Sanitary Landfills: Toward Sustainable Development - lumes

LUMES 2000-2001
Sanitary Landfills: Toward Sustainable Development
2.1 Causal-loop Diagram
Causal-loop diagram (CLD) is an effective tool to assist us to understand, structure and
conceptualise problems in a systematic way. It can be used to evaluate and to understand the
cause and effect between different components within a defined system. And further to predict
the overall behaviour of the system and the sequence of different causal links will behave
(Haraldsson, 2000). There is no one-way relation between all these elements. All the problems
are interrelated. The cause of one element could be an effect of another element. In order to have
a clearer picture of the functioning system of the landfill and its impacts to the environment,
economic and society, a CLD will be used for illustration.
The following diagram (Figure 1) illustrates the various cause-effect relationships between
different components in the municipal solid waste disposal system. The arrow () shows the
causation between one component to another while the “ + “ and “ – “ indicates the direction of
change (Haraldsson, 2000).
Production & Consumption
Source Reduction
+
-
+
+
Resources
+
-
Legislation
Municipal Solid Waste
-
+
+
Landfill
Resources Recovery
+
-
Figure1: Causal Loop Diagram
+
-
Negative
Environmental
Impacts
Negative
Socio-economic
Impacts
Welfare
-
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+
+
-
Technology
In the human society, whether it is a modern economic or subsistence economic, production and
consumption are inevitable. And solid waste is the by-product of these activities. When the
production and consumption increase, this will in crease the municipal solid waste. The
magnitude of change in municipal solid waste will be influenced by different factors such as
population, per capital income, industrialisation, urbanisation, living standards, seasons, etc.
When the municipal solid waste accumulates, the local authorities must find a way to dispose it.
The easiest, simplest and most probably the most thrifty way to dispose municipal solid waste is
to dump it at crude dumping landfills. Dumping all municipal solid waste in landfill without any
recovery will cause the natural resources deplete and will in a way have negative effects on
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