Author(s): Yangwen Jia; Wenhai Zhang; Cunwen Niu
Keywords: No Keywords
Abstract: The indicator of hydrological alteration (IHA) has been widely used to assess the extent of ecological hydrological changes in a river basin and its impact on the ecosystem. However, the lack of local data or hydrological long series data will affect the credibility of the evaluation results. Based on the length of record (LOR) method, we comprehensively analyze the data length requirements for each group of indicators of IHA and study the influence of the LOR results caused by the data mutation characteristics and the change of confidence level at the Panzhihua hydrology station in the Jinshajiang River of China. The results show that: 1) under the same confidence interval, the required data lengths show seasonal differences for the indicators of the monthly flux group (GROUP1) and the annual extreme hydrology condition group (GROUP2), whereas those maintain relatively high values for the indicators of the timing of annual extreme flow group (GROUP3), the pulse group (GROUP4) and the change rate of flow rate and frequency group (GROUP5); 2) The greater the deviation from the data points in the hydrological series is, the greater the LOR results are.