This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise...This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the eleva- tion of Tongguan, which is defined as the stage corresponding to a discharge of 1000 m3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream en- ergy that integrates the current and the preceding years’ flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a rela- tively large range of variations, then the elevation of Tong- guan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primar- ily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.展开更多
文摘This paper presents a study of the variation of the elevation of Tongguan, which is located in the backwater zone of the Sanmenxia Reservoir, in response to changes in flow runoff. The analysis indicated that the rise of the eleva- tion of Tongguan, which is defined as the stage corresponding to a discharge of 1000 m3/s at Tongguan station, is controlled by the stream energy. A close relationship existed between the elevation of Tongguan and the superimposed stream en- ergy that integrates the current and the preceding years’ flow and dam operation conditions. When the flow runoff remains relatively constant and the pool level of the dam has a rela- tively large range of variations, then the elevation of Tong- guan is primarily controlled by the dam operation conditions. On the other hand, if the flow runoff has a relatively large range of variations and the pool level of the dam remains relatively constant, then the elevation of Tongguan is primar- ily controlled by the flow conditions. These findings are of importance for optimizing the dam operation in order to lower and control the elevation of Tongguan, and therefore to minimize the backwater effect of the dam operation.
文摘矿山尾矿库地址的选择,涉及到一个矿山生产的经济效益与环境污染等问题。选择尾矿库时除了要选择低洼区外,还要考虑的因素有离选矿厂的距离、是否有断裂带、尾矿库容量等问题。G IS的空间叠加、缓冲区分析等强大空间分析功能,为矿山尾矿库地址的选择提供了帮助。应用ArcV iew和M apG IS等软件,对个旧锡矿某矿山的地形图与地质图进行了矢量化处理,建立了矿区的数字高程模型(DEM),运用DEM直观地判断出矿区的低洼区,并对各低洼区进行了容积的计算。通过对矿区位置图、地质图和DEM的叠置分析、离矿厂距离的缓冲区分析,以及矿区低洼区容积的比较后,得出了该矿山尾矿库的最优位置。研究后认为该方法具有选址直观、效率高等特点,值得推广。
