This page has only limited features, please log in for full access.

Unclaimed
Christian Bernhofer
Faculty of Environmental Sciences, Department of Hydrosciences, Institute of Hydrology and Meteorology, Chair of Meteorology, Technical University of Dresden, 01737 Tharandt, Germany

Basic Info

Basic Info is private.

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 26 July 2021 in Hydrology
Reads 0
Downloads 0

Numerical simulations of rainfall-runoff processes are useful tools for understanding hydrological processes and performing impact assessment studies. The advancements in computer technology and data availability have assisted their rapid development and wide use. This project aims to evaluate the applicability of a physically based, fully distributed rainfall-runoff model TOPKAPI-X for the simulation of flood events in two small watersheds of Saxony, Germany. The results indicate that the model was calibrated well for 4.88 km2 Wernersbach catchment (NSE 0.89), whereas 276 km2 Wesenitz catchment calibration was only satisfactory (NSE 0.7). The addition of the second soil layer improved the model’s performance in comparison to the simulations with only one soil layer for Wernersbach (NSE increase from 0.83 to 0.89). During the validation process, the model showed a variable performance. The best performance was achieved for Wernersbach for the year with the highest runoff (NSE 0.95) in the last decade. The lowest performance for the Wernersbach and Wesenitz catchments was 0.64 for both. The reasons for the model’s low performance in some years are discussed, and include: (i) input data quality and data insufficiency, (ii) methods used within the simulations (interpolation, ETP estimation, etc.), and (iii) assumptions made during the calibration (manual calibration, parameter selection, etc.).

ACS Style

Firas Janabi; Nurlan Ongdas; Christian Bernhofer; Julian Reyes Silva; Jakob Benisch; Peter Krebs. Assessment of TOPKAPI-X Applicability for Flood Events Simulation in Two Small Catchments in Saxony. Hydrology 2021, 8, 109 .

AMA Style

Firas Janabi, Nurlan Ongdas, Christian Bernhofer, Julian Reyes Silva, Jakob Benisch, Peter Krebs. Assessment of TOPKAPI-X Applicability for Flood Events Simulation in Two Small Catchments in Saxony. Hydrology. 2021; 8 (3):109.

Chicago/Turabian Style

Firas Janabi; Nurlan Ongdas; Christian Bernhofer; Julian Reyes Silva; Jakob Benisch; Peter Krebs. 2021. "Assessment of TOPKAPI-X Applicability for Flood Events Simulation in Two Small Catchments in Saxony." Hydrology 8, no. 3: 109.

Journal article
Published: 12 April 2021 in Water
Reads 0
Downloads 0

Convective rainfall can cause dangerous flash floods within less than six hours. Thus, simple approaches are required for issuing quick warnings. The flash flood guidance (FFG) approach pre-calculates rainfall levels (thresholds) potentially causing critical water levels for a specific catchment. Afterwards, only rainfall and soil moisture information are required to issue warnings. This study applied the principle of FFG to the Wernersbach Catchment (Germany) with excellent data coverage using the BROOK90 water budget model. The rainfall thresholds were determined for durations of 1 to 24 h, by running BROOK90 in “inverse” mode, identifying rainfall values for each duration that led to exceedance of critical discharge (fixed value). After calibrating the model based on its runoff, we ran it in hourly mode with four precipitation types and various levels of initial soil moisture for the period 1996–2010. The rainfall threshold curves showed a very high probability of detection (POD) of 91% for the 40 extracted flash flood events in the study period, however, the false alarm rate (FAR) of 56% and the critical success index (CSI) of 42% should be improved in further studies. The proposed adjusted FFG approach has the potential to provide reliable support in flash flood forecasting.

ACS Style

Thanh Luong; Judith Pöschmann; Rico Kronenberg; Christian Bernhofer. Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany. Water 2021, 13, 1061 .

AMA Style

Thanh Luong, Judith Pöschmann, Rico Kronenberg, Christian Bernhofer. Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany. Water. 2021; 13 (8):1061.

Chicago/Turabian Style

Thanh Luong; Judith Pöschmann; Rico Kronenberg; Christian Bernhofer. 2021. "Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany." Water 13, no. 8: 1061.

Journal article
Published: 09 November 2020 in Hydrology
Reads 0
Downloads 0

Highly-resolved data on water balance components (such as runoff or storage) are crucial to improve water management, for example, in drought or flood situations. As regional observations of these components cannot be acquired adequately, a feasible solution is to apply water balance models. We developed an innovative approach using the physically-based lumped-parameter water balance model BROOK90 (R version) integrated into a sensor network platform to derive daily water budget components for catchments in the Free State of Saxony. The model is not calibrated, but rather uses available information on soil, land use, and precipitation only. We applied the hydro response units (HRUs) approach for 6175 small and medium-sized catchments. For the evaluation, model output was cross-evaluated in ten selected head catchments in a low mountain range in Saxony. The mean values of Kling–Gupta efficiency (KGE) for the period 2005–2019 to these catchments are 0.63 and 0.75, for daily and monthly discharge simulations, respectively. The simulated evapotranspiration and soil wetness are in good agreement with the SMAP_L4_GPH product in April 2015–2018. The study can be enhanced by using different data platforms as well as available information on study sites.

ACS Style

Thanh Thi Luong; Judith Pöschmann; Ivan Vorobevskii; Stefan Wiemann; Rico Kronenberg; Christian Bernhofer. Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony. Hydrology 2020, 7, 84 .

AMA Style

Thanh Thi Luong, Judith Pöschmann, Ivan Vorobevskii, Stefan Wiemann, Rico Kronenberg, Christian Bernhofer. Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony. Hydrology. 2020; 7 (4):84.

Chicago/Turabian Style

Thanh Thi Luong; Judith Pöschmann; Ivan Vorobevskii; Stefan Wiemann; Rico Kronenberg; Christian Bernhofer. 2020. "Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony." Hydrology 7, no. 4: 84.

Preprint
Published: 19 October 2020
Reads 0
Downloads 0

Highly-resolved data on water balance components (like runoff or storage) are crucial to improve water management, e.g., in drought or flood situations. Because regional observations of these components cannot be acquired adequately, applying water balance models is a feasible solution. We developed an innovative approach using the physically-based lumped-parameter water balance model BROOK90 (R version) integrated into a sensor network platform to derive daily water budget components for catchments in the Free State of Saxony. The model is not calibrated but rather uses available information on soil, land use and precipitation only. We applied the hydro response units (HRUs) approach for 6175 small and medium-sized catchments. For the evaluation, model output was cross-evaluated in ten selected head catchments in a low mountain range in Saxony. The mean values of Kling-Gupta efficiency (KGE) for the period 2005-2019 to these catchments are 0.63 and 0.75 for daily and monthly discharge simulations, respectively. The simulated evapotranspiration and soil wetness are in good agreement with the SMAP_L4_GPH product in April 2015-2018. The study can be enhanced by using different data platforms as well as available information on study sites.

ACS Style

Thanh Thi Luong; Judith Poeschmann; Ivan Vorobevskii; Stefan Wiemann; Rico Kronenberg; Christian Bernhofer. Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony. 2020, 1 .

AMA Style

Thanh Thi Luong, Judith Poeschmann, Ivan Vorobevskii, Stefan Wiemann, Rico Kronenberg, Christian Bernhofer. Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony. . 2020; ():1.

Chicago/Turabian Style

Thanh Thi Luong; Judith Poeschmann; Ivan Vorobevskii; Stefan Wiemann; Rico Kronenberg; Christian Bernhofer. 2020. "Pseudo-Spatially-Distributed Modeling of Water Balance Components in the Free State of Saxony." , no. : 1.

Journal article
Published: 14 September 2020 in Remote Sensing
Reads 0
Downloads 0

Management of water resources under climate change is one of the most challenging tasks in many arid and semiarid regions. A major challenge in countries, such as Yemen, is the lack of sufficient and long-term climate data required to drive hydrological models for better management of water resources. In this study, we evaluated the accuracy of accessible satellite and reanalysis-based precipitation products against observed data from Al Mahwit governorate (highland region, Yemen) during 1998–2007. Here, we evaluated the accuracy of the Climate Hazards Group Infrared Precipitation with Station (CHIRPS) data, National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR), Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), Tropical Rainfall Measuring Mission (TRMM 3B42), Unified Gauge-Based Analysis of Global Daily Precipitation (CPC), and European Atmospheric Reanalysis (ERA-5). The evaluation was performed on daily, monthly, and annual time steps by directly comparing the data from each single station with the data from the nearest grid box for each product. At a daily timescale, CHIRPS captures the daily rainfall characteristics best, such as the number of wet days, with average deviation from wet durations around 11.53%. TRMM 3B42 is the second-best performing product for a daily estimate with an average deviation of around 34.7%. However, CFSR (85.3%) and PERSIANN-CDR (103%) and ERA-5 (−81.13%) show an overestimation and underestimation of wet days and do not reflect rainfall variability of the study area. Moreover, CHIRPS is the most accurate gridded product on a monthly basis with high correlation and lower bias. The average monthly correlation between the observed and CHIRPS, TRMM 3B42, PERSIANN-CDR, CPC, ERA-5, and CFSR is 0.78, 0.56, 0.53, 0.15, 0.20, and 0.51, respectively. The average monthly bias is −2.9, −5.25, 7.35, −25.29, −24.96, and 16.68 mm for CHIRPS, TRMM 3B42, PERSIANN-CDR, CPC, ERA-5, and CFSR, respectively. CHIRPS displays the spatial distribution of annual rainfall pattern well with percent bias (Pbias) of around −8.68% at the five validation points, whereas TRMM 3B42, PERSIANN-CDR, and CFSR show a deviation of greater than 15.30, 22.90, and 66.21%, respectively. CPC and ERA-5 show Pbias of about −88.6% from observed data. Overall, in absence of better data, CHIRPS data can be used for hydrological and climate change studies on the highland region of Yemen where precipitation is often episodical and measurement records are spatially and temporally limited.

ACS Style

Ali Hamoud Al-Falahi; Naeem Saddique; Uwe Spank; Solomon H. Gebrechorkos; Christian Bernhofer. Evaluation the Performance of Several Gridded Precipitation Products over the Highland Region of Yemen for Water Resources Management. Remote Sensing 2020, 12, 2984 .

AMA Style

Ali Hamoud Al-Falahi, Naeem Saddique, Uwe Spank, Solomon H. Gebrechorkos, Christian Bernhofer. Evaluation the Performance of Several Gridded Precipitation Products over the Highland Region of Yemen for Water Resources Management. Remote Sensing. 2020; 12 (18):2984.

Chicago/Turabian Style

Ali Hamoud Al-Falahi; Naeem Saddique; Uwe Spank; Solomon H. Gebrechorkos; Christian Bernhofer. 2020. "Evaluation the Performance of Several Gridded Precipitation Products over the Highland Region of Yemen for Water Resources Management." Remote Sensing 12, no. 18: 2984.

Journal article
Published: 17 July 2020 in Water
Reads 0
Downloads 0

The number of global open-source hydrometeorological datasets and models is large and growing. However, with a constantly growing demand for services and tools from stakeholders, not only in the water sector, we still lack simple solutions, which are easy to use for nonexperts. The new R package incorporates the BROOK90 hydrologic model and global open-source datasets used for parameterization and forcing. The aim is to estimate the vertical water fluxes within the soil–water–plant system of a single site or of a small catchment (2). This includes data scarce regions where no hydrometeorological measurements or reliable site characteristics can be obtained. The end-user only needs to provide a location and the desired period. The package automatically downloads the necessary datasets for elevation (Amazon Web Service Terrain Tiles), land cover (Copernicus: Land Cover 100 m), soil characteristics (ISRIC: SoilGrids250), and meteorological forcing (Copernicus: ERA5 reanalysis). Subsequently these datasets are processed, specific hydrotopes are created, and BROOK90 is applied. In a last step, the output data of all desired variables on a daily scale as well as time-series plots are stored. A first daily and monthly validation based on five catchments within various climate zones shows a decent representation of soil moisture, evapotranspiration, and runoff components. A considerably better performance is achieved for a monthly scale.

ACS Style

Ivan Vorobevskii; Rico Kronenberg; Christian Bernhofer. Global BROOK90 R Package: An Automatic Framework to Simulate the Water Balance at Any Location. Water 2020, 12, 2037 .

AMA Style

Ivan Vorobevskii, Rico Kronenberg, Christian Bernhofer. Global BROOK90 R Package: An Automatic Framework to Simulate the Water Balance at Any Location. Water. 2020; 12 (7):2037.

Chicago/Turabian Style

Ivan Vorobevskii; Rico Kronenberg; Christian Bernhofer. 2020. "Global BROOK90 R Package: An Automatic Framework to Simulate the Water Balance at Any Location." Water 12, no. 7: 2037.

Journal article
Published: 23 December 2019 in Water
Reads 0
Downloads 0

There is a lack of information about the effect of climate change on the water budget for the eastern side of Colombia, which is currently experiencing an increased pressure on its water resources due to the demand for food, industrial use, and human demand for drinking and hygiene. In this study, the lumped model BROOK90 was utilized with input based on the available historical and projected meteorological data, as well as land use and soil information. With this data, we were able to determine the changes in the water balance components in four different regions, representing four different water districts in Eastern Colombia. These four regions reflect four different sets of climate and geographic conditions. The projected data were obtained using the Statistical Downscaling Model (SDSM), in which two global climate models were used in addition to two different climate scenarios from each. These are the Representative Concentration Pathways (RCP) RCP 2.6 and RCP 8.5. Results showed that the temporal and spatial distribution of water balance components were considerably affected by the changing climate. A reduction in the generated streamflow for all of the studied regions is shown and changes in the evapotranspiration and stored water were varied for each region according to both the climate scenario as well as the characteristics of soil and land use for each area. The results of spatial change of the water balance components showed a direct link to the geography of each region. Soil moisture was reduced considerably in the next decades, and the percentage of decrease varied for each scenario.

ACS Style

Oscar Molina; Thi Thanh Luong; Christian Bernhofer. Projected Changes in the Water Budget for Eastern Colombia Due to Climate Change. Water 2019, 12, 65 .

AMA Style

Oscar Molina, Thi Thanh Luong, Christian Bernhofer. Projected Changes in the Water Budget for Eastern Colombia Due to Climate Change. Water. 2019; 12 (1):65.

Chicago/Turabian Style

Oscar Molina; Thi Thanh Luong; Christian Bernhofer. 2019. "Projected Changes in the Water Budget for Eastern Colombia Due to Climate Change." Water 12, no. 1: 65.

Journal article
Published: 20 December 2019 in Water
Reads 0
Downloads 0

Regions located on the eastern side of Colombia are vulnerable to climate change due to the high diversity of fauna and flora located there, the potentially direct impact on agricultural activities, as well as the pressure on water resources. Limited research and work have been conducted to accurately create a description of the climate of these specific regions. The characteristics of the available records, which is valuable information, together with complementary data can be used to simulate the impacts of climate change and the effects it has on the water cycle. A description of the climate for the eastern region of Colombia was made and historical daily records from 669 hydrometeorological stations were considered in order to analyze the robustness and spatial distribution of the data. According to the available data, four of the water districts that compose the eastern region of the country were selected to show both a representative analysis of the climate variability and a consistency analysis using a cross-correlation procedure. A high percentage of missing values was found in the available records; however, with regards to the climatological analysis for the period from 1980 to 2015, 40% of missing values or less seems to be a good threshold for the datasets to be used. Temperature records show monthly small variations and a decreasing average rate from lower to higher elevations, i.e., 5 °C every 1000 m. Precipitation shows different patterns according to the region with monomodal and bimodal patterns. Correlations between datasets of the same region are positive and a significant correlation is obtained with temperature for stations at similar elevations or those located close to each other, and low correlations of precipitation are found. These data records are considered a good source of input data which could be used to perform further analysis such as a climate downscaling procedure, as well as a potential water budget approach for the four studied regions.

ACS Style

Oscar Molina; Christian Bernhofer. Assessment of Regional and Historical Climate Records for a Water Budget Approach in Eastern Colombia. Water 2019, 12, 42 .

AMA Style

Oscar Molina, Christian Bernhofer. Assessment of Regional and Historical Climate Records for a Water Budget Approach in Eastern Colombia. Water. 2019; 12 (1):42.

Chicago/Turabian Style

Oscar Molina; Christian Bernhofer. 2019. "Assessment of Regional and Historical Climate Records for a Water Budget Approach in Eastern Colombia." Water 12, no. 1: 42.

Journal article
Published: 15 October 2019 in Water
Reads 0
Downloads 0

Projected climate changes for the 21st century may cause great uncertainties on the hydrology of a river basin. This study explored the impacts of climate change on the water balance and hydrological regime of the Jhelum River Basin using the Soil and Water Assessment Tool (SWAT). Two downscaling methods (SDSM, Statistical Downscaling Model and LARS-WG, Long Ashton Research Station Weather Generator), three Global Circulation Models (GCMs), and two representative concentration pathways (RCP4.5 and RCP8.5) for three future periods (2030s, 2050s, and 2090s) were used to assess the climate change impacts on flow regimes. The results exhibited that both downscaling methods suggested an increase in annual streamflow over the river basin. There is generally an increasing trend of winter and autumn discharge, whereas it is complicated for summer and spring to conclude if the trend is increasing or decreasing depending on the downscaling methods. Therefore, the uncertainty associated with the downscaling of climate simulation needs to consider, for the best estimate, the impact of climate change, with its uncertainty, on a particular basin. The study also resulted that water yield and evapotranspiration in the eastern part of the basin (sub-basins at high elevation) would be most affected by climate change. The outcomes of this study would be useful for providing guidance in water management and planning for the river basin under climate change.

ACS Style

Naeem Saddique; Muhammad Usman; Christian Bernhofer. Simulating the Impact of Climate Change on the Hydrological Regimes of a Sparsely Gauged Mountainous Basin, Northern Pakistan. Water 2019, 11, 2141 .

AMA Style

Naeem Saddique, Muhammad Usman, Christian Bernhofer. Simulating the Impact of Climate Change on the Hydrological Regimes of a Sparsely Gauged Mountainous Basin, Northern Pakistan. Water. 2019; 11 (10):2141.

Chicago/Turabian Style

Naeem Saddique; Muhammad Usman; Christian Bernhofer. 2019. "Simulating the Impact of Climate Change on the Hydrological Regimes of a Sparsely Gauged Mountainous Basin, Northern Pakistan." Water 11, no. 10: 2141.

Journal article
Published: 20 June 2016 in Meteorologische Zeitschrift
Reads 0
Downloads 0
ACS Style

Uwe Spank; Barbara Köstner; Uta Moderow; Thomas Grunwald; Christian Bernhofer. Surface Conductance of Five Different Crops Based on 10 Years of Eddy-Covariance Measurements. Meteorologische Zeitschrift 2016, 25, 251 -266.

AMA Style

Uwe Spank, Barbara Köstner, Uta Moderow, Thomas Grunwald, Christian Bernhofer. Surface Conductance of Five Different Crops Based on 10 Years of Eddy-Covariance Measurements. Meteorologische Zeitschrift. 2016; 25 (3):251-266.

Chicago/Turabian Style

Uwe Spank; Barbara Köstner; Uta Moderow; Thomas Grunwald; Christian Bernhofer. 2016. "Surface Conductance of Five Different Crops Based on 10 Years of Eddy-Covariance Measurements." Meteorologische Zeitschrift 25, no. 3: 251-266.

Book chapter
Published: 20 April 2016 in Integrated Water Resources Management: Concept, Research and Implementation
Reads 0
Downloads 0

Integrated Water Resources Management often needs specific climate data, e.g. for water use assessment in agriculture or reservoir design for drinking water supply and flood retention. Needed data are often missing. Climate Change aggravates this problem, as in contrast to the past, measured data only are probably insufficient to be used in IWRM studies for future impact. A scheme is presented to replace measured data by climate model output. Model performance assessment is done for General Circulation Models (GCMs) with the example regions of Eastern Europe (Western Bug catchment), the Arabian Peninsula and the region of Brasília (Brazil). The ranking of GCMs was sensitive to region, performance measure and reference data. However, HADCM3 (Hadley Centre) and MPEH5 (MPI Hamburg) show a good resemblance with two differing references for two out of three regions. Regional downscaling is demonstrated with two examples: dynamical with the mesoscale CCLM for the Western Bug, statistical with the SDSM for Brasília. Both approaches differ in observational data requirements (lower for dynamical downscaling) and need for bias correction (more for dynamical downscaling). Impact modelling based on climate model output shows significant changes in SWAT simulations of runoff in the Western Bug catchment for the B1 and A2 scenarios at the end of the 21st century. Climate change is an IWRM relevant problem in all three regions, increasing evaporation of irrigated agriculture in the Middle East, changing soil erosion into drinking water reservoirs in central Brazil or the Bug runoff. Which climate information is adequate depends on many factors, primarily the specific IWRM problem.

ACS Style

Christian Bernhofer; Klemens Barfus; Dirk Pavlik; Pablo Borges; Dennis Söhl. Climate Change Information for IWRM. Integrated Water Resources Management: Concept, Research and Implementation 2016, 171 -197.

AMA Style

Christian Bernhofer, Klemens Barfus, Dirk Pavlik, Pablo Borges, Dennis Söhl. Climate Change Information for IWRM. Integrated Water Resources Management: Concept, Research and Implementation. 2016; ():171-197.

Chicago/Turabian Style

Christian Bernhofer; Klemens Barfus; Dirk Pavlik; Pablo Borges; Dennis Söhl. 2016. "Climate Change Information for IWRM." Integrated Water Resources Management: Concept, Research and Implementation , no. : 171-197.

Journal article
Published: 22 January 2016 in International Journal of Climatology
Reads 0
Downloads 0

Grazing intensity effects on the evapotranspiration (ET) partitioning into evaporation (E) and transpiration (T) were investigated using eddy covariance measurement data during the growing season (May to September) from 2005 to 2008 over typical steppes in Inner Mongolia, China. Four grazing intensities were examined (UG79, ungrazed since 1979; WG, winter grazed; CG, continuously grazed; HG, heavily grazed). Soil water content (SWC) significantly influenced daily T/ET by affecting T and E in different ways. On a monthly scale, T/ET at UG79 (0.46–0.77) increased with vegetation growth regardless of the uneven distribution of precipitation. The mean T/ET at UG79 for the growing season ranged from 0.50 to 0.74 for 2005 to 2008. In the normal precipitation year (2006), WG and HG reduced T/ET because they significantly reduced T through the removal of leaf area. In the dry year (2005), this negative effect on T was depressed by summer droughts, while WG and HG decreased E primarily due to the decreased interception of rainfall by the canopy. The grazing effect on T/ET was opposite to that in 2006. These results indicate that grazing effects on ET partitioning could vary with soil water conditions in the semiarid typical steppe ecosystems.

ACS Style

Lei Wang; Huizhi Liu; Christian Bernhofer. Grazing intensity effects on the partitioning of evapotranspiration in the semiarid typical steppe ecosystems in Inner Mongolia. International Journal of Climatology 2016, 36, 4130 -4140.

AMA Style

Lei Wang, Huizhi Liu, Christian Bernhofer. Grazing intensity effects on the partitioning of evapotranspiration in the semiarid typical steppe ecosystems in Inner Mongolia. International Journal of Climatology. 2016; 36 (12):4130-4140.

Chicago/Turabian Style

Lei Wang; Huizhi Liu; Christian Bernhofer. 2016. "Grazing intensity effects on the partitioning of evapotranspiration in the semiarid typical steppe ecosystems in Inner Mongolia." International Journal of Climatology 36, no. 12: 4130-4140.

Articles
Published: 18 February 2014 in International Journal of Remote Sensing
Reads 0
Downloads 0

Validation of Moderate-Resolution Imaging Spectroradiometer (MODIS) land surface reflectance products is important to effective utilization of such products for earth systems science. Ground-based measurements are normally utilized for such validation. However, the major scale mismatch between the ground ‘point’ measurement and MODIS resolution (500 m and 1 km) makes direct comparison infeasible over many land surface types. In this paper, an indirect comparison between ground ‘point’ measurements and MODIS land surface products via high-resolution remotely sensed imagery (Landsat Thematic Mapper/TM) was utilized in semi-arid grassland of Inner Mongolia in summer 2005, where ground measurements are relatively sparse in comparison with other locations around the world. Within the validation, the TM reflectance imagery was first calibrated by the ground ‘point’ measurements, and then aggregated to MODIS data resolution for determination of their accuracy. Besides common direct spectral band comparison of reflectance between TM and MODIS, empirical/indirect comparison between TM and MODIS was also implemented. Both types of validation showed that the absolute error of bidirectional reflectance from atmospheric correction (MOD09) is less than 9.4%, and for nadir bidirectional reflectance distribution function (BRDF)-adjusted reflectance (MOD43B4) it is less than 3.1%, in which the error of visible bands of two data sets is less than 1.35% and 0.95%, respectively. This validation will help improve the accuracy of MODIS products used in this area.

ACS Style

Liya Fan; Franz H. Berger; Huizhi Liu; Christian Bernhofer. Validating MODIS land surface reflectance products using ground-measured reflectance spectra – a case study in semi-arid grassland in Inner Mongolia, China. International Journal of Remote Sensing 2014, 35, 1715 -1728.

AMA Style

Liya Fan, Franz H. Berger, Huizhi Liu, Christian Bernhofer. Validating MODIS land surface reflectance products using ground-measured reflectance spectra – a case study in semi-arid grassland in Inner Mongolia, China. International Journal of Remote Sensing. 2014; 35 (5):1715-1728.

Chicago/Turabian Style

Liya Fan; Franz H. Berger; Huizhi Liu; Christian Bernhofer. 2014. "Validating MODIS land surface reflectance products using ground-measured reflectance spectra – a case study in semi-arid grassland in Inner Mongolia, China." International Journal of Remote Sensing 35, no. 5: 1715-1728.

Journal article
Published: 18 October 2013 in SpringerPlus
Reads 0
Downloads 0

Grasslands in Inner Mongolia are important for livestock farming while ecosystem functioning and water consumption are dominated by evapotranspiration (ET). In this paper we studied the spatiotemporal distribution and variability of ET and its components in Inner Mongolian grasslands over a period of 10 years, from 2002 to 2011. ET was modelled pixel-wise for more than 3000 1 km(2) pixels with the physically-based hydrological model BROOK90. The model was parameterised from eddy-covariance measurements and daily input was generated from MODIS leaf area index and surface temperatures. Modelled ET was also compared with the ET provided by the MODIS MOD16 ET data. The study showed ET to be highly variable in both time and space in Inner Mongolian grasslands. The mean coefficient of variation of 8-day ET in the study area varied between 25% and 40% and was up to 75% for individual pixels indicating a high innerannual variability of ET. Generally, ET equals or exceeds P during the vegetation period, but high precipitation in 2003 clearly exceeded ET in this year indicating a recharge of soil moisture and groundwater. Despite the high interannual and innerannual variations of spatial ET, the study also showed the existence of an intrinsic long-term spatial pattern of ET distribution, which can be explained partly by altitude and longitude (R(2) = 0.49). In conclusion, the results of this research suggest the development of dynamic and productive rangeland management systems according to the inherent variability of rainfall, productivity and ET in order to restore and protect Inner Mongolian grasslands.

ACS Style

David Schaffrath; Christian Bernhofer. Variability and distribution of spatial evapotranspiration in semi arid Inner Mongolian grasslands from 2002 to 2011. SpringerPlus 2013, 2, 547 .

AMA Style

David Schaffrath, Christian Bernhofer. Variability and distribution of spatial evapotranspiration in semi arid Inner Mongolian grasslands from 2002 to 2011. SpringerPlus. 2013; 2 (1):547.

Chicago/Turabian Style

David Schaffrath; Christian Bernhofer. 2013. "Variability and distribution of spatial evapotranspiration in semi arid Inner Mongolian grasslands from 2002 to 2011." SpringerPlus 2, no. 1: 547.

Journal article
Published: 13 September 2013 in European Journal of Agronomy
Reads 0
Downloads 0

One of the most decisive natural framework conditions of agriculture – the regional climate – is in transition. This requires considering climate change and climate change impact for decision making. Although this knowledge is uncertain and depends on future green-house gas emission, it is rapidly expanding and improving. Therefore, it is important to create flexible systems with adaptable data bases and analytical tools to integrate knowledge of future climate change in agronomy for impact studies and adaptation planning. The joint project LandCaRe (Land, Climate, and Resources) 2020 aimed at developing a conceptual framework and prototype of a model-based decision support system (DSS) based on improved process knowledge and stakeholder communication. The final product, the LandCaRe DSS should combine grid-based information on regional climate and land surface, robust climate impact models and socio-economic boundary conditions to develop spatially explicit climate impact scenarios. Emphasis was put on the integration of different knowledge from science and practice. Climate projections had to be adapted to the needs of impact modelling of agricultural and ecological processes at regional and farm scale. Impact modelling included new process knowledge, especially related to the CO2 fertilisation effect on crop rotations. A new Free Air Carbon Dioxide Enrichment Experiment (FACE) on the C4 plant maize was conducted during the project. A new agro-ecosystem model was developed which integrates soil–plant–atmosphere exchange and plant production to predict crop yield as well as water, carbon and nitrogen fluxes. Stakeholders included representatives of agricultural and environmental administrations, managers of agro-enterprises and large farms as well as organisations for regional planning and nature conservation. Their central common interests were future land use, water availability and management. Stakeholders from agriculture requested not only to assess potential impacts of regional climate change on yield but also to interpret climate impact on farm economy. This required the design of a farm-economy module linking effects of management and adaptation on crop yield with scenarios of costs and prices. Here an introduction to the project, components of the DSS and its further perspectives are presented.

ACS Style

B. Kostner; K.-O. Wenkel; M. Berg; Ch. Bernhofer; H. Gömann; H.-J. Weigel. Integrating regional climatology, ecology, and agronomy for impact analysis and climate change adaptation of German agriculture: An introduction to the LandCaRe2020 project. European Journal of Agronomy 2013, 52, 1 -10.

AMA Style

B. Kostner, K.-O. Wenkel, M. Berg, Ch. Bernhofer, H. Gömann, H.-J. Weigel. Integrating regional climatology, ecology, and agronomy for impact analysis and climate change adaptation of German agriculture: An introduction to the LandCaRe2020 project. European Journal of Agronomy. 2013; 52 ():1-10.

Chicago/Turabian Style

B. Kostner; K.-O. Wenkel; M. Berg; Ch. Bernhofer; H. Gömann; H.-J. Weigel. 2013. "Integrating regional climatology, ecology, and agronomy for impact analysis and climate change adaptation of German agriculture: An introduction to the LandCaRe2020 project." European Journal of Agronomy 52, no. : 1-10.

Journal article
Published: 07 June 2013 in Journal of Hydrology
Reads 0
Downloads 0

Numerical water balance models are widely used in ecological and hydro sciences. However, their application is related to specific problems and uncertainties. The reliability of model prediction depends on (i) model concept, (ii) parameters, (iii) uncertainty of input data, and (iv) uncertainty of reference data. How model concept (i) and parameters (ii) effect the model’s performance is an often treated problem. However, the effects of (iii) and (iv) are typically ignored or only barely treated in context of regionalisation and generalisation. In this study, the actual measurement uncertainties of input and reference data are the main focus. Furthermore, the evaluation of model results is analysed with regard to uncertainties of reference data. A special feature is the use of evapotranspiration (measured via the eddy covariance) instead of runoff for evaluation of simulation results. It is shown that seemingly small uncertainties of measurements can create significant uncertainties in simulation results depending on the temporal scale of investigation. As an example, the uncertainty of measurements of daily global radiation sum up to an uncertainty of 250 MJ (equivalent to 100 mm) on an annual scale, which causes an uncertainty of 40 mm in simulated grass-reverence evapotranspiration. Summarised and generalised, the measurement uncertainties of all input data create an uncertainty on average of around 5% in the simulated annual evapotranspiration and of around 10% in the simulated annual seepage. However, the effects can be significantly higher in years with extreme events and can reach up to 15%. It is demonstrated that uncertainties of individual variables are not simply superposed but interact in a complex way. Thereby, it has become apparent that the effects of measurement uncertainties on model results are similar for complex and for simple models.

ACS Style

Uwe Spank; Kai Schwärzel; Maik Renner; Uta Moderow; Christian Bernhofer. Effects of measurement uncertainties of meteorological data on estimates of site water balance components. Journal of Hydrology 2013, 492, 176 -189.

AMA Style

Uwe Spank, Kai Schwärzel, Maik Renner, Uta Moderow, Christian Bernhofer. Effects of measurement uncertainties of meteorological data on estimates of site water balance components. Journal of Hydrology. 2013; 492 ():176-189.

Chicago/Turabian Style

Uwe Spank; Kai Schwärzel; Maik Renner; Uta Moderow; Christian Bernhofer. 2013. "Effects of measurement uncertainties of meteorological data on estimates of site water balance components." Journal of Hydrology 492, no. : 176-189.

Journal article
Published: 01 January 2013 in Atmospheric and Climate Sciences
Reads 0
Downloads 0

In this study, recurrent networks to downscale meteorological fields of the ERA-40 re-analysis dataset with focus on the meso-scale water balance were investigated. Therefore two types of recurrent neural networks were used. The first approach is a coupling between a recurrent neural network and a distributed watershed model and the second a nonlinear autoregressive with exogenous inputs (NARX) network, which directly predicted the component of the water balance. The approaches were deployed for a meso-scale catchment area in the Free State of Saxony, Germany. The results show that the coupled approach did not perform as well as the NARX network. But the meteorological output of the coupled approach already reaches an adequate quality. However the coupled model generates as input for the watershed model insufficient daily precipitation sums and not enough wet days were predicted. Hence the long-term annual cycle of the water balance could not be preserved with acceptable quality in contrary to the NARX approach. The residual storage change term indicates physical restrictions of the plausibility of the neural networks, whereas the physically based correlations among the components of the water balance were preserved more accurately by the coupled approach.

ACS Style

Rico Kronenberg; Klemens Barfus; Johannes Franke; Christian Bernhofer. On the Downscaling of Meteorological Fields Using Recurrent Networks for Modelling the Water Balance in a Meso-Scale Catchment Area of Saxony, Germany. Atmospheric and Climate Sciences 2013, 03, 552 -561.

AMA Style

Rico Kronenberg, Klemens Barfus, Johannes Franke, Christian Bernhofer. On the Downscaling of Meteorological Fields Using Recurrent Networks for Modelling the Water Balance in a Meso-Scale Catchment Area of Saxony, Germany. Atmospheric and Climate Sciences. 2013; 03 (04):552-561.

Chicago/Turabian Style

Rico Kronenberg; Klemens Barfus; Johannes Franke; Christian Bernhofer. 2013. "On the Downscaling of Meteorological Fields Using Recurrent Networks for Modelling the Water Balance in a Meso-Scale Catchment Area of Saxony, Germany." Atmospheric and Climate Sciences 03, no. 04: 552-561.

Review article
Published: 15 August 2011 in Agricultural and Forest Meteorology
Reads 0
Downloads 0

At the study site Tharandt Anchor Station in Saxony/Germany sap flow measurements are conducted in an old Norway spruce (Picea abies [L.] KARST.) stand. During the study period from 2001 to 2007 several events like thinning, long and short drought periods and a winter storm significantly affected the amount of canopy water use. We show that intra-annual variation of Ec is strongly related to VPD and PPFD. While there is a non-linear relationship between daily Ec and VPD, daily Ec is limited by daily integrated PPFD indicating stomatal control of Ec through photosynthesis. On a monthly or seasonal basis, reduction of Ec is not only related to high VPD and non-saturating PPFD, but also to higher frequencies of precipitation. In comparison to this, nearly 55% of canopy precipitation and 20% of available energy were used for transpiration during the growing season. Intensive seasonal soil water measurements at the site revealed that on average about 74% of soil water removal within the rooting zone can be related to tree water uptake. A good correlation was found between annual Ec and Ecmax, usually occurring in June or July. Further, the monthly sums of June plus July were good predictors of annual Ec. Within the study period, the extreme drought in 2003 revealed a clear threshold of soil water content by 9.5 vol% and had the most pronounced effect on annual Ec followed by a stand thinning. The winter storm “Kyrill” in January 2007 had caused loss of green needles and twigs. It is assumed that the observed reduction in Ec during spring was related to the reduced leaf biomass and potentially to root damage of bended trees. Excluding the effect of extreme drought and forest management, a mean inter-annual variation in Ec of ±15% and in Ec/VPD of ±8% remained. It is concluded that lag-effects of drought and the winter storm add lacking explanation to the inter-annual variability of canopy transpiration besides the typical variation of atmospheric conditions.

ACS Style

Falko Clausnitzer; Barbara Köstner; Kai Schwärzel; Christian Bernhofer. Relationships between canopy transpiration, atmospheric conditions and soil water availability—Analyses of long-term sap-flow measurements in an old Norway spruce forest at the Ore Mountains/Germany. Agricultural and Forest Meteorology 2011, 151, 1023 -1034.

AMA Style

Falko Clausnitzer, Barbara Köstner, Kai Schwärzel, Christian Bernhofer. Relationships between canopy transpiration, atmospheric conditions and soil water availability—Analyses of long-term sap-flow measurements in an old Norway spruce forest at the Ore Mountains/Germany. Agricultural and Forest Meteorology. 2011; 151 (8):1023-1034.

Chicago/Turabian Style

Falko Clausnitzer; Barbara Köstner; Kai Schwärzel; Christian Bernhofer. 2011. "Relationships between canopy transpiration, atmospheric conditions and soil water availability—Analyses of long-term sap-flow measurements in an old Norway spruce forest at the Ore Mountains/Germany." Agricultural and Forest Meteorology 151, no. 8: 1023-1034.

Journal article
Published: 09 August 2011 in Environmental Earth Sciences
Reads 0
Downloads 0

In semi-arid regions of Central Asia, water shortage results from low annual precipitation (P) with high interannual variability. Evapotranspiration (ET) dominates water balance losses entirely. Previous studies showed large differences between individual grassland sites in the partitioning of ET into evaporation and transpiration, but only little difference in the evaporative ratio ET/P. The hydrological model BROOK90 was applied to the Xilin river catchment in Inner Mongolia (China) in combination with data from moderate resolution imaging spectroradiometer (MODIS) and ET measurements. The ET part of the model was parameterised using several years of eddy covariance (EC) measurements over grasslands differing in grazing intensity and leaf area index (LAI). Using a relatively well-established relationship of LAI and P as well as LAI and temperature derived from MODIS, the water balance components of a 16 km² sample area in the catchment were modelled with a 1 km² resolution for the vegetation period of 2006. All pixels were modelled assuming a similar ET control as at the EC sites. Spatial variation in ET as well as in the partitioning of ET between transpiration and evaporation could be identified. The results indicate the potential of using MODIS data and BROOK90 to upscale ET of semi-arid grasslands from site to larger grass dominated catchments.

ACS Style

Sylvia H. Vetter; David Schaffrath; Christian Bernhofer. Spatial simulation of evapotranspiration of semi-arid Inner Mongolian grassland based on MODIS and eddy covariance data. Environmental Earth Sciences 2011, 65, 1567 -1574.

AMA Style

Sylvia H. Vetter, David Schaffrath, Christian Bernhofer. Spatial simulation of evapotranspiration of semi-arid Inner Mongolian grassland based on MODIS and eddy covariance data. Environmental Earth Sciences. 2011; 65 (5):1567-1574.

Chicago/Turabian Style

Sylvia H. Vetter; David Schaffrath; Christian Bernhofer. 2011. "Spatial simulation of evapotranspiration of semi-arid Inner Mongolian grassland based on MODIS and eddy covariance data." Environmental Earth Sciences 65, no. 5: 1567-1574.

Journal article
Published: 15 June 2011 in Agricultural and Forest Meteorology
Reads 0
Downloads 0

The advection initiative ADVEX within CarboEurope-IP conducted advection experiments at three European coniferous sites in 2005 and 2006. All experiments shared the same geometry and instrumentation. Data of the ADVEX experiments were used to calculate advective fluxes of carbon dioxide and sensible heat using exactly the same method. However, the advective flux of sensible heat can be assessed more easily than the carbon dioxide flux with its associated complex measurements of gas concentrations. We explored the possibility to use advective fluxes of sensible heat as a proxy for the corresponding flux of carbon dioxide despite somewhat differing sinks and sources. On average, advective fluxes of sensible heat were of opposite sign in relation to the advective fluxes of carbon dioxide for the three investigated sites, especially during nighttime. Therefore, the respective gradients were of opposite sign, on average, for vertical and (to a lesser extent) horizontal direction. This is not as obvious for horizontal direction as for the vertical direction. A scheme is presented to explain the correlation of the respective gradients for different conditions. Based on the gained insights and regression statistics, two simple empirical models were tested to derive advective fluxes of carbon dioxide from advective fluxes of sensible heat. Our results suggest that the advective flux of sensible heat could be taken as an indicator concerning the presence and sign of carbon dioxide advection. However, the suitability of advective fluxes of sensible heat as a quantitative proxy for advective fluxes of carbon dioxide is more problematic because the representativeness including the magnitude of advection derived from advection measurements is not yet clarified. An inspection of the budget of sensible heat and carbon dioxide revealed considerable changes by advection. The results indicate that the budget of carbon dioxide might be generally more affected by the investigated non-turbulent advective fluxes than the budget of sensible heat.

ACS Style

Uta Moderow; Christian Feigenwinter; Christian Bernhofer. Non-turbulent fluxes of carbon dioxide and sensible heat—A comparison of three forested sites. Agricultural and Forest Meteorology 2011, 151, 692 -708.

AMA Style

Uta Moderow, Christian Feigenwinter, Christian Bernhofer. Non-turbulent fluxes of carbon dioxide and sensible heat—A comparison of three forested sites. Agricultural and Forest Meteorology. 2011; 151 (6):692-708.

Chicago/Turabian Style

Uta Moderow; Christian Feigenwinter; Christian Bernhofer. 2011. "Non-turbulent fluxes of carbon dioxide and sensible heat—A comparison of three forested sites." Agricultural and Forest Meteorology 151, no. 6: 692-708.