Modelling water, nutrients, and organic carbon in forested catchments: a HYPE application

Abstract

Abstract:Both monitoring and model simulation are useful for understanding and detecting changes in the environment. To understand and simulate leaching in small forested catchments, it is important to have knowledge of soil processes. Here, we describe recent development of the Hydrological Predictions for the Environment (HYPE) model for forested catchments. HYPE includes an organic carbon (OC) variable in addition to previously published nitrogen (N), phosphorus (P), and water flow models. The aspects addressed in the current study included P concentrations under low-flow conditions and high concentrations of inorganic N. HYPE was further developed based on nine small forested catchments (0.5-200 ha) in Sweden, which were calibrated separately using local data. The model (excluding the OC variable) was tested on a larger set of forest catchments from the operational HYPE model of Sweden (S-HYPE). We observed the following: (1) dissolved organic P could make a significant contribution to the total P concentration in a stream during low-flow periods, (2) the inorganic N concentration simulated in a stream improved when part of the atmospheric N was retained in the soil, (3) the soil flow path formulation was critical for simulating concentration dynamics, and (4) evaluating an additional variable (OC) further elucidated the soil runoff processes in the model.

Hydrological modeling of freshwater discharge into Hudson Bay using HYPE

“…Four representations of frozen soils in A-HYPE are considered: 1) none, 2) frozen soils limiting infiltration, 3) frozen soils limiting subsurface runoff, and 4) frozen soils limiting both subsurface runoff and infiltration. Soil layer temperatures are calculated following the equations presented in Pers et al (2016). Prior to this study, there was no representation of frozen soils in A-HYPE (Option 1).…”

Assessment of the Hype Model for Simulation of Water and Nutrients in the Upper uMngeni River Catchment in South Africa

“…The seasonal distribution of runoff was reproduced well, with the highest flow in January-February and the lowest in September, as also reported by Kienzle et al (1997). Moreover, in-stream erosion and soil erosion which are not modelled in HYPE, are reported to contribute significantly to the phosphorus concentration (Pers et al, 2016). In addition, it appeared that HYPE 405 lagged the observations of nutrients (especially TP) and streamflow at sub-catchments 7, 1510 and 2511 ( Fig.…”

“…However, the model also works well at small scales (for example, a catchment of 99.5 km 2 ) (Jiang et al, 2014;Andersson et al, 2015;Pers et al, 2016). The model's establishment was based on previous Swedish models, HBV and HBV-NP (Lindström et al, 2010;Yin et al, 2016).…”

“…The model simulates nitrogen (dissolved inorganic (DIN) and organic (ON)) and phosphorus (particulate (PP) and soluble reactive phosphorus (SRP)), and 140 total nitrogen (TN) and total phosphorus (TP) are calculated as the sum of their respective fractions. In addition, organic carbon and conservative tracers, such as chloride and 18 O, can also be modelled (Lindström et al, 2010;Jiang and Rode, 2012;Pers et al, 2016). A schematic illustration of the processes and routing of water and nutrients (N and P) in the HYPE model is shown in Fig.…”

“…Examples of this include the whole of Sweden (Strömqvist et al, 2012;Arheimer et al, 2015;Pers et al, 2016), a European multi-basin study Hundecha et al, 2016), simulation 150 of nutrient losses in Germany (Jiang and Rode, 2012), the Baltic Sea (Donnelly et al, 2011), the assessment of climate change effects on water resources in the whole of India and in few studies on the African continent (Andersson et al, 2014;Andersson et al, 2015), but limited to West Africa. <Figure 2> 155…”