Environmental
Impact
Both spatial and temporal considerations are systematically included in BEES. Measured data are recorded on worksheets. This facilitates transformation of data into environmental quality value for each parameter for the "with" and "without" project conditions. To achieve this the following sequential steps are taken.
1. A relative importance value is assigned to the respective elements of the evaluation.
2. This importance value is multiplied by the representative elements of the evaluation.
3. The relevant cells of the worksheet are summed up to arrive at the parameter value.
Parameter value
Where
i = Spatial index
j = Temporal index
Cij = Importance of cell ij
Xij = Measurement in cell ij
n = Number of spatial areas considered
m = Number of time factors considered
Under the premise of BEES 'environmental impact' for each parameter is the product of 'parameter importance' and 'environmental quality'.
The above equation is used in BEES to assess the likely future environment 'without' the project and then 'with' the project. A net improvement or degradation is identifiable by comparing the numerical values under these two situations. A loss in EIU represent an adverse impact on a parameter while a gain in EIU represent beneficial impact. An overall impact evaluation is determined by using the following equation.
Where
EI = environmental impact
(Vi)1 = value in environmental quality of parameter i with project
(Vi)2 = value in environmental quality of parameter i without project
Wi = relative weight (PIU) of parameter i
M = total number of parameters
Warning System
EIA studies should reveal the critical impacts to enable the decision-makers to pay more attention towards parameters and actions requiring greater care. BEES considers each of the 78 parameters to be a potential fragile element of the overall environment. Attention to potential problem areas is drawn by tagging significant adverse impacts with 'major or minor red flags'. Elements of the environment that may be significantly changed in an adverse direction are represented as either a minor or major 'red flag'.
Communication
BEES utilises a summary table for communicating the identified, measured and interpreted impacts. Following three important results of the environmental impact analysis are included in the summary table
1. Net environmental impact measured in EIU.
2. Minor and major 'red flags'.
3. Date needs.
From the above discussion on BEES following salient points may be noted.
1. A pre-decided list of parameters is used to identify impacts. 2. Impacts are measured by specified environmental measurements 3. For the purpose of interpretation of impacts a technique for conversion to a commensurate unit (termed environmental impact unit) is used. 4. A summary sheet displays the results of the environmental impact assessment.
BEES is a detailed, complex and thoroughly quantitative EIA methodology. A fairly detailed guideline is provided for assessing each of the 78 parameters. Complexities such as spatio-temporal considerations are taken into account.
BEES defines an 'without project' situation as 'an expression of the modified current condition of the environment' representing 'the likely future environment without the project'. BEES thus takes care of non-project related changes and attempts to assess the impacts to be caused due to the project.
Replicability of BEES is very high. Although devised for water resource development projects the principle of this methodology can be adopted to develop similar "environmental evaluation system" (EES) for other sectors. Depending on the nature of the project and the environmental settings the number of parameters can be changed. This will however require extensive work to determine PIU and EQ values for each of the parameters before commencement of any project specific EIA study.
An outstanding feature of BEES is its full-scale attempt at quantification. This may however be criticised as 'rough-and-ready and highly controversial' (Warner and Preston 1973). Moreover the treatment of uncertainty and risk are very inadequate and the need for monitoring is not directly considered. An absolute reliance on quantification makes the system inflexible. Resource requirement for BEES is rather high which restrict the use of this approach only to major projects (Jain et al. 1977). Westman (1985) pointed out that application of scalars based on dubious scientific criteria (in many cases) makes BEES a flawed system. At times double counting of environmental parameters are encountered. For example vegetation impacts appear under ecology, aesthetics and human interest. Subjective judgements are often lost to detection by numerical scores. As has rightly been pointed out by Wathern (1984) many subjective elements are subsumed within both the weighting scheme and the value functions. The same feeling was echoed by Bisset (1984): 'the subjectivity involved in these computations is hidden within a spurious objectivity'.
Most of the EIA textbooks give good coverage on BEES. Many EIA articles appearing in journals also give a good account of the methodology.
Both spatial and temporal considerations are systematically included in BEES. Measured data are recorded on worksheets. This facilitates transformation of data into environmental quality value for each parameter for the "with" and "without" project conditions. To achieve this the following sequential steps are taken.
1. A relative importance value is assigned to the respective elements of the evaluation.
2. This importance value is multiplied by the representative elements of the evaluation.
3. The relevant cells of the worksheet are summed up to arrive at the parameter value.
Parameter value
Where
i = Spatial index
j = Temporal index
Cij = Importance of cell ij
Xij = Measurement in cell ij
n = Number of spatial areas considered
m = Number of time factors considered
Under the premise of BEES 'environmental impact' for each parameter is the product of 'parameter importance' and 'environmental quality'.
|
Environmental Impact =
|
Parameter Importance x
|
Environmental Quality
|
|
(EIU)
|
(PIU)
|
(EQ)
|
The above equation is used in BEES to assess the likely future environment 'without' the project and then 'with' the project. A net improvement or degradation is identifiable by comparing the numerical values under these two situations. A loss in EIU represent an adverse impact on a parameter while a gain in EIU represent beneficial impact. An overall impact evaluation is determined by using the following equation.
| Environmental Impact = | Evaluation with Project - | Evaluation without project |
Where
EI = environmental impact
(Vi)1 = value in environmental quality of parameter i with project
(Vi)2 = value in environmental quality of parameter i without project
Wi = relative weight (PIU) of parameter i
M = total number of parameters
Warning System
EIA studies should reveal the critical impacts to enable the decision-makers to pay more attention towards parameters and actions requiring greater care. BEES considers each of the 78 parameters to be a potential fragile element of the overall environment. Attention to potential problem areas is drawn by tagging significant adverse impacts with 'major or minor red flags'. Elements of the environment that may be significantly changed in an adverse direction are represented as either a minor or major 'red flag'.
Communication
BEES utilises a summary table for communicating the identified, measured and interpreted impacts. Following three important results of the environmental impact analysis are included in the summary table
1. Net environmental impact measured in EIU.
2. Minor and major 'red flags'.
3. Date needs.
From the above discussion on BEES following salient points may be noted.
1. A pre-decided list of parameters is used to identify impacts. 2. Impacts are measured by specified environmental measurements 3. For the purpose of interpretation of impacts a technique for conversion to a commensurate unit (termed environmental impact unit) is used. 4. A summary sheet displays the results of the environmental impact assessment.
BEES is a detailed, complex and thoroughly quantitative EIA methodology. A fairly detailed guideline is provided for assessing each of the 78 parameters. Complexities such as spatio-temporal considerations are taken into account.
BEES defines an 'without project' situation as 'an expression of the modified current condition of the environment' representing 'the likely future environment without the project'. BEES thus takes care of non-project related changes and attempts to assess the impacts to be caused due to the project.
Replicability of BEES is very high. Although devised for water resource development projects the principle of this methodology can be adopted to develop similar "environmental evaluation system" (EES) for other sectors. Depending on the nature of the project and the environmental settings the number of parameters can be changed. This will however require extensive work to determine PIU and EQ values for each of the parameters before commencement of any project specific EIA study.
An outstanding feature of BEES is its full-scale attempt at quantification. This may however be criticised as 'rough-and-ready and highly controversial' (Warner and Preston 1973). Moreover the treatment of uncertainty and risk are very inadequate and the need for monitoring is not directly considered. An absolute reliance on quantification makes the system inflexible. Resource requirement for BEES is rather high which restrict the use of this approach only to major projects (Jain et al. 1977). Westman (1985) pointed out that application of scalars based on dubious scientific criteria (in many cases) makes BEES a flawed system. At times double counting of environmental parameters are encountered. For example vegetation impacts appear under ecology, aesthetics and human interest. Subjective judgements are often lost to detection by numerical scores. As has rightly been pointed out by Wathern (1984) many subjective elements are subsumed within both the weighting scheme and the value functions. The same feeling was echoed by Bisset (1984): 'the subjectivity involved in these computations is hidden within a spurious objectivity'.
Most of the EIA textbooks give good coverage on BEES. Many EIA articles appearing in journals also give a good account of the methodology.