tgp_silk_road_canal_built_effect

tgp_silk_road_canal_built_effect = {
	situation:silk_road_situation ?= {
		if = {
			limit = { situation_has_catalyst = catalyst_silk_road_china_grand_canal_expanded }
			situation_sub_region:region_silk_road_proper_china ?= {
				trigger_sub_region_catalyst = {
					catalyst = catalyst_silk_road_china_grand_canal_expanded
					character = scope:owner
				}
			}
		}
		if = {
			limit = { situation_has_catalyst = catalyst_silk_road_china_grand_canal_expanded_secondary }
			situation_sub_region:region_silk_road_proper_tibet ?= {
				trigger_sub_region_catalyst = {
					catalyst = catalyst_silk_road_china_grand_canal_expanded_secondary
					character = scope:owner
				}
			}
			situation_sub_region:region_silk_road_proper_central_asia ?= {
				trigger_sub_region_catalyst = {
					catalyst = catalyst_silk_road_china_grand_canal_expanded_secondary
					character = scope:owner
				}
			}
		}
		if = {
			limit = { situation_has_catalyst = catalyst_silk_road_china_grand_canal_expanded_tertiary }
			situation_sub_region:region_silk_road_proper_india ?= {
				trigger_sub_region_catalyst = {
					catalyst = catalyst_silk_road_china_grand_canal_expanded_tertiary
					character = scope:owner
				}
			}
			situation_sub_region:region_silk_road_proper_transcaspia ?= {
				trigger_sub_region_catalyst = {
					catalyst = catalyst_silk_road_china_grand_canal_expanded_tertiary
					character = scope:owner
				}
			}
		}
	}
}

As written in game/common/scripted_effects/10_dlc_tgp_silk_road_scripted_effects.txt.