Alain N. Rousseau

Forest certification has become an important market-based tool for promoting environmental sustainability, biodiversity conservation, and improved governance across agricultural and forest production systems. This state-of-the-art (SotA) review examines forest and cocoa certification schemes in Brazil, focusing on cocoa-based agroforestry systems in southern Bahia. Major programs, including the Forest Stewardship Council (FSC), Brazilian Forest Certification Program (Cerflor), Instituto Biodinâmico (IBD), UTZ Certified (UTZ), Rainforest Alliance (RA), and Geographical Indication (GI) systems, were analyzed for implementation, sustainability outcomes, and accessibility across producer groups. This SotA review identifies persistent barriers to certification adoption, including high costs, complex regulations, limited technical capacity, and unequal access among producers. Certification adoption varies substantially among producer groups, with cooperatives playing a critical role as intermediaries that reduce barriers and facilitate market access. Finally, this SotA review proposes a conceptual classification of cocoa producers and an AI-enabled perspective for deforestation-free certification in biodiversity hotspots such as southern Bahia, offering new insights into sustainable cocoa production and forest conservation.

Glacier retreat is an important contributor to discharge in mountainous watersheds, affecting downstream water uses. In a data-sparse region, changes in glacier retreat and associated discharge, while remaining mostly unknown, threaten the sustainability of ecosystems, the traditional ways of living of First Nation communities, and the (UYW, ~20,000 km²), where 5% of its area is covered by glaciers which on the other end accounts for ~1% of the total glacial coverage of the Gulf of Alaska (GOA). To assess glacier retreat and its hydrological implications, two independent approaches were used and compared: (i) a GRACE time-variable gravity dataset downscaled to the watershed scale via a constrained forward modelling approach, and (ii) a glacier dynamics module of a distributed hydrological model. In addition to estimating glacier retreat rates, the hydrological model was used to assess the effect of glacier mass changes on basin-scale fluxes through an average annual water balance analysis of the Atlin sub-watershed. The two approaches led to a mass loss within the UYW of [137 144] Mt/yr over 2003-2016, respectively. This narrow range corresponds to a discrepancy of only 7 Mt/yr (<5.2% of the estimated glacier mass loss), highlighting the strong agreement between the two independent approaches. Remaining discrepancies stem from limitations inherent to each method, including uncertainties in GRACE signal decomposition and hydrological model forcings and calibration. Overall, this study demonstrates the value of a multiple-line-of-evidence approach for improving glacier retreat assessments while providing insights into the hydrological consequences of glacier change in data-scarce, high-latitude watersheds. The hydrological analysis indicates that glacier runoff remains a major contributor to discharge within glacierized sub-watersheds of the UYW despite their relatively limited glacier coverage.

Wind erosion threatens the organic soils used for agricultural production in the Montérégie region of southwestern Quebec, Canada. Despite estimated regional soil losses of 1 to 4 cm per year, little research globally has focused on wind erosion in soils with high organic matter content. In this study, wind erosion was monitored from July 2019 to October 2022 at two sites in the Montérégie region. This paper presents the results of an intensive effort to quantify soil losses and characterize windblown sediments trapped during multiple erosion events. The field monitoring suggests that organic soils are particularly vulnerable to erosion during the spring. The most severe erosion episode occurred in June 2020, during which major dust storms were recorded. Inter- and intra-annual variations in wind erosion were primarily driven by meteorological variables such as rainfall, relative humidity, and wind speed. Additionally, soil losses appeared to vary with the degree of soil decomposition. While wind-eroded material became finer with height, aggregates as large as 1.9 mm were still detected at 85 cm above the soil surface. Furthermore, aggregates with a mean diameter of 4 mm were transported by saltation up to a height of 25 cm. This suggests that, due to their lower density, the wind-erodible fraction of organic soils is greater than that of mineral soils. These findings demonstrate that wind erosion partly governs the subsidence of organic soils, even when wind events are sporadic. Farmers are thus advised to take measures to reduce soil exposure to mitigate wind erosion.

The snow module of the HYDROTEL (version 2.8.x-078-00-4.1.15.5551) hydrological model was modified to incorporate a multilayer structure composed of ice and air layers within the snowpack, as well as to account for the impact of freezing rain on snow cover. This study examines whether this enhanced physical representation of snow processes improves the accuracy of streamflow simulations. The analysis was conducted across ten watersheds in Quebec, Canada. The multilayer snow model consistently improved low-flow simulations during both calibration and validation periods and enhanced the representation of the falling limb during the calibration period. However, the monolayer snow model performs slightly better during the rising limb of the freshet season for the calibration phase. In addition, the multilayer configuration reduced the bias of the cumulative freshet volumes and annual maximum freshet discharge. Overall, the multilayer snow model achieved comparable performance to the monolayer model for high-flow simulations while outperforming it for low-flow conditions, leading to a more accurate representation of freshet volumes and falling limb dynamics.

Freeze–thaw (F/T) cycles can have substantial effect on soil properties, hydrological processes, and carbon dynamics in cold regions. As global temperatures rise, these cycles are shifting in timing and extent, underscoring the need for improved detection and monitoring at multiple scales. This study presents a comprehensive assessment of the Soil Moisture Active Passive (SMAP) satellite F/T product and the process-based HYDROTEL hydrological model which simulates vertical soil temperature profiles and estimates frost depth by solving thermal conduction equations in a mixed agro-forested watershed in southern Quebec, Canada. In situ soil temperature measurements from two meteorological stations served as ground truth to validate F/T detection for varying land covers, soil depths, and satellite overpass times. The results reveal that the SMAP detection accuracy for shallow depths (5 cm) is highest for open cropland areas ranging from 75.3% to 84.4%, particularly during the PM (ascending) overpass, but decreases for greater depths for forested areas, reflecting the influence of canopy cover and vertical soil temperature gradients. Meanwhile, HYDROTEL showed strong agreement for thawed states but tended to overestimate frozen conditions when compared against SMAP’s detection. Spatial analysis highlighted the effects of land cover heterogeneity and sub-pixel variability on the detection accuracy and emphasized persistent challenges in simulating frozen state of the soil under snow cover and heterogeneous landscapes. By integrating satellite products, modeling results, and in situ observations, this study advances our understanding of F/T cycle dynamics and identifies sources of uncertainty of the studied remote sensing and modeling approaches. These findings reveal the value of combining process-based models and satellite data for hydrological monitoring and modeling of small watersheds and inform future efforts to improve the detection of F/T states for water resources management and crop insurance assessment in cold regions. Keywords— SMAP, Cold Regions, Freeze and Thaw Cycles, Frost Depth, HYDROTEL

Climate change is increasingly driving severe and prolonged hydrological droughts—even in humid regions—causing many rivers to shift from perennial to intermittent flow regimes. This trend is especially critical for agricultural watersheds like the Bécancour River basin (Québec, Canada), where expanding cranberry production intensifies water demand during vulnerable low-flow conditions. Addressing these coupled pressures requires capturing the feedback between streamflow and agricultural withdrawals, particularly given the complex reservoir management inherent to cranberry farming. This study presents an integrated socio-hydrological modelling framework to assess the co-evolution of cranberry farm expansion, water availability, and social constraints in the Bécancour River basin. We translate socio-economic survey data from cranberry producers into a System Dynamics (SD) model, capturing key feedback mechanisms related to economic pressure, social license to operate, conflict perception, and future expansion decisions. The SD model is loosely coupled with the distributed hydrological model HYDROTEL through a Python-based wrapper, allowing dynamic exchange between hydrological stress signals and socio-economic decision variables. The coupled framework is applied to explore scenarios, including climate stress, regulatory tightening, conservation-oriented policies, and technological adoption for water-use efficiency. Results highlight how social constraints and adaptive behaviors can significantly modulate hydrological impacts, emphasizing the importance of integrating human decision-making into watershed-scale water management models.

Climate-driven alterations of river flow regimes are increasing the occurrence of hydrological droughts and low-flow conditions in many humid watersheds, raising new challenges for basin-scale water management. In the Bécancour River basin (Québec, Canada), these pressures coincide with the expansion of cranberry production, a water-intensive agricultural activity supported by irrigation and reservoir-based water storage. Based on an initial watershed-scale assessment of individual and cumulative agricultural, municipal, and industrial water withdrawals, the first step of this research identifies agricultural water use—and particularly cranberry production—as a water use type that becomes especially influential under low-flow conditions. This highlights the need for a detailed, daily representation of cranberry farm-level water demand and reservoir operations, which cannot be adequately captured by conventional hydrological models alone. Building on this foundation, a Cranberry Farm Water Management Model is developed to explicitly simulate daily water use, storage, and recirculation processes. The model is coupled with HYDROTEL, a distributed hydrological model, allowing direct assessment of the impacts of cranberry farming practices on streamflow dynamics of the hydrographic network of the watershed. The outputs of this coupled framework then will serve as a basis for integration with a socio-economic model, enabling the analysis of farmer behavior, governance regulations, and feedback between water availability and management decisions. Together, this integrated socio-hydrological model provides a structured platform for evaluating future climate change scenarios and exploring mitigation and adaptation strategies for sustainable water governance in the Bécancour River basin. Accordingly, this communication focuses on the development and structure of the Cranberry Farm Water Management Model, as the central building block of this broader socio-hydrological governance framework.