Table 4.1 - Assimilative Capacity by ashrafp


									                                    Table 4.1 Assimilative Capacity Assessment Techniques and Tools: Matrix

  S.No.     Environment/ Zone             Algorithm/ Models                                Brier Remarks                                 Description
1.0       Air Environment
          Plain Terrain         Ventilation Coefficient (VC)                 In an airshed assimilative capacity
                                = Mixing Height X Wind Speed                 assessment is based on quantification of air
                                                                             pollutant's removal mechanism. viz.
                                                                             dilution/diffusion, removal by rain/smog         Management Plan proposals are
                                Assimilative Capacity:
                                                                             fog/snow, phase transformation, chemical         based on CPCB standards
                                                                             reaction and attenuation by vegetation. In       promulgated for areas of residential/
                                Maximum allowable pollution                  the plain valley zone only dilution and          rural settlements. Whereas, WHO
                                load is calculated based on detailed         diffusion are the major factors                  standards have been adopted for
                                emission inventory and meteorological                                                         evolving management plans for long
                                data generation using following models:                                                       term developmental proposals

                                Point Source = Valley, Box and ISCST2
                                                                             Based on VC, different zones of air pollution
                                                                             potential are classified.

                                                                             Categories 1, 2 & 3 (i.e. VC < 6000 m2/sec)
                                                                             represent high pollution potential, leading to
                                Area Source = ATDL & Box                     wide spread occurrence of high
                                                                             concentration of pollution

                                                                             Categories 4,5 and 6 (i.e. VC in the range of
                                                                             6000 -12.000 m2/sec) represent medium
                                                                             pollution potential and categories 7, 8 & 9
                                                                             (i.e. greater than 12,000 m2/sec) represent
                                                                             low pollution potential that leads to high
                                Line Source = California                     dilution of pollutants.
                                Source model for highway ATDL & Box
                                model for intracity road
          Hilly Terrain         Air Pollution Sink Potential index           Biological sink forms the major natural          For hilly terrain the standards
                                                                             phenomenon for removal of air pollutants         prescribed for sensitive zone have
                                Pollution attenuation through green zone     from the air basin within hilly terrain          been used
                                can also be used for assimilative capacity   ecosystem because surface wind profile is
                                assessment                                   largely governed by topography

                                Where: X2 = width of green belt,
                                he = effective height of green belt,
                                λ = Pollution attenuation coefficient X1
                                X1 = separation distance between the
                                green belt and pollution source,
                                FD (X1 + X2) and FD (X1) are plume
depletion factors
λ = Kρt Vd /Vc

Where: ρt= foliage surface area density
of single tree, K = ρc/ρt
ρc = foliage surface area density of
green belt
Vd = dry deposition velocity of pollutants
  S.No.     Environment/ Zone             Algorithm/ Models                                Brier Remarks                                  Description
2.0       Noise Environment
                                                                                                                              CPCB ambient noise standards
                                Attenuation through Atmospheric Media        For the acoustic environment assimilative        Leq (dBA)
                                Ae1 = 7.4f2 r/Φ x 10-x dB                    capacity is based on characterization of                      Day        Night
                                where: f = frequency of sound wave,          noise and consideration of sound                 Industrial    75         70
                                Φ = relative humidity                        attenuation so as to ascertain the maximum       Commercial    65         55
                                r = distance between source and receptor     amount of noise load than can be                 Residential   55         45
                                Attention by solid barrier=A+B+C             discharged without causing private public
          Plain Terrain                                                                                                       Silence Zone 50          40
                                Where:                                       nuisance for the designated use of land
                                A=distance between source and barrier        units.
                                B=distance between source and receptor                                                        EPA noise criteria for residential area
                                C=distance source and receptor               In the plain terrain the attenuation is due to   Ldn = 55 dBA
                                                                             solid barriers eg. Buildings/houses              Barriers, vegetation, & air
                                                                             social/avenue forestry etc.                      attenuation forms major factor of
                                Sound levels from various sources.
                                                                                                                              sound attenuation in this region
          Point Sources         Wave Divergence                             The vegetation in the form of forests, tea
                                Lp2 = Lp1-20 log r2/r1-Ae1.2                garden etc. are major attenuators of sound                        Day       Night
                                Ae1.2=excess attenuation along the path r2-                                                   Leq (dBA)       50        40
                                                                                                                              Attenuation by Vegetation (dB) at
          Area Sources          Ldn: day-night noise levels                                                                   1000Hz frequency
                                                                                                                              Item       Path Length (m)
                                Ldn=                                                                                                      10   50     100
                                10 log {1/24[15(10ld/10)+9(10ln+10/10)]}
          Line Sources          Federal Highway Model                                                                         Shrubs       2.3   11.5     23
                                Leq (h) total = 10 log [10Leq A/10 + 10Leq                                                    Trees
                                      + 10Leq HT/10]                                                                          Forests      1.0   5.0     10.0
          Hilly Terrain         Attenuation by Grass, Shrubs or trees
                                Aes = (0.18 log f –0.31) r

                                Attenuation by forests
                                Aef = 0.01 f1/3 r
                                f = frequency of sound (Hz)
                                r = path length through shrubbery or over
                                grass (m)
   S.No.    Environment/ Zone            Algorithm/ Models                                    Brier Remarks                                Description
3.0        Water Environment    River DO-BOD nutrient interaction model,       The river water quality model QUAL2E can       Classification for river as per CPCB
                                QUAL2E                                         simulate upto 15 water quality constituents    guidelines.
                                                                               under steady state as a dynamic model. It
           Plain Terrain
                                Assimilative capacity of given river stretch   assumes that the major transport
                                for the minimum river flow condition is        mechanisms advection and dispersion are
                                estimated for any desired water quality        significant only along the main direction of
                                parameters/goals e.g. BOD, DO etc. by          flow. The model includes the major
                                computing maximum load the river can           interactions of the nutrient cycles (N&P),
                                assimilate without deteriorating the river     algae production, benthic oxygen uptake,
                                water quality beyond the permissible           atmospheric aeration and their effects on
                                threshold as specified for the designated      the total oxygen balance. Coliforms and
                                usages.                                        arbitrary non-conservative constituents are
                                                                               modeled as non-conservative decaying

                                As there is no major perennial surface water source in the hill region, no separate modeling has been carried out. QUAL2E may
           Hilly Terrain
                                also be applied for fast flowing river.
   S.No.     Environment/ Zone              Algorithm/ Models                                Brier Remarks                              Description
4.0        Land Environment      Assimilative Capacity                       Assimilative Capacity of land environment is    Adsorption, degradation,
                                 = maximum allowable                         calculated by estimation of degradation and     immobilization, precipitation and
                                 pollution load                              assimilation potential of soil-plant system     plant uptake are major natural
                                                                             for critical land limiting constituents (LLC)   phenomena for removal of pollutants
                                                                                                                             in land component
                                 Major reactive parameters                   Degradation, adsorption and precipitation
                                 Soil                                        are major phenomenon in determining the
                                 -Physical-Hydraulic conductivity, texture   assimilative capacity.
                                 and structure
                                 -Chemical-soil CEC, organic matter, pH,
                                 -Microbial-bacteria, actinomycets, fungi

                                 Plant Canopy                                Efficiency of biological barrier system of
                                 -Pollutant uptake capacity of plants.       plants in controlling the absorption of
                                                                             pollutants or assimilation of pollutants
                                                                             without showing toxicity is significant
   S.No.     Environment/ Zone              Algorithm/ Models                                Brier Remarks                               Description
5.0        Biological            Importance value index                       IVI which is combination of three indices      Plant leaves function as efficient gas
           Environment           IVI = (RD + RDOM + RF) / 3                   viz. density, dominance and frequency is an    exchange systems having large
                                 Where                                        appropriate measure for assessing the          surface area bearing stomata pores.
                                 RD = Relative Density                        overall significance of a species in a given   Therefore, differences in frequency
                                 RDOM = Relative Dominance                    eco system. Thus it gives information about    and size of stomata play an important
                                 RF = Relative Frequency                      the most importance species in the samples     role in determining the assimilative
                                                                              system.                                        capacity of a particular vegetation
                                 Sink Potential Index                                                                        structure of a region
                                                                              SPI has been constructed as an appropriate
                                 SPI = (n2 – n1)/n2 X S.D.   (n)
                                                                              measure of site-specific sink potential of a
                                                                              dominant species with respect to air
                                 Where                                        pollutants with in the ecosystem.
                                 n2 = Stomatal Density of controlled plant
                                 n1 = Stomatal Density of /polluted plant
                                 SD (N) = Stomatal Density of Species under

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