Preprints
Filtering by Subject: Earth Sciences
GLOBAL WATER TRANSFER MEGAPROJECTS: A SOLUTION FOR THE WATER-FOOD-ENERGY NEXUS?
Published: 2018-09-07
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Globally, freshwater is unevenly distributed, both in space and time. Climate change, land use alteration, and increasing human exploitation will further increase the pressure on water as a resource for human welfare and on inland water ecosystems. Water transfer megaprojects (WTMP), i.e. large-scale engineering interventions to divert water within and between catchments, represent an approach in [...]
Effects of estuarine mudflat formation on tidal prism and large-scale morphology in experiments
Published: 2018-08-31
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Human interference in estuaries has led to increasing problems of mud, such as hyper‐turbidity with adverse ecological effects and siltation of navigation channels and harbours. To deal with this mud sustainably, it is important to understand its long‐term effects on the morphology and dynamics of estuaries. The aim of this study is to understand how mud affects the morphological evolution of [...]
Mapping and Monitoring Rice Agriculture with Multisensor Temporal Mixture Models
Published: 2018-08-31
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Other Earth Sciences, Other Environmental Sciences, Physical Sciences and Mathematics, Soil Science
Rice feeds more humans than any other crop on Earth. Accurate prediction of the timing and volume of rice harvests therefore has considerable global importance for food security and economic stability, especially in the developing world. Optical and thermal satellite imagery can provide critical constraints on the spatial extent of rice planting and the timing of rice phenology. We present a [...]
Why does Amazon precipitation decrease when tropical forests respond to increasing CO2?
Published: 2018-08-30
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Earth system models predict a zonal dipole of precipitation change over tropical South America, with decreases over the Amazon and increases over the Andes. Much of this has been attributed to the physiological response of the rainforest to elevated CO2, which describes a basin-wide reduction in stomatal conductance and transpiration. While robust in Earth system model experiments, details of [...]
A mathematical morphology approach to the identification of drought events in space and time
Published: 2018-08-30
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics, Water Resource Management
Drought events occur worldwide and possibly incur severe consequences. Trying to understand and characterizing drought events is of primordial importance in order to improve the preparedness for coping with future events. In this paper, drought events are characterized by exploiting their spatio-temporal nature. Operators borrowed from mathematical morphology are applied to represent drought [...]
Mechanistic coupling of social and biophysical models of water management through agent typologies
Published: 2018-08-29
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Modeling the coupled social and biophysical dynamics of water resource systems is increasingly important due to expanding population, fundamental transitions in the uses of water, and changes in global and regional water cycling driven by climate change. Models that explicitly represent the coupled dynamics of biophysical and social components of water resource systems are challenging to design [...]
Diatom evidence of 20th Century ecosystem change in Lake Baikal, Siberia
Published: 2018-08-29
Subjects: Earth Sciences, Physical Sciences and Mathematics
Lake Baikal has been experiencing limnological changes from recent atmospheric warming since the 1950s, with rising lake water temperatures, reduced ice cover duration and reduced lake water mixing due to stronger thermal stratification. This study uses lake sediment cores to reconstruct recent changes (c. past 20 years) in Lake Baikal’s pelagic diatom communities relative to previous 20th [...]
Climate Change and Curtailment: Evaluating Water Management Practices in the Context of Changing Runoff Regimes in a Snowmelt-Dominated Basin
Published: 2018-08-28
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Climate change directly affects the hydrologic cycle in mountainous watersheds, which has consequences for downstream users. Improved water projections under diverse potential climate futures are critical to improving water security and management in these watersheds. The hydrologic science researchers and water resource managers, however, often focus on different metrics of flow regimes in [...]
Diatom community responses to long-term multiple stressors at Lake Gusinoye, Siberia
Published: 2018-08-28
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Global freshwater systems are threatened by multiple anthropogenic stressors via impacts on ecological structure and function necessary to maintain their health. In order to properly manage freshwater ecosystems, we must have a better understanding of the ecological response to human‐induced stressors, especially in multiple stressor environments. When long‐term observational records are scarce [...]
Earthquake Swarms and Slow Slip on a Sliver Fault in the Mexican Subduction Zone
Published: 2018-08-25
Subjects: Earth Sciences, Geophysics and Seismology, Life Sciences, Physical Sciences and Mathematics
The Mexican Subduction Zone is an ideal location for studying subduction processes due to the short trench-to-coast distances that bring broad portions of the seismogenic and transition zones of the plate interface inland. Using a recently generated seismicity catalog from a local network in Oaxaca, we identified 20 swarms of earthquakes (M<5) from 2006-2012. Swarms outline what appears to be [...]
A Review of Machine Learning Applications to Coastal Sediment Transport and Morphodynamics
Published: 2018-08-23
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
A range of computer science methods termed machine learning (ML) enables the extraction of insight and quantitative relationships from multidimensional datasets. Here, we review the use of ML on supervised regression tasks in studies of coastal morphodynamics and sediment transport. We examine aspects of ‘what’ and ‘why’, such as ‘what’ science problems ML tools have been used to address, ‘what’ [...]
DEM-based Geomorphological Mapping and Landforms Characterization of a Tropical Karst Environment in Southeastern Brazil
Published: 2018-08-23
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
This work presents a 1:10,000 geomorphological mapping of an area in southeastern Brazil, based on morphometric analysis of Digital Elevation Models (DEMs), while classical methods focus on photo interpretation. Data derived from the DEM include elevation, slope gradient, slope aspect, vertical and horizontal curvatures, amplitude, elongation and wavelength of landforms. These parameters were [...]
A calibration workflow for coastal dune models
Published: 2018-08-21
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Numerical models of coastal dune growth encode feedbacks and nonlinearities between sediment transport and plant growth. The range of processes and tunable parameters involved make model calibration an important step when using models for prediction. In this paper we outline a method to calibrate models of coastal dune formation and describe the process from end to end. The first step is [...]
Controls of basement fabric on rift coupling and development of normal fault geometries: Insights from the Rukwa – North Malawi Rift
Published: 2018-08-20
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Rukwa Rift and North Malawi Rift Segments (RNMRS) both define a major rift-oblique segment of the East African Rift System (EARS), and although the two young rifts show colinear approaching geometries, they are often regarded as discrete rifts due to the presence of the intervening Mbozi Block uplift located in-between. This problem has been complicated by the dominance of the Rungwe volcanic [...]
Using polygonal layer-bound normal faults as tools to delimit clastic reservoirs in the Levant Basin offshore Lebanon
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure
The Levant Basin offshore Lebanon contains an array of layer-bound normal faults in the Oligo-Miocene units. The faults are believed to have nucleated in soft-grained sediments similar to polygonal fault systems worldwide, and as a result are influenced by lithological heterogeneities in the host rock unit. We used 3D seismic data and amplitude extraction from offshore Lebanon to map deepwater [...]