sentences: sky land slope drop rate freshwater to drain coastal perimeter
docs: geological_basin is slope. low_lying_wetland is wetland. shoreline is land_topographical_feature. apron_topographical is slope. slope is land_topographical_feature. precipitation is drop. soil_horizon is horizon. blowout_topographical is land_topographical_feature. drop_zone is zone. watershed is land_topographical_feature.