Prediction of the long-term groundwater recharge by hydropedotransfer functions

A method is outlined to predict actual evapotranspiration and groundwater recharge considering climate, soil and depth to groundwater

Organic matter modeling at the landscape scale based on multitemporal soil pattern analysis using RapidEye data

This study proposes the development of a landscape-scale multitemporal soil pattern analysis (MSPA) method for organic matter (OM) estimation using RapidEye time series data analysis and GIS spatial data modeling, which is based on the methodology of Blasch et al. The results demonstrate (i) the potential of MSPA to predict OM for single fields and field composites with varying geomorphological, topographical, and pedological backgrounds and (ii) the method conversion of MSPA from the field scale to the multi-field landscape scale. For single fields, as well as for field composites, significant correlations between OM and the soil pattern detecting first standardized principal components were found. Thus, high-quality functional OM soil maps could be produced after excluding temporal effects by applying modified MSPA analysis steps. A regional OM prediction model was developed using four representative calibration test sites. The MSPA-method conversion was realized applying the transformation parameters of the soil-pattern detection algorithm used at the four calibration test sites and the developed regional prediction model to a multi-field, multitemporal, bare soil image mosaic of all agrarian fields of the Demmin study area in Northeast Germany. Results modeled at the landscape scale were validated at an independent test site with a resulting prediction error of 1.4 OM-% for the main OM value range of the Demmin study area

Estimating Pore Water Electrical Conductivity of Sandy Soil from Time Domain Reflectometry Records Using a Time-Varying Dynamic Linear Model

Despite the importance of computing soil pore water electrical conductivity (σp) from soil bulk electrical conductivity (σb) in ecological and hydrological applications, a good method of doing so remains elusive. The Hilhorst concept offers a theoretical model describing a linear relationship between σb, and relative dielectric permittivity (εb) in moist soil. The reciprocal of pore water electrical conductivity (1/σp) appears as a slope of the Hilhorst model and the ordinary least squares (OLS) of this linear relationship yields a single estimate ( 1/σpˆ ) of the regression parameter vector (σp) for the entire data. This study was carried out on a sandy soil under laboratory conditions. We used a time-varying dynamic linear model (DLM) and the Kalman filter (Kf) to estimate the evolution of σp over time. A time series of the relative dielectric permittivity (εb) and σb of the soil were measured using time domain reflectometry (TDR) at different depths in a soil column to transform the deterministic Hilhorst model into a stochastic model and evaluate the linear relationship between εb and σb in order to capture deterministic changes to (1/σp). Applying the Hilhorst model, strong positive autocorrelations between the residuals could be found. By using and modifying them to DLM, the observed and modeled data of εb obtain a much better match and the estimated evolution of σp converged to its true value. Moreover, the offset of this linear relation varies for each soil depth.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität BerlinDFG, GRK 2032, Grenzzonen in urbanen Wassersysteme

Filter properties of seam material from paved urban soils

International audienceDepositions of all kinds of urban dirt and dust including anthropogenic organic substances like soot change the filter properties of the seam filling material of pervious pavements and lead to the formation of a new soil substrate called seam material. In this study, the impact of the particular urban form of organic matter (OM) on the seam materials CECpot, the specific surface area (As), the surface charge density (SCD), the adsorption energies (Ea) and the adsorption of Cd and Pb were assessed. The Cd and Pb displacement through the pavement system has been simulated in order to assess the risk of soil and groundwater contamination from infiltration of rainwater in paved urban soils. As, Ea and SCD derived from water vapor adsorption isotherms, CECpot, Pb and Cd adsorption isotherms where analyzed from adsorption experiments. The seam material is characterized by a darker munsell-color and a higher Corg (12 to 48g kg-1) compared to the original seam filling. Although, the increased Corg leads to higher As (16m2g-1) and higher CECpot (0.7 to 4.8cmolckg-1), with 78cmolckg-1C its specific CECpot is low compared to OM of non-urban soils. This can be explained by a low SCD of 1.2×10-6molc m-2 and a low fraction of high adsorption energy sites which is likely caused by the non-polar character of the accumulated urban OM in the seam material. The seam material shows stronger sorption of Pb and Cd compared to the original construction sand. The retardation capacity of seam material for Pb is similar, for Cd it is much smaller compared to natural sandy soils with similar Corg concentrations. The simulated long term displacement scenarios for a street in Berlin do not indicate an acute contamination risk for Pb . For Cd the infiltration from puddles can lead to a breakthrough of Cd through the pavement system during only one decade. Although they contain contaminations itself, the accumulated forms of urban OM lead to improved filter properties of the seam material and may retard contaminations more effectively than the originally used construction sand

Evaluating the variation of dissolved metals on a highway roadside using a generalized additive mixed model (GAMM)

Assessing metal concentrations in roadside soils requires a better understanding of the extent to which they are affected by different environmental factors such as soil texture, depth, pH, runoff concentration, and precipitation. Monthly data of dissolved Cd, Ni, Cr, Pb, Cu, and Zn concentrations in three different roadside soils (sandy loam, gravel (0–32 mm) and a mixture of sandy loam and gravel) were measured during a 2-year lysimeter field study at different depths. The data was used to assess the variation of trace elements and how they were affected by environmental factors. For data interpretation, generalized additive mixed models (GAMMs) were used to explore the complex behavior of metals in heterogeneous soils by detecting linear and nonlinear trends of metal concentrations in the soil solution. As a result, the modeling approach showed that Cd, Ni, Cr, Pb, Cu, and Zn concentrations are functions of different environmental variables, which have either linear or nonlinear behavior. All investigated metals showed that pH could explain their variation. With exception of precipitation, Ni and Cr variations can nearly be explained by the same environmental factors used in this study (time, pH, infiltration volume, roadside soil type, runoff concentrations, and depth). During the study period, we found that Zn variation can be explained by its nonlinear relationship with all the significant studied environmental factors. As the depth increases from the surface to 30 cm of depth, the metal concentration of Cd, Ni, Cr, Pb, and Zn increases. Surprisingly, the roadside soil consisting of gravel has the lowest organic carbon and showed the lowest median concentration of Cd, Ni, Pb, Cu, and Zn at 30 cm. Moreover, the model showed that the surface runoff volume has no effect on the metal variation in the soil solutionPostprint (published version

Analyzing temporal trends of urban evaporation using generalized additive models

This study aimed to gain new insights into urban hydrological balance (in particular, the evaporation from paved surfaces). Hourly evaporation data were obtained simultaneously from two high-resolution weighable lysimeters. These lysimeters are covered in two pavement sealing types commonly used for sidewalks in Berlin, namely cobble-stones and concrete slabs. A paired experiment in field conditions is designed to determine the mechanism by which these two types of soil sealing affect the evaporation rate under the same climatic conditions. A generalized additive model (GAM) is applied to explain how the climatic conditions interact with soil sealing and to evaluate the variation of evaporation rate according to pavement type. Moreover, taking the advantage of the fact that the experimental design is paired, the study fits a new GAM where the response variable is the difference between the evaporation rate from the two lysimeters and its explanatory variables are the climatic conditions. As a result, under the same climatic conditions, cobble-stones are more prone to increasing the evaporation rate than concrete slabs when the precipitation accumulated over 10 h, solar radiation, and wind speed increases. On the other hand, concrete slabs are more inclined to increase the evaporation rate than cobblestones when the relative humidity increases. GAM represents a robust modeling approach for comparing different sealing types in order to understand how they alter the hydrological balanceFunding: The German Research Foundation DFG (GRK 2032) and the Open Access Publication Fund of TU Berlin.Peer ReviewedPostprint (published version

Predicting water supply and evapotranspiration of street trees using hydro-pedo-transfer functions (HPTFs)

The climate, soil properties, groundwater depth, and surrounding settings in cities vary to a tremendous extent, which all lead to different growing conditions and health for street trees. Because of climate change, the availability of water in cities will undergo changes in the next decades. As urban trees have a very positive influence not only on microclimate but also on biodiversity and life quality in general, they need to be protected. Thus, we need to know how to measure and calculate the availability of water for street trees to optimize their site conditions and water supply. This study presents Hydro-Pedo-Transfer Functions (HTPFs) for predicting water supply and actual evapotranspiration of street trees for varying urban conditions. The HTPFs are easy to use, and the input parameters can either be mapped easily or taken from local climate agencies or soil surveys. The first part of the study focuses on the theoretical background and related assumptions of the HTPFs for predicting water supply, and on obtaining the potential and actual evapotranspiration of urban street trees using easily available data. The second part gives information and exemplifies how this input data can be measured, mapped, or predicted. Calibration of the HTPFs were done using the sap-flow measurements of three Linden trees (Tilia cordata). Exemplarily, the HTPF scenarios for the varying urban site conditions of Berlin are presented. The water supply and actual evapotranspiration of the street trees severely depend on the local climate (summer rainfall and potential evapotranspiration), site conditions (catchment area, soil available water, and degree of sealing), and on the tree characteristics (species, age, and rooting depth). The presented concept and the equations build a good and flexible frame that is easy to program using a spreadsheet tool or an R script. This tool should be tested and validated also for other cities and climate regions.DFG, 414044773, Open Access Publizieren 2021 - 2022 / Technische Universität Berli

Archivfunktion von Böden: Der Teufelsberg als Kriegs-denk-mal

Durch den zweiten Weltkrieg fielen in Deutschland ca. 400 Mio. m³ Trümmerschutt an. So waren in Berlin 30% der Wohngebäude völlig und 45% zumindest teilweise zerstört; daraus resultierte eine Trümmerschuttmenge von ca. 75 Mio. m³. Der nicht wieder verwertbare Teil des Trümmerschutts wurde nach Kriegsende im Stadtgebiet sowohl punktuell in Bombentrichtern, als auch flächenhaft in Parks und Freiflächen verkippt und mit Oberboden bedeckt. Bekannte Park- oder Erholungsflächen in Berlin, die Trümmerschutt im Untergrund aufweisen, sind der Volkspark Prenzlauer Berg, der Schlosspark Charlottenburg und der Humboldthain. Die bekannteste Trümmerschuttdeponie ist der 115 m hohe Teufelsberg, der aus ca. 25 Mio. m³ Schutt besteht. Nach Abschluss der Aufschüttungsarbeiten wurde ein waldgeprägtes Freizeitgelände aufgebaut sowie auf dem Gipfel eine Abhörstation von den Amerikanern in den Osten eingerichtet. Diese war anfangs mobil, wurde aber schnell durch eine feste Installation mit fünf Radarkuppeln abgelöst. So erhielt der Teufelsberg sein bis heute charakteristisches Erscheinungsbild. Nach dem Fall der Berliner Mauer wurde die Station von den Amerikanern aufgegeben und die elektronischen Einrichtungen entfernt. Zwischenzeitlich wurde die ehemalige Abhörstation an einen privaten Investor verkauft. Die damals hochgesteckten Planungen für eine exklusive Wohnanlage, ein Museum sowie ein Hotel- und Tagungszentrum scheiterten allerdings, weil der Generalunternehmer mit den Einlagen der Investorengruppe verschwand... Heute wird der Teufelsberg vor allem von Erholungssuchenden, Spaziergängern, Joggern und Mountainbikern intensiv genutzt. Im Winter lädt ein Skihang und eine Langlauf-Loipe zum Wintersport ein; im Jahr 1986 fand sogar anlässlich der 750-Jahr-Feier Berlin ein Weltcup-Slalom auf dem Skihang statt. Was jedoch fehlt, ist eine historisch-bodenkundliche Aufbereitung zur Entstehungsgeschichte. Ziel sollte es sein, ein Konzept zu entwickeln, das nicht nur eine Freizeitnutzung vorsieht, sondern den Ort auch als Kriegs-Mahnmal und Ort der Erinnerung würdigt

Body as Display: Augmenting the Face through Transillumination

ABSTRACT In this paper we describe our explorations of the design space offered by augmenting parts of the human face, in this case, the ears. Using light-emitting add-ons behind the ears we aim to enhance social interactions. Scenarios range from indirect notifications of events, messaging directed to the wearer but communicated via a person face to face, or adding information regarding the internal state of the wearer, like loudness discomfort levels, concentration fatigue, or emotional strain levels

Schwermetallimmobilisierung auf ehemaligen Rieselfeldern - Statuskontrolle 20 Jahren nach einer Sanierung

Das Abwasser von Berlin wurde über einen Zeitraum von 100 Jahren auf Rieselfeldern behandelt. Infolge dessen sind im Umland der Stadt großflächige Altlasten entstanden, von denen auch nach Einstellung der Berieselung erhebliche Gefahren für die Umwelt ausgehen. Auf den ehemaligen Rieselfeldern von Berlin-Buch im Norden der Stadt wurden vor 20 Jahren Maßnahmen durchgeführt, um das Gefährungspotenzial der Schadstoffe einzudämmen, den Bodenwasserhaushalt zu verbessern und eine Wiederaufforstung zu ermöglichen. Dazu wurde Geschiebemergel auf die Böden aufgebracht und teilweise eingearbeitet (HOFFMANN 2001). Der Vortrag betrachtet die aktuellen Resultate dieser Sanierungs- bzw. Sicherungsmaßnahmen hinsichtlich der Schwermetallkontamination. Es werden zwei mit unterschiedlichen Maßnahmen sanierte Flächen vorgestellt und mit einem unsanierten Standort verglichen. Dazu wurden bodenchemische und bodenphysikalisch Labormessungen sowie numerische Simulationen durchgeführt. An Hand der Effekte auf den Bodenwasserhaushalt und die Mobilität der Schwermetalle wird abschließend die Wirksamkeit der Maßnahmen bewertet