processing.run('native:buffer', {"INPUT": delta, "DISTANCE":QgsProperty.fromExpression("bande"), "OUTPUT": "memory"})
    blayer=QgsVectorLayer("MultiPolygon?crs=epsg:2154", "Bande Etude", "memory")
    QgsProject.instance().addMapLayer(blayer)
    blayer_feat= blayer.getFeatures()
    blayer.startEditing()
    j=0
    for feat in blayer_feat :
      blayer.changeAttributeValue(feat.id(), 1, delta_t[j])
      j=j+1
    target_field = 'delta_t'

    myRangeList = []

    symbol = QgsSymbol.defaultSymbol(blayer.geometryType())
    symbol.setColor(QColor("#f7fbff"))
    symbol.setOpacity(0.6)
    #symbol(0).setStrokeStyle(Qt.PenStyle(Qt.NoPen))
    myRange = QgsRendererRange(0, 10.0, symbol, '0 a 10')
    myRangeList.append(myRange)

    symbol = QgsSymbol.defaultSymbol(blayer.geometryType())
    symbol.setColor(QColor("#08306b"))
    symbol.setOpacity(0.6)
    myRange = QgsRendererRange(10.1, 100.0, symbol, '10 a 100')
    myRangeList.append(myRange)

    myRenderer = QgsGraduatedSymbolRenderer(target_field, myRangeList)
    myRenderer.setMode(QgsGraduatedSymbolRenderer.Custom)

    blayer.setRenderer(myRenderer)
    blayer.setFeatureBlendMode(QPainter.CompositionMode_Darken