ABSTRACT

Hydrological methodologies are the most efficient approaches for environmental flow (eflow) assessments. This paper presents a hydrological methodology for determining eflows in rivers with scarce development to promote proactive environmental water allocations that limit flow alteration and unsustainable water use. The analysis includes the natural intra-annual and inter-annual ranges of flow variability. Eflows are determined based on four hydrological low-flow conditions and a flood regime. The main contribution is that the flow regime components are adjusted to a four-tiered environmental objective class system based on a novel “frequency-of-occurrence” approach. The method is applied in three rivers in western Mexico with highly variable flow regimes. The eflows are largely (96%) within the central range of previous implementations, and the outcomes reveal an overall good and acceptable level of the method’s performance (for 83% of the cases R ² ≥ 0.84, slope = 1 ± ≤ 0.2), consistent with supporting indices of flow variability.

摘要

水文方法学是评估环境流量的最有效方法。本文提出了一种水文方法学，用于确定发展稀少的河流中的水流，以促进积极的环境用水分配，从而限制流量变化和不可持续的用水。该分析包括流量变化的自然年度内和年度间范围。流量是根据四个水文低流量条件和洪水状况确定的。主要贡献在于，基于新颖的“发生频率”方法，将流态成分调整为四层环境目标类别系统。该方法被应用在墨西哥西部的三条河流中，这些河流的流量变化很大。流出量大部分（96％）在先前实施方案的中心范围内，[R ²  ≥0.84，斜率= 1±≤0.2）中，用支撑流变性指数一致。