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DIMINISHING MANGROVE FORESTS AND SPREADING EROSION OF RIVER BANKS DUE TO INLANDWATERWAY NAVIGATION IN THE MEKONG DELTA
| 题名： | DIMINISHING MANGROVE FORESTS AND SPREADING EROSION OF RIVER BANKS DUE TO INLANDWATERWAY NAVIGATION IN THE MEKONG DELTA |
| 作者： | Yuzo AKATSUKA; Takashi ASAEDA; Norio TANAKA; Thanh VU Ca |
| 关键词： | DIMINISHING MANGROVE FORESTS ; SPREADING EROSION OF RIVER BANKS ; NAVIGATION |
| 摘要： | In the Mekong delta, dense networks of inland waterways have been developed as transport infrastructures to support local communities mainly because of the virtual lack of land transportation systems due to geographical conditions in the delta. River banks of waterways which extend over tens of thousand kilometers have been used to be covered and protected by thick mangrove and nipa forests for many years. In recent years, however, it has been noted that mangrove and nipa forests are rapidly diminishing away and bank erosion is spreading along the waterways, being caused by waves generated by motorized vessel navigation. The diminishing of mangrove and nipa forests and erosion of river banks have been observed particularly where traffic of motorized vessels is heavy. In recognition of this alarming situation, field surveys were conducted in late 1999 for the first time and then in early 2001 with a view to identifying the facts. During the field surveys, propagated waves waked by the navigation were frequently observed to break at the river banks stirring up the soils, thereby eroding the bank. When the water level is low, waves tended to stir up the sub-soils of exposed roots of mangrove and nipa forests, thereby gradually but steadily destructing the vegetation. It is also noted that almost all the vessels, irrespective of their type, size and age, have been motorized and further that every household in the rural communities located along the waterways posses small boats equipped with an outboard motor for their family use. This is an alarming situation for the local communities in the delta, and further the ecological systems are exposed to entire collapse adversely affecting the fishery resources in the waterways. |
| 总页数： | Proceedings of the 30th PIANC-AIPCN Congress. Sydney Australia. 22-26 Sept. 2002. pp9 |
| 报告类型： | 科技报告 |
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