The accompanying dataset include results of surface water area trends (SWaT) analysis for rivers and basins in India. 

These data are licensed for free and open use, under Creative Commons Attribution 4.0 International license. See here for more: https://creativecommons.org/licenses/by/4.0/

Cite this work as:
    Pradeep Koulgi and Suman Jumani, (2023) Temporal trends of surface water area in India's rivers and basins. Zenodo. https://doi.org/10.5281/zenodo.7803903

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Each of the following ZIP archives contains a ESRI Shapefile (along with its sidecar files) with estimated trends in annual surface water area from 1991 to 2020, for the basins and reaches (transects) of our analysis. The name suffix following the '_' denotes season: "dry" for dry season water, "wet" for wet season water and "permanent" for permanent water.
  - annualTrendsBasins_dry.zip
  - annualTrendsBasins_permanent.zip
  - annualTrendsBasins_wet.zip
  - annualTrendsTransects_dry.zip
  - annualTrendsTransects_permanent.zip
  - annualTrendsTransects_wet.zip
  Each feature in these files have the following attributes:
    - HYBAS_ID or txId (string): feature's unique identifier. 
      - HYBAS_ID is for basins. It is the same as the basin's identifier HYBAS_ID in the HydroBASINS dataset
      - txId is for transects. It is the '_' concatenated string derived from the longitude and latitude values, truncated to 4 decimals, of the transect's centroid point. Specifically, it is "xx.xxxx_yy.yyyy" where xx.xxxx and yy.yyyy are the centroid's longitude and latitude values truncated to 4 decimals.
    - season (string): Denotes the season. It is of the format "sss_mmm".
      - "sss" denotes the season. "dry" is for dry season water, "wet" is for wet season water and "prm" is for permanent water.
      - "mmm" denotes the months the season spans (except for "permanent", when this is "DnW" indicating dry and wet season). "fma" is for dry season of February-March-April, "ond" is for wet season of October-November-December.
    - sl_perYr (float): Regression slope of the surface water area vs. year Sen's slope regression analysis. "_perYear" denotes its units, per year. The value -9999 indicates invalid trend, and occurs for cases where the trend was not estimated in our analysis because the feature was deemed to have inadequate valid data points in its area time series.
    - offset (float): Regression offset of the surface water area vs. year Sen's slope regression analysis. NULL indicates invalid trend offset, and occurs where the trend was not estimated in our analysis because the feature was deemed to have inadequate valid data points in its area time series.
    - tsPtCount (integer): Number of valid data-points in the area time series. Trend is estimated for features with this being 5 or greater.

Each of the following ZIP archives contains a table, in CSV (comma separated value) format, with time series of surface water areas from 1991 to 2020, for the basins and reaches (transects) of our analysis. These are the time series from which trends were estimated.
  - annualTimeseriesBasins.zip
  - annualTimeseriesTransects.zip
  Each of these tables have the following attributes:
    - HYBAS_ID or txId (string): feature's unique identifier. 
      - HYBAS_ID is for basins. It is the same as the basin's identifier HYBAS_ID in the HydroBASINS dataset
      - txId is for transects. It is the '_' concatenated string derived from the longitude and latitude values, truncated to 4 decimals, of the transect's centroid point. Specifically, it is "xx.xxxx_yy.yyyy" where xx.xxxx and yy.yyyy are the centroid's longitude and latitude values truncated to 4 decimals.
    - area_ha (float): Feature's area in hectares
    - year (float): Hydrologic year (June-May)
    - dry_fma_water_ha: Area of water pixels in the feature in the dry season band of the annual composite image, in hectares
    - dry_fma_nodata_ha: Area of nodata pixels in the feature in the dry season band of the annual composite image, in hectares.
    - wet_ond_water_ha: Area of water pixels in the feature in the wet season band of the annual composite image, in hectares.
    - wet_ond_nodata_ha: Area of nodata pixels in the feature in the wet season band of the annual composite image, in hectares.
    - prm_DnW_water_ha: Area of water pixels in the feature in the permanent band of the annual composite image, in hectares.
    - total_nodata_ha: Area of nodata pixels in the feature in the permanent band of the annual composite image, in hectares.