Water resources management is a non-trivial process requiring a holistic understanding of the factors driving the dynamics of human-water systems. Policy-induced or autonomous behavioral changes in human systems may affect water and land management, which may affect water systems and feedback to human systems, further impacting water and land management. Currently, hydro-economic models lack the ability to describe such dynamics either because they do not account for the multi-factor/multi-output nature of these systems, and/or are not designed to operate at a river basin scale. This paper presents a flexible and replicable methodological framework for integrating a microeconomic multi-factor/multi-output Positive Multi-Attribute Utility Programming (PMAUP) model with an eco-hydrologic model, the Soil and Water Assessment Tool (SWAT). The connection between the models occurs in a sequential modular approach through a common spatial unit, the “Hydrologic-Economic Representative Units” (HERUs), derived from the boundaries of decision-making entities and hydrologic responsive units. The resulting SWAT-PMAUP model aims to provide the means for exploring the dynamics between the behavior of socio-economic agents and their connection with the water system through water and land management. The integrated model is illustrated by simulating the impacts of irrigation restriction policies on the Río Mundo sub-basin in south-eastern Spain. The results suggest that agents’ adaptation strategies in response to the irrigation restrictions have broad economic impacts and subsequent consequences on surface and groundwater resources. We suggest that the integrated modeling framework can be a valuable tool to support decision-making in water resources management across a wide range of scales.

Tropical montane cloud forests (TMCF) are recognized for their capacity to maintain high dry-season baseflow, and a host of other, ecosystem services. Despite their importance, they are endangered with a multidirectional array of land use changes, including conversion to pasture and crops such as coffee, while there are places where forest is being recovered. However, little is known about the effects of this complex dynamic on catchment hydrology. We investigated the effect of land use on rainfall-runoff response in five neighboring headwater micro-catchments in central Veracruz, Mexico, by comparing primary TMCF (PF), young (20 yr-old) and intermediate (40 yr-old) naturally regenerating TMCF (YF and IF, respectively), shaded coffee (SC), and an intensively grazed pasture (IP). We used a 4-year record of high-resolution rainfall and streamflow (10 min) data, collected from 2015 to 2019. These data were analyzed via hydrologic metrics and statistical tests. Results showed no statistical difference in the regulation capacity of high flows after 20 years of natural regeneration, compared to the PF. In terms of baseflow sustenance, our results suggested that PF and IF better promote this hydrological service than the other land uses, although all the catchments showed high mean annual low flows. SC exhibited a high capacity to modulate peak flows comparable to that of PF, and an intermediate capacity to sustain baseflow, suggesting that the integrated functioning of this catchment was largely preserved. Finally, we found that 40 years of pasture management can decrease the soil hydraulic properties in the area, causing a fivefold increase in the peak discharge response, and a much lower baseflow maintenance compared to PF.