scholarly journals A distributed soil moisture, temperature and infiltrometer dataset for permeable pavements and green spaces

2020 ◽  
Vol 12 (1) ◽  
pp. 501-517
Author(s):  
Axel Schaffitel ◽  
Tobias Schuetz ◽  
Markus Weiler

Abstract. Knowledge of water and energy fluxes is key for urban planning and design. Nevertheless, hydrological data from urban environments are sparse, and, as a result, many processes are still poorly understood and thus inadequately represented within models. We contribute to reducing this shortfall by providing a dataset that includes time series of soil moisture and soil temperature measured underneath 18 different permeable pavements (PPs) and 4 urban green spaces located within the city of Freiburg (Germany). Time series were recorded with a high temporal resolution of 10 min using a total of 65 individual soil moisture sensors and covering a measurement period of 2 years (November 2016–October 2018). The recorded time series contain valuable information on the soil hydrological behavior of PPs and demonstrate the effect of surface properties and surrounding urban structures on soil temperatures. In addition, we performed double-ring infiltration experiments, which in combination with the soil moisture measurements yielded soil hydrological parameters for the PPs, including porosity, field capacity and infiltration capacity. We present this unique dataset, which is a valuable source of information for studying urban water and energy cycles. We encourage its usage in various ways, e.g., for model calibration and validation purposes, study of thermal regimes of cities, and derivation of urban water and energy fluxes. The dataset is freely available from the FreiDok plus data repository at https://freidok.uni-freiburg.de/data/151573 and https://doi.org/10.6094/UNIFR/151573 (Schaffitel et al., 2019).

2019 ◽  
Author(s):  
Axel Schaffitel ◽  
Tobias Schuetz ◽  
Markus Weiler

Abstract. Knowledge on water and energy fluxes is a key for urban planning and design. Nevertheless, hydrological data for urban environments is sparse and as a result, many processes are still poorly understood and thus inadequately represented within models. We contribute to reduce this shortcoming by providing a dataset, which includes time series of soil moisture and soil temperature measured underneath 18 different permeable pavements (PPs) and 4 urban greenspaces located within the city of Freiburg (Germany). Time series were recorded with a high temporal resolution of 10 min with a total of 65 individual soil moisture sensors and cover a measuring period of 2 entire years (Nov. 2016 – Oct. 2018). The recorded time series contain valuable information on the soil hydrological behavior and demonstrate the effect of surface properties and surrounding urban structures on soil temperatures. In addition, we performed double-ring infiltration experiments, which in combination with the soil moisture measurements yielded soil hydrological parameters for the PPs including porosity, field capacity and infiltration capacity. We present this unique dataset, which is a valuable source of information for studying urban water and energy cycles. We encourage its usage in various ways e.g. for model calibration and validation purposes, to study thermal regimes of cities and to derive urban water and energy fluxes. The dataset is freely available at the FreiDok plus data repository at https://freidok.uni-freiburg.de/data/149321 and https://doi.org/10.6094/UNIFR/149321 (Schaffitel et al., 2019).


2020 ◽  
Author(s):  
Lena-Marie Kuhlemann ◽  
Doerthe Tetzlaff ◽  
Birgit Kleinschmit ◽  
Stenka Vulova ◽  
Chris Soulsby

<p>Urban areas, more than many experimental catchments, are characterized by a markedly heterogeneous distribution of land covers, with different degrees of permeability that radically vary partitioning of precipitation into evapotranspiration (“green” water fluxes) and runoff and groundwater recharge (“blue” water fluxes). While the quantification of ecohydrological fluxes using stable isotopes in water as environmental tracers has been an established method for many years, surprisingly few studies have been applied to the highly complex urban water cycle. To determine the effects of representative urban green space “types” on water partitioning, we carried out plot-scale studies at a heterogenous field site in Berlin-Steglitz that integrates climate, soil moisture and sap flow data, with isotope sampling of precipitation and soil moisture on a regular basis. Soil moisture and isotope measurements were conducted at different depths and under contrasting soil-vegetation units (grassland, trees, shrub) with different degrees of permeability. Our investigations revealed uniformly decreasing soil moisture content during the dry summer of 2019, with only temporary re-wetting of the uppermost soil layers despite heavy convective precipitation events. Soils under trees were driest, whilst grassland soils were wettest, with shrubs intermediate. Isotope-based modelling indicated that this was the result, of greater interception, transpiration and – surprisingly – soil evaporation from forest sites. The isotope signatures of soil water also revealed stronger “memory effects” of summer drying in forest soils, which persisted until the major re-wetting of the system in autumn allowed drainage from the soil profile to contribute to groundwater recharge. Modelling showed that recharge under grasslands could be over 3 times higher compared to under trees and shrubs. Upscaling these findings with large-scale isotope studies of surface and groundwater across Berlin highlights the importance of the vegetation in urban green spaces to water partitioning in heterogeneous city landscapes and the need for careful integration of vegetation management in urban water and land use planning.</p>


2017 ◽  
Vol 21 (1) ◽  
pp. 345-355 ◽  
Author(s):  
Hjalte Jomo Danielsen Sørup ◽  
Stylianos Georgiadis ◽  
Ida Bülow Gregersen ◽  
Karsten Arnbjerg-Nielsen

Abstract. Urban water infrastructure has very long planning horizons, and planning is thus very dependent on reliable estimates of the impacts of climate change. Many urban water systems are designed using time series with a high temporal resolution. To assess the impact of climate change on these systems, similarly high-resolution precipitation time series for future climate are necessary. Climate models cannot at their current resolutions provide these time series at the relevant scales. Known methods for stochastic downscaling of climate change to urban hydrological scales have known shortcomings in constructing realistic climate-changed precipitation time series at the sub-hourly scale. In the present study we present a deterministic methodology to perturb historical precipitation time series at the minute scale to reflect non-linear expectations to climate change. The methodology shows good skill in meeting the expectations to climate change in extremes at the event scale when evaluated at different timescales from the minute to the daily scale. The methodology also shows good skill with respect to representing expected changes of seasonal precipitation. The methodology is very robust against the actual magnitude of the expected changes as well as the direction of the changes (increase or decrease), even for situations where the extremes are increasing for seasons that in general should have a decreasing trend in precipitation. The methodology can provide planners with valuable time series representing future climate that can be used as input to urban hydrological models and give better estimates of climate change impacts on these systems.


2017 ◽  
Author(s):  
Mikko Peltoniemi ◽  
Mika Aurela ◽  
Kristin Böttcher ◽  
Pasi Kolari ◽  
John Loehr ◽  
...  

Abstract. In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. Networked cameras can provide information about snow cover and vegetation status with a broad spatial coverage and high temporal resolution, and serve as ground truths to earth observations, and be useful for gap-filling of cloudy areas in earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen-science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1–3 cameras. Here, we document the network, basic camera information and access to images (see, https://doi.org/10.5281/zenodo.777952) in the permanent data repository (https://www.zenodo.org/communities/phenology_camera/). Individual DOI-referenced image time series from cameras are consisted of half-hourly images collected between 2014 and 2016. Additionally, we present example colour index time series derived from image time series from two contrasting sites.


2020 ◽  
Author(s):  
Axel Schaffitel ◽  
Tobias Schuetz ◽  
Markus Weiler

Abstract. Water fluxes at the soil-atmosphere interface are a key information for studying the terrestrial water cycle. However, measuring and modelling water fluxes in the vadose zone poses great challenges. While direct measurements require costly lysimeters, common soil hydrologic models rely on a correct parametrization, a correct representation of the involved processes and on the selection of correct initial and boundary conditions. In contrast to lysimeter measurements, soil moisture measurements are relatively cheap and easy to perform. Using such measurements, data-driven approaches offer the possibility to derive water fluxes directly. Here we present FluSM (Fluxes from Soil Moisture measurements), which is a simple, parsimonious and robust data-driven water balancing framework. FluSM requires only one single input parameter (the infiltration capacity) and is especially valuable for cases where the application of Richards based models is critical. Since Permeable Pavements (PPs) present such a case, we apply FluSM on a recently published soil moisture dataset to obtain the water balance of 15 different PPs over a period of two years. Consistent with findings from previous studies, our results show that vertical drainage dominates the water balance of PPs, while surface runoff plays only a minor role. An additional uncertainty analysis demonstrates the ability of the FluSM-approach for water balance studies, since input and parameter uncertainties have only small effects on the characteristics of the derived water balances. Due to the lack of data on the hydrologic behavior of PPs under field conditions, our results are of special interest for urban hydrology.


2021 ◽  
Vol 60 (1) ◽  
pp. 251-259
Author(s):  
Yichuan Zhang ◽  
Lifang Qiao ◽  
Chaoping Chen ◽  
Li Tian ◽  
Xiaozhen Zheng

2018 ◽  
Vol 10 (1) ◽  
pp. 173-184 ◽  
Author(s):  
Mikko Peltoniemi ◽  
Mika Aurela ◽  
Kristin Böttcher ◽  
Pasi Kolari ◽  
John Loehr ◽  
...  

Abstract. In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. With broad spatial coverage and high temporal resolution, networked cameras can provide information about snow cover and vegetation status, serve as ground truths to Earth observations and be useful for gap-filling of cloudy areas in Earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1–3 cameras. Here, we document the network, basic camera information and access to images in the permanent data repository (http://www.zenodo.org/communities/phenology_camera/). Individual DOI-referenced image time series consist of half-hourly images collected between 2014 and 2016 (https://doi.org/10.5281/zenodo.1066862). Additionally, we present an example of a colour index time series derived from images from two contrasting sites.


2021 ◽  
Vol 25 (2) ◽  
pp. 927-943
Author(s):  
Lena-Marie Kuhlemann ◽  
Doerthe Tetzlaff ◽  
Aaron Smith ◽  
Birgit Kleinschmit ◽  
Chris Soulsby

Abstract. In cities around the world, urban green spaces provide a range of benefits and ecosystem services. However, recent years have shown how prolonged warm and dry periods can affect urban water resources and lead to water stress in vegetation in urban green spaces, even in temperate regions. Consequently, quantitative knowledge about ecohydrological partitioning in different types of urban green space is crucial for balancing sustainable water needs in cities during future challenges of increasing urbanization and climate warming. Using isotopic tracers in precipitation and soil water, along with conventional hydrometric measurements in a plot-scale study in Berlin, Germany, we investigated water partitioning under different generic types of urban vegetation (grassland, shrub and trees). This allowed for the assessment of urban vegetation effects on evapotranspiration, subsurface flow paths and storage during a prolonged drought period with episodic rainfall. Despite higher soil evaporation losses under urban grassland, higher interception and transpiration likely contributed to slower turnover of soil water and older groundwater recharge under urban trees. Shrub vegetation seemed to be most resilient to prolonged drought periods, with lower evapotranspiration losses. Our results contribute to a better understanding of ecohydrological partitioning under mixed urban vegetation communities and an evidence base for better adaptive management of urban water and irrigation strategies to sustainably meet the water demands of urban green spaces in the future.


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