Karst hydrogeology of the Chalk and implications for groundwater protection
نویسندگان
چکیده
Abstract The Chalk is an unusual karst aquifer with limited cave development, but extensive networks of smaller solutional conduits and fissures enabling rapid groundwater flow. Small-scale features (stream sinks, dolines, dissolution pipes, springs) are common, hundreds stream sinks recorded. Tracer velocities from 27 connections between springs have median mean 4700 4600 m d −1 . Tests to abstraction boreholes also demonstrate very thousands metres per day. Natural gradient tests observation There strong geological control on focused stratigraphical inception horizons. Surface concentrated near the Paleogene boundary, or where thin superficial cover occurs, flow common in other areas. has higher storage contaminant attenuation than classical karst, recharge, influenced by karst. Point recharge through losing rivers, vertical fissures, soakaways enables unsaturated zone Saturated create vulnerability subsurface activities, enable long distance transport point source diffuse pollutants, which may be derived outside modelled catchment areas protection zones.
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ژورنال
عنوان ژورنال: Geological Society, London, Special Publications
سال: 2021
ISSN: ['2041-4927', '0305-8719']
DOI: https://doi.org/10.1144/sp517-2020-267