灞河流域气候因子对水沙变化的影响

利用灞河流域蓝田气象站和马渡王水文站1960—2012年的气象、水文实测资料,分析灞河流域气候及水沙变化规律,同时运用相关性分析、灰色关联分析、多元线性回归模型等多种方法探讨了该流域水沙变化与气候变化的关系。结果表明:灞河流域降雨量、蒸发量、径流量和输沙量皆呈显著下降趋势,而气温呈上升趋势;降雨量与水沙都有重要的相关关系,1960—1990年影响径流量的气候因子敏感度由大至小依次为降雨量、气温、蒸发量,而1991—2012年则为降雨量、蒸发量、气温,当气温和蒸发量不变时,降雨量每增加1 mm,两阶段的年径流量分别增加0.14亿m3和0.08亿m3;1960—2012年影响输沙量的气候因子敏感度由大至小依次为降雨量、气温、蒸发量,当气温和蒸发量不变时,降雨量每增加1 mm,年输沙量增加0.668万t。

Impact of climate factors on variations of water and sediment in Bahe River Basin

Based on the the climate data of Lantian meteorological station and hydrology data of Maduwang hydrological station and the climate data of Lantian meteorological station in the Bahe River Basin collected from 1960 to 2012, this paper analyzed climate and water-sediment change rules of the said basin, at the same time the relationship between water-sediment variation and climate change was discussed by using correlation analysis, gray relational analysis and multiple linear regression model, etc. The results showed that the rainfall, evaporation, runoff and sediment discharge in the Bahe River Basin all showed a significant downward trend while the temperature was on the rise. Rainfall had an important relationship with water and sediment, from the year 1960 to 1990 the sensitivity of climate factors affecting runoff was rainfall, temperature and evaporation in turn, and between the year 1991 and 2012 the sensitivity was rainfall, evaporation and temperature. When the temperature and evaporation were constant, if the rainfall increased 1mm each time, the annual runoff would increase by 0. 014×10⁸ m³ and 0. 008×10⁸ m³ respectively in the above two period. From the year 1960 to 2012, the climate factors affecting the sediment discharge in the Bahe River Basin were rainfall, temperature and evaporation. When temperature and evaporation were unchanged, the annual sediment discharge increased by 0. 668 ×10⁸ tons for each increase of rainfall by1mm.