THE RECONSTRUCTION OF PAST HYDROLOGIES OF RIVER TISZA USING MULTIVARIABLE ARCHEOMALACOLOGICAL ANALYSIS Sándor Gulyás 1* -Pál Sümegi 1,2 1.University of Szeged, Department of Geology and Paleontology H-6722 Szeged, Egyetem u.2-6. Hungary. *corresponding author: gulyas-sandor@t-online.hu 2. Institute of Archeology Hungarian Academy of Sciences H-1014 Budapest Úri u. 49. Abstract: Paleoenvironmental studies are gaining increasing importance in understanding relations of man and environment for prehistoric communities world-wide. Several methods have been deployed to capture various aspects of the past environment hosting archeological cultures, most of which have long-lasted scientific background and are extensively used in daily research. In those areas where prehistoric sites are confined to rivers or lakes, a new promising tool in capturing the interaction of man and riparian environment might be that of the extensive analysis of freshwater mollusks retrieved from archeological sites. Since these mollusks collected by humans on the one hand characterize the quality of the water body from which they derive. Furthermore, they also yield us information about the use of second-line aquatic resources in subsistence. Faunal changes observable in the shellfish material must be attributed to various factors, if we appreciate the human or cultural context of the material. Thus to resolve issues of temporal change observable in the studied archeofauna a complex analysis of several lines of information is needed. To achieve this goal a new multi-proxy paleoecological analytical method was developed based on the collective handling of faunal taxonomic and demographic data as well as the geochemistry of the shells along with information on taphonomic bias and role of shellfish in both subsistence and other type social, behavioral activities. As a first step the main physical and chemical properties of fluvial and floodplain aquatic habitats (substrate conditions, hydraulic parameters, water temperature, pH, bioproduction, sediment accumulation) surrounding the site is reconstructed based on the analysis of faunal abundance, ecological and geochemical data. A regional reconstruction of the riparian environment highlighting potential differences and short-term sub-centennial transformations as well as background causes follows. The received pattern is then interpreted in the light of cultural, economic and human behavioral patterns gleaned partly from the archeology of the sites and proxies gained via the analysis of taxonomic and demographic composition of the studied faunas reflecting foraging strategies. Finally, potential alterations inferred for the local natural shellfish population as a result of foraging strategies employed is also assessed. The paper will highlight the most important aspects of the method touching upon the mat-stat components used to derive proxies for describing the physico-chemical properties of the studied freshwater system of the River Tisza with examples for the Hungarian Early Neolithic. Keywords: multivariable paleoecological analysis, freshwater shellfish, riparian environment, paleohydrology, multivariate statistics