Spatially distributed process models represent soil-water-plant-nutrient interactions within a watershed. We investigated spatial patterns of water balance components and nitrate transport simulated using the fully distributed AgES (Agricultural Ecosystems Services) and the semi-distributed SWAT (Soil and Water Assessment Tool, 2012) models in the Big Dry Creek Watershed, a mixed agricultural and suburban watershed in semi-arid Colorado, USA. We analyzed patterns of hydrological fluxes using daily model outputs for the period 2010–2018. The two models simulated drastically different spatial patterns. SWAT predicted extremely low interflow and routed excess irrigation water to surface runoff and groundwater discharge. AgES produced realistic estimation of streamflow, irrigation return flows, and nitrate; simulation of less surface runoff and greater interflow and baseflow contributed to improved simulation of nitrate transport in the interior watersheds. This study demonstrated the impacts of simulating spatially explicit hydrology that captures interactions among fields and other areas within a managed watershed.

空间分布的过程模型表示流域内的土壤-水-植物-养分相互作用。我们调查了在农业和郊区混合的大干溪流域中使用完全分布式的AgES（农业生态系统服务）和半分布式的SWAT（土壤和水评估工具，2012）模型模拟​​的水平衡成分和硝酸盐迁移的空间格局。美国半干旱科罗拉多州的分水岭。我们使用2010-2018年期间的每日模型输出分析了水文通量的模式。这两个模型模拟了截然不同的空间格局。SWAT预测流量极低，并将多余的灌溉水排入地表径流和地下水。AgES对流量，灌溉回流和硝酸盐进行了实际估算。较少的地表径流和较大的内流和基流的模拟有助于改进内部流域中硝酸盐迁移的模拟。这项研究证明了模拟空间明确的水文学的影响，该水文学捕捉了受管理流域内田间和其他区域之间的相互作用。