An assessment of the hydromorphological conditions of the middle and lower Guadalquivir River (southern Spain)

An overall hydromorphological assessment of the middle to lower Guadalquivir River (southern Spain) was conducted using the Morphological Quality Index (MQI) and a novel extension, the Hydro-Morphological Quality Index (HMQI), with the following aims: (1) investigate the morphological problems and (2) describe and test the HMQI on a case study characterized by relevant hydrological alterations related to the presence of dams. The assessment was preceded by a delineation phase of spatial units using the REFORM hydromorphological framework. The MQI results show that moderate is the dominant quality class, with some cases falling into the poor class and a few cases with good conditions. The results in terms of the HMQI are slightly worse, given the remarkable hydrological alterations related to the dams, with approximately half of the reaches classified as poor and the remaining half classified as moderate. The main conclusions of this case study are that (1) the methodology is effective in diagnosing hydromorphological problems and in allowing a sound understanding of the responses to pressures (i.e., cause-effect relationships), and (2) the overall evaluation based on HMQI appears to be a useful integration with the MQI, particularly in a case study characterized by a large number of dams.