Iahris: New Software to Assess Hydrologic Alteration

Indicators of Hidrologic Alteration in RIverS (IAHRIS) is a software designed to fulfill: 1. Parameters for the characterization of the natural or regulated flow regime, in a section of the river. These parameters evaluate those aspects of the flow regime with the highest environmental meaning (magnitude, variability, seasonality and duration). Their definition has given priority to the consideration of the singular characteristics of the Mediterranean regimes. 2. If the user enters data of the natural flow regime and data for any other flow regime in the same section or reach (altered regime, environmental regime, management scenario, …) the software calculates, furthermore, a set of indicators that assess the degree of hydrologic alteration in comparison with the natural regime. These indicators of alteration have been defined attending to the CIS-WFD recommendations for the Ecological Quality Ratios. The software requires, at least, 15 entire years with data (daily average flows and/or monthly volumes). The type of data entered in IAHRIS determines, directly, the results accomplished. In particular, they depend on the data periodicity –daily or monthly-, and the simultaneous character of the data associated to the natural and the altered flow regimes. IAHRIS is free software, available at the website of the Spanish Ministry of the Environment.