Northern brazilian river deltas: River impacts versus pristine discharge

巴西北部河流三角洲：河流影响与原始排放

• 批准号: 64816243
• 负责人: Professor Dr. Karl Stattegger
• 金额: --
• 依托单位: Departamento de Geologia PPGG (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/64816243?language=en
• 关键词: Northern; brazilian; river; deltas; River

At present we observe a basic change in the hydro-sedimentological regime of the São Francisco river mouth. The shut-off of riverine sediment transport to the coastal zone and continental shelf by constructing dams for reservoirs along the river initiates a switch of the former wave-dominated delta to an estuary. Ongoing suppression of sediment supply has produced already significant deficits in the sediment budget at the river mouth including destruction of small villages by coastal erosion. Hydro- and sediment dynamics of this basic change will be investigated in the framework of Holocene coastal evolution. To gain more insight into the principal coastal and shelf processes governing the turnover of the São Francisco delta to an estuary, actual dynamics and Holocene evolution of the pristine wave- and tide-dominated delta of the Parnaíba River, the largest delta between the Rio São Francisco and the Amazon, will be investigated. Pure estuarine conditions at the mouth of a river of the same magnitude will be studied in the tide and wave dominated estuary of the Rio Pará/Tocantins. Detailed comparative studies of hydrodynamics, sediment dynamics and late-Holocene evolution of the three river-mouth systems provide the unique opportunity to evaluate the effects of the shut-off of riverine sediment supply on coastal and shelf sedimentation in wave- and tide-dominated settings.

目前，我们观察到弗朗西斯科河口的水文沉积状况发生了基本变化。通过修建沿着水库大坝，切断了河流泥沙向海岸带和大陆架的输送，从而开始了由以前的波浪控制三角洲向河口的转变。目前对沉积物供应的抑制已经造成河口沉积物预算的严重不足，包括海岸侵蚀对小村庄的破坏。将在全新世海岸演变的框架内研究这一基本变化的水文和沉积动力学。为了更深入地了解控制圣弗朗西斯科三角洲转变为河口的主要海岸和大陆架过程，将调查圣弗朗西斯科河和亚马逊河之间最大的三角洲-Parnaíba河原始波浪和潮汐三角洲的实际动态和全新世演变。将在Rio Pará/托坎廷斯潮汐和波浪主导的河口研究相同量级河流河口的纯河口条件。详细的比较研究的水动力学，沉积物动力学和晚全新世演变的三个河口系统提供了独特的机会，以评估关闭河流沉积物供应对海岸和大陆架沉积在波浪和潮汐为主的设置的影响。