{"id":47,"date":"2020-09-29T20:28:08","date_gmt":"2020-09-29T20:28:08","guid":{"rendered":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/?post_type=chapter&p=47"},"modified":"2020-12-19T18:19:42","modified_gmt":"2020-12-19T18:19:42","slug":"zero-exchange-or-parallel-flow-conditions","status":"publish","type":"chapter","link":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/chapter\/zero-exchange-or-parallel-flow-conditions\/","title":{"raw":"1.5 Zero-Exchange or Parallel Flow Conditions","rendered":"1.5 Zero-Exchange or Parallel Flow Conditions"},"content":{"raw":"A zero-exchange or parallel flow condition occurs where no exchange is observable. This is found when the water table elevation is equal to the surface-water stage (river, lake, and wetland) (Figure 8). As both the stage and water table are at a common elevation, no hydraulic gradient is present, and the groundwater flow is parallel to the surface-water flow. Representative monitoring wells, open only at the bottom, illustrate that the water levels in wells finished at multiple depths are equal to the surface-water stage. No equipotential lines are shown in Figure 8 because wells and the surface-water stage are a common equipotential line. Flow is illustrated as parallel to the surface-water feature (out of the page). In these settings the stage represents the local water table elevation.<\/a>\r\n\r\n[caption id=\"attachment_349\" align=\"alignnone\" width=\"951\"]\"Figure Figure 8 - <\/strong>Conceptual model of parallel flow or zero-exchange conditions under steady-state isotropic and homogeneous conditions. Numbers represent relative values of head. No equipotential lines are shown as the groundwater heads are the same as the surface-water stage. Water levels in monitoring wells open only at the bottom equal the surface-water stage elevation. Flow is at right angles to the cross section (Woessner, 2020).[\/caption]","rendered":"

A zero-exchange or parallel flow condition occurs where no exchange is observable. This is found when the water table elevation is equal to the surface-water stage (river, lake, and wetland) (Figure 8). As both the stage and water table are at a common elevation, no hydraulic gradient is present, and the groundwater flow is parallel to the surface-water flow. Representative monitoring wells, open only at the bottom, illustrate that the water levels in wells finished at multiple depths are equal to the surface-water stage. No equipotential lines are shown in Figure 8 because wells and the surface-water stage are a common equipotential line. Flow is illustrated as parallel to the surface-water feature (out of the page). In these settings the stage represents the local water table elevation.<\/a><\/p>\n

\"Figure
Figure 8 – <\/strong>Conceptual model of parallel flow or zero-exchange conditions under steady-state isotropic and homogeneous conditions. Numbers represent relative values of head. No equipotential lines are shown as the groundwater heads are the same as the surface-water stage. Water levels in monitoring wells open only at the bottom equal the surface-water stage elevation. Flow is at right angles to the cross section (Woessner, 2020).<\/figcaption><\/figure>\n","protected":false},"author":1,"menu_order":5,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-47","chapter","type-chapter","status-publish","hentry"],"part":3,"_links":{"self":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapters\/47","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":6,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapters\/47\/revisions"}],"predecessor-version":[{"id":563,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapters\/47\/revisions\/563"}],"part":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapters\/47\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/wp\/v2\/media?parent=47"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/pressbooks\/v2\/chapter-type?post=47"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/wp\/v2\/contributor?post=47"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/books.gw-project.org\/groundwater-surface-water-exchange\/wp-json\/wp\/v2\/license?post=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}