#hydrology term

• Washing away — The act of washing away or eroding and its result; an archaic or regional term describing the process of erosion, washing out, or structural digging of riverbanks under the action of hydraulic currents. This natural physical phenomenon gradually modifies the riparian relief, historically used by locals to explain the loss of arable land near rivers.
• Scour — The act of scouring and its result; a hydrodynamic phenomenon of local erosion, washing away, and excavation of a riverbed or soil at the base of a hydraulic structure, such as bridge piers or dikes, under the direct action of strong currents. This structural process can jeopardize the stability of the entire foundation if consolidation measures are not applied.
• Upstream — The upper sector of a watercourse, located towards the source, relative to a given reference point; the direction opposite to the water flow. Often used in hydraulic engineering and ecology to describe the location of structures or phenomena situated upstream.
• Downstream — The part of a watercourse located in the direction of the current, toward the mouth (as opposed to amonte); (adverbially) in the direction of the water flow; (in economics and law) a written personal guarantee, usually on a bill of exchange or promissory note, whereby a person (avalist) binds themselves to pay the mentioned amount if the primary debtor fails to fulfill their obligation.