Deltas are complex environmental systems resulting from the coevolution of water, sediment, and nutrients. They are often densely populated, rich in ecosystem activity and economic resources, and vulnerable to natural and human perturbations. A quantitative description of the morphology of deltas and their dynamics is fundamental to address how they react to changes in climate forcing and human pressure. This project proposed to advance fundamental research on deltas by approaching them as spatio-temporal evolving systems in which spatial organization and process dynamics are intricately connected and give clues to system health and vulnerability to perturbations, important components for any adaptive management strategy.

The main goal of this project was to develop a research/educational framework, called the Delta Connectome, based on the general idea of a delta as a directed network of connected paths (physical, functional, and conceptual paths of process coupling) which interact continuously at a broad range of space and time scales and dictate system response to change. In particular, this project addressed the following goals:  (1) Quantification of delta network structure (topology and geometry of channels and islands) to identify the signature of processes responsible for delta formation and evolution, vegetation, and anthropogenic disturbance; (2) Development of image processing based tools for the automatic extraction of delta networks and channel and island properties from remotely sensed data; (3) Identification of the environmental controls on channel network and shoreline dynamics; (4) Quantification of strength, directionality, statistical significance, and scale of couplings among key variables and the effect of anthropogenic disturbance and change on such couplings.

The Delta Connectome project introduced the concept of connectivity in deltaic systems and analyzed it in all aspects: (i) structural, (ii) functional, and (iii) process connectivity. The intellectual merit of this work included the design and application of Innovative image processing tools to automatically extract delta network structure from remotely sensed data. The delta network structure was analyzed statistically and descriptive delta- specific metrics were identified. The connectivity analysis highlighted the leakiness of delta networks, which is a fundamental property of these systems for the maintenance of the delta plain. An information theory approach was developed to quantify strength, directionality, scale, and statistical significance of dynamic couplings among key variables with measures such as transfer entropy. As a result, a delta process network was built and used to quantify how environmental fluxes are transported through the delta network, how several processes interact, how couplings vary during delta evolution and in response to change and disturbance, and how to validate numerical models.

The project developed also an educational activity, in collaboration with the UTeach Engineering Program, directed to high school students. In this unit, remote sensing imagery and visual arts are used to present environmental problems such as coastal restoration and the effect of humans and climate on the natural environment.

This project has developed four open source tools for the analysis of remotely sensed imagery, the extraction of water masks and channel networks, and the analysis of delta networks through time. The advances made within this project have been widely disseminated at national and international conferences and in peer-reviewed journals. 4 MS students and 4 PhD students have benefited from participation in this project.

Last Modified: 08/27/2020
Modified by: Paola Passalacqua