TY  - JOUR
A1  - Reiche, Matthias
A1  - Funk, Roger
A1  - Zhang, Zhuodong
A1  - Hoffmann, Carsten
A1  - Reiche, Johannes
A1  - Wehrhan, Marc
A1  - Li, Yong
A1  - Sommer, Michael
T1  - Application of satellite remote sensing for mapping wind erosion risk and dust emission-deposition in Inner Mongolia grassland, China
JF  - Grassland science
N2  - Intensive grazing leads to land degradation and desertification of grassland ecosystems followed by serious environmental and social problems. The Xilingol steppe grassland in Inner Mongolia, China, which has been a sink area for dust for centuries, is strongly affected by the negative effects of overgrazing and wind erosion. The aim of this study is the provision of a wind erosion risk map with a spatial high resolution of 25 m to identify actual source and sink areas. In an integrative approach, field measurements of vegetation features and surface roughness length z0 were combined with Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image data for a land use classification. To determine the characteristics of the different land use classes, a field observation (ground truth) was performed in April 2009. The correlation of vegetation height and z0 (R2 = 0.8, n = 55) provided the basis for a separation of three main classes, grassland, non-vegetation and other. The integration of the soil-adjusted vegetation index (SAVI) and the spectral information from the atmospheric corrected ASTER bands 1, 2 and 3 (visible to near-infrared) led to a classification of the overall accuracy (OA) of 0.79 with a kappa () statistic of 0.74, respectively. Additionally, a digital elevation model (DEM) was used to identify topographical effects in relation to the main wind direction, which enabled a qualitative estimation of potential dust deposition areas. The generated maps result in a significantly higher description of the spatial variability in the Xilingol steppe grassland reflecting the different land use intensities on the current state of the grassland less, moderately and highly degraded. The wind erosion risk map enables the identification of characteristic mineral dust sources, sinks and transition zones.
KW  - Advanced Spaceborne Thermal Emission and Reflection Radiometer data
KW  - dust emission and deposition
KW  - soil-adjusted vegetation index
KW  - semiarid grassland
KW  - wind erosion
Y1  - 2012
U6  - https://doi.org/10.1111/j.1744-697X.2011.00235.x
SN  - 1744-6961
VL  - 58
IS  - 1
SP  - 8
EP  - 19
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Zielhofer, Christoph
A1  - Schmidt, Johannes
A1  - Reiche, Niklas
A1  - Tautenhahn, Marie
A1  - Ballasus, Helen
A1  - Burkart, Michael
A1  - Linstädter, Anja
A1  - Dietze, Elisabeth
A1  - Kaiser, Knut
A1  - Mehler, Natascha
T1  - The lower Havel River Region (Brandenburg, Germany)
BT  - a 230-Year-Long historical map record indicates a decrease in surface water areas and groundwater levels
JF  - Water
N2  - Instrumental data show that the groundwater and lake levels in Northeast Germany have decreased over the past decades, and this process has accelerated over the past few years. In addition to global warming, the direct influence of humans on the local water balance is suspected to be the cause. Since the instrumental data usually go back only a few decades, little is known about the multidecadal to centennial-scale trend, which also takes long-term climate variation and the long-term influence by humans on the water balance into account. This study aims to quantitatively reconstruct the surface water areas in the Lower Havel Inner Delta and of adjacent Lake Gulpe in Brandenburg. The analysis includes the calculation of surface water areas from historical and modern maps from 1797 to 2020. The major finding is that surface water areas have decreased by approximately 30% since the pre-industrial period, with the decline being continuous. Our data show that the comprehensive measures in Lower Havel hydro-engineering correspond with groundwater lowering that started before recent global warming. Further, large-scale melioration measures with increasing water demands in the upstream wetlands beginning from the 1960s to the 1980s may have amplified the decline in downstream surface water areas.
KW  - long-term hydrological changes
KW  - historical maps
KW  - review of written
KW  - sources
KW  - preindustrial to industrial period
KW  - hydro-engineering history;
KW  - effects of global warming
KW  - drying trend
KW  - wetlands
KW  - drainage works to
KW  - create cropland
KW  - Lower Havel River Region
KW  - Brandenburg
KW  - Germany
Y1  - 2022
U6  - https://doi.org/10.3390/w14030480
SN  - 2073-4441
VL  - 14
IS  - 3
PB  - MDPI
CY  - Basel
ER  -