#hydrology terms

• 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.