. 9A).

File: Fig2D.nc

• Description: 
  Purpose:
  NetCDF file containing the gridded datasets used to generate Fig. 2D (IMERG precipitation, ERA5 winds, typhoon best-track, and terrain elevation), used to demonstrate a modern case in which a northward typhoon triggers extreme rainfall and flooding over the Central Plains region of China.

Variables and definitions:

• Rainfall_IMERG (unit: mm) — Daily accumulated precipitation, with coordinate fields Lat_for_Rain and Lon_for_Rain for plotting.

• U, V (unit: m/s) — Horizontal wind components used for plotting wind vectors in Fig. 2D，with coordinate fields Lon_for_Wind, Lat_for_Wind (2D) for plotting.

• Lon_Typhoon_track, Lat_Typhoon_track (unit: degrees) — Best-track typhoon center positions at 12UTC.

• Terrain (unit: m) — Terrain height for the plotted domain，with coordinate fields Lon_terrain, Lat_terrain for plotting.

File: Fig3A.xlsx

• Description: 
  Purpose:
  Demonstrate the archaeological evidence of flood occurrence in the Chengdu Plain and its temporal co-variation with westward typhoon activity, including (i) the growth rate of archaeological site numbers and (ii) the ratio of sites containing flood layers, as used to generate Fig. 3A in the manuscript.The goal is to show the impacts of westward typhoons on flooding and social change in Chengdu Plain.

Worksheet: Growth Rate in number

• Variables and definitions:

• Year_for_Growth_rate (BP) — Time bin in years before present corresponding to Growht_rate.

• Growht_rate(%) — Growth rate of the number of archeological sites within each time bin.

Worksheet: Flood_Ratio

Variables and definitions:

• Year (BP) — Time bin in years before present corresponding to Flood Ratio.

• Flood Ratio (%) — Percentage of archaeological sites within each time bin that contain identified flood layers.

• Third-party data notice (CC0 compliance):
  The westward typhoon activity series shown in Fig. 3A is based on previously published material and is not redistributed in this Dryad package because Dryad requires CC0. Readers should obtain the original material from the original publication and cite:

Li, P., Li, M., Gan, H., & Xia, Z. (2021). A preliminary study on sediment records of possible typhoon in the northern South China Sea during the past 6500 yr. Holocene, 31, 1221–1228 (see Fig. 5a).

File: Fig3B.nc

• Description: 
  Purpose:
  NetCDF file containing the gridded datasets used to generate Fig. 3B (CMFD precipitation, ERA5 precipitation, ERA5 winds, typhoon best-track), used to demonstrate a modern case in which a westward typhoon triggers extreme rainfall and flooding over Chengdu Plain.

Variables and definitions:

• Rain_CMFD (unit: mm) — Daily accumulated precipitation, with coordinate fields lat_rain_CMFD and lon_rain_CMFD for plotting.

• Rain_ERA5 (unit: mm) — Daily accumulated precipitation, with coordinate fields lat_rain and lon_rain for plotting.

• U_ERA5, V_ERA5 (unit: m/s) — Horizontal wind components for wind vectors, with coordinate fields lon_wind and lat_wind for plotting.

• typhoon_track_lat, typhoon_track_lon (unit: degrees) — Best-track typhoon center positions at 12UTC.

File: Fig3C_D.xlsx

• Purpose:
  Excel file containing the geographic coordinates (longitude/latitude) of archaeological sites used to generate Fig. 3C–D, which compares the spatial distribution of sites in Chengdu Plain during two time windows associated with weaker vs. stronger westward typhoon activity.

Worksheets:

• Archeological site(3000-3100BP) — site locations for the earlier window (~3100–3000 BP; corresponds to the weak westward typhoon period shown in Fig. 3C).

• Archeological site(2700-2800BP) — site locations for the later window (~2800–2700 BP; corresponds to the strong westward typhoon period shown in Fig. 3D).

Variables and definitions (same in each worksheet):

• longitude (unit: degrees) — site longitude

• latitude (unit: degrees) — site latitude

File: Fig4A_B.nc

• Purpose：
  This NetCDF file provides the data for Fig. 4A–B (northward typhoons). It is designed to examine how changes in typhoon intensity affect moisture flux convergence (MFC), and thereby inform the simulated changes in extreme rainfall. Specifically, the file includes 850 hPa wind fields (U, V) and specific humidity (SH) for the composite environment, as well as an MFC bias field (MFC_bias) representing the difference between simulations with strong versus weak typhoons. It also contains the tracks for weak and strong typhoons and the locations of flood deposits around ~3000 BP used as reference points in the figure.

Variables and definitions

• SH (unit: kg/kg) — A 2-D field of 850-hPa specific humidity composited during northward typhoon occurrences, with coordinate fields Lat and Lon for plotting (used for Fig. 4A).

• U (unit: m/s) and V (unit: m/s) — 2-D fields of 850-hPa wind components (zonal/meridional) composited during northward typhoon occurrences, with coordinate fields Lat and Lon for plotting (used for Fig. 4A).

• MFC_bias (unit: kg/kg/s) — A 2-D field representing the intensity-related change in MFC, defined as the difference in the upper-quartile of maximum moisture flux convergence (MFC) between simulations with strong and weak northward typhoons (strong − weak; used for Fig. 4B), designed to explore how typhoon intensity changes modulate MFC.The coordinate fields are Lat and Lon.

• Typhoon_weak_track_lon/lat (unit: degrees) — Longitude/latitude arrays describ the tracks of weak northward typhoons.

• Typhoon_strong_track_lon/lat (unit: degrees) — Longitude/latitude arrays describ the tracks of strong northward typhoons.

• Flood_deposition_location_lon/lat (unit: degrees) — Longitude/latitude arrays give the locations of flood deposits documenting flood events around ~3000 BP.

File: Fig4D_E.nc

Same as Fig4A_B.nc but for westward typhoons.

File: Fig4C_F.xlsx

• Purpose:
  Excel file containing paired daily values of moisture flux convergence (MFC) and rainfall used to generate Fig. 4C and Fig. 4F, which quantify the MFC–rainfall relationship and support analyses of how changes in typhoon intensity may influence extreme rainfall via changes in MFC.

Worksheets:

• Fig.4C — paired MFC and daily rainfall samples for the Central Plains.

• Fig.4F — paired MFC and daily rainfall samples for Chengdu Plain.

Variables and definitions (same in each worksheet):

• MFC (unit: kg/kg/s) — moisture flux convergence.

• Rainfall (unit: mm/day) — daily rainfall corresponding to the MFC value.

Access information

Other publicly accessible locations of the data:

Rainfall data (ERA5_land) is from https://www.ecmwf.int/en/era5-land. Rainfall data (CMFD) is available at  https://data.tpdc.ac.cn/en/data/8028b944-daaa-4511-8769-965612652c49/. Meteorological data of wind, specific humidity, and geopotential height are from ERA5: https://www.ecmwf.int/en/forecasts/dataset/ecmwf-reanalysis-v5. Typhoon tracks data (CMABSTdata) is openly accessible at https://tcdata.typhoon.org.cn/zjljsjj.html. The satellite precipitation data is from Integrated Multi-satellite Retrievals for GPM (IMERG), which is available at https://gpm.nasa.gov/data/imerg. The source code of the WRF model is available from http://www2.mmm.ucar.edu/wrf/users/download/get_sources.html.
The related data sources have been provided in the main manuscript.