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

(1)于2000年7月至9月和2001年7月在石垣岛白鹤礁进行了带各种记录仪式传感器的系泊浮标系统和安装了gps的小型漂船等的野外观测，研究了海流、波浪、温度、盐度、浊度等特征。研究发现，礁体的水动力特征，特别是平均流场，受礁体地形的空间不均匀性（如尺寸、通道、浅滩和礁体边缘的位置）的支配。2)同一时期在白鹤礁进行了较小尺度的观测，观察了珊瑚群落周围的三维局部水流和温度场，揭示了珊瑚群落的特征，以及珊瑚比珊瑚砂更有效地吸收光线的事实。3)利用降水、植被、土壤类型和地形等输入数据，建立了基于流域的模拟土壤侵蚀和随后向邻近珊瑚礁区排放的数值模型，并与2000年6月以来连续采集的Todoroki河浊度时间历史的野外数据进行了验证。1998年夏季，利用高频海洋雷达系统、新开发的安装了gps的漂流器和其他设备进行了实地测量，以澄清连接Kerama Ms.和冲绳岛西海岸的区域的海面上的海流的物理过程和示踪剂的拉格朗日轨迹。此外，在实验室研究了幼虫在水柱中的行为和底部的沉降。这些结果表明，喀喇玛群岛。5) 2001年7月和8月，在福木户和宫原河蛾区进行了实地观测，以阐明红树林和海草区自然环境的基本特征。6)利用这些野外数据，分别以SDS-Q3D模型和POM-dual sigma坐标模型为基础，建立了控制珊瑚礁内物质和热输运的浅水湍流和大范围内海岸三维流的数值模拟模型。7)建立了珊瑚冠三维光学模型，作为底栖生物覆盖等珊瑚礁环境遥感的基础理论工具。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