07 Decompose exposure effect

var geometry = ee.FeatureCollection("projects/heatwave0214/assets/basicpolygon/Chinaregion_NOTW")
// .filter(ee.Filter.eq('zone', 'Central China'))
.geometry();
 
var basePath = "projects/heatwave0214/assets/";
var datasets = [
  {path: "Age_pop_exposure_TM_SSP585/", variable: "TM_SSP585"},


  {path: "Age_pop_exposure_TM_SSP245/", variable: "TM_SSP245"},

  // {path: "Age_pop_exposure_TX_SSP245/", variable: "TX_SSP245"}
];

var years = [];
for (var i = 2041; i <= 2100; i++) {
    years.push( i.toString() );
}

// Function to calculate effects for a single dataset
function calculateEffectsForDataset(dataset) {
  var effectsList = years.map(function(year) {
    var heatwave_base = ee.Image("projects/heatwave0214/assets/Age_pop_exposure_TM_historical/Interpolation_Agepop_exposure_TM_historical_2001").select("HWF");
    var heatwave_future = ee.Image(basePath + dataset.path + "Interpolation_agepop_exposure_" + dataset.variable + "_withoutsum_" + year).select("HWF");
    var population_base = ee.Image("projects/heatwave0214/assets/Age_pop_exposure_TM_historical/Interpolation_Agepop_exposure_TM_historical_2001").select("age_pop");
    var population_future = ee.Image(basePath + dataset.path + "Interpolation_agepop_exposure_" + dataset.variable + "_withoutsum_" + year).select("age_pop");

    var delta_heatwave = heatwave_future.subtract(heatwave_base);
    var delta_population = population_future.subtract(population_base);

    var climate_effect = population_base.multiply(delta_heatwave).rename("climate_effect");
    var population_effect = heatwave_base.multiply(delta_population).rename("population_effect");
    var combined_effect = delta_population.multiply(delta_heatwave).rename("combined_effect");

    var climate_effect_sum = climate_effect.reduceRegion({
      reducer: ee.Reducer.sum(),
      geometry: geometry,
      scale: 11132,
      maxPixels: 1e9 
    });

    var population_effect_sum = population_effect.reduceRegion({
      reducer: ee.Reducer.sum(),
      geometry: geometry,
      scale: 11132,
      maxPixels: 1e9
    });

    var combined_effect_sum = combined_effect.reduceRegion({
      reducer: ee.Reducer.sum(),
      geometry: geometry,
      scale: 11132,
      maxPixels: 1e9
    });

    return ee.Feature(null, {
      'year': year,
      'variable': dataset.variable,
      'climate_effect': climate_effect_sum.get('climate_effect'),
      'population_effect': population_effect_sum.get('population_effect'),
      'combined_effect': combined_effect_sum.get('combined_effect')
    });
  });

  return ee.FeatureCollection(effectsList);
}

// Calculate effects for all datasets
var allDatasetsEffects = datasets.map(calculateEffectsForDataset);

// Combine all dataset effects into a single FeatureCollection
var combinedEffects = ee.FeatureCollection(allDatasetsEffects).flatten();

// print("combinedEffects:",combinedEffects)

// Export the results as a CSV file
Export.table.toDrive({
  collection: combinedEffects,
  description: 'Decompose_effects_summary_2001base',
  fileFormat: 'CSV',
  folder: 'futureheatwave-batch-change1'
});