optimal sensor placement and measurement of wind for water quality studies in urban reservoirs
Post on 10-Feb-2016
50 Views
Preview:
DESCRIPTION
TRANSCRIPT
Optimal Sensor Placement and Measurement of Wind for Water
Quality Studies in Urban ReservoirsWan Du, Zikun Xing, Mo Li,
Bing sheng He, Lloyd Hock Chye Chua, Haiyan MiaoIPSN 2014
Introduction • A healthy aquatic ecosystem and water quality monitoring is essential
for good understanding of the water resources and social security
• The distribution of wind stress on the surface of a lake can significantly impact water hydrodynamics and affects water quality.
• Existing limnological studies
Introduction A limited number of wind sensors =>the wind direction and speed=>derive the wind distribution over the entire Marina reservoir
The accurate wind distribution is critical for studying and predicting the water quality.
Introduction• Gaussian distribution & Gaussian Process (正态分布 )• entropy /mutual information
Our study• Wind directions do not follow Gaussian distribution over time.• Existing approaches require prior knowledge to train GP.• The water quality has sensitivity to the wind input at different locations.
Problem statement• Divide Marina Reservoir into small grids of 20m*20m.• V: all locations. (More than 5k)• The observations at each location vi can be modeled as a random
variable Xi.• A: optimal sensor placement.
Common approaches => GP
The GP assumption, however, does not hold for winddirections over a large time period in our applicationPrior-knowledgeÞ more than 5k monitors
Consider the water quality modeling
Approach overview• Divide into two monsoon seasons and two intermonsoon seasons
• In each segment, select optimal sensor locations
• Combine the results
CDF modeling => wind distributionsELCOM-CAEDYM =>quantify the sensitivity of water quality to wind input at different locations
Approach overview
Monsoon based time series segmentation• Time series segmentation algorithm• Maximum likelihood
• Result analysis
CFD Modeling• Inputs: • atmospheric flow • topography information of
the land surface
• Cannot provide instant wind distribution
CFD Modeling• 16-point compass rose• 10 gradually incoming speeds
=>160 independent surface wind distributions
Divide the historical wind data into 160 segments.
Sensor placement• Obtain a GP of wind for each season• Heuristic algorithm can be used to find optimal locations. (entropy)
• Transformation of Uniform Distribution• Sensor Placement for the Whole Year
• Sensitivity of water quality
Spatial Prediction
Deployment and evaluation
top related