I conduct local to global scale research on a wide range of environmental themes
The impacts of global warming are, sadly, all around us. These images, captured by the MODIS instruments aboard Terra and Aqua satellites, illustrate the particularly severe melt of Greenland’s ice sheet.
This animation shows Greenland’s albedo over 2019, from mid-March through early-October. Notice in particular the melt progression along the western coast.
Albedo is a fundamental physical measurement of Earth’s surface, representing the proportion of sunlight reflected back into space. This image shows satellite-derived albedo over part of the NASA ABoVE study domain, based on observations from the MODIS sensors aboard the Aqua and Terra Satellites.
High Res Canopy Mapping
Lidar and High Resolution Image Segmentation
Urban Tree Canopy Mapping and Change Detection
I created a high spatial resolution (~1 m) tree canopy map for Worcester, MA. This type of map is essential in quantifying and understanding the benefits of the so-called green infrastructure.
Mapping Urban Heat islands
Land Surface Temperature (LST) derivation from Landsat TM, ETM+, and OLI/TIRS.
Urban heat island dynamics
I investigated the seasonal and inter-annual trends in Land Surface Temperature (LST), in order to determine the impact of urban tree canopy loss.
Time series analysis
I used Seasonal Trends Analysis, a component of the TerrSet geospatial software suite, to quantify shifts in the magnitude and seasonal timing of LST following an episode of extensive tree loss in Worcester, MA.
Urban Tree mortality
Temperature mitigation is one important ecosystem service delivered by urban trees. Additional important services include: water runoff control, air and water filtration, carbon uptake and storage, and cultural/aesthetic values. It is critical to understand the drivers of tree mortality, particularly during the first five years after planting; this knowledge will allow us to create and maintain more net benefit from the urban forest. I have investigated drivers of juvenile tree mortality using machine learning and statistical modeling.
Species dispersal modeling
Asian Longhorned Beetle (ALB) movement modeling using circuit theory dispersal
Invasive species dispersal
The Asian Longhorned Beetle (ALB) is one of several exotic pest species currently damaging or threatening North American forests. Containment and mitigation of these species relies in part on accurate predictions of their movement. I have modeled the movement of ALB using circuit theory, which models species movements as the culmination of many random walks.
Spectral Mixture Analysis
Subpixel unmixing of Landsat imagery, combined with decision tree classification methods.
artisanal/Small-scale gold mining Detection
Artisanal/Small-Scale Mining (ASM) poses a proximal and downstream environmental and human health risk. I have used moderate and high resolution satellite imagery to detect this activity, which can help management and governance in remote, inaccessible regions.