考虑过程变化的黄河河口区水文情势变化评价

Evaluation of Hydrological Regime Change in Estuary Region of Yellow River Considering Process Changes

正确理解黄河河口区河流水文情势变化程度对该地区河流生态系统的维持及修复具有重要意义。目前最常用的评价河流水文情势的方法为变动范围法(RVA),其通过比较水文过程突变前后水文情势指标落在统计范围内的频次变化衡量变化程度,但RVA法缺乏对水文要素过程变化的评价,可能低估评价结果。分别利用基于欧氏距离(ED)及基于动态时间规整算法(DTW)的两种考虑水文要素过程变化的改进RVA法评价黄河河口利津水文站水文情势变化,并与原始RVA法进行对比。结果表明,基于ED、DTW的改进RVA法与原始RVA法所得的黄河河口区水文情势改变度分别为0.78(高度)、0.60(中度)、0.62(中度);相较于基于DTW的RVA法,基于ED的改进RVA法对水文要素过程变化更加敏感;黄河河口区近30多年来河流水文情势变化较大,应重视依据不同指标变化程度采取针对性改善措施。

Correct understanding of the degree of changes in the hydrological situation of the Yellow River estuary is of great significance to the maintenance and restoration of the river ecosystem in the region.At present,the most used method for evaluating the hydrological situation of a river is the range of variation method(RVA),which measures the degree of change by comparing the frequency change of the hydrological situation index falling within the statistical range before and after the sudden change of the hydrological process.However,the traditional RVA lacks the evaluation of the process changes of hydrological elements,which leads to underestimating the evaluation results.This paper uses two improved RVA methods based on Euclidean distance(ED)and dynamic time warping algorithm(DTW),which consider the process changes of hydrological elements,respectively,to evaluate the changes in hydrological conditions at the Lijin hydrological station in the lower reaches of the Yellow River.Compare the results obtained with the original RVA.The results show that the hydrological regime changes of the Yellow River estuary area obtained by the two improved RVA methods based on ED and DTW and the original RVA method are 0.78(altitude),0.60(medium)and 0.62(medium),respectively;Compared with DTW based the RVA method,the ED-based RVA method is more sensitive to changes in hydrological elements;The river hydrological situation in the Yellow River estuary has changed greatly in the past 30 years,and attention should be paid to taking targeted improvement measures based on the degree of change of different indicators.