{"id":1406,"date":"2026-05-12T21:47:48","date_gmt":"2026-05-12T21:47:48","guid":{"rendered":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/chapter\/solution-exercise-14\/"},"modified":"2026-05-13T17:01:11","modified_gmt":"2026-05-13T17:01:11","slug":"solution-exercise-14","status":"publish","type":"chapter","link":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/chapter\/solution-exercise-14\/","title":{"raw":"Solution Exercise 14","rendered":"Solution Exercise 14"},"content":{"raw":"
\r\n
\r\n\r\nPart 1: Drawdowns would be greater than expected due to the well loss associated with the lower efficiency.\r\n\r\n<\/div>\r\n
\r\n\r\nPart 2: Well loss is directly proportional to a power (greater than 1) of the pumping rate with greater well loss at higher pumping rates. The well efficiency at a higher pumping rate (i.e., at 600\u00a0m3<\/sup>\/d) would therefore be lower than that at the previous pumping rate (500\u00a0m3<\/sup>\/d).\r\n\r\n<\/div>\r\n
\r\n\r\nPart 3:\r\n\r\n<\/div>\r\n
    \r\n \t
  1. The drawdown at 24 hours is 14.44 m, this is calculated from the Theis Equation with [latex]u =\u00a0 [\/latex] 8.68x10\u20118<\/sup> and [latex]W(u) =\u00a0 [\/latex] 15.68.<\/li>\r\n \t
  2. The well efficiency is 85\u00a0percent (calculated as 14.44 m \/ 17 m). The well loss is 2.56\u00a0m (calculated as (17 m \u2013 14.44 m).<\/li>\r\n<\/ol>\r\n
    \r\n\r\nPart 4:\r\n\r\n<\/div>\r\n
    \r\n\r\nThe answer is (c) test results underestimate the formation transmissivity.\r\n\r\n<\/div>\r\n
    \r\n
    The transmissivity estimated from the test is based upon the measured drawdowns in the well. Lower efficiency means greater drawdown than expected from a well with 100\u00a0percent efficiency. Since the observed drawdowns are greater than expected, the calculated transmissivity would be less than expected, and therefore the test results would underestimate the actual transmissivity.<\/blockquote>\r\n<\/div>\r\n
    \r\n\r\nReturn to Exercise 14<\/strong><\/span><\/a>\u2ba5\r\n\r\n<\/div>\r\n
    \r\n\r\nReturn to where text linked to Exercise\u00a014<\/strong><\/span><\/a>\u2ba5\r\n\r\n<\/div>\r\n<\/div>","rendered":"
    \n
    \n

    Part 1: Drawdowns would be greater than expected due to the well loss associated with the lower efficiency.<\/p>\n<\/div>\n

    \n

    Part 2: Well loss is directly proportional to a power (greater than 1) of the pumping rate with greater well loss at higher pumping rates. The well efficiency at a higher pumping rate (i.e., at 600\u00a0m3<\/sup>\/d) would therefore be lower than that at the previous pumping rate (500\u00a0m3<\/sup>\/d).<\/p>\n<\/div>\n

    \n

    Part 3:<\/p>\n<\/div>\n

      \n
    1. The drawdown at 24 hours is 14.44 m, this is calculated from the Theis Equation with [latex]u =\u00a0[\/latex] 8.68×10\u20118<\/sup> and [latex]W(u) =\u00a0[\/latex] 15.68.<\/li>\n
    2. The well efficiency is 85\u00a0percent (calculated as 14.44 m \/ 17 m). The well loss is 2.56\u00a0m (calculated as (17 m \u2013 14.44 m).<\/li>\n<\/ol>\n
      \n

      Part 4:<\/p>\n<\/div>\n

      \n

      The answer is (c) test results underestimate the formation transmissivity.<\/p>\n<\/div>\n

      \n

      The transmissivity estimated from the test is based upon the measured drawdowns in the well. Lower efficiency means greater drawdown than expected from a well with 100\u00a0percent efficiency. Since the observed drawdowns are greater than expected, the calculated transmissivity would be less than expected, and therefore the test results would underestimate the actual transmissivity.<\/p><\/blockquote>\n<\/div>\n

      \n

      Return to Exercise 14<\/strong><\/span><\/a>\u2ba5<\/p>\n<\/div>\n

      \n

      Return to where text linked to Exercise\u00a014<\/strong><\/span><\/a>\u2ba5<\/p>\n<\/div>\n<\/div>\n","protected":false},"author":8,"menu_order":125,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-1406","chapter","type-chapter","status-publish","hentry"],"part":1531,"_links":{"self":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapters\/1406","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/wp\/v2\/users\/8"}],"version-history":[{"count":3,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapters\/1406\/revisions"}],"predecessor-version":[{"id":1884,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapters\/1406\/revisions\/1884"}],"part":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/parts\/1531"}],"metadata":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapters\/1406\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/wp\/v2\/media?parent=1406"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/pressbooks\/v2\/chapter-type?post=1406"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/wp\/v2\/contributor?post=1406"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/books.gw-project.org\/basic-hydrogeology-an-introduction-to-the-fundamentals-of-groundwater-science\/wp-json\/wp\/v2\/license?post=1406"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}