Long-Term Hydrological Changes Based on Sedimentary and Archaeological Evidence

Abstract

In this chapter, hydrological variability and changes that occurred in the Carpathian Basin are discussed, on millennial, centennial and decadal scale, presenting the results of multiproxy sedimentary research and archaeological investigations. Major topics of the chapter concern water-level and hydroclimatic changes of lakes, wetlands and peat bogs in entire Middle Ages, analysed by using complex multiproxy sedimentary macro-/microfossil-based hydroclimate reconstructions. Based on archaeological evidence, the potential water-level changes of the largest lakes, wetlands and some detected grounwater-table changes are also presented, partly concerning the late early-medieval, but mainly regarding the high-and late-medieval period. Largest in quantity, potential river flood changes, great and extraordinary floods, flood-rich periods, mainly those occurred on the Danube and partly on other rivers, are discussed, detected predominantly in archaeological and partly in sedimentary evidence. Concluding results, a humid period of the sixth–ninth century is followed by a drier period that culminated in the eleventh and thirteenth centuries. The fourteenth and fifteenth centuries are more complex, but generally wetter conditions were detected that became especially visible in the fifteenth century. The most complex, sedimentary and archaeological set of information, available for the fourteenth and fifteenth centuries, may also pinpoint on multidecadal variations and high water/flood-rich/wetter periods, especially around the turn of the fourteenth–fifteenth and that of the fifteenth–sixteenth century, but on the Danube periods, potentially richer in great floods, were as well suggested for the early and the mid/late thirteenth centhuries that probably extended to the turn of the thirteenth and fourteenth centuries. However, significant spatial differences were identified, especially in sedimentary evidence, in water-level and flood changes over the Middle Ages.