This paper announces through a brief communication the coupling of PCLake to a variety of hydrody... more This paper announces through a brief communication the coupling of PCLake to a variety of hydrodynamic models of various spatial representations (0D, 1D, 3D) via the Framework for Aquatic Biogeochemical Models (FABM). Of particular significance is (1) fully coupled linkage and feedback between PCLake and the physical model, (2) open source code with supporting contact persons, (3) compilation of code using Public License software, and (4) tailored output modules for comprehensive visualization.
The safety of drinking water is constantly being evaluated. In the last few decades, however, man... more The safety of drinking water is constantly being evaluated. In the last few decades, however, many drinking waters sources in the world, including in China, have undergone serious eutrophication and consequently water quality deterioration due to anthropogenic induced stressors such as elevated external nutrient inputs. In this study, we used the state-of-the-art complex, dynamic, mechanistic model GOTM-FABM-PCLake (a coupled one-dimensional hydrodynamic-lake ecosystem model) to quantitatively assess the impacts of external nutrient loading on the temperate Jihongtan reservoir in Shandong Province, China. Simulated values of all variables targeted in calibration (water temperature, dissolved oxygen, total nitrogen, total phosphorus, and chlorophyll a) agreed well with observations throughout the entire calibration and validation period and generally mimicked seasonal dynamics and inter-annual variations as found in the monitoring data. A series of scenarios, representing changed ext...
Climate extremes, which are steadily increasing in frequency, can have detrimental consequences f... more Climate extremes, which are steadily increasing in frequency, can have detrimental consequences for lake ecosystems. We used a state-of-the-art, one-dimensional, hydrodynamic-ecosystem model [General Ocean Turbulence Model (GOTM)-framework for aquatic biogeochemical models (FABM)-PCLake] to determine the influence of extreme climate events on a temperate and temporarily summer stratified lake (Lake Bryrup, Denmark). The model was calibrated (eight years data) and validated (two years data), and the modeled variables generally showed good agreement with observations. Then, a span of extreme warming scenarios was designed based on weather data from the heatwave seen over northern Europe in May–July 2018, mimicking situations of extreme warming returning every year, every three years, and every five years in summer and all year round, respectively. We found only modest impacts of the extreme climate events on nutrient levels, which in some scenarios decreased slightly when looking at t...
Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-c... more Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-compensation across districts. Although policies regarding river eco-compensation have been issued in China since 2008, due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, a simplified method based solely on water quality (both water quality and water volume included in the Taihu method) was proposed for North Jiangsu province (NJP). However, the formula was flawed and it led to payments being too low. Three problems need to be solved: (1) how to specify the eco-compensation areas; (2) how to test a reasonable eco-compensation model and (3) how to determine the compensation criterion. Solving these issues is already a priority. In this paper, three potential solutions surrounding eco-compensation are discussed: (1) three principles for selecting the representative eco-compensation areas are suggested; (2) the compensation calculation method based on contaminant flux above the ultra standard is revised and (3) a compensation criterion model based on the treatment costs of sewage is proposed. In the NJP case in 2009, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY and 80,000 CNY per ton, respectively. Five districts needed to be compensated. The payments in the revised scheme were 4.15-586 million CNY, which were 16-48 times greater than that in the draft method. The new method can provide an important template for managers when drafting river eco-compensation schemes.
Aquatic ecosystems provide essential ecosystem services, they are, for instance, a source for dri... more Aquatic ecosystems provide essential ecosystem services, they are, for instance, a source for drinking water and a sink for waste water. Aquatic ecosystem models play an important role in understanding the functioning of these ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. Here we present a community perspective on how to explore, exploit and evolve the existing diversity in aquatic ecosystem models. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set and by analysing the models for their diversity. We then focus on how to exploit the synergy that arises when different disciplines, frameworks, models, spatial configurations and approaches are combined. Finally we discuss how model diversity has evolved in the past and could evolve in the future. Throughout our study we use anal...
This paper announces through a brief communication the coupling of PCLake to a variety of hydrody... more This paper announces through a brief communication the coupling of PCLake to a variety of hydrodynamic models of various spatial representations (0D, 1D, 3D) via the Framework for Aquatic Biogeochemical Models (FABM). Of particular significance is (1) fully coupled linkage and feedback between PCLake and the physical model, (2) open source code with supporting contact persons, (3) compilation of code using Public License software, and (4) tailored output modules for comprehensive visualization.
The safety of drinking water is constantly being evaluated. In the last few decades, however, man... more The safety of drinking water is constantly being evaluated. In the last few decades, however, many drinking waters sources in the world, including in China, have undergone serious eutrophication and consequently water quality deterioration due to anthropogenic induced stressors such as elevated external nutrient inputs. In this study, we used the state-of-the-art complex, dynamic, mechanistic model GOTM-FABM-PCLake (a coupled one-dimensional hydrodynamic-lake ecosystem model) to quantitatively assess the impacts of external nutrient loading on the temperate Jihongtan reservoir in Shandong Province, China. Simulated values of all variables targeted in calibration (water temperature, dissolved oxygen, total nitrogen, total phosphorus, and chlorophyll a) agreed well with observations throughout the entire calibration and validation period and generally mimicked seasonal dynamics and inter-annual variations as found in the monitoring data. A series of scenarios, representing changed ext...
Climate extremes, which are steadily increasing in frequency, can have detrimental consequences f... more Climate extremes, which are steadily increasing in frequency, can have detrimental consequences for lake ecosystems. We used a state-of-the-art, one-dimensional, hydrodynamic-ecosystem model [General Ocean Turbulence Model (GOTM)-framework for aquatic biogeochemical models (FABM)-PCLake] to determine the influence of extreme climate events on a temperate and temporarily summer stratified lake (Lake Bryrup, Denmark). The model was calibrated (eight years data) and validated (two years data), and the modeled variables generally showed good agreement with observations. Then, a span of extreme warming scenarios was designed based on weather data from the heatwave seen over northern Europe in May–July 2018, mimicking situations of extreme warming returning every year, every three years, and every five years in summer and all year round, respectively. We found only modest impacts of the extreme climate events on nutrient levels, which in some scenarios decreased slightly when looking at t...
Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-c... more Eco-compensation is a multi-disciplinary topic. There is no consensus on the issue of river eco-compensation across districts. Although policies regarding river eco-compensation have been issued in China since 2008, due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, a simplified method based solely on water quality (both water quality and water volume included in the Taihu method) was proposed for North Jiangsu province (NJP). However, the formula was flawed and it led to payments being too low. Three problems need to be solved: (1) how to specify the eco-compensation areas; (2) how to test a reasonable eco-compensation model and (3) how to determine the compensation criterion. Solving these issues is already a priority. In this paper, three potential solutions surrounding eco-compensation are discussed: (1) three principles for selecting the representative eco-compensation areas are suggested; (2) the compensation calculation method based on contaminant flux above the ultra standard is revised and (3) a compensation criterion model based on the treatment costs of sewage is proposed. In the NJP case in 2009, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY and 80,000 CNY per ton, respectively. Five districts needed to be compensated. The payments in the revised scheme were 4.15-586 million CNY, which were 16-48 times greater than that in the draft method. The new method can provide an important template for managers when drafting river eco-compensation schemes.
Aquatic ecosystems provide essential ecosystem services, they are, for instance, a source for dri... more Aquatic ecosystems provide essential ecosystem services, they are, for instance, a source for drinking water and a sink for waste water. Aquatic ecosystem models play an important role in understanding the functioning of these ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. Here we present a community perspective on how to explore, exploit and evolve the existing diversity in aquatic ecosystem models. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set and by analysing the models for their diversity. We then focus on how to exploit the synergy that arises when different disciplines, frameworks, models, spatial configurations and approaches are combined. Finally we discuss how model diversity has evolved in the past and could evolve in the future. Throughout our study we use anal...
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Papers by Fenjuan Hu