The architecture and prototype implementation of the Model Environment system

International audienceAn approach that simplifies software development of the model based decision support systems for environmental management has been introduced. The approach is based on definition and management of metadata and data related to computational model without losing data semantics and proposed methods of integration of the new modules into the information system and their management. An architecture of the integrated modelling system is presented. The proposed architecture has been implemented as a prototype of integrated modelling system using. NET/Gtk{#} and is currently being used to re-design European Decision Support System for Nuclear Emergency Management RODOS (http://www.rodos.fzk.de) using Java/Swing

RivWidthCloud: An Automated Google Earth Engine Algorithm for River Width Extraction from Remotely Sensed Imagery

The wetted width of a river is one of the most important hydraulic parameters that can be readily measured using remote sensing. Remotely sensed river widths are used to estimate key attributes of river systems, including changes in their surface area, channel storage, and discharge. Although several published algorithms automate river network and width extraction from remote sensing images, they are limited by only being able to run on local computers and do not automatically manage cloudy images as input. Here we present RivWidthCloud, a river width software package developed on the Google Earth Engine cloud computing platform. RivWidthCloud automatically extracts river centerline and widths from optical satellite images with the ability to flag observations that are obstructed by features like clouds, cloud shadows, and snow based on existing quality band classification. Because RivWidthCloud is built on a popular cloud computing platform, it allows users to easily apply the algorithm to the platform's vast archive of remote sensing images, thereby reducing the users' overhead for computing hardware and data storage. By comparing RivWidthCloud-derived widths from Landsat images to in situ widths from the U.S. and Canada, we show that RivWidthCloud can estimate widths with high accuracy (root mean square error: 99 m; mean absolute error: 43 m; mean bias:-21 m). By making RivWidthCloud publicly available, we anticipate that it will be used to address both river science questions and operational applications of water resource management

Planetary-scale surface water detection from space

This thesis studies automated methods of surface water detection from satellite imagery. Multiple existing methods are explored, discussed, and some new algorithms are introduced to allowvery accurate detection of surface water and surfacewater changes. Themethods range in applicability from the local level to global, and from detecting high-frequency changes to low-frequency changes. Their trade-offs regarding the accuracy and applicability of the surface water detection methods are also discussed.Several applications are presented to test the introduced methods. One of the studies focuses on a long-term global surface water change detection over the past 30 years at 30m resolution. The other application looks at the generation of a permanent surface water mask for Murray-Darling River Basin in Australia. Additionally, an in-depth validation for a small reservoir in California, USA is presented, to demonstrate performance of the new methods.The algorithms discussed in the thesis were applied and tested to process both passive optical multispectral and active Synthetic Aperture Radar (SAR) satellite data. Combining data fromall freely available satellite sensors requires harmonizations of the satellite data, but also, significant computing resources. In this thesis, Google Earth Engine parallel processing platformwas used to performmost of the experiments.We will see, thatwhen studying surface water dynamics, the best results can be achieved by combining discriminative and generative methods of surface water detection. This way, the surface water can also be detected from satellite images where surface water is only partially visible.In the thesis, top-of-atmosphere reflectance images are used to detect surface water. The atmospheric correction is not required when dynamic local thresholding methods are used to detect surface water.Water Resource

Erratum to: The State of the World’s Beaches (Scientific Reports, (2018), 8, 1, (6641), 10.1038/s41598-018-24630-6)

Erratu

The State of the World's Beaches

Coastal zones constitute one of the most heavily populated and developed land zones in the world. Despite the utility and economic benefits that coasts provide, there is no reliable global-scale assessment of historical shoreline change trends. Here, via the use of freely available optical satellite images captured since 1984, in conjunction with sophisticated image interrogation and analysis methods, we present a global-scale assessment of the occurrence of sandy beaches and rates of shoreline change therein. Applying pixel-based supervised classification, we found that 31% of the world’s ice-free shoreline are sandy. The application of an automated shoreline detection method to the sandy shorelines thus identified resulted in a global dataset of shoreline change rates for the 33 year period 1984–2016. Analysis of the satellite derived shoreline data indicates that 24% of the world’s sandy beaches are eroding at rates exceeding 0.5 m/yr, while 28% are accreting and 48% are stable. The majority of the sandy shorelines in marine protected areas are eroding, raising cause for serious concern

Benefits of the use of natural user interfaces in water simulations

The use of natural user interfaces instead of conventional ones has become a reality with the emergence of 3D motion sensing technologies. However, some problems are still unsolved (for example, no haptic or tactile feedback); so this technology requires careful evaluation before the users can benefit from it. We argue, that the best benefits can be achieved when these natural user interface technologies are combined with classical computer interaction devices such as mouse and keyboard. In our demonstration, we will show how the LEAP Motion controller can be applied in environmental modeling when combined with the shallow water flow model engine D-Flow Flexible Mesh and a 3D scientific visualization library. We will analyze where the new approach provides benefits compared to the classical computer input devices such as mouse and keyboard. We will also demonstrate a number of visualization and interaction techniques used during manipulation of model input data (bathymetry, roughness, etc.) or during exploration of the results of a running morel.Hydraulic EngineeringCivil Engineering and Geoscience

Functional coverages

A new Application Programming Interface (API) is presented which simplifies working with geospatial coverages as well as many other data structures of a multi-dimensional nature. The main idea extends the Common Data Model (CDM) developed at the University Corporation for Atmospheric Research (UCAR). The proposed function object model uses the mathematical definition of a vector-valued function. A geospatial coverage will be expressed as a vector-valued function whose dependent variables (the vector components) are fully defined by its independent variables (the coordinates). Our goal is to provide an API using a terminology and an object model that is both appealing to computer scientists and numerical modelers and is flexible enough to enable defining data structures for a wide range of applications. Examples of such data structures can be: wind velocity as a continuous variable defined along the channels in a river network. Precipitation data defined as a time-dependent variable on a set of sub-catchments of a drainage basin, preserving association with sub-catchment features. The new object model provides a basis for both continuous and discrete coverages including non-geospatial data structures such as time series. Different storage models for variables are implemented, based on the Network Common Data Format (NetCDF), the Geospatial Data Abstraction Library (GDAL) and memory. The API is available as set of open source libraries developed in C# consisting of a multi-dimensional arrays library; a scientific data structures library defining variables, functions, units of measure; a geospatial extensions library built on top of GeoAPI.NET and NetTopologySuite, defining specialized coverages: network coverage, feature coverage, regular grid coverage, and unstructured grid coverage.Hydraulic EngineeringCivil Engineering and Geoscience

Model Message Interface

<p>The Model Message Interface (MMI): a draft protocol for serializing messages between numerical models and between numerical modesl and other programs.</p