56,559 research outputs found

    Variations in the predicted spatial distribution of atmospheric nitrogen deposition and their impact on carbon uptake by terrestrial ecosystems

    Get PDF
    Widespread mobilization of nitrogen into the atmosphere from industry, agriculture, and biomass burning and its subsequent deposition have the potential to alleviate nitrogen limitation of productivity in terrestrial ecosystems, and may contribute to enhanced terrestrial carbon uptake. To evaluate the importance of the spatial distribution of nitrogen deposition for carbon uptake and to better quantify its magnitude and uncertainty NOy-N deposition fields from five different three-dimensional chemical models, GCTM, GRANTOUR, IMAGES, MOGUNTIA, and ECHAM were used to drive NDEP, a perturbation model of terrestrial carbon uptake. Differences in atmospheric sources of NOx-N, transport, resolution, and representation of chemistry, contribute to the distinct spatial patterns of nitrogen deposition on the global land surface; these differences lead to distinct patterns of carbon uptake that vary between 0.7 and 1.3 Gt C yr−1 globally. Less than 10% of the nitrogen was deposited on forests which were most able to respond with increased carbon storage because of the wide C:N ratio of wood as well as its long lifetime. Addition of NHx-N to NOy-N deposition, increased global terrestrial carbon storage to between 1.5 and 2.0 Gt C yr−1, while the “missing terrestrial sink” is quite similar in magnitude. Thus global air pollution appears to be an important influence on the global carbon cycle. If N fertilization of the terrestrial biosphere accounts for the “missing” C sink or a substantial portion of it, we would expect significant reductions in its magnitude over the next century as terrestrial ecosystems become N saturated and O3 pollution expands

    Analysis of Flood Patterns in Adams County, Pennsylvania Utilizing Drone Technology and Computer Simulations

    Full text link
    Drone imagery and photogrammetry models of the Gettysburg College campus and the terrain at Boyer Nurseries and Orchards were utilized to study flood patterns in Adams County, Pennsylvania. Gettysburg College has lower-sloped land and moderately built infrastructure while Boyer Orchards has drastically sloped land with many patches of abundant vegetation. The two locations were selected due to the fact that they have starkly different surface features, while the bedrock geology of the areas are very similar. The terrain of the models was isolated before a 3D carver and 3D printer were used to construct physical models to further analyze potential water flow and speed through virtual, modeled flood simulations. The models were used to compare real world rainfall data and flood events in the investigated areas from the months of June to August in 2018. I hypothesized that the Gettysburg College campus would experience more severe flooding that would take longer to subside in comparison to Boyer Orchards due to the steeper slope of the orchards’ terrain. The research revealed that Boyer Orchards experienced more extreme flooding and rainfall than Gettysburg College but was able to neutralize the effects due to plentiful vegetation and physio-graphic differences. Modeled flood simulations demonstrated less rainfall in comparison to actual rainfall values: there were differences of 0.78 cm and 1.32 cm between the actual and simulated rainfall amounts for Gettysburg and the Boyer Orchards area, respectively

    Modeling the impact of climate change and land use change scenarios on soil erosion at the Minab Dam Watershed

    Get PDF
    Climate and land use change can influence susceptibility to erosion and consequently land degradation. The aim of this study was to investigate in the baseline and a future period, the land use and climate change effects on soil erosion at an important dam watershed occupying a strategic position on the narrow Strait of Hormuz. The future climate change at the study area was inferred using statistical downscaling and validated by the Canadian earth system model (CanESM2). The future land use change was also simulated using the Markov chain and artificial neural network, and the Revised Universal Soil Loss Equation was adopted to estimate soil loss under climate and land use change scenarios. Results show that rainfall erosivity (R factor) will increase under all Representative Concentration Pathway (RCP) scenarios. The highest amount of R was 40.6 MJ mm ha(-1) h(-1)y(-1) in 2030 under RPC 2.6. Future land use/land cover showed rangelands turning into agricultural lands, vegetation cover degradation and an increased soil cover among others. The change of C and R factors represented most of the increase of soil erosion and sediment production in the study area during the future period. The highest erosion during the future period was predicted to reach 14.5 t ha(-1) y(-1), which will generate 5.52 t ha(-1) y(-1) sediment. The difference between estimated and observed sediment was 1.42 t ha(-1) year(-1) at the baseline period. Among the soil erosion factors, soil cover (C factor) is the one that watershed managers could influence most in order to reduce soil loss and alleviate the negative effects of climate change.FCT-Foundation for Science and Technology - PTDC/GES-URB/31928/2017; FEDER ALG-01-0247-FEDER-037303info:eu-repo/semantics/publishedVersio

    The development of a mapping tool for the evaluation of building systems for future climate scenarios on European scale

    Full text link
    The paper presents a tool for the mapping of the performance of building systems on European scale for different (future) time periods. The tool is to use for users and be applicable for different building systems. Users should also be able to use a broad range of climate parameters to assess the influence of climate change on these climatic parameters. Also should the calculation time be reasonable short. The mapping tool is developed in MATLAB, which can be used by other users for their own studies.Comment: 21 pages, 24 figures, pre-conferenc

    Predicting China’s Land-use Change and Soil Carbon Sequestration under Alternative Climate Change Scenarios

    Get PDF
    This paper examines and predicts the effects of climate change and climate extremes on China’s land use conversion and soil carbon sequestration under two alternative climate change scenarios. It intends to investigate the following three questions. 1) How did climate factors affect land-use conversion in China from 1988 to 2000 and what was the relative importance of these factors? 2) How would the predicted future climate change pattern affect land-use choice under alternative climate change scenarios? 3) How would the predicted future climate pattern change the spatial distribution of soil organic carbon in China? The study makes two contributions to the literature. First, it integrates climate change, land use conversion, and soil carbon sequestration into a whole model, which facilitates a comprehensive, systematic analysis. Second, it employs a unique dataset, consisting of high-quality Geographic Information System (GIS) data on climate, land use, and soil properties. To the best of our knowledge, no one has used such detailed Chinese data for economic research.Land-use change, soil carbon sequestration, climate change, Environmental Economics and Policy, Land Economics/Use,

    Environmental features of Chinese architectural heritage: the standardization of form in the pursuit of equilibrium with nature

    Get PDF
    We present a scientific discussion about Chinese historical architecture and cultural paradigms in order to analyze the formation of building patterns objectively connected to environmental features. In this regard, we will demonstrate the process of standardization from architectural modules related in different levels of composition around “voids”, onto cosmological urban tissues in harmony with nature. The conclusions show that we can only understand Chinese architectural patterns in relation to Dào or nature, and in turn, they possess profound social and environmental values from which we receive useful lessons to advance towards sustainability in architecture and urban planning. The authors believe that it is critical for China and the world to find a new approach to the building construction industry with an ecological and philosophical background recognizable as “Chinese” and based in its own past. In order to support the information provided in the first part of the article, the authors have conducted an environmental analysis of the traditional Chinese urban layout whose results greatly confirm the initial hypotheses, i.e. the historical fashion of constructing neighborhoods improves conditions of the town in terms of comfort and is able to save energy, thus reducing pernicious change effects

    Northern Hemisphere interdecadal variability: A coupled air-sea mode

    Get PDF
    A coupled air–sea mode in the Northern Hemisphere with a period of about 35 years is described. The mode was derived from a multicentury integration with a coupled ocean–atmosphere general circulation model and involves interactions of the thermohaline circulation with the atmosphere in the North Atlantic and interactions between the ocean and the atmosphere in the North Pacific. The authors focus on the physics of the North Atlantic interdecadal variability. If, for instance, the North Atlantic thermohaline circulation is anomalously strong, the ocean is covered by positive sea surface temperature (SST) anomalies. The atmospheric response to these SST anomalies involves a strengthened North Atlantic Oscillation, which leads to anomalously weak evaporation and Ekman transport off Newfoundland and in the Greenland Sea, and the generation of negative sea surface salinity (SSS) anomalies. These SSS anomalies weaken the deep convection in the oceanic sinking regions and subsequently the strength of the thermohaline circulation. This leads to a reduced poleward heat transport and the formation of negative SST anomalies, which completes the phase reversal. The Atlantic and Pacific Oceans seem to be coupled via an atmospheric teleconnection pattern and the interdecadal Northern Hemispheric climate mode is interpreted as an inherently coupled air–sea mode. Furthermore, the origin of the Northern Hemispheric warming observed recently is investigated. The observed temperatures are compared to a characteristic warming pattern derived from a greenhouse warming simulation with the authors’ coupled general circulation model and also with the Northern Hemispheric temperature pattern associated with the 35-yr climate mode. It is shown that the recent Northern Hemispheric warming projects well onto the temperature pattern of the interdecadal mode under consideration
    • 

    corecore