scholarly journals Comparison of different base flow separation methods in a lowland catchment

2009 ◽  
Vol 6 (2) ◽  
pp. 3483-3515 ◽  
Author(s):  
A. L. Gonzales ◽  
J. Nonner ◽  
J. Heijkers ◽  
S. Uhlenbrook

Abstract. Assessment of water resources kept in different storages and moving along different pathways in a catchment is important for its optimal use and protection, and also for the prediction of floods and low flows. Moreover, understanding of the runoff generation processes is essential for assessing the impacts of climate and land use changes on the hydrological response of a catchment. Many methods for base flow separation exist, but hardly one focuses on the specific behaviour of temperate lowland areas. This paper presents the results of a base flow separation study carried out in a lowland area in the Netherlands. In this research, field observations of precipitation, groundwater and surface water levels and discharges, together with tracer analysis are used to understand the runoff generation processes in the catchment. Several tracer and non-tracer based base flow separation methods were applied to the discharge time series, and their results are compared. The results show that groundwater levels react fast to precipitation events in this lowland area with shallow groundwater tables. Moreover, a good correlation was found between groundwater levels and discharges meaning that most of the measured discharge also during floods comes from the groundwater storage. It was determined using tracer hydrological approaches that approximately 90% of the total discharge is groundwater displaced by event water infiltrating in the northern part of the catchment, and only the remaining 10% is surface runoff. The impact of remote recharge causing displacement of near channel groundwater during floods could also be motivated with hydraulic approximations. The results show further that when base flow separation is meant to separate groundwater contributions to stream flow, process based methods (e.g. rating curve method; Kliner and Knezek, 1974) are more reliable than other simple non-tracer based methods. Also, the recursive filtering method (proposed by Eckhardt, 2005) can be calibrated well using the results of tracer investigation, and this resulted in good results. Consequently, simple non-tracer based base flow separation methods that could be validated for some events may provide a powerful tool for groundwater assessment or model calibration/validation in lowland areas.

2009 ◽  
Vol 13 (11) ◽  
pp. 2055-2068 ◽  
Author(s):  
A. L. Gonzales ◽  
J. Nonner ◽  
J. Heijkers ◽  
S. Uhlenbrook

Abstract. Assessment of water resources available in different storages and moving along different pathways in a catchment is important for its optimal use and protection, and also for the prediction of floods and low flows. Moreover, understanding of the runoff generation processes is essential for assessing the impacts of climate and land use changes on the hydrological response of a catchment. Many methods for base flow separation exist, but hardly one focuses on the specific behaviour of temperate lowland areas. This paper presents the results of a base flow separation study carried out in a lowland area in the Netherlands. In this study, field observations of precipitation, groundwater and surface water levels and discharges, together with tracer analysis are used to understand the runoff generation processes in the catchment. Several tracer and non-tracer based base flow separation methods were applied to the discharge time series, and their results are compared. The results show that groundwater levels react fast to precipitation events in this lowland area with shallow groundwater tables. Moreover, a good correlation was found between groundwater levels and discharges suggesting that most of the measured discharge also during floods comes from groundwater storage. It was estimated using tracer hydrological approaches that approximately 90% of the total discharge is groundwater displaced by event water mainly infiltrating in the northern part of the catchment, and only the remaining 10% is surface runoff. The impact of remote recharge causing displacement of near channel groundwater during floods could also be motivated with hydraulic approximations. The results show further that when base flow separation is meant to identify groundwater contributions to stream flow, process based methods (e.g. the rating curve method; Kliner and Knezek, 1974) are more reliable than other simple non-tracer based methods. Also, the recursive filtering method (proposed by Eckhardt, 2005) can be calibrated well using the results of tracer investigation giving good results. Consequently, non-tracer based base flow separation methods that can be validated for some events may provide a powerful tool for groundwater assessment or model calibration/validation in lowland areas.


2020 ◽  
Vol 27 (3) ◽  
pp. 62-71
Author(s):  
Taison Anderson Bortolin ◽  
Lucas Moraes Dos Santos ◽  
Adriano Gomes Da Silva ◽  
Vania Elisabete Schneider

The basic flow rate is characterized by an important hydrological component being responsible for the estimation of the water recharge. Due to the difficulty of measurement, mathematical methods are used to calculate the flow separation. However, when hydrographic analysis is based on long historical series, the use of these methods becomes impracticable, making it necessary to use computational resources. A WebGIS (Web Geographical Information System) was developed for data selection and calculation of base flow separation, based on hydrological data from fluviometric stations located in the Taquari-Antas basin, located in the state of Rio Grande do Sul. A modified version of the Unified Process was used as a software development methodology. We used the MVC software architecture standard and the programming languages PHP 7.0, HTML5, JS and CSS3 for programmatic development of the constituent layers of the system. The hydrological data comes from the HIDROWEB portal, part of the National Information System on Water Resources (SNIRH), with hydrological information collected by the National Hydrometeorological Network (RHN) coordinated by the National Water Agency (ANA). The system facilitates the use of remote and distributed hydrological data, shared over the Internet, for various hydrological analyzes.


2020 ◽  
Author(s):  
Marjolein H.J. van Huijgevoort ◽  
Janine A. de Wit ◽  
Ruud P. Bartholomeus

<p>Extreme dry conditions occurred over the summer of 2018 in the Netherlands. This severe drought event led to very low groundwater  and surface water levels. These impacted several sectors like navigation, agriculture, nature and drinking water supply. Especially in the Pleistocene uplands of the Netherlands, the low groundwater levels had a large impact on crop yields and biodiversity in nature areas. Projections show that droughts with this severity will occur more often in the future due to changes in climate. To mitigate the impact of these drought events, water management needs to be altered.</p><p>In this study, we evaluated the 2018 drought event in the sandy regions of the Netherlands and studied which measures could be most effective to mitigate drought impact. We have included meteorological, soil moisture and hydrological drought and the propagation of the drought through these types. Droughts were determined with standardized indices (e.g. Standardized Precipitation Index) and the variable threshold level method. Investigated measures were, for example, higher water levels in ditches, reduced irrigation from groundwater, and increased water conservation in winter. We also studied the timing of these measures to determine the potential for mitigating effects during a drought versus the effectiveness of long term adaptation. The measures were simulated with the agro-hydrological Soil–Water–Atmosphere–Plant (SWAP) model for several areas across the Netherlands for both agricultural fields and nature sites.</p><p>As expected, decreasing irrigation from groundwater reduced the severity of the hydrological drought in the region. Severity of the soil moisture drought also decreased in fields that were never irrigated due to the effects of capillary rise from the groundwater, but, as expected, increased in currently irrigated fields. Increasing the level of a weir in ditches had a relatively small effect on the hydrological drought, provided water was available to sustain higher water levels. This measure is, therefore, better suited as a long term change than as ad hoc measure during a drought. The effectiveness of the measures depended on the characteristics of the regions; for some regions small changes led to increases in groundwater levels for several months, whereas in other regions effects were lost after a few weeks. This study gives insight into the most effective measures to mitigate drought impacts in low-lying sandy regions like the Netherlands.</p>


2016 ◽  
Vol 52 (8) ◽  
pp. 6526-6540 ◽  
Author(s):  
Chun-Hsu Su ◽  
Tim J. Peterson ◽  
Justin F. Costelloe ◽  
Andrew W. Western

Author(s):  
S. A. Shevchuk ◽  
O. V. Zorina ◽  
A. M. Shevchenko ◽  
O. M. Kozytsky ◽  
Y. O. Mavrykin

Analyzed the results of their own research to assess the impact of the Vyrovsky granite quarry on the state of surface and ground waters within the village of Vyry, Sarny district, Rivne region of Ukraine. Research methods: hydrogeological, sanitary-chemical, analytical. It has been established that the technological process of extracting granite and producing construction crushed stone does not involve the use of a large amount of water. Pit water is used as process water without additional intake of surface or groundwater. The main problems during the exploitation of the car, which are found on the enterprises, are connected with water. The stench is overwhelmed by the surging of ground and surface waters and the need for input for the safety of normal minds of their exploitation. Significant watering of the area's surface is due to the abundance of atmospheric precipitation, relatively flat relief, the presence of a small thickness of sedimentary rocks covering the crystalline massifs. So, the chemical and biological pollution of the river. The extraction by quarry waters does not occur, since the results of laboratory studies of the quarry water did not show its contamination. In general, the Vyrovsky granite quarry does not affect the volume of the river flow. Alignment, for a long time of operation of the Vyrovsky granite quarry, the groundwater levels of the aquifer have already been established and currently remain relatively stable. Further development of the open pit area will not affect the lowering of the groundwater level within the village. Vyry. Decrease in water levels in wells and wells within the village. Vyry in recent years (2015-2020) is associated with climatic changes, which led to a decrease in precipitation, an increase in temperature and evaporation and, as a consequence, a very low water content in rivers practically throughout Ukraine.


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