2949775690

GEOGRAPHIA POLONICA 68,1997

ANTHROPOGENIC CHANGES IN THE SUSPENDED LOAD TRANSPORTATION BY AND SEDIMENTATION RATES

OF THE RIYER YISTULA, POLAND

Adam Łajczak

Institute of Naturę Conservation Polish Academy of Sciences

Lubicz 46, 31-512 Kraków, Poland

ABSTRACT: Eyidence is presented that regulation works on the Vistula channel have introduced very significant and rapid changes in the magnitude of river load transportation and sedimentation. It is acknowledged that human interference represents the most significant cause of change in the Vistula catchment within historical times. The alluviation ofthe Yistula yalley floodplain as described here, which was initiated about 150 years ago, may be compared with the eąually rapid changes of load transportation by and sedimentation rates of other rivers influenced by intensive urbanization.

KEY WORDS: bedload, channelization, overbank sedimentation, reservoir siltation, suspended load, Yistula River.

INTRODUCTION

Changes in river processes and adjustments to river channel and floodplain morphology can be induced by both climatic fluctuations and human activity. Man’s impact on fluvial processes is generally manifested by marked changes in transportation and sedimentation rates. On a time scalę of hundreds, or even thousands of years, the impact has probably been the most important factor in promoting changes of sediment transportation. The end-products of this are changes in the river pattern and rapid alluviation of floodplains. Short-term morphological changes of valley floors and channels are often ąuickly manifested in strongly populated areas where deforestation, morę intensive cultivation, over-grazing, and burning of degraded pastures has taken place (Strahler 1956; Starkel 1960, 1983, 1988, 1990; Trimble 1970, 1974; Butzer 1971; Schumm 1977; Maruszczak 1982; Sundborg and White 1982; Sundborg 1983, 1986; Sundborg and Rapp 1986; Gębica and Starkel