The Delta is no longer really a delta — or at least, it doesn’t function like one, scientists conclude in a new report.The estuary as we know it only superficially resembles the river delta that existed 200 years ago, before the rivers were dredged for navigation, and before the vast marshes were drained for farms and cities.The fundamental character of a river delta — a place where fresh water from the mountains meets tidal water from the bay, and spreads [...]