Field Measurements
The Chair for Hydrology and River Basin Management holds different field labs in the catchment areas as well as a soil lab and a water lab.
There the scientists of the chair can make essential investigations for their research projects.
The district of Neustadt a.d. Aisch-Bad Windsheim faces significant landscape water balance challenges due to climate change, historic drainage structures, low precipitation, and low groundwater recharge. To address these, the project “GrüneGräben+” has been initiated to improve water retention and promote infiltration. The project aims to enhance water retention in "green ditches" using controllable weirs and develop additional measures with various stakeholders to optimize the landscape water balance. It will also investigate the spatial and temporal infiltration capacity along the ditches and assess the transferability of the measures to the entire Bavaria region.
The project examines three study areas: Buchholzgraben (0.17 km²), Langenwasengraben (1.88 km²), and Bodenfeldgraben (0.34 km²). Buchholzgraben is situated in a geological unit of loess/loess loam and has a storage length of approximately 100 m, with a storage volume of about 56 m3 and a storage height of around 0.75 m. Langenwasengraben is located in the geological unit of gypsum keuper and has a storage length of about 36 m, a storage volume of approximately 10 m2, and a storage height of around 0.6 m. Bodenfeldgraben, also in the geological unit of gypsum keuper, has a storage length of approximately 65 m, a storage volume of about 19 m3, and a storage height of around 0.55 m.
Each weir is equipped with various measuring instruments, including rain gauges, water level sensors, temperature sensors and soil moisture probes. Additionally, in-situ measurements and laboratory analyses are conducted to capture the local soil properties, providing a detailed understanding of infiltration processes. Soil samples are taken at various depths, soil moisture is measured using the TDR method, and infiltration tests are conducted with double-ring infiltrometers. High-resolution digital terrain models of the nearby ditches are created using data from drone flights.
The Weidfilz bog is a partially rewetted raised bog near Königsdorf in Upper Bavaria. As part of the KliMoBay project, it serves as a pilot area for hydrological modelling of peatlands. As a basis, hydrometeorological monitoring was set up with a climate station, gauges for monitoring peat water levels and monitoring of surface inflows and outflows.
Due to the high requirements on the accuracy of the measured data, appropriate measuring instruments from OTT Hydromet GmbH were used. A combination of a compact weather station (Luft WS500), a pluviometer (OTT Pluvio² L), a net radiometer (NR-LITE2 Kipp&Zonen) and a soil heat flux sensor (Hukseflux HFP01SC-L) was selected and installed for the climate station. The installed sensors allow precise measurements of precipitation and evapotranspiration parameters. An important aspect of the meteorological measurements was the construction of a "floating" weather station on the peat. This was to combine the demands for high measurement accuracy with minimal interference in the biotope. Based on the experience of the HSWT, a large wooden substructure combined with steel guy ropes was used. The weather stations have so far shown no tendency to sink, nor have they been damaged during storms.
OTT Orpheus Mini data loggers were installed to precisely measure the water levels in the peat body. The latter can map the water levels to a high degree of accuracy. Due to the already integrated atmospheric pressure compensation, a correction in the post-processing is no longer necessary. The pressure probes were installed in standard PVC level pipes and measured using differential GPS.
The inflows and outflows from the test area are registered by means of continuous water level measurements (OTT Orpheus Mini). Regular discharge measurements are used to derive rating curves.
The measuring area is a sub-catchment of the extensively used fen peatland on the grounds of Benediktbeuren Monastery. As part of the KliMoBay project, it serves as a pilot area for the hydrological modelling of peatlands. As a basis, hydrometeorological monitoring was set up with a climate station, gauges for monitoring bog water levels and recording surface inflows and outflows. The technical standard of the monitoring corresponds to that of the Weidfilz bog.
The Freisinger Moos is a large fen complex west of Freising. It is primarily used as grassland and farmland. As part of the KliMoBay project, a sub-area of it serves as a pilot area for hydrological modelling of peatlands. As a basis, hydrometeorological monitoring was set up with a climate station, gauges for monitoring bog water levels and recording surface inflows and outflows. The technical standard of the monitoring corresponds to that of the Weidfilz bog. The Moosach defines the southern boundary condition in the Freisinger Moos, as it is directly connected to the peat body. Therefore, the water level of the Moosach is continuously recorded for later modelling.
The study area is located in a drained fen peatland on the grounds of the Karolinenfeld Experimental Station of the Bavarian State Research Centre for Agriculture (LfL). As part of the KliMoBay project, it serves as a pilot area for hydrological modelling of peatlands. As a basis, hydrometeorological monitoring was set up with a climate station and gauges to observe bog water levels. At times, experiments with short-rotation plantations were carried out on the site (see photo).
Martell valley, situated in South Tyrol/Italy, is a 62 km² Alpine catchment discharging in the artificial Giovaretto reservoir and glaciers covered 15.6% of the catchment area in 2015. Within the framework of the SEHAG project, TUM installed four stream gauges measuring water level, stream temperature and electrical conductivity on tributaries (upper Plima, Zufall and Fuerkele creek) and at the catchment outlet (lower Plima) in 2019. Moreover, we are operating an automated salt injection system of the Canadian company Fathom Scientific for automated discharge measurements. In the second SEHAG phase (2022-2024), we will start monitoring subsurface flows and quantifying subsurface water storage. Moreover, isotope measurements will be performed at different locations and periods of the year.
The study area is located at the end of the Kauner valley in Tyrol/Austria and it covers the upper Kauner valley south of the Gepatsch reservoir closed at the gauge Gepatschalm with an approximated size of 54 km². The Gepatsch glacier, the second largest glacier of Austria, covers together with the Weißseeferner approximately 37% of the catchment. Within the framework of the SEHAG project, TUM installed three stream gauges measuring water level, stream temperature and electrical conductivity on tributaries (Krummgampenbach, Rifflerbach and upper Fagge) in 2019. Moreover, we are operating an automated salt injection system of the Canadian company Fathom Scientific for automated discharge measurements. In the second SEHAG phase (2022-2024), we will start monitoring subsurface flows and quantifying subsurface water storage. Moreover, isotope measurements will be performed at different locations and periods of the year.
The Horlach valley is located in the Stubai Alps in Tyrol/Austria and is a right-hand side tributary of the Oetz valley. The catchment size is about 55 km² and has a small glacier coverage (1.8% in 2015). Within the framework of the SEHAG project, TUM installed three stream gauges measuring water level, stream temperature and electrical conductivity on tributaries (Finstertal, Larstigtal and Grastal) in 2019. Moreover, we are operating an automated salt injection system of the Canadian company Fathom Scientific for automated discharge measurements. In the second SEHAG phase (2022-2024), we will start monitoring subsurface flows and quantifying subsurface water storage. Moreover, isotope measurements will be performed at different locations and periods of the year.
The study area of the project Hydromix is located in the Province of Trento between Mezzocorona and Lavis and comprehends the Adige, the Noce and the Avisio rivers. The Adige and, above all, the Noce River are strongly affected by hydropeaking. We are currently collecting groundwater level, temperature and electrical conductivity data at 10 piezometers in the Adige valley aquifer, as well as water level, temperature and electrical conductivity data of the Noce River.
The Baget catchment is located in the lower part of the Pyrenees, in the Ariege department, in the Southwest of France. It is a small-scale (13km2) highly dynamic karst system dominated by limestone formations. At the spring, we are currently collecting continuous electrical conductivity data and performing event-based sampling campaigns as well as discharge measurements. The catchment is a study area within the ROCKAT project.
The Kerschbaum spring is located south of the city of Waidhofen a.d. Ybbs, Austria. It is a pre-alpine springshed of approximately 2.5 km2 and is part of the eastern foothills of the Northern Calcareous Alps. It is an important source of fresh water providing a mean discharge of 34 l/s to the regional water supply. We are continuously measuring the electrical conductivity and performing event-based automatic sampling campaigns. The catchment is a study area within the ROCKAT project.
Adige Catchment
The Adige is the second longest river in Italy, with a length of 410 km and a drainage area of 12000 km2. In this catchment, the main stressor for the aquatic ecosystem derives form hydrological alterations.