Impactos Ambientais nos Impactos Ambientais nos Solos CarsticosSolos Carsticos

By By

Jennifer RimesJennifer Rimes

(traduzido por N. Barreto)(traduzido por N. Barreto)

FormaçFormaçãoão Carstica Carstica

Caracteristicas carsticas são Caracteristicas carsticas são produzidas porque calcario produzidas porque calcario pode ser dissolvido em pode ser dissolvido em água, contendo dioxido de água, contendo dioxido de carbono e acidos organicos. carbono e acidos organicos. A chuva absorve dioxido de A chuva absorve dioxido de carbono da atmosfera . carbono da atmosfera . Quando a água passa pelo Quando a água passa pelo solo mais dioxido de solo mais dioxido de carbono, originado em carbono, originado em raizes de plantas e materia raizes de plantas e materia vegetal em decomposição, vegetal em decomposição, éé absorvido, junto com acidos absorvido, junto com acidos organicos complexos, organicos complexos, conhecidos como acidos conhecidos como acidos humicos. Essa água humicos. Essa água facilmente consegue facilmente consegue dissolver o calcario, dissolver o calcario, formando mais cavernas.formando mais cavernas.

Caracteristicas Carsticas Caracteristicas Carsticas afetam o uso de águas afetam o uso de águas subterraneassubterraneasCavernasCavernas

AquiferosAquiferos

Sistemas de rios Sistemas de rios subterrâneossubterrâneos

Impactos UrbanosImpactos Urbanos

• Impactos urbanos em sistemas de Impactos urbanos em sistemas de águas subterraneas são, em maior águas subterraneas são, em maior parte, efeitos negativos por causa de parte, efeitos negativos por causa de uma falta de educação dos cidadãos uma falta de educação dos cidadãos que utilizam o meio ambiente. que utilizam o meio ambiente. Contaminações graves poderiam ser Contaminações graves poderiam ser mais facilmente contidas se regulações mais facilmente contidas se regulações sobre a disposição de lixo, esgoto e sobre a disposição de lixo, esgoto e rebaixamento fossem impostas e rebaixamento fossem impostas e cumpridas.cumpridas.

DrenagemDrenagem

• Calcario perto ou na superfice tende a Calcario perto ou na superfice tende a deformar por fraturas frageis o que cria deformar por fraturas frageis o que cria junções complexas formando junções complexas formando permeabilidade media para o fluxo permeabilidade media para o fluxo subterraneo de soluções de drenagem subterraneo de soluções de drenagem o que leva a criação de cavernas. o que leva a criação de cavernas. Fraturas Verticais normalmente Fraturas Verticais normalmente formadas na superfice deixando a formadas na superfice deixando a solução fluir mais rapidamente pelas solução fluir mais rapidamente pelas fraturas.fraturas.

Casos UrbanosCasos Urbanos

• Explorando os diferentes tipos de Explorando os diferentes tipos de contaminação e soluções variadas contaminação e soluções variadas

usadas em cidades do mundo todo é usadas em cidades do mundo todo é possivel formular novas maneiras de possivel formular novas maneiras de educar os cidadãos do mundo como educar os cidadãos do mundo como se reduz a contaminação de lençois se reduz a contaminação de lençois

freaticos numa maneira freaticos numa maneira economicamente razoavel. economicamente razoavel.

Hai Yai, ThailandHai Yai, Thailand• Hai Yai fica na Tailândia que sofre Hai Yai fica na Tailândia que sofre

de contaminação por causa de ma de contaminação por causa de ma colocação e controle de canais de colocação e controle de canais de esgoto. esgoto. (detalhes maiores abaixo, em (detalhes maiores abaixo, em inglês)inglês)

• Hat Yai, Thailand is located on low-Hat Yai, Thailand is located on low-lying coastal alluvial deposits, which lying coastal alluvial deposits, which forces the city to utilize drainage forces the city to utilize drainage canals for storm runoff as well as canals for storm runoff as well as sanitation purposes. The unlined sanitation purposes. The unlined drainage canals have leaked into the drainage canals have leaked into the semi-confined aquifer beneath the semi-confined aquifer beneath the city. The result is that high levels of city. The result is that high levels of ammonium, sulphate, and chloride are ammonium, sulphate, and chloride are in the water supply. In the worst areas in the water supply. In the worst areas the water is 60-80% canal seepage the water is 60-80% canal seepage and 20-40% unpolluted aquifer water. and 20-40% unpolluted aquifer water. A possible solution is to line the A possible solution is to line the drainage canals however this is a very drainage canals however this is a very costly proposition for the city to costly proposition for the city to undertake (Jiabing, 1988). undertake (Jiabing, 1988).

Alabama StudyAlabama Study

• Dry weather flows from storm drain pipes are often Dry weather flows from storm drain pipes are often generated by illicit or illegal connections to the storm generated by illicit or illegal connections to the storm drain system, and thus have a strong probability of drain system, and thus have a strong probability of containing high concentrations of soluble heavy containing high concentrations of soluble heavy metals, pesticides, and pathogenic microorganisms. metals, pesticides, and pathogenic microorganisms.

• Combined sewer overflow discharges should be kept Combined sewer overflow discharges should be kept away from infiltration practices given their poor water away from infiltration practices given their poor water quality (especially pathogens) and high clogging quality (especially pathogens) and high clogging potential. potential.

• Snowmelt runoff from roads and parking lots produce Snowmelt runoff from roads and parking lots produce high concentrations of chlorides that cannot be high concentrations of chlorides that cannot be effectively treated with infiltration effectively treated with infiltration

• Manufacturing sites produce stormwater that has a Manufacturing sites produce stormwater that has a high potential for elevated concentrations of organic high potential for elevated concentrations of organic compounds and heavy metals. compounds and heavy metals.

• Construction sites do not normally contain toxicants, Construction sites do not normally contain toxicants, however the high sediment levels quickly clog however the high sediment levels quickly clog infiltration practices infiltration practices

• . In less contaminated areas the adequate . In less contaminated areas the adequate pretreatment of runoff prior to the use of gas stations, pretreatment of runoff prior to the use of gas stations, vehicle maintenance operations, and large commercial vehicle maintenance operations, and large commercial parking lots would greatly reduce contaminants that parking lots would greatly reduce contaminants that are generally allowed to build up are generally allowed to build up

• . Residential areas pose the least risk of groundwater . Residential areas pose the least risk of groundwater contamination, and therefore, infiltration practicecan contamination, and therefore, infiltration practicecan be utilized without extensive pretreatment. However, be utilized without extensive pretreatment. However, the use of grass buffer strips as a form of pretreatment the use of grass buffer strips as a form of pretreatment is advisable to prevent premature failure of the is advisable to prevent premature failure of the infiltration practice due to clogging from sediment infiltration practice due to clogging from sediment

• Contaminação do lençol freático por ligações ilegais aos sistemas de drenagem de águas pluviais.

Albuquerque Albuquerque

• Subsidências de 80 a 120 m que irão Subsidências de 80 a 120 m que irão acontecer por causa do rebaixamento acontecer por causa do rebaixamento do lençol freático.do lençol freático.

• The dewatering of the aquifer in the Albuquerque The dewatering of the aquifer in the Albuquerque area has raised concerns about land subsidence. area has raised concerns about land subsidence. (Shoemaker, 1997) using the work of (Haneberg, (Shoemaker, 1997) using the work of (Haneberg, 1996) indicates that significant rates of subsidence 1996) indicates that significant rates of subsidence would begin at a drawdown of 80 to 120 m. would begin at a drawdown of 80 to 120 m.

• Concerns have also been raised about the quality of Concerns have also been raised about the quality of the groundwater supply and many of the highly the groundwater supply and many of the highly productive wells along the river have been removed productive wells along the river have been removed from service due to contamination from surrounding from service due to contamination from surrounding industry industry

• The City of Albuquerque has instituted a Water The City of Albuquerque has instituted a Water Conservation Long-Term Strategy that involves an Conservation Long-Term Strategy that involves an increase in the water-use rate as well as increase in the water-use rate as well as implementing conservation programs for residential implementing conservation programs for residential users such as water restriction times, the restriction users such as water restriction times, the restriction of high water use plants in new landscaping or areas of high water use plants in new landscaping or areas less than 10 ft in any dimension, the use of older less than 10 ft in any dimension, the use of older parks for irrigation management, recycling treated parks for irrigation management, recycling treated wastewater for use in irrigation systems, the wastewater for use in irrigation systems, the conversion of toilets in all public buildings to low conversion of toilets in all public buildings to low flush systems, and a reduction in vehicle washing by flush systems, and a reduction in vehicle washing by the Transit and Fire Departments. the Transit and Fire Departments.

Kingston, JamaicaKingston, Jamaica• Contaminação do lençol freático por Contaminação do lençol freático por

causa de falta de planejamento com causa de falta de planejamento com relação as águas subterrâneas. A relação as águas subterrâneas. A contaminação do lençol freático contaminação do lençol freático com esgoto resultou na proliferação com esgoto resultou na proliferação de cólera.de cólera.

• The main resource for water is an The main resource for water is an alluvium aquifer. alluvium aquifer.

• Lack of recharge areas due to Lack of recharge areas due to urbanization without proper urbanization without proper groundwater resource planning has led groundwater resource planning has led to contamination by sewage, which has to contamination by sewage, which has led to outbreaks of dysentery and led to outbreaks of dysentery and cholera resulting from fecal content in cholera resulting from fecal content in drinking water supplies. drinking water supplies.

• In 1995, the Water Resource Act (WRA) In 1995, the Water Resource Act (WRA) was passed in Jamaica. The WRA has was passed in Jamaica. The WRA has tried to focus on the continual tried to focus on the continual assessment and proper management of assessment and proper management of water resources, the promotion of water resources, the promotion of conservation and protection, and the conservation and protection, and the promotion of optimal development. promotion of optimal development. They have ensured that the water They have ensured that the water supply is adequate by implementing a supply is adequate by implementing a plan of action that includes taking an plan of action that includes taking an inventory of resources and demands for inventory of resources and demands for domestic, industrial and touristic use, domestic, industrial and touristic use, establishing water quality control areas, establishing water quality control areas, abstraction licensing, and groundwater abstraction licensing, and groundwater risk mapping (Walters, 1998).risk mapping (Walters, 1998).

Perth, Australia Perth, Australia

• Em razão da utilização do lençol Em razão da utilização do lençol freático como fonte de água preve-se freático como fonte de água preve-se falta de água no futuro.falta de água no futuro.

• The population of Perth, Australia is The population of Perth, Australia is expected to double by 2020. A sandy expected to double by 2020. A sandy superficial aquifer underlies much of the city superficial aquifer underlies much of the city and this in turn is underlain by confined and this in turn is underlain by confined sandstone aquifers.sandstone aquifers.

• Groundwater provides about 40% of Perth's Groundwater provides about 40% of Perth's potable supply and 70% of the city's total potable supply and 70% of the city's total water usage. Groundwater is widely tapped water usage. Groundwater is widely tapped for the irrigation of gardens and parks and for the irrigation of gardens and parks and there are about 100 000 irrigation bores in there are about 100 000 irrigation bores in the Perth metropolitan area. Contamination the Perth metropolitan area. Contamination is found in the water supply bores in urban is found in the water supply bores in urban areas, as well as problems from local areas, as well as problems from local saltwater intrusion due to nearby coastal saltwater intrusion due to nearby coastal areas. There are also concerns about the areas. There are also concerns about the discharge of nutrients by groundwater to discharge of nutrients by groundwater to wetlands and coastal environments wetlands and coastal environments

• The solutions being planned include using The solutions being planned include using groundwater protection zones in groundwater protection zones in undeveloped areas to protect potable water undeveloped areas to protect potable water supplies as well as mapping to identify areas supplies as well as mapping to identify areas that are highly susceptible to contamination that are highly susceptible to contamination

Lima, Peru Lima, Peru • Contaminação do lençol freático com Contaminação do lençol freático com

esgoto e efluentes industriais. Previsão esgoto e efluentes industriais. Previsão de falta de água para a população.de falta de água para a população.

• The quality of the groundwater is the main The quality of the groundwater is the main issue in Lima. The aquifer is heavily issue in Lima. The aquifer is heavily contaminated by industrial and domestic fecal contaminated by industrial and domestic fecal pollution, as well as the polluted River Rimac pollution, as well as the polluted River Rimac that recharges it. that recharges it.

• A majority of groundwater sources, which A majority of groundwater sources, which supply the distribution network in Lima, are supply the distribution network in Lima, are chlorinated to disinfect the water with the goal chlorinated to disinfect the water with the goal of providing a chlorine free residual to prevent of providing a chlorine free residual to prevent recontamination in the distribution network recontamination in the distribution network

• The main sources of fecal contamination of the The main sources of fecal contamination of the Lima aquifer are abandoned dug wells, Lima aquifer are abandoned dug wells, especially those that are in the industrial sites especially those that are in the industrial sites that are not sealed, currently used dug wells that are not sealed, currently used dug wells which do not have a complete sanitary system, which do not have a complete sanitary system, inefficient and unlined waste stabilization inefficient and unlined waste stabilization pond, and the River Rimac that recharges the pond, and the River Rimac that recharges the aquifer is grossly contaminated with high aquifer is grossly contaminated with high levels of nitrate and other organic compounds levels of nitrate and other organic compounds

• The sealing of all unused and unprotected The sealing of all unused and unprotected wells in the city with low-permeability material wells in the city with low-permeability material such as clay is a priority to prevent continued such as clay is a priority to prevent continued contamination of groundwater. This would contamination of groundwater. This would remove obvious point sources of contamination remove obvious point sources of contamination of groundwater within the city, which would of groundwater within the city, which would help to reduce the vulnerability of the aquifer help to reduce the vulnerability of the aquifer to contamination. Other preventive measures to contamination. Other preventive measures include lining of the waste stabilization pond to include lining of the waste stabilization pond to the south of Lima, control of the quality of the south of Lima, control of the quality of domestic sewage and industrial discharges domestic sewage and industrial discharges into rivers and near groundwater sources into rivers and near groundwater sources

Vazante – Minas Gerais – BrasilVazante – Minas Gerais – Brasilsão retirados 8000 m³/hora de água para operar uma mina são retirados 8000 m³/hora de água para operar uma mina

subterranea.subterranea.Maior rebaixamento no Brasil.Maior rebaixamento no Brasil.

• Contaminação do lençol freático Contaminação do lençol freático • Drenagem e secagem levando a Drenagem e secagem levando a

desertificação de uma área de 92 desertificação de uma área de 92 km²km²

• Assoreamento e poluição do Rio Assoreamento e poluição do Rio Sta. Catarina – afluente do São Sta. Catarina – afluente do São FranciscoFrancisco

• Centenas de subsidências Centenas de subsidências conforme foto ao lado (abaixo)conforme foto ao lado (abaixo)

• Comprometimento do patrimônio Comprometimento do patrimônio EspeleolEspeleoloogico (cavernas).gico (cavernas).

• Contaminação do ar e águas, e Contaminação do ar e águas, e morte de animaismorte de animais

• Agressões em área de interesse Agressões em área de interesse extremo para a biodiversidade de extremo para a biodiversidade de Minas GeraisMinas Gerais

• Possibilidade de contaminação do Possibilidade de contaminação do aquifero Guarani com metais aquifero Guarani com metais pesadospesados

Cajamar – São Paulo, BrasilCajamar – São Paulo, Brasil

• Em 12 de agosto de 1986 houveEm 12 de agosto de 1986 houve; em ; em Lavrinhas, Cajamar; uma subsidencia Lavrinhas, Cajamar; uma subsidencia de 32 m de diametro por 13 de de 32 m de diametro por 13 de profundidade em decorrencia de profundidade em decorrencia de bombeamento de águas do bombeamento de águas do subsolo.subsolo.Varias casas e ruas foram Varias casas e ruas foram destruídas.destruídas.

• O IPT de São Paulo realizou estudos O IPT de São Paulo realizou estudos (Prandini, 1990) que identificou varias (Prandini, 1990) que identificou varias outras cavidades em formação em outras cavidades em formação em razão da área ser de solo carstico. razão da área ser de solo carstico. Aparentemente a área estava em Aparentemente a área estava em equilíbrio, mas o bombeamento de equilíbrio, mas o bombeamento de dois poços artesianos com vazões de dois poços artesianos com vazões de 20 m³ provocou todos os danos.20 m³ provocou todos os danos.

• A área foi delimitada e A área foi delimitada e considerada de considerada de “alto risco”“alto risco” e e considerada imprópria para considerada imprópria para uso urbano e condenada para uso urbano e condenada para moradias.moradias.

Criciúma – Santa Catarina, Criciúma – Santa Catarina, BrasilBrasil

• Em razão de Em razão de mineração mineração subterrânea foram subterrânea foram verificadas varias verificadas varias subsidências e subsidências e secagem de poços secagem de poços de abastecimento de abastecimento de água.de água.

A necessidade de proteger A necessidade de proteger lençois freaticos é urgente, lençois freaticos é urgente,

especialmente se é num local especialmente se é num local onde essas águas são uma onde essas águas são uma

fonte de água para uma area fonte de água para uma area urbana ou uma fonte para urbana ou uma fonte para

agricultura.agricultura.

Planos de ProteçãoPlanos de ProteçãoAlguns paises já iniciaram seus planos de proteção de águas subterraneasAlguns paises já iniciaram seus planos de proteção de águas subterraneas

Estes estão abaixo.Estes estão abaixo.

• The Division of Planning (DWR) for The Division of Planning (DWR) for California California

• . The Australian Environmental . The Australian Environmental Information Network (ERIN) Information Network (ERIN)

• The Edwards Aquifer page The Edwards Aquifer page provides information about the provides information about the unique Texas groundwater unique Texas groundwater system and artesian aquifers system and artesian aquifers

• The Texas Water Resources The Texas Water Resources Institute (TWRI) performs water Institute (TWRI) performs water related research for the state of related research for the state of Texas Texas

• The Montana Natural Resource The Montana Natural Resource Information System Information System

• The National Water Data Exchange The National Water Data Exchange (NAWDEX) is a group of water-(NAWDEX) is a group of water-oriented organizations working oriented organizations working together to improve the access to together to improve the access to water data and water information water data and water information

• The Canada Center for Inland The Canada Center for Inland Waters (CCIW) does water Waters (CCIW) does water research, generating research, generating environmental information and environmental information and knowledge about the Great Lakes knowledge about the Great Lakes

• Urban Planning and Architecture Urban Planning and Architecture Resources is a WWW site offering Resources is a WWW site offering resources such as listings of resources such as listings of conferences, competitions, and conferences, competitions, and exhibits as well as census exhibits as well as census information, and environmental information, and environmental archives archives

• Illinois District of the Water Illinois District of the Water Resources Division (WRD), which Resources Division (WRD), which is part of the U.S. Geological is part of the U.S. Geological Survey Survey

• Impactos urbanos em sistemas de águas subterraneas são, em Impactos urbanos em sistemas de águas subterraneas são, em maior parte, efeitos negativos por causa de uma falta de maior parte, efeitos negativos por causa de uma falta de educação dos cidadãos que utilizam o ambiente urbano. educação dos cidadãos que utilizam o ambiente urbano. Contaminações graves poderiam ser mais facilmente contidas se Contaminações graves poderiam ser mais facilmente contidas se regulações sobre a disposição de lixo, esgoto e rebaixamento regulações sobre a disposição de lixo, esgoto e rebaixamento fossem impostas. Existem muitas coisas que podem ser feitas por fossem impostas. Existem muitas coisas que podem ser feitas por cidadões individuais como conservar água, mudanças de cidadões individuais como conservar água, mudanças de topografia informadatopografia informada, disposição responsavel de materiais perigosos, e compromisso de utilização de água de acordo com horarios. Essas contribuições pequenas podem ter um grande efeito positivo se mais cidadãoãos participarem para manter a fonte de água de suas cidades (ou fazendas e empresas) limpas e abundantes.