A comprehensive field survey and analysis on a physical and ecological system of coral reef environment under adjacent land and ocean influence

1)2000年7-9月和2001年7月在石垣岛白鹤礁进行了带各种记录仪传感器的系泊浮标系统和安装了GPS的小型漂移器等的现场观测，以了解流、浪、温、盐、浊度等特征。在同一时期，白鹤礁的水动力特征，特别是平均流场，被发现是由礁石地形的空间不均匀所决定的，如海峡、浅滩和礁缘的大小和位置。2)在同一时期，白鹤礁还进行了一次较小尺度的测量，以观测珊瑚群落周围的三维局部流和温度场。3)建立了基于流域的土壤侵蚀数值模型，利用降水、植被、土壤类型和地形等输入数据，建立了基于流域的土壤侵蚀数值模型，利用…用2000.4年6月以来连续采集的托多罗基河浊度时间历史的现场数据进行了更多的验证)，以检查珊瑚幼虫的长途运输。1998年夏天，利用高频海洋雷达系统、新开发的全球定位系统安装的漂浮器和其他设备进行了现场测量，以澄清海面流的物理过程和连接喜马拉雅群岛和冲绳ID西海岸的海面示踪剂的拉格朗日轨迹。此外，还在实验室中调查了幼虫在水柱中的行为和底部的定居情况。这些结果表明，KARAMA是一个ISLS。可作为冲绳岛西岸相当数量的珊瑚幼虫的源区。5)2001年7月和8月，在藤户岛和宫原河蛾区进行了一次现场观测，以阐明红树林和海草地区物理环境的基本特征。6)利用这些现场资料，建立了控制珊瑚礁物质和热量输送的浅水湍流流动和海岸三维流动的数值模式，该模式基于SDS-Q3D模型和POM-Dual Sigma坐标模型，7)作为珊瑚礁环境遥感的基础理论工具，建立了珊瑚冠层的三维光学模型。较少

1) Field observations using moored buoy systems with various logger-type sensors, GPS-installed small drifters and others were performed at Shiraho reef in Ishigaki Island in July to September 2000 and July in 2001to find characteristics of currents, waves, temperature salinity, turbidity, etc. The hydrodynamic feature, especially the mean flow field, in the reef are found to be governed by the spatial non-uniformity of the reef topography such as the S1ze and locations of the channels, shoals and reef edges.2) A smaller scale measurement to observe 3-D local current and temperature fields around coral communities was made also at Shiraho reef in the same period, revealing their characteristic features and the fact that corals may absorb light more effectively than coral sands.3) The watershed-based numerical model to simulate soil erosion and subsequent discharge into adjacent reef areas with input data such as precipitation, vegetation, soil type and topography has been developed and … More validated with the field data on time histories of turbidity at the Todoroki river taken continuously from June 2000.4) For examining the long-distance transport of coral larvae. which may be important in the restoration process of the heavily damaged coral reefs due to mass bleaching in 1998 summer a field measurement using an HF-ocean radar system, newly-developed GPS-installed drifters and others was performed to clarify the physical process of the sea-surface currents and the Lagrangian trajectories of tracers at the sea surface in the region connecting the Kerama Ms. and the west coast of the Okinawa Id. Besides larval behavior in the water column and settlement at the bottom were investigated in a laboratory. These results demonstrate that Kerama Isls. may act as a source area supplying appreciable amount of coral larvae to the west coast of Okinawa Isl.5) At Fukido and Miyara river moth areas in July and August 2001 a field observation was made to clarify the fundamental characteristics of physical environments of mangrove and sea-grass areas.6) With these field data, numerical models to simulate shallow water turbulent flows in the reef, which governs material and thermal transport in the reef, and coastal 3-D currents in a wide have been developed with the basis of SDS-Q3D model and POM-dual sigma coordinate model, respectively.7) As a basic theoretical tool for remote sensing of coral reef environments such as benthic cover, a 3-D optical model for coral canopy was developed. Less