Location-specific forms of agroforestry management can reduce problems in the forest–water–people nexus, by balancing upstream and downstream interests, but social and ecological finetuning is needed. New ways of achieving shared understanding of the underlying ecological and social-ecological relations is needed to adapt and contextualize generic solutions. Addressing these challenges between thirteen cases of tropical agroforestry scenario development across three continents requires exploration of generic aspects of issues, knowledge and participative approaches. Participative projects with local stakeholders increasingly use ‘serious gaming’. Although helpful, serious games so far (1) appear to be ad hoc, case dependent, with poorly defined extrapolation domains, (2) require heavy research investment, (3) have untested cultural limitations and (4) lack clarity on where and how they can be used in policy making. We classify the main forest–water–people nexus issues and the types of land-use solutions that shape local discourses and that are to be brought to life in the games. Four ‘prototype’ games will be further used to test hypotheses about the four problems identified constraining game use. The resulting generic forest–water–people games will be the outcome of the project “Scenario evaluation for sustainable agroforestry management through forest-water-people games” (SESAM), for which this article provides a preview.

Human population growth and land-use changes raise demand and competition for water resources. The Upper OumErRabia River Basin is experiencing high rangeland and matorral conversion to irrigated agricultural land expansion. Given Morocco's per capita water availability, River-basin hydrologic modelling could potentially bring together agricultural, water resources and conservation objectives. However, not everywhere have hydrological models considered events and continuous assessment of climatic data. In this study, HEC-HMS modelling approach is used to explore the event-based and continuous-process simulation of land-use and land cover change (LULCC) impact on water balance. The use of HEC-GeoHMS facilitated the digital data processing for coupling with the model. The basin's physical characteristics and the hydro-climatic data helped to generate a geospatial database for HEC-HMS model. We analyzed baseline and future scenario changes for the 1980-2016 period using the SCS Curve-Number and the Soil Moisture Accounting (SMA) loss methods. SMA was coupled with the Hargreaves evapotranspiration method. Model calibration focused on reproducing observed basin runoff hydrograph. To evaluate the model performance for both calibration and validation, the Coefficient of determination (R 2), Nash-Sutcliffe efficiency (NSE), Root Mean Square Error (RSR) and Percent Bias (PBIAS) criteria were exploited. The average calibration NSE values were 0.740 and 0.585 for event-based (daily) and continuous-process (annual) respectively. The R 2 , RSR and PBIAS values were 0.624, 0.634 and +16.7 respectively. This How to cite this paper: Msaddek, M., Kimbowa, G. and El Garouani, A. (2020) Hydrological Modeling of Upper Ou-mErRabia Basin (Morocco), Comparative Study of the Event-Based and Continuous-Process HEC-HMS Model Methods.

In Morocco, the mountainous areas are often exposed to bulky and vicious flows of water and sediment. This process is exacerbated by the decrease in vegetation cover and the disruption in rainfall-runoff conditions that frequently cause significant flooding. By exploring the main hydrologic elements of these processes, it is possible to understand the behavior and hydrological response of watersheds and thus plan accordingly. In this study, the authors focused on determining the morphometric characteristics of the upper Oum Er-Rbia River basin (UOERRB by assessing/ evaluating the land use and land cover changes for a period of 32 years . Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) was applied to simulate four daily hydrological events. The concentration time was 7.7 hours. The four storm events examined to calibrate and validate the simulated outflow at the outlet indicated a good agreement between the hydrographs of the measured and simulated flows, with an average Nash-Sutcliffe efficiency (NSE) value ranging from 0.63 to 0.76. Between 2002 and 2016, an average 6.21 percent increase in vegetation cover of with annual rainfall increasing from 690 to 714.1 mm/year was observed. These results can contribute to a better understanding of the hydrologic processes and better estimation of the return flows and thus guiding management decisions and developments in the UOERRB.

Metrics of hydrological mimicry (‘mimetrics’) reflect similarity in ecological structure and/or functions between managed and natural ecosystems. Only the land-surface parts of hydrological cycles are directly visible and represented in local knowledge and water-related legislation. Human impacts on water cycles (HIWC) can, beyond climate change, arise through effects on local and regional hydrological processes, from both reduced and increased water use compared to a natural reference vegetation with which landscape structure and hydrology are aligned. Precipitationsheds, the oceanic and terrestrial origin of rainfall, depend on evapotranspiration and thus on vegetation. The political commitment to reduce agricultural impact on nature requires hydrological mimetrics to trickle down through institutions to actions. Existing metrics do not suffice. For example, the water footprint metric that relates agricultural water use to consumption decisions, suggests minimizing water use is best, ignoring full hydrological impacts. We explore principles, criteria and indicators for understanding HIWC, via modified evapotranspiration, effects on streamflow (downstream impacts) and atmospheric fluxes and precipitation (downwind impacts). Comprehensive HIWC mimetrics for a set of pantropical watersheds suggest hydrological mimicry options for forest-derived land use patterns through intermediate densities of trees with diversity in rooting depth and water use, interacting with soils, crops and livestock.