Disasters due to floods, sediment runoff and beach erosion

这项联合研究旨在开发预测降雨径流、产沙量和径流、河流变化和海岸侵蚀的方法，并为印度尼西亚减轻水沙灾害提供科学依据。主要研究成果如下：对苏塔米水库流域的水量平衡和径流灾害进行了长期和短期降雨-降雨模式的检验。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模型，并将该模型应用于布伦塔斯河支流普提利河，模拟了1990年布伦塔斯火山喷发后7年间的产沙量。KEHID和估算了影响产沙量的有效入渗深度。基于SAMP…对流域内约30个点位的铅床料、土壤性质和颗粒大小进行了调查。布伦塔斯中游采用了一维和二维河床变化模型。L-D模型研究了航道宽度对河床变化的影响和悬移质的影响，结果表明，航道宽度的快速变化导致河床变化较大。二维模型表明，河段加宽处发生水流分叉，悬移质加剧了弯道内岸泥沙的粗化；南爪哇岛滨海临海工程正在建设中，进行了沿岸监测和数值预报；采用考虑波浪影响的三维水动力模型，对爪哇海受东西季风影响的风潮环流进行了一年的模拟。用第三代海浪预报模式WAM计算了海浪场和与波浪相关的海面和海底阻力系数，海面以上10英寸处的6小时风场由ECMLWF的全球气候再分析资料给出。模拟了普通示踪剂的运动轨迹，以了解物质在海面和海底的传输情况。本项目建立了由涌涌型破碎波模型、三维近岸环流模型和泥沙运动模型组成的三维滩涂变化预报模型。它在日本和印度尼西亚的海岸继续进行核查。较少

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