Transparency in Complex Computational Systems

Scientists depend on complex computational systems that are often ineliminably opaque, to the detriment of our ability to give scientific explanations and detect artifacts. Some philosophers have s..

Characterization of the woody biomass feedstock potential resulting from California's drought.

Regional tree die-off events generate large quantities of standing dead wood, raising concern over catastrophic wildfire and other hazards. Governmental responses to tree die-off have often focused on incentivizing biomass energy production that utilizes standing dead trees removed for safety concerns. However, the full distribution of potential woody bioenergy feedstock after tree die-off has not been evaluated due to the complexities of surveying and precisely measuring large forested areas. In this paper, we present a novel method for estimating standing dead biomass at a fine spatial resolution that combines aerial survey data with forest structure maps. Using this method, we quantify biomass generated by the unprecedented tree die-off that occurred in California following a 4-year drought and widespread pest outbreaks. The results are used to estimate feasibly recoverable feedstock for energy production. We find that approximately 95.1 million bone-dry tons (BDT) of dead biomass resulted from 2012-2017 mortality, with a lower bound of 26.2 million BDT. In other words, of the aboveground live tree biomass in 2012, ~1.3-4.8% died by 2017. Of the standing dead biomass, 29% meets minimum constraints for potential cost-effective bioenergy feedstock. This proportion drops to as low as 15% in the most affected areas due to terrain slope, wilderness status, and other factors, highlighting the need to complement disposal via biomass energy with other strategies to mitigate the risks of the tree mortality crisis, which is likely to only become more severe over time due to climate change

Coastal Groundwater Watch: A Citizen Science Project - Report No. 477

The goals of this study were to utilize citizen scientists in groundwater research in a coastal community where groundwater plays a large role in sustainable water resources management, and assess the extent of groundwater and marine inundation in response to future sea-level rise scenarios. A total of 7 citizen scientists participated in the study by measuring water levels from 15 groundwater monitoring wells using water level meters once a week over a 10-week period. Automated water level loggers were deployed in three of the same wells to assess the quality of the data collected by the citizen scientists. Additional water level loggers were deployed in other groundwater monitoring wells to increase the amount of water level data collected across the island. Several methods were used to assess agreement (i.e., validity) between water level measurements collected by citizen scientists and automated water level loggers. Scatter plots showed that data did not significantly deviate from the line of linearity, suggesting that the data collected by the citizen scientists were comparable to the data collected by automated water level loggers. The Pearson correlation coefficient was greater than 0.9 for all plots that revealed a linear correlation between measurements from different methods. The Bland-Altman method was also used to evaluate the validity of measurements by assessing agreement between measurements from citizen scientists and automated water level loggers. The intraclass correlation coefficient (ICC) and the concordance correlation coefficient (CCC) were used to assess reliability of measurements of water levels from citizen scientists. The values for the ICC and CCC were greater than 0.95 indicating excellent agreement. These values demonstrate that environmental data collected by citizen scientists can be trustworthy. A pretest-posttest survey design and a focus group were used to examine how participants perceived the citizen science project, and how participation as a citizen scientist influenced the participants’ knowledge about water resources and stormwater flooding. Qualitative data suggest that citizen scientists improved their knowledge about groundwater systems on the island. Additionally, the citizen scientists found the project to be enriching and beneficial to their understanding of issues facing the island (e.g., storm water flooding). The groundwater data from both the citizen scientists and automated water level loggers were used to calibrate a numerical groundwater model that characterized the baseline conditions of the water table on the island. Impacts of projected sea-level rise ranging from 0.2 m to 1.4 m on the baseline water table were then simulated under steady state conditions. Finally, geospatial techniques were used to estimate the proportion of land that would be lost to marine inundation and groundwater inundation under identical sea-level rise scenarios. Results indicate that marine and groundwater inundation would have comparable effects on the island, with between 7 and 22% of the land being lost under sea-level rise scenarios of 0.2 to 1.2 m. At extreme sea-level rise scenarios (1.4 m), the effects of groundwater inundation are far much greater than those of marine inundation (with losses of 28% for marine inundation and 40% for groundwater inundation). As a consequence, groundwater inundation may therefore play an important role in future discussions about how climate change and sea-level rise may impact groundwater resources in coastal communities. Involving community residents in scientific research such as the project described in this report may therefore be an effective way for positively engaging with residents about important environmental issues such as climate change, sea-level rise and groundwater resources

Annual Report: 2009

I submit herewith the annual report from the Agricultural and Forestry Experiment Station, School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks, for the period ending December 31, 2009. This is done in accordance with an act of Congress, approved March 2, 1887, entitled, “An act to establish agricultural experiment stations, in connection with the agricultural college established in the several states under the provisions of an act approved July 2, 1862, and under the acts supplementary thereto,” and also of the act of the Alaska Territorial Legislature, approved March 12, 1935, accepting the provisions of the act of Congress. The research reports are organized according to our strategic plan, which focuses on high-latitude soils, high-latitude agriculture, natural resources use and allocation, ecosystems management, and geographic information. These areas cross department and unit lines, linking them and unifying the research. We have also included in our financial statement information on the special grants we receive. These special grants allow us to provide research and outreach that is targeted toward economic development in Alaska. Research conducted by our graduate and undergraduate students plays an important role in these grants and the impact they make on Alaska.Financial statement -- Grants -- Students -- Research Reports: Partners, Facilities, and Programs; Geography; High-Latitude Agriculture; High-Latitude Soils; Management of Ecosystems; Natural Resources Use and Allocation; Index to Reports -- Publications -- Facult

Unmanned Aerial Vehicle (UAV) for monitoring soil erosion in Morocco

This article presents an environmental remote sensing application using a UAV that is specifically aimed at reducing the data gap between field scale and satellite scale in soil erosion monitoring in Morocco. A fixed-wing aircraft type Sirius I (MAVinci, Germany) equipped with a digital system camera (Panasonic) is employed. UAV surveys are conducted over different study sites with varying extents and flying heights in order to provide both very high resolution site-specific data and lower-resolution overviews, thus fully exploiting the large potential of the chosen UAV for multi-scale mapping purposes. Depending on the scale and area coverage, two different approaches for georeferencing are used, based on high-precision GCPs or the UAV’s log file with exterior orientation values respectively. The photogrammetric image processing enables the creation of Digital Terrain Models (DTMs) and ortho-image mosaics with very high resolution on a sub-decimetre level. The created data products were used for quantifying gully and badland erosion in 2D and 3D as well as for the analysis of the surrounding areas and landscape development for larger extents

Geothermal Energy: Delivering on the Global Potential

After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology, This book draws together some of the latest developments in concepts and technology that are enabling the growing realisation of the global potential of geothermal energy in all its manifestations.After decades of being largely the preserve of countries in volcanic regions, the use of geothermal energy—for both heat and power applications—is now expanding worldwide. This reflects its excellent low-carbon credentials and its ability to offer baseload and dispatchable output - rare amongst the mainstream renewables. Yet uptake of geothermal still lags behind that of solar and wind, principally because of (i) uncertainties over resource availability in poorly-explored reservoirs and (ii) the concentration of full-lifetime costs into early-stage capital expenditure (capex). Recent advances in reservoir characterization techniques are beginning to narrow the bounds of exploration uncertainty, both by improving estimates of reservoir geometry and properties, and by providing pre-drilling estimates of temperature at depth. Advances in drilling technologies and management have potential to significantly lower initial capex, while operating expenditure is being further reduced by more effective reservoir management — supported by robust mathematical models — and increasingly efficient energy conversion systems (flash, binary and combined-heat-and-power). Advances in characterization and modelling are also improving management of shallow low-enthalpy resources that can only be exploited using heat-pump technology. Taken together with increased public appreciation of the benefits of geothermal, the technology is finally ready to take its place as a mainstream renewable technology

Geomorphological and statistical analysis of the dune changes in Lido di Classe (Ravenna, Italy) based on remote sensing techniques

Coastal dunes are well-known for their significance in providing vital ecosystem services. However, its highly dynamic nature and its exposure to climatic and anthropogenic pressures make them one of the most vulnerable geologic features along the coastal zones worldwide. On a local perspective, the coast of Ravenna – a low-lying coastal zone located along the Northern Adriatic Sea in Italy, is among the areas that are subjected to increasing environmental risks such as coastal erosion, storm surge, groundwater and soil salinization. Restoration initiatives have been implemented in some of the protected dune areas to combat against impending risks. This thesis aimed to contribute to the assessment of the dune restoration project in the protected natural area of the Bevano River mouth in Ravenna using UAV monitoring surveys from 2016 to 2021. The restoration measure included two windbreak wooden fences that were installed in front of the dune foot and parallel to the coast to stop wind and facilitate sand deposition and accumulation. Primarily, the objective is to assess the impact of the 2016 restoration project in the dune development in terms of sand volume changes by utilizing the Structure from Motion (SfM) photogrammetry and the Geomorphic Change Detection (GCD) toolset. Next is to establish a systematic workflow for UAV data processing and elevation data analysis that is suitable for sediment volume calculations. Last is to explore the utility of orthomosaic images for vegetation change detection in order to determine other contributing factors to the overall geomorphology of the dune ridge. For the methodology, the UAV topographic survey, coupled with GPS ground survey using Real-time Kinematic (RTK) positioning, were carried out from 2016 to 2021 in order to assess the geomorphological evolution of the area over time. SfM photogrammetry was utilized to generate and classify the point cloud and orthomosaic images for each survey year using Agisoft Metashape Professional. The classified ground points were interpolated in ArcMap to create Digital Elevation Models (DEMs), while the orthomosaic images were utilized to confirm the possible sources of data noise in the model and assess vegetation changes. GPS points and profiles were used to validate the elevation models. The volumetric changes in sediment storage and error analysis were calculated using the DEM of Difference (DoD) approach under the Geomorphic Change Detection (GCD) extension toolbar in ArcMap. The results show that sand accumulation was observed along the dune foot where the wood fences were established. The following changes have also been observed - progradation of the front dune, development of insipient dunes, decrease in slope stoss, decrease of blowout features due to increase in vegetation colonization. There is also an increase in vegetation and debris cover within and near the wood fences. Overall, it can be concluded that the windbreak fence has proven to be an effective intervention to prevent dune erosion since significant geomorphological changes and vegetation colonization have occurred based on the comparison between the 2016 and 2021 data. This is despite numerous factors affecting the overall sediment budget dynamics in the study area. The GCD toolset can be an effective monitoring tool for coastal dunes provided that the sources of uncertainties are well accounted for. In a coastal management perspective, the results of this thesis can supplement in showcasing the importance of implementing sand trapping fences and limiting debris cleaning as nature-based solutions to combat dune degradation along the coastal zones of Ravenna. The proposed systematic workflow in this research can also be explored in creating transferable guidelines to relevant stakeholders in implementing its integrated coastal zone management (ICZM). The manuscript has a total of five (5) chapters. Chapter one includes a comprehensive literature review on the basic principles relevant to coastal dune geomorphology and the gaps that this study would like to fill in. It also includes the information about the scope and area of the research. Chapter two provides the in-depth details about the methodology of the study that includes the data acquisition and processes, the implemented workflow for SfM, DEM creation, quality check and assessment, and vegetation analysis using the high-resolution orthomosaic images. All the results are presented in Chapter three, while the detailed discussions are in Chapter four. Conclusions and recommendations are presented in Chapter five.would also like to thank the Water and Coastal Management (WACOMA) and the Erasmus Mundus Joint Master’s Degree (EMJMD) programs for giving me the opportunity to study in Europe and to widen my research career in the field of coastal management

SPECIALIZATION PROCESS FOR THE BIOENGINEERING SECTOR IN THE MEDITERRANEAN ENVIRONMENT. ECOMED PART II. PROTOCOLS AND CASE STUDIES

O livro apresenta metodologia e protocolos de obras de engenharia natural, assim como casos de estudo de seis países mediterrânico