caa a22 4500 44581487X CHVBK 20180317145223.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10040-011-0762-x doi (NATIONALLICENCE)springer-10.1007/s10040-011-0762-x Zhou Yangxiao UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, The Netherlands aut Sources of water, travel times and protection areas for wells in semi-confined aquifers [Elektronische Daten] [Yangxiao Zhou] Origine de l'eau, temps de transfert et périmètres de protection de captages d'aquifères semi-captifs Fuentes de agua, tiempos de tránsito y áreas de protección para pozos en acuíferos semiconfinados 越流含水层开采井的水源、滞流时间与水源保护区的划分 Origens da água, tempos de percolação e áreas de proteção para poços em aquíferos semiconfinados This paper presents new findings in interpreting analytical solutions of steady radial flow to a well in a semi-confined aquifer (overlain by a phreatic aquifer and aquitard), and demonstrates that 95% of pumped water is derived from leakage water within a radius of 4 times the leakage factor. The travel times of the leakage water from the radii of influence to the well are usually much longer than those derived from the travel time criteria currently used to delineate the well protection areas. The delineation of well protection zones based on the travel time criteria will not properly protect the source of water to the well. Therefore, the percentage of leakage water to the well is used as a new criterion to define the well protection areas. Within each well protection area, the mean residence time is used as an indicator of the renewable period of the aquifer system. Leakage-rate weighted residence times are used to calculate the mean residence time. For the safety and sustainability of drinking water supplies, groundwater in the phreatic aquifer within the radius of influence should be protected. Springer-Verlag, 2011 Analytical solutions nationallicence Groundwater hydraulics nationallicence Semi-confined aquifer nationallicence Source of water nationallicence Protection area nationallicence Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1285-1291 1431-2174 19:7<1285 2011 19 10040 https://doi.org/10.1007/s10040-011-0762-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0762-x text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Zhou Yangxiao UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, The Netherlands aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/7(2011-11-01), 1285-1291 1431-2174 19:7<1285 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer