Application of Information Entropy to Assessment Environmental …
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ecosystem conservation and social, economic, institutional and environmental subsystems into a single system (Ni et al. 2012). In this context, hydrographic basins
are a natural unit or unique system that allow for this integration (Tundisi 2008;
Guidolini et al. 2018a).
Some global assessment methods use subjective weights to calculate subsystem
weights, such as the AHAS—Analytic Hierarchy Process (Saaty 2013), ARAS—
Additive Ratio Assessment (Zavadskas et al. 2010) and ANP—Analytic Network
Process (Carlucci 2010), among others. These methods present certain drawbacks,
such as a non-standardized rating system and results that may be inconsistent with
actual data due to subjective weights. On the other hand, so-called objective methods
disregard the preferences of the decision-maker from statistical models and are based
on the inherent amount of information provided by the indicators (Toumi et al. 2017).
Among objective methods, the entropic weight method is highlighted in several
types of analyses, such as water resource allocation (Sun et al. 2013); water resource
transport capacity (Ma et al. 2012); efficiency phosphorus evaluation use (Laner et al.
2017); environmental vulnerability assessments (Zhao et al. 2018); sustainable sport
development level assessments (Liu and Cui 2008) and sustainability assessments
for Latin American countries (Toumi et al. 2017). This method is based on Shannon’s entropy coefficient (1948), which comprises a number of desirable properties
and allows for weight determination solely on the basis of the amount of statistical
information provided by the indicators (Toumi et al. 2017).
In this context, the present study aimed to assess the environmental sanitation
sustainability condition of two water management units in the Rio Grande Basin
(BHRG): GD1 (Alto Rio Grande) and GD8 (Baixo Rio Grande), Brazil, considering
water supply, sewage disposal, and solid waste disposal. The results of this study
display the potential to contribute to action-planning and decision-making to reach
the SDG 6 up to 2030.
2 Methodology
2.1 Study Area
The River Grande Basin (BHRG) is located in southeastern Brazil. The river basin
contribution area is of 144,689.54 km
2 , divided between the states of Minas Gerais
(MG)—60% of the total basin area and São Paulo (SP)—40% of the total basin area.
The BHRG comprises 393 municipalities, totally or partially inserted in the basin,
housing 8.6 million people, corresponding to 4.5% of the Brazilian population in
2010 (ANA 2016). Inserted in the Paraná Hydrographic Region, one of the most
important hydrographic regions in Brazil, the river basin is subdivided into 14 water
management units (UGHs). UGHs are administered by state river basin committees
and are given different names in MG and SP. In MG, the eight UGHs affluent to
the Rio Grande are called UPGRHs—Water Resource Planning and Management
275
ecosystem conservation and social, economic, institutional and environmental subsystems into a single system (Ni et al. 2012). In this context, hydrographic basins
are a natural unit or unique system that allow for this integration (Tundisi 2008;
Guidolini et al. 2018a).
Some global assessment methods use subjective weights to calculate subsystem
weights, such as the AHAS—Analytic Hierarchy Process (Saaty 2013), ARAS—
Additive Ratio Assessment (Zavadskas et al. 2010) and ANP—Analytic Network
Process (Carlucci 2010), among others. These methods present certain drawbacks,
such as a non-standardized rating system and results that may be inconsistent with
actual data due to subjective weights. On the other hand, so-called objective methods
disregard the preferences of the decision-maker from statistical models and are based
on the inherent amount of information provided by the indicators (Toumi et al. 2017).
Among objective methods, the entropic weight method is highlighted in several
types of analyses, such as water resource allocation (Sun et al. 2013); water resource
transport capacity (Ma et al. 2012); efficiency phosphorus evaluation use (Laner et al.
2017); environmental vulnerability assessments (Zhao et al. 2018); sustainable sport
development level assessments (Liu and Cui 2008) and sustainability assessments
for Latin American countries (Toumi et al. 2017). This method is based on Shannon’s entropy coefficient (1948), which comprises a number of desirable properties
and allows for weight determination solely on the basis of the amount of statistical
information provided by the indicators (Toumi et al. 2017).
In this context, the present study aimed to assess the environmental sanitation
sustainability condition of two water management units in the Rio Grande Basin
(BHRG): GD1 (Alto Rio Grande) and GD8 (Baixo Rio Grande), Brazil, considering
water supply, sewage disposal, and solid waste disposal. The results of this study
display the potential to contribute to action-planning and decision-making to reach
the SDG 6 up to 2030.
2 Methodology
2.1 Study Area
The River Grande Basin (BHRG) is located in southeastern Brazil. The river basin
contribution area is of 144,689.54 km
2 , divided between the states of Minas Gerais
(MG)—60% of the total basin area and São Paulo (SP)—40% of the total basin area.
The BHRG comprises 393 municipalities, totally or partially inserted in the basin,
housing 8.6 million people, corresponding to 4.5% of the Brazilian population in
2010 (ANA 2016). Inserted in the Paraná Hydrographic Region, one of the most
important hydrographic regions in Brazil, the river basin is subdivided into 14 water
management units (UGHs). UGHs are administered by state river basin committees
and are given different names in MG and SP. In MG, the eight UGHs affluent to
the Rio Grande are called UPGRHs—Water Resource Planning and Management