淮河流域河道内生态需水保障程度时空特征解析

Spatio-temporal analysis of satisfactory degree of ecological water demand in Huaihe River Basin

为了反映出河道内水量满足生态保护与修复需求的状况,以淮河流域为研究对象,构建了适合于快速评估流域尺度河道内生态需水保障程度时空特征的方法。采用生态需水年内展布计算法计算了流域主要干支流的生态需水阈值,并结合实测径流资料开展了生态需水保障程度计算。利用时间序列法、Mann-Kendall检验法、聚类分析以及GIS空间分析功能对流域生态需水保障程度进行时空特征解析。结果表明:1流域生态需水保障程度整体呈现上游地区高于下游地区,淮河干流南岸地区高于北岸地区的特征;2颍河、涡河、沱河等支流的生态需水保障程度较低,且呈显著下降的趋势;3流域年内4—6月份的生态需水保障程度整体表现最低,且空间差异性大,为流域河道内生态需水敏感时期;4流域涡河玄武、蒙城断面,池河明光断面和沱河永城断面生态需水保障程度整体最低,且年内过程变异程度最大,为河道内生态需水优先保障区。评估结果可为优化流域水资源配置、制定维护河流健康对策和保障措施提供重要的依据。

In order to reflect the statuson instream flow to meet the demand of ecological protection and restoration, this study adopts dynamic calculation method of ecological water demand to calculate the satis-factory degree of ecological water demand of the main rivers in the Huaihe River Basin. Based on the Clus-ter analysis, Mann-Kendall test and the function of spatial analysis of GIS, this papermainly addresses identification of the sensitivity areas and periods of the satisfactory degree of ecological water demand, and its spatial distribution characteristics. The results sho wthat;①Overall, satisfactory degree of ecological wa-ter demand in this basin is higher in the west thanthat in the east, higher in the north and lower in the south;②Satisfactory degrees of ecological water demand in the Yinghe, the Wohe and the Tuohe rivers are lower, and present a significant downward trend;③The satisfactory degree of ecological water deman-dat thethird period （Apr-Jun） is the lowest, and has the largest spatial difference. So, it can be recog-nized as the sensitive period of the ecological water demand;and ④ The sensitivity areas of ecological wa-ter demand are some sub-basins in the Huaihe River Basin,such as the Wohe,the Chihe and the Tuohe rivers. Ecological water demand in these rivers cannot be guaranteed at more than one-third of the time in a year.