Environmental Pollution Monitoring and Control Systems - Environmental - Environmental Protection Agency
POLLUTION SOURCE DIFFUSION MONITORING AND SIMULATION
The research on the diffusion of radioactive pollutants and the corresponding early warning mechanism is a difficult problem in the world. The nuclear power plants under operation and construction in China are located in coastal areas, and the meteorological and topographic conditions are complex, which brings great challenges to the early warning of nuclear proliferation.
The main meteorological conditions affecting pollutant diffusion are atmospheric stability and three-dimensional wind field. The conventional weather stations and numerical prediction can not accurately realize the monitoring and simulation of small-scale wind field. The emergence of laser remote sensing equipment provides a new direction for solving this problem.
Combined with advanced diffusion models such as LPDM, high-precision terrain data and remote sensing lidar monitoring data, pollution source diffusion simulation can be carried out, and such information as pollution height, diffusion time and leakage intensity can be freely selected.
Applicable scenarios: chemical leakage, forest fire, nuclear pollution diffusion, major pollution explosion accidents, etc.
MONITORING OF DUST TRANSPORT & DYNAMIC MECHANISM OF DUST RISING AND SETTLEMENT
Programme overview
The dust rising, transport and settlement all depend on the wind. The sand rising condition is closely related to the critical friction velocity u*t. In the process of transport, the dust will move with the wind, and the dynamic settlement of sand dust is related to the vertical velocity. When the subsidence movement is obvious, the dust settlement is also obvious. Different types of atmospheric boundary layer structure have different effects on sediment deposition. Through the signal-to-noise ratio (SNR), horizontal wind speed and vertical velocity, lidar can detect the process of dust rising, transportation and settling. As one of the main lidar partners for 'one belt, one road' lidar network in China, Leice has participated in the construction of the northwest sand dust observation network.
Features of the scheme
The 3D lidar is used to scan the three-dimensional images at different heights. The extinction coefficient and backscattering coefficient of aerosols at different heights are calculated by using the aerosol parameter calculation method. The types and sizes of aerosols are distinguished by calculating the lidar ratio. The deposition and transport fluxes of aerosol particles are calculated according to the distribution of aerosols in different space and time.
REGIONAL MOBILE WIND MEASUREMENT
Programme overview
Based on its advanced detection principle, the wind lidar is greatly reduced in size. It can be placed on a vehicle-mounted platform for navigation monitoring. Through advanced attitude adjustment algorithms, it can realize the function of measuring while driving, which greatly expands the application area of the lidar. By round-trip navigation monitoring along the urban pollution transmission channel, the pollutant information on the transmission path can be tracked and monitored, and the transmission path and range can be determined.
Features of the scheme
Because the vehicle platform is unstable, the direction of laser beam deviates from the set direction during lidar measurement, resulting in the deviation of wind speed, wind direction and atmospheric boundary layer height. Whilst, the motion speed of the vehicle itself will be superimposed on the measured radial velocity, resulting in wind speed measurement error. The vertical wind speed requires high resolution, especially affected by the attitude of the vehicle body. Therefore, the influence of the vehicle’s navigation attitude can not be ignored. The attitude correction of the original data is needed to obtain more accurate data products. Leice has mastered the core algorithm of attitude correction for mobile observation. Through real-time correction of heading angle, pitch angle and roll angle, the true wind data in the moving process can be obtained.
