SSCI 165Lgw Lecture Notes - Lecture 18: Evapotranspiration, Fish Ladder, Impervious Surface
Document Summary
Cities and water: compex combo of phys infrastructure w/natural h2o cycle. Phys infra: water provisioning, water treatment/flood control. Separated: h2o = key resource for restoring nature in city. Limited supply off reshwater: salt water + freshwater. In freshwater: ground water, ice/permanent snow, surface water. In surface water: rivers, lakes, soil moisture, water vapor. Global water stress: overpumping groundwater, damage from systems that remove too much h2o from rivers/streams. History: cities often founded where water was avil (except roman aqueducts, ritual baths, public supply. Watershed concept: land area feeds into given river/stream, labeled at diff scales, urfa(cid:272)e watershed does(cid:374)"t (cid:373)at(cid:272)h grou(cid:374)dwater (cid:862)(cid:271)asi(cid:374)s(cid:863) Urbanized watershed: amt of runoff depends on filtration of land, areas w/near 100% impervious surface. 15% intercepted by streets, bldgs. , roofs: leads to big flood risks, less groundwater recharge. Us water pollution regulatory scheme: point sources. Mining (regulated via permits since 1970s: non-point sources.
