@inproceedings{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water balance dynamics of the constructed Chicken Creek catchment as influenced by 12 years of ecological development}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Experimental catchments with well-known boundaries and characteristics may contribute valuable data to hydrological, critical zone and landscape evolution research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha area including a 0.4 ha pond, Brandenburg, Germany) representing an initial ecosystem undergoing a highly dynamic ecological development starting from clearly defined starting conditions. The water balance dynamics of the catchment was calculated using a simple mass balance approach to reveal the impact of ecological development during 12 years. Water storage in the catchment was calculated from a 3D-model of groundwater volumes, soil moisture measurements and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Due to the known boundary conditions and the inner structure of the catchment, we were able to quantify the different storage compartments and their role in hydrologic response. Our results indicate that for small catchments with a highly dynamic ecological development like the Chicken Creek, the knowledge about saturated and unsaturated storage volumes enables a good estimate and closure of the water balance using a rather simple approach, at least in annual resolution. We found a significant relationship between vegetation cover in the catchment and calculated ET. Time series of meteorological, hydrological, soil and vegetation data over 12 years enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology. The dataset from the Chicken Creek catchment indicate at least three phases in ecosystem development, where initial abiotic feedbacks (e.g. erosion) were followed by more and more biotic controls (e.g. biological soil crusts, vegetation succession and growth). Data from Chicken Creek in high spatial and temporal resolution provide a valuable database underlining the high importance of abiotic/biotic feedback effects that change the hydrologic functioning and response of the catchment more than the water balance itself revealed and thus have to be included in catchment models.}, language = {en} } @incollection{SchaafHinzGerwinetal., author = {Schaaf, Wolfgang and Hinz, Christoph and Gerwin, Werner and Zaplata, Markus K. and H{\"u}ttl, Reinhard F.}, title = {Ecosystem Development in the Constructed Catchment "Chicken Creek"}, series = {Hydrology of Artificial and Controlled Experiments}, booktitle = {Hydrology of Artificial and Controlled Experiments}, editor = {Liu, Jiu-Fu and Gu, Wei-Zu}, publisher = {Intech Open}, address = {London}, isbn = {978-1-78923-559-3}, pages = {75 -- 93}, abstract = {Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances, or transgression of thresholds. We propose a conceptual framework of feedback processes in early states of ecosystem development affected by spatiotemporal environmental drivers. To test this concept, we used 10-year time series of hydrological, biological, geomorphological, and soil data from the constructed catchment Chicken Creek." The 6ha site was left to unrestricted development since 2005 and was intensively monitored. The data showed a very rapid development of the site with an increasing complexity and heterogeneity. In the first years, stochastic signals like the initial substrate conditions and external drivers like extreme weather events were the most important factors resulting in abiotic/abiotic feedback mechanisms shaping the morphology of the site and creating site diversity. Initial abiotic feedback mechanisms between water and substrate were soon followed by abiotic/biotic feedbacks between biological soil crusts, invading vegetation, geomorphology, and hydrology resulting in state transitions of catchment functioning.}, language = {en} } @misc{GerwinBadorreckSchaafetal., author = {Gerwin, Werner and Badorreck, Annika and Schaaf, Wolfgang and Hinz, Christoph and H{\"u}ttl, Reinhard F.}, title = {Das H{\"u}hnerwasser-Einzugsgebiet in SO-Brandenburg im {\"U}bergang von einem abiotischen zu einem biotisch kontrollierten Wasserhaushalt}, series = {Hydrologie und Wasserbewirtschaftung}, volume = {62}, journal = {Hydrologie und Wasserbewirtschaftung}, number = {3}, issn = {0012-0235}, doi = {10.5675/HyWa_2018,3_1}, pages = {134 -- 144}, abstract = {Das H{\"u}hnerwasser-Einzugsgebiet ist ein 6 ha großes, k{\"u}nstlich geschaffenes Wassereinzugsgebiet im Tagebau Welzow-S{\"u}d in S{\"u}dost-Brandenburg. Das Zweischichtsystem mit einer Ton- und einer dar{\"u}ber liegenden Sandschicht wurde im Jahr 2005 fertiggestellt und ohne weitere Rekultivierungsmaßnahmen f{\"u}r Forschungszwecke bereitgestellt. Es l{\"a}sst exemplarisch die Untersuchung der initialen Landschaftsgenese zu. Insbesondere die Entwicklung von einem zun{\"a}chst noch abiotisch kontrollierten hin zu einem biotisch gesteuerten System l{\"a}sst sich hier beobachten. In diesem Beitrag werden beispielhaft einige in diesem Kontext aufgetretene Interaktionen zwischen abiotischen und biotischen Strukturelementen vorgestellt. Dies sind zum einen Erosions- und Sedimentationsprozesse und ihre Wechselwirkungen mit der Vegetation. Zum anderen wird der Einfluss der Vegetation auf die Grundwasserentwicklung dargestellt.}, language = {de} } @misc{NsiahSchaaf, author = {Nsiah, Paul Kofi and Schaaf, Wolfgang}, title = {The potentials of biological geotextiles in erosion and sediment control during gold mine reclamation in Ghana}, series = {Journal of Soils and Sediments}, volume = {19}, journal = {Journal of Soils and Sediments}, number = {4}, issn = {1614-7480}, doi = {10.1007/s11368-018-2217-7}, pages = {1995 -- 2006}, abstract = {Purpose Soil erosion is a significant environmental impact of surface mining affecting the initial establishment of vegetation, especially on steep slopes, during reclamation. Consequently, we investigated the potentials of biological geotextiles constructed from two local plants, Pennisetum purpureum and Broussonetia papyrifera, in reducing erosion and sedimentation during reclamation at Newmont Ghana Gold Limited. Materials and methods Six experimental plots were constructed on a 33\% slope waste rock, covered with a 70-cm layer of stockpiled subsoil. Concrete gutters, lined with silt fence, were installed at the lower end of each plot to collect eroded sediment. The two kinds of biological geotextiles, BYork^ mat and elephant grass mat, were used with bare ground as control in a randomized block design with two replicates each. Data on sediment yield was collected after each substantial rainfall. The performance of each geotextile in reducing soil loss was expressed as a percentage from the mean total sediment yield. Results and discussion With total precipitation of 306 mm in the period April 18, to July 4, 2016, both elephant grass mat and York mat significantly (p < 0.05) reduced soil loss by 56.6\% and 97.3\%, respectively, compared to the control, indicating both mats were effective in erosion and sediment control. The relatively high performance of York mat was mainly attributed to its more fibers that provided less surface cover (70\%) as well as flexibility of the fibers which enabled the mat to absorb more water during rainfall thus increasing its weight. This increase in weight promoted better drapability, with better erosion and sediment control. Gully formations at the site were primarily due to high concentrated runoff flows from the top of reclaiming benches, with time delays between completion of earthworks, geotextile placement, and seeding of plants as predisposing factors. Conclusions The York mat (YM) and the elephant grass mat (EM) individually acted as cover and protected the highly erodible graded mine slope against the erosive forces of tropical rain and runoff until vegetation establishment. Even so, planning and coordinating the reclamation program such that all earthworks are completed at the end of the dry season to enable geotextile installation and plant seeding at the onset of rains, together with installation of temporary slope drains in preventing gully formations from concentrated runoff flows, are considered to contribute significantly to the general reclamation success at Newmont Ghana Gold Limited (NGGL) and similar mine sites.}, language = {en} }