Disasters due to floods, sediment runoff and beach erosion

开展这项联合研究的目的是制定预测降雨径流、产沙量和径流、河流变化和海岸侵蚀的方法，并为减轻印度尼西亚的水和沉积物灾害奠定科学基础。主要研究结果如下：对Sutami水库流域的水平衡和径流损失进行了长期和短期的模拟试验。利用遥感影像和地理信息系统（GIS）建立了分布式洪水泥沙径流水文模型，并将该模型应用于布兰塔斯河支流普蒂利河流域的洪水泥沙径流模拟，结果表明，该模型能较好地模拟热带流域的日径流量，重现了1990年火山爆发后的七年中的产沙量。Kehid模型，并估算了影响产沙的有效入渗深度 ...更多信息 对流域内约30个点的河床物质、土壤性质和颗粒大小进行了调查。应用一维和二维河床变化模型对布兰塔斯河中游河段进行了模拟.一维模型研究了河道宽度对河床变化的影响以及悬移质的影响，结果表明，河道宽度的快速变化会引起较大的河床变化。二维数学模型表明，在变宽河段发生了河流分叉，悬移质加剧了弯曲河段内岸泥沙的粗化（南爪哇），面对印度洋，是河流的捷径工程正在建设中。潮汐和风驱动的爪哇海环流的一年模拟，wiuich是受西部和东部季风的影响，进行了使用三维水动力学模式，包括波浪的影响。采用第三代海浪预报模式WAM计算了波浪场和与波浪有关的海面和海底阻力系数，并以ECMLWF全球气候再分析资料给出的海面10英寸处的6小时风场作为代表风场。模拟了海洋示踪剂的运动轨迹，以了解海洋表面和底部物质的输运。本研究建立了一个三维海滩变化预测模型，该模型由钻孔式破碎波模型、三维近岸环流模型和泥沙输运模型组成。在日本和印度尼西亚的海岸继续进行核查。少

This joint research has been conducted to develop methods for predicting rainfall runoff, sediment yield and runoff, river changes and coastal erosion, as well as to develop scientific basis for water and sediment hazards mitigation in Indonesia. The principal results are swninarized as follows :A long- and short-term rainfall-nuioif model was tested to evaluate the water balance and rainfhll a runoff disehaige in the Sutami reservoir basin. The results show this model can reproduce daily rainfall-runoff using the variable infiltration capacity model, even in tropical drainage basins.Remote sensing images and geographic information systems (GIS) were used for establishing a distributed hydrological model for flood and sediment runoff The model applied to the Putili river, a tributary of the Brantas, reproduced the sediment yield during the seven years following the 1990 eruption of Mt. Kehid and estimated the effective infiltration depth that contributes to sediment yield.Based on samp … More led bed materials at about thirty points in the basin, soil property and particle size were investigated. One- and two- dimensional bed variation models were applied to the middle reach of the Brantas. The l-D model investigated the effect of channel width on bed variation and the effect of suspended load, and revealed that the rapid change in channel width causes greater river bed variation. The 2-D model showed that the stream bifurcation took place in broadening reaches and suspended load accentuated the coarsening of sediment at the inner bank of curved sections of the river.Coastal monitoring and numerical prediction have been conducted in Pangandaran coast (South Java), facing the Indian Ocean, were river short-cut works are under construction.One-year simulation of tide- and wind-driven circulation in Java Sea, wiuich is influenced by the west- and east- monsoons, was carried out using a three-dimensional hydrodynamic model incorporating the influence of waves. A third-generation ocean wave prediction model, WAM, was employed to calculate the wave fields and the wave-dependent sea surface and bottom drag coefficients.Six-hourly wind fields at 10 in above the sea surface ware given by ECMLWF's global climate reanalysis data as a representative wind. The trajectory of munnerical tracers was simulated to understand transport of materials at both the sea surface and bottom. A 3-D beach change prediction model which consists of a bore type breaking wave model, 3-D near-shore circulation model and sediment transport model, has been developed in this project. Its verification has been continued on coasts both in Japan and Indonesia. Less