Environmental flow assessment for benthic macroinvertebrate communities using pseudo‐2D hydraulic habitat modelling at a green small hydropower plant

Abstract The determination of minimum flow requirements for green small hydropower plants (GSHP) in China primarily relies on hydrological methods such as the Tennant method with no seasonal variation. However, direct application without local ecological data calibration lacks validity, potentially resulting unsuitable recommendations aquatic biota. Hydraulic‐habitat modelling (HHM) is assumed to provide more ecologically relevant and reliable environmental (EFRs), but benthic macroinvertebrates (BMs), crucial food web, have rarely been focus HHM studies. Moreover, strong subjectivity processes hinders comparison EFRs across different biota geographical regions. This study aims investigate validity using set BM communities impacts various used derived EFRs. To achieve this, a pseudo‐2D approach employed, integrating 1D hydraulic models HEC‐RAS CASiMiR habitat model HABFUZZ. downstream Jiufeng reservoir, one China's first GSHPs, are wet (April–June) dry seasons (July–September). Our findings highlight that setting alone inadequate preserving community integrity GSHPs. It incorporate diverse criteria, including flows peak flows, into GSHP assessment standards, recommended levels varying seasons. Additionally, development standardized methodology essential mitigate inherent facilitate generated from study's innovative framework will enhance optimization criteria China, deepen understanding e‐flow communities, refine recommendation.