著者

NAGUMO Naoko SUGAI Toshihiko KUBO Sumiko

出版者

The Association of Japanese Geographers

雑誌

Geographical review of Japan series B (ISSN:18834396)

巻号頁・発行日

vol.87, no.2, pp.115-121, 2015 (Released:2015-07-04)

参考文献数

21

被引用文献数

3 5

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Tributaries of Lake Tonle Sap in the Lower Mekong Basin are strongly influenced by seasonal changes of water level in Lake Tonle Sap and discharge of the Mekong River. The aim of this research was to gain a better understanding of the fluvial geomorphology of the Stung Sen River, a tributary of Lake Tonle Sap. We used stereopairs of aerial photographs and satellite images to identify the microtopography of the floodplain and riverbed, and field surveys to observe bankside topography and deposits. We recognized four types of channel bar in the lower Stung Seng River: lateral bars (type A), point bars (type B), concave-bank benches (type C), and diagonal and island bars (type D). Type A appears to have a complementary relationship with type D. In some instances types A and D bars transition to type B bars and, in rare instances, into type C bars. These changes are probably related to channel sinuosity and changes in the volume of transported sediment. Sediment transport and construction of the channel bars appears to be controlled by shifts of the flow regime of the Stung Sen River related to differences in the rate of water level rise in the river compared to those in Lake Tonle Sap. The riverine environment differs greatly from that of the floodplain, where sediment is deposited from suspension during periods of inundation.