MCT-05: Un marco de evaluación para la planificación de la restauración fluvial. Validación con 9 años de datos de seguimiento de un río mediterráneo.

Víctor Cristóbal Bernal Díaz 

Long-term monitoring of Mediterranean rivers often reveals contrasting ecological trajectories even where restoration interventions are similar. These long-term datasets provide limited guidance for interpreting whether observed changes reflect structural ecological condition or temporal variability of indicators. Using nine years of monitoring data from 21 stations in the Ripoll River (NE Spain), we present an integrative diagnostic framework (MCT-05) that explicitly separates ecological state from trajectory of change.
MCT-05 operates as a synthetic layer built on standard Water Framework Directive (WFD) monitoring indicators. Ecological state is quantified through a state index (Γ*) integrating three complementary dimensions: ecosystem physiology (Am), community structure (Pp) and riparian connectivity (Ln). Temporal dynamics are captured independently through a active recovery index (Td) that measures the trend of ecological recovery.
Across the monitoring network, the three state dimensions showed low mutual correlation (mean |r| = 0.24) and Γ* correlated significantly with traditional indicators (QBR: r = 0.76, p < 0.001; IBMWP: r = 0.59, p < 0.01). In contrast, Td showed no correlation with mean index values (|r| < 0.28), confirming that it captures information distinct from structural ecological condition. Connectivity (Ln) emerged as the limiting dimension in 81% of stations, consistent with widespread riparian degradation in the basin.
A paired comparison of two adjacent stations receiving identical restoration intervention demonstrated the diagnostic value of the framework. Station R1 showed strong ecological recovery (Γ* = 0.529; Td = 0.567) with IBMWP increasing from 29 to 101 (p = 0.043), reaching WFD "Good" status for the first time. Station R4 (Γ* = 0.544; Td = 0.277), located downstream of an untreated tributary (Riu Sec), showed no significant change (p = 0.269). Sensitivity analysis (1,000 random perturbations of weights ±20%) confirmed framework robustness: Td ranges for R1 and R4 did not overlap, the limiting dimension remained stable in 100% of stations, and ecological classification was maintained in 96.8% of cases.
By separating ecological state from trajectory of change, MCT-05 allows monitoring datasets to be interpreted in terms of both structural condition and recovery dynamics. The framework is presented as an open diagnostic approach, directly implementable with routine biomonitoring data through ready-to-use tools (Excel calculator, Python script), enabling the river management and research community to evaluate its utility in other contexts and contribute to its refinement.