Sedimentary and aquatic dynamics are currently causing major environmental problems in the Mediterranean countries, water and soil resources are steadily decreasing over time. Therefore, simulation and estimation of flows and sediments have currently a direct implication in the sustainable management of water and soils. In the present study, a Mediterranean watershed (North-West of Morocco) was benefited from the functionalities of Hydrological Model SWAT, version 2012 (semi-distributed and physically based), by adopting a monthly simulation. The main objective of this study is to calibrate and validate the SWAT model in the Arbaa Ayacha watershed (18,854 ha) between 1980 and 2000 by a multi-objective optimization approach using the Sufi-2 algorithm of the SWAT-CUP program. The performance of the model was tested using three objective functions NSE, PBIAS and R2, while the sensitivity analysis of the model was performed by adjusting 19 parameters of sensitivities related to flow rates and sediment concentrations. The results obtained are satisfactory with a significant correlation between the observed and simulated values of variables flow and sediments. The results also show that evapotranspiration and surface runoff are predominante in the basin compared to the other components of the water balance, while the sediment yield was estimated at 28.09 t/ha/year. Since the model is validated in the study area, it will later be used to simulate the evolution of scenarios based on climate change and land use. It will also help to determine the best managment practices in the watershed.

沉积物和水动力学目前正在引起地中海国家的主要环境问题，水和土壤资源随着时间的推移稳步减少。因此，水流和沉积物的模拟和估算目前对水和土壤的可持续管理有着直接的影响。在本研究中，通过采用每月模拟，地中海分水岭（摩洛哥西北部）受益于2012年版水文模型SWAT（半分布式和基于物理）的功能。这项研究的主要目的是通过多目标优化方法，使用SWAT-CUP程序的Sufi-2算法，在1980年至2000年之间对Arbaa Ayacha流域（18,854公顷）的SWAT模型进行校准和验证。使用三个目标函数NSE，PBIAS和R2对模型的性能进行了测试，而模型的敏感性分析则通过调整与流速和沉积物浓度相关的19个敏感性参数进行。所获得的结果令人满意，并且流量和沉积物变量的观测值与模拟值之间存在显着相关性。结果还表明，与水平衡的其他组成部分相比，流域的蒸散量和地表径流量占主导地位，而沉积物产量估计为28.09吨/公顷/年。由于该模型已在研究区域进行了验证，因此以后将用于基于气候变化和土地利用来模拟情景的演变。它还将有助于确定分水岭的最佳管理实践。同时通过调整与流速和沉积物浓度相关的19个敏感度参数进行模型的敏感度分析。所获得的结果令人满意，并且流量和沉积物变量的观测值与模拟值之间存在显着相关性。结果还表明，与水平衡的其他组成部分相比，流域的蒸散量和地表径流量占主导地位，而沉积物产量估计为28.09吨/公顷/年。由于该模型已在研究区域进行了验证，因此以后将用于基于气候变化和土地利用来模拟情景的演变。它还将有助于确定分水岭的最佳管理实践。同时通过调整与流速和沉积物浓度相关的19个敏感度参数进行模型的敏感度分析。所获得的结果令人满意，并且流量和沉积物变量的观测值与模拟值之间存在显着相关性。结果还表明，与水平衡的其他组成部分相比，流域的蒸散量和地表径流量占主导地位，而沉积物产量估计为28.09吨/公顷/年。由于该模型已在研究区域进行了验证，因此以后将用于基于气候变化和土地利用来模拟情景的演变。它还将有助于确定分水岭的最佳管理实践。