ФОРМИРОВАНИЕ И ДИНАМИКА РУСЛОВЫХ РАЗВЕТВЛЕНИЙ В ДЕЛЬТОВЫХ РУКАВАХ ВОЛГИ (НА ПРИМЕРЕ ОСТРОВОВ АСТРАХАНСКОГО ВОДНОГО УЗЛА)

Аннотация

During the period 1798–2010 braided channel formed two times in one and the same part of the main delta branch near the Astrakhan’ City. Braid bars within this zone developed into vegetated and relatively stabilized islands. Main causes of substantial decrease of bedload sediments mobility were lower discharge in the main branch as a result of significant flow interception by secondary branches and local widening of the main channel. First braiding zone existed for about 90 years. The second (recurrent) braiding began to form in 1910–1914. The so-called Gorodskoy Island still exists today. Main reasons for prolonged existence of the braided channel are human activities, namely water discharge and sediment transport regulation by the Volgograd Reservoir dam and dredging in the main channel arms around the island.