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A survey of pond loss in Essex, South‐east England
Author(s) -
Heath D. J.,
Whitehead A.
Publication year - 1992
Publication title -
aquatic conservation: marine and freshwater ecosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 77
eISSN - 1099-0755
pISSN - 1052-7613
DOI - 10.1002/aqc.3270020306
Subject(s) - field survey , soil loss , geography , environmental science , hydrology (agriculture) , physical geography , ecology , geology , biology , surface runoff , cartography , geotechnical engineering
1. Sample areas of the county were used to estimate pond loss. An extensive survey used only maps while a smaller, intensive survey combined maps with a field study. In total, 283.43 km 2 were surveyed, approximately 7% of the total area. 2. Fifty‐five per cent of the ponds present in 1870 had disappeared by 1960 with the greatest loss occurring between 1920 and 1960. 3. Loss of ponds in agricultural locations contributed most to this because of their high initial number and their high rates of loss. Percentage losses of large and small ponds were greater than for medium‐sized ponds. 4. A field survey showed that a further 23% of a random sample of ponds shown on maps of 1960 could not be found in 1989. Overall loss rates for the period 1870–1989 are estimated to be 68.6% for the extensive area and 54.8% for the intensive area.