Impact assessment for the river environment due to climate change and human activities evaluated by focusing on the network structure of river systems

本研究项目开发了一种河流环境管理的网络型模型，该模型利用河流排序引入河流网络的层次累积结构。利用河流温度网络模型考察了人类活动和气候变化对河流环境的影响。在本研究的试验流域伊波河流域，网络模型的结果表明，夏季河流的热平衡主要由水面热通量主导，而冬季河流的热量平衡主要由河床地下水的热量输送构成。对于气候变化的影响，模型分析了气温和降水变化引起的水温变化，表明上游的温升似乎大于下游。

This research project developed a network-type model for river environmental management, in which hierarchical accumulation structure of the stream network was introduced using the stream orderings. The network model for stream temperature was used to examine the effects of the impact of human activity and climate change on the river environment. In Ibo River basin, a test basin of this study, the results of the network model indicated that the heat balance in stream in summer was dominated by the heat flux on the water surface, whereas in winter significance was formed by the heat transport from ground water on the riverbed. As for the effects of climate change, the model analyzed the stream temperature changes due to changes in air temperature and precipitation, indicating that temperature rise in the upstream seems to be larger than that in the downstream of the river basin.