The Abandonment of the ZH‐Mozartstrasse Early Bronze Age Lake‐settlement. GIS Computer Simulation of the Lake‐level Fluctuation Hypothesis

Although ‘lake‐dwellings’ existed from the middle of the fifth millennium to the eighth century BC, the entire phenomenon was not a continuous one. There are several periods when the lake shores were abandoned and subsequently reoccupied. The pattern of occupation depends on cultural as well as environmental factors, amongst them the topography and the climate. Unlike the southern part of the Alps, which seems to have had a more regular occupational pattern throughout the Neolithic and the Bronze Age, the northern Alpine region shows a marked discontinuity along most of the lake shores. Two relevant breaks in lake‐shore occupation are known within the northern Alpine region Bronze Age. The first occurred between the 24th and the 20th centuries BC, and the second from the 15th to the middle of the 12th century BC. The Early Bronze Age site of ZH‐Mozartstrasse, situated on the western extreme of Lake Zurich (Switzerland), was abandoned immediately before the beginning of the second major occupational gap in 1503 BC. Two other Early Bronze Age sites namely Bodman‐Schachen 1 on Lake Constance, and Arbon‐Bleiche 2 on the Swiss part (the southern shore) of the same lake, follow a similar chronology in occupation; and they were both abandoned in the last decade of the 16th century BC. A possible cause of abandonment is discussed in this paper using an environmental approach related to an abrupt change of climatic conditions which resulted in an increase of the lake levels which forced those prehistoric populations to leave the proximity of the lake shores. Following the implications of pollen and sedimental analyses, the transformation of the Bronze Age landscape caused by the lake water invasion will be simulated with the help of CAD and GIS computer programs.