不同基流分割方法在香溪河流域的应用对比研究

三峡水库蓄水后，库区水质水量备受关注。基流分割是水文学中的一个重点和难点，其结果对水文分析计算、水资源管理等方面的影响较大。为了找到一种可靠的基流分割方法，以三峡库区香溪河流域兴山水文站2007~2009年流量监测数据为依据，利用滤波平滑最小值法进行基流分割，并与数字滤波法和平滑最小值法分割结果进行对比。结果表明：平滑最小值法、数字滤波法和滤波平滑最小值法年均基流分割系数BFI分别为042、039和036；滤波平滑最小值法处理的结果最为平滑，比较符合实际的物理汇流过程，在起涨阶段能较好的追踪数字滤波法，在衰退阶段又能较好的追踪平滑最小值法，能够更好的表现基流完整变化过程；相比数字滤波法，滤波平滑最小值法只需1次向前的滤波。综合而言，滤波平滑最小值法为这3种方法中最优的基流分割方法

COMPARATIVE RESEARCH ON THE APPLICATION OF DIFFERENT BASEFLOW SEPARATION METHODS IN THE XIANGXI RIVER WATERSHED

After the impoundment of the Three Gorges Reservoir,the water quality and quantity have been focused seriously.Baseflow separation is regarded as one of the most important and difficult issues in hydrology,so its separation results have great influence on many aspects,such as hydrological analysis and calculation,water resources management,etc.In order to find a reliable baseflow separation method,we chose flow datas in 2007~2009 provided by Xingshan hydrologic station of the Xiangxi River watershed in the Three Gorges Reservoir,used filtered smoothed minima method to have a baseflow separation,and made a comparison with digital filtering and the smoothed minima method.The results showed that the BFI of smoothed minima,digital filtering and filtered smoothed minima were 042,039 and 036,respectively.The results that dealed with filtered smoothed minima were the most smooth,and corresponded with actual converge physical process.Filtered smoothed minima was able to have a better performance for tracing the digital filter method during ascension period and the smoothed minima method during the recession,required only one pass filtering in the forward direction instead of three pass(forward backward forward)in the digital filtering.Therefore,it is the best separation method among this three baseflow separation methods