Hydrological and multi‑benefit outcomes of ecological restoration and managed aquifer recharge across land‑use types: a systematic literature review

Ecological restoration and managed aquifer recharge (MAR) are widely promoted to enhance groundwater resources and buffer hydrological extremes, yet quantitative evidence on their effectiveness and co-benefits remains fragmented across land-use types and disciplinary silos. Existing reviews rarely compare not only hydrological responses but also side-benefits such as flood peak reduction, carbon sequestration, water quality improvements, biodiversity gains, and associated implementation costs across contrasting land-use/land-cover (LULC) settings. This study presents a systematic literature review that (i) maps the global evidence base on groundwater recharge responses to restoration and MAR, (ii) compares co-benefits and trade-offs across major LULC classes (river lowlands, wetlands, mountainous aquifers, forests, urban areas, cropland, pasture), and (iii) evaluates how study design, metrics, and cost information influence the strength of inference and decision relevance.​

Searches in three bibliographic databases follow a pre-specified protocol with semi-automated deduplication and AI-assisted screening. Two reviewers independently screen titles/abstracts and full texts in a dedicated review platform, targeting substantial to almost perfect agreement (Cohen’s κ ≥ 0.7 for titles/abstracts; κ ≥ 0.8 for full texts). Eligible studies are coded for hydroclimatic region, LULC, intervention type, study design (before–after, control–impact, paired-catchment, BACI), and methodological approach (field monitoring, tracer tests, modelling). Extracted response variables include quantitative metrics of groundwater recharge, baseflow and storage, flood peak attenuation, carbon-related indicators, water quality parameters, biodiversity indices where available, and reported capital and operational costs or cost proxies. Risk of bias and inferential strength are appraised using criteria adapted for quasi-experimental hydrological studies and economic evaluations.​

The review is expected to yield a sufficient number of primary studies (on the order of 80-150) to enable cross-LULC comparisons of hydrological effectiveness, co-benefits, and costs. Anticipated outputs include evidence maps identifying LULC-intervention combinations with robust multi-benefit support versus critical gaps, and syntheses highlighting where relatively small investments deliver disproportionately high recharge gains and side-benefits. These insights will inform the design of future experiments and models and support practitioners and policy-makers in prioritising restoration and MAR options that maximise groundwater recharge while delivering broader ecosystem and societal benefits.