mudflat

upright=1.45|thumb|General sketch-map of a tidal plain, showing the typical tripartition in supratidal zone|supratidal, [[intertidal and subtidal zones. The most apparent character of the area is the development of tidal channels, affecting mainly the intertidal zone. In this case, the tidal flat is protected seaward by a beach barrier, but in many cases (low-energy waves and longshore currents) the tidal flats may directly pass into a shallow marine environment.]] alt=Aerial photograph showing shallow turquoise water and scattered rocky outcrops forming tidal flats near Roscoff in Brittany, France.|thumb|Aerial view of rocky tidal flats off the coast of Roscoff, Brittany, France Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal flat ecosystems are as extensive globally as mangroves, covering at least of the Earth's surface. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries; they are also seen in freshwater lakes and salty lakes (or inland seas) alike, wherein many rivers and creeks end. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays and aquatic animal detritus. Most of the sediment within a mudflat is within the intertidal zone, and thus the flat is submerged and exposed approximately twice daily.

A recent global remote sensing analysis estimated that approximately 50% of the global extent of tidal flats occurs within eight countries (Indonesia, China, Australia, United States, Canada, India, Brazil, and Myanmar) and that 44% of the world's tidal flats occur within Asia (). A 2022 analysis of tidal wetland losses and gains estimates that global tidal flats experienced losses of between 1999 and 2019, which were largely offset by global gains of over the same time period.