Wetlands Mapping Methods Research
Wetlands provide innumerable benefits, such as water storage for gradual recharge of aquifers and mitigation of flood impacts, highly biologically productive wildlife habitat and human food sources, and opportunities for recreation. Wetland maps currently used in wetland management and policy efforts are two-dimensional representations of a four-dimensional phenomenon (the three dimensions of space combined with time). Our research focuses on developing novel wetland mapping methods that will take into account temporal dynamics. Specifically, we are investigating newly available data types such as RADAR (Radio Detection and Ranging) and LIDAR (Light Detection and Ranging), both of which show great potential for monotoring temporal variations in wetland diagnostic parameters such as moisture content and hydrologic cycle.
Automated Assessment of Forest Change
Assessing change in forest cover is of critical importance in studying natural and anthropogenic impacts on the environment. However, in spite of the importance of this problem we still lack robust methods to quantify the patterns and effects of deforestation and provide information that can be used for decision making and policy planning purposes. Our research focuses on innovative forest change assessment algorithms that use multi-year time series of bi-weekly global vegetation phenology measurements derived from satellite images. By examining the forest’s phenological response, previously unavailable parameters such as the approximate date the change occurred, the rate of the change (e.g. a sudden forest fire vs. gradual logging), and the extent, speed, and pattern of regrowth can be derived. This approach also has the potential to determine the post-deforestation land use of an area.
Lake Clarity Monitoring
Minnesota has significant water resources in the form of approximately 12,000 lakes with extents greater than 10 acres. Urbanization and chemical use (e.g. fertilizers, pesticides) has negatively impacted the water quality in many Minnesota lakes. Monitoring lake water clarity (an indicator of water quality) is important so that the status and trends of Minnesota's valuable water resources are known. Remotely sensed images are well suited for use in such monitoring due to their large area coverage and frequent revisit times. Our research focuses on developing methods to use satellite image data such as that from NASA's MODIS sensor to monitor interannual changes in lake water clarity.
Impervious Surface Mapping
One of the most significant land uses in terms of impact on the environment is the creation of impervious surfaces such as roads and buildings. The amount of impervious surface in an area affects environmental factors such as the amount and chemical composition of runoff to lakes and streams, the magnitude of the urban heat island effect, the degree of wildlife habitat fragmentation, and the impact on human-perceived values such as aesthetics. Therefore, mapping and monitoring impervious areas is an essential component in managing urban growth. The objective of our research is to develop innovative methods by which vegetation phenology information derived from MODIS image data can be used to accurately map impervious surfaces.
Ecology of Cryptococcus in Sub-Saharan Africa
Fungal menigitis, which is caused by the fungus Cryptococcus neoformans, is the main cause of mortality in AIDS patients in sub Saharan Africa, resulting in approximately 600,000 deaths per year. The means by which humans are exposed to Cryptococcus in sub Saharan Africa is unknown. Identification of the source of Cryptococcus will lead to better guidelines for AIDS patients to reduce their risk of exposure. Our research seeks to identify the ecological niche of Cryptococcus through the analysis of environmental parameters such as water regime, land use, vegetation type, weather patterns, and topographic position.
