The impact of different evapotranspiration models in rainfall runoff modelling using HBV- light
(2021) In TVVR21/5012 VVRM05 20211Division of Water Resources Engineering
- Abstract
- The choice of which potential evapotranspiration (PET) model to use when estimating streamflow using a rainfall-runoff model have been the topic of many studies. The aim with this thesis was to assess the robustness of six different PET models using HBV-light as rainfall-runoff model over three catchments in Sweden. The robustness was evaluated by using a differential split sample test (DSST) based on four climatic conditions with regard of temperature and precipitation. Data from a period of 24 years (1997-2020) was used in order to get a wide range of climatic conditions. The calibration was based on the objective function Kling-Gupta Efficiency (KGE), while the validation of the model was evaluated based on the Nash-Sutcliffe efficiency... (More)
- The choice of which potential evapotranspiration (PET) model to use when estimating streamflow using a rainfall-runoff model have been the topic of many studies. The aim with this thesis was to assess the robustness of six different PET models using HBV-light as rainfall-runoff model over three catchments in Sweden. The robustness was evaluated by using a differential split sample test (DSST) based on four climatic conditions with regard of temperature and precipitation. Data from a period of 24 years (1997-2020) was used in order to get a wide range of climatic conditions. The calibration was based on the objective function Kling-Gupta Efficiency (KGE), while the validation of the model was evaluated based on the Nash-Sutcliffe efficiency (NSE) and the volume error (VE). These objective functions are commonly used when evaluating streamflow and are know to provide good estimations of the model performance. The result showed a large difference in efficiency between each PET model and between each catchment (ranging from a KGE of 0.85-0.54 and a NSE of 0.68-0.07), proving that the optimal choice of PET model may be site specific. The Hargreaves-Samani and the Jensen-Haise model were the two PET models which showed an acceptable performance for both calibration and validation over all catchments. It could be noted that calibration and validation on similar climatic conditions would provide models with higher efficiency and that the model parameters are climate dependant. (Less)
- Popular Abstract
- The evapotranspiration returns two thirds of all the precipitation back to the atmosphere making it one of the most important processes in the hydrological cycle. Different models, with varying complexity and data requirement, can be used to estimate the evapotranspiration. The evapotranspiration is one of the main parameters needed in order to estimate stream flow when using the rainfall runoff model HBV-light. Accurate estimations of stream flow is important in the hydro-power business as it will result in more accurate future predictions. As we are more and more dependent on sustainable energy sources it is essential to have robust models for the hydro-power industry. It is also important to see how these models performs under different... (More)
- The evapotranspiration returns two thirds of all the precipitation back to the atmosphere making it one of the most important processes in the hydrological cycle. Different models, with varying complexity and data requirement, can be used to estimate the evapotranspiration. The evapotranspiration is one of the main parameters needed in order to estimate stream flow when using the rainfall runoff model HBV-light. Accurate estimations of stream flow is important in the hydro-power business as it will result in more accurate future predictions. As we are more and more dependent on sustainable energy sources it is essential to have robust models for the hydro-power industry. It is also important to see how these models performs under different climatic conditions, especially for a country such as Sweden where the climate varies between different locations.
In this thesis six evapotranspiration models have been compared when used to estimate stream flow for three catchments in Sweden. The evapotranspiration models were chosen based on similar studies done in similar climates. The thesis was done together with the energy company Uniper where they choose the catchments so that they would differ in size, elevation and climatic conditions. The performance of the estimations of stream flow were based on the objective function Kling-Grupta efficiency and Nash-Sutcliffe efficiency. These functions describes how well the estimated stream flow agrees with the observed stream flow.
The main conclusion of the thesis is that there is a big difference between each evapotranspiration model but also between the catchments. Some models could provide acceptable stream flow estimations in one catchment but perform poorly in another. This suggests that the choice of evapotranspiration model is site specific and that no general model could be found. In order to achieve robust models with better stream flow predictions a way could be to divide all catchments into different categories based on climate and try to find a evapotranspiration model which performs well for each category.
In order to obtain reliable stream flow predictions it is important to choose the right evapotranspiration model. This will increase the efficiency for the hydro-power industry, one of our biggest sustainable energy sources. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9059196
- author
- Maxander, Oscar LU
- supervisor
- organization
- course
- VVRM05 20211
- year
- 2021
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- HBV-light, Rainfall runoff modelling, Evapotranspiration
- publication/series
- TVVR21/5012
- report number
- 21/5012
- ISSN
- 1101-9824
- language
- English
- additional info
- Examiner: Linus Zhang
- id
- 9059196
- date added to LUP
- 2021-06-29 10:04:39
- date last changed
- 2021-06-29 10:04:39
@misc{9059196,
abstract = {{The choice of which potential evapotranspiration (PET) model to use when estimating streamflow using a rainfall-runoff model have been the topic of many studies. The aim with this thesis was to assess the robustness of six different PET models using HBV-light as rainfall-runoff model over three catchments in Sweden. The robustness was evaluated by using a differential split sample test (DSST) based on four climatic conditions with regard of temperature and precipitation. Data from a period of 24 years (1997-2020) was used in order to get a wide range of climatic conditions. The calibration was based on the objective function Kling-Gupta Efficiency (KGE), while the validation of the model was evaluated based on the Nash-Sutcliffe efficiency (NSE) and the volume error (VE). These objective functions are commonly used when evaluating streamflow and are know to provide good estimations of the model performance. The result showed a large difference in efficiency between each PET model and between each catchment (ranging from a KGE of 0.85-0.54 and a NSE of 0.68-0.07), proving that the optimal choice of PET model may be site specific. The Hargreaves-Samani and the Jensen-Haise model were the two PET models which showed an acceptable performance for both calibration and validation over all catchments. It could be noted that calibration and validation on similar climatic conditions would provide models with higher efficiency and that the model parameters are climate dependant.}},
author = {{Maxander, Oscar}},
issn = {{1101-9824}},
language = {{eng}},
note = {{Student Paper}},
series = {{TVVR21/5012}},
title = {{The impact of different evapotranspiration models in rainfall runoff modelling using HBV- light}},
year = {{2021}},
}