Jefferson Project: Use Case Driving Questions

Printer-friendly version

The project addresses concerns from a diversified number of stakeholders. Use cases are used to translate these concerns into actionable questions that should be addressed by the underlying infrastructure, sensor network and models in support of the project. Below, we group some of project's use cases according to the group of stakeholders raising concerns about Lake George's sustainability.


1. Scientific Use Cases


1.1. RPI-Wide Use Case Questions

Nutrients


  • Where do nutrients enter the lake, in what amounts and what form (soluble, etc.), and how do the inputs vary seasonally? What is the form of these nutrients (soluble, particulate, organic, inorganic)? What layer do these nutrients spread in the lake (thermocline; below thermocline, from groundwater, surface, etc.)?
  • After large scale episodic events what are the impacts of total suspended solids on habitat for invasive species, delta formation and nutrient loading?
  • Assuming future loading from increased development combined with changes in climate, how could nutrient loading be limited (e.g. upgrade nitrogen removal at LG WWTF and septic system upgrades)?
  • What is the spatial variation and form of the nutrients (available or in biomass) in the lake both vertically and horizontally? How fast is nutrient uptake?
  • Construct a better nutrient budget for the lake (including P, N, Si, C and Ca). Differentiate between external point sources, non-point sources, and internal loading from sediment. Also, include uptake by algae and deposition back into the sediments versus nutrients being transported downstream. Assess how changes in this loading can impact the lake.
  • Construct a calcium budget for the lake with the specific goal of determining the impact of Asian clams and Zebra mussels.
  • What percent of the phosphorus budget is the internal cycling of phosphorus and how will this relationship change with more eutrophication and therefore more hypoxic release in the hypolimnion?

Nutrient Flux to Primary Producers


  • What is the detailed temporal and spatial variation of chlorophyll a, other photosynthetic pigments and individual algal species? How does algal growth relate to the availability of the nutrients in the lake (horizontally and vertically)? Is the fall algal bloom related to the mixing in the lake and entrainment of nutrients from the hypolimnion? How does algal growth and die-off affect reduced dissolved oxygen levels in the deepest reaches of the lake?
  • How do the nutrients influence algal distribution, and hence lake clarity?
  • Is P the key nutrient or do N, Si or C control algal abundance and community dynamics under certain scenarios?
  • How have benthic plant (algae & macrophyte) communities changed since surveys were last conducted in the 1980s and 90’s?
  • How have nitella meadows (macroalgae) changed relative to nutrient loadings overtime?
  • What are the driving variables for any observed changes (invasive species, nutrients, transparency, contaminants, etc.)?
  • How has the lakes’ phytoplankton population changed over time relative to other chemical and physical changing conditions? What are the driving variables for this change (invasive species, predation, nutrients, transparency, contaminants, etc.)?
  • What are the relative contributions of primary productivity from macrophytes, macroalgae and algae?

Energy Flux Through Food Web


  • How does the lake’s current zooplankton community compare with historical survey results?
  • How are invasive species (e.g. spiny waterflea, Asian clams, etc.) altering the food web structure?
  • Has introduction of the spiny waterflea affected the diurnal vertical migration of the zooplankton population and if so does that have ecosystem level altercations?
  • What are the current standing stocks of forage fish species (in particular rainbow smelt and Cisco)? What are the standing stocks of fish at all trophic levels (in littoral and pelagic zones)?
  • How does the lake’s carrying capacity for piscivorous game fish vary with (1) the proportion of total phytoplankton primary productivity associated with diatoms vs cyanobacteria, (2) zooplankton and (3) the sizes of rainbow smelt and Cisco standing stocks? What is the relative importance of grazing versus nutrient availability in controlling food web dynamics? Does this change seasonally and/or with the introduction of invasive species?
  • How has the increased nutrient load affected the benthic community?

Invasive Species


  • What are the impacts of invasive species on food web structure and dynamics?
  • What are the effects on chemistry, phytoplankton (including epiphytic algae) zooplankton, as well as direct and indirect effects on larger organisms?
  • Are there potential natural biological controls (predators) for Asian clams than can help to manage their populations?

Salt Based Questions

  • How does the circulation of the lake change with salt concentrations, intensity & frequency of atmospheric deposition events, increasing temperature, lack of winter ice cover, and changing duration of thermal stratification?
  • How critical are salt concentrations in the lake versus streams and groundwater?
  • What is the residence time of the hypolimnetic and epilimnetic compartments of each major basin? How does the bathymetry of the Narrows and the other sub-basins affect this interaction?
  • What are the current impacts of salt on phytoplankton, algae, zooplankton, benthos, etc. in the lake, streams and soils? What are the effects of salt on soil processes?
  • If a salt alternative was used, what would be the impact ?
  • What is the impact of salt on the primary producers? What are the impacts of individual and combined nutrients/chemicals?

Wetlands


  • What is the impact of an artificially constructed wetland (Westbrook) on Lake George water quality?
  • Impact on primary succession on several levels of the ecosystem?
  • Impact on nutrients and metals?
  • Does this provide a new methylation source for mercury in the watershed?

1.2. Run-off Use Case

The Impacts of Salt


  • Humans: EPA limits at 20 ppm sodium, 250 ppm chloride
  • Fish: affected at 250 pm, LD50 at 6743 ppm
  • Algae: critical level at 12 ppm
  • Associated with loss of abundances and diversity
  • Degrades habitat, leads to success of non-native species

Salt in Lake George


SaltLakeGeorgeGraph.png

  • 9,000 tons applied annually
  • lake salt levels have doubled in last 30 years

Salt and The Seasons


  • Salts accumulate while ground is frozen
  • Accumulation is released during snowmelt
  • Developed streams: exceed 1000 ppm upon snowmelt
  • Pristine streams: typically 2 ppm

The Questions


  • Is there a significant seasonal difference in stream salt concentration response to a precipitation event?
  • What are the current impacts of salt on phytoplankton in the lake and streams?
    • How does the circulation of the lake change with salt concentrations?
    • How are the current impacts of lake circulation changes on phytoplankton?

SaltLakeGeorgeInterested.png




2. Sensor Network Management Use Cases

Retrieving Agent Information


  • List all things of type prov:Agent
  • List all things of type hasneto:Configurator
  • List all things of type foaf:Organization
  • List people and their organizations
  • List people working for RPI’s DFWI
  • List organizations with sub-organizations
  • Name people working for RPI

Retrieving Sensor Information


  • List all things of type hasneto:Instrument
  • List the physical features and the characteristics of these features that are/will be measured in the Jefferson Project
  • List the physical features, the characteristics of these features, and the sensors used to measure these characteristics in the Jefferson Project
  • List sensors that are currently deployed
  • List sensors that are currently not deployed
  • List sensors that are currently deployed and active
  • List available platforms
  • List available platforms and the sensors deployed at each platform
  • If sensor S is deployed, list its configuration parameters
  • If sensor S is deployed, list the values assigned to its configuration parameters
  • If sensor S is deployed, list the agent responsible for deploying it
  • If sensor S is deployed, list the agent responsible for its configuration


3. Data Access Use Cases

Data Capabilities Questions


  • List datasets associated with each physical feature characteristic measured in the Jefferson Project
  • List datasets generated by sensors that are currently deployed
  • List datasets generated by sensors that are currently deployed and active

Spatial Queries


  • List datasets by sensors when deployed at platform P
  • List datasets generated by sensor S while deployed at platform P
  • List datasets measured at latitude LAT and longitude LONG

Temporal Queries


  • List datasets generated on 01/01/14
  • List datasets generated on 01/01/14 at 1:00 pm
  • List datasets generated by sensor S on 01/01/14 at 1:00 pm