|
|
Workshop
on Sustainable Development Indicators
Chung-Li,
Taiwan, 17-19 November 2001
Sustainable
Development Indicators for Taiwan
Jiunn-Rong
Yeh1, Shang-Lien Lo2, Ling-Ling Lee3, Jin-Tan Liu4,
Juju Chin-Shou Wang5, and Shu-Li Huang6
3.
Resource and Ecosystem State Indicators
3.1
Process of Developing Resource and Ecosystem Indicators
Natural
resources are the foundation of sustainable development.
Therefore one of the main consideration of sustainability
is sustainable use of natural resources. When selecting
indicators of resource state, we concentrate on the indicators
which can measure sustainable use of renewable natural resources.
The sustainability of non-renewable resources, on the other
hand, is more relevant to the degree and efficiency of use,
and recycling of waste. Indicators relevant to use of non-renewable
resources are included in the dimensions of environmental
state, and social and economic pressure of this SDI system.
Meanwhile, the production or regeneration of renewable natural
resources depend strongly on the health of various types
of ecosystem. For example, the supply of timber and other
forest products depend on the health of forest, and the
supply of fish and other marine resources depend on the
health of marine and coastal ecosystem. Therefore, the condition
of various types of ecosystem relevant to the production
of natural resources is also under consideration.
After
reviewing other SDI work around the world, it became clear
that most indicators measuring sustainable resource use
and ecosystem health can be categorized into the following
areas: land use, forest, agriculture, fisheries, marine
and coast, water and biodiversity. The specific indicators
to be included and the calculation of these indicators vary
enormously between different SDI framework, due to differences
in the specific goals and characteristics of each SDI project.
It is important for a country to identify its goal and specific
environmental, social, economic and political factors affecting
its development before selecting relevant indicators. Therefore,
the specific features of Taiwan's natural environment and
resources state are considered when selection these indicators.
3.2
Taiwan's Natural Environment and Resource State
Taiwan
is a continental island with approximately 1200 km of coastline.
The surrounding marine ecosystem provides local people with
abundance resources. The long coastline gives rise to a
range of habitat types, including coral reef, rocky shoreline,
mangrove, sandy beach, mud flats, estuaries, etc. These
variety of coastal habitats and the diverse animal and plant
species inhabit here serve important functions of resource
production, erosion prevention, recreation, etc. However,
at present, Taiwan's coastal habitat face a number of problems,
including natural erosion, human development, man-made pollution,
the covering of shorelines with concrete, and subsidence
caused by the excessive pumping of ground water. Other urgent
issues like the threat of over-fishing are also directly
menacing the marine environment and its biological diversity.
Therefore, a close monitoring of the marine and coastal
ecosystem and the fisheries resources is crucial for assessment
of sustainable development in Taiwan.
The
geological Taiwan is relatively young, ranging from very
recent alluvial deposits to early sedimentary and crystalline
rocks. A tilted fault block running along the entire length
of the island forms its structure. This gives Taiwan its
fundamental topographic feature-the Central Mountain Range,
which runs from north to south. The steep slope of this
central range faces east, while the rock mass slopes more
gently to the west. Within the 140-km horizontal distance
between the east and west coasts, the elevation ranges from
sea level to 3,950 meters. Steep mountain terrain over 1,000
meters constitutes about 30% of the island's total land
area; hills and terraces make up around 40%; and low-lying
alluvial plains make up the remaining 30%. Therefore, land
areas suitable for human development is limited.
Taiwan's
high population density and a national development framework
guided by demand for rapid economic growth, national construction
and industrial zone policies mean that the struggle to appropriate
land resources is not restricted to urban and suburban areas.
Marginal land in non-urban areas, including hillside and
coastal areas, also faces the threat of destruction through
human development. The inappropriate usage of hillside and
mountain areas is causing the ecological balance in these
areas to collapse. Taiwan's coastal areas, meanwhile, continue
to be converted into industrial land or are being earmarked
for the creation of new towns and cities. This unending
development is continually changing Taiwan's coastline to
the point that, even though it is surrounded by ocean, much
of Taiwan's land no longer directly faces the sea. As the
geology and environment of these areas is usually more fragile
and sensitive to human interference, this type of development
could easily lead to soil erosion and other environmental
disasters unless appropriate planning and management of
these areas is undertaken.
Due
to the steep gradient of its mountain hills, Taiwan's rivers
are short and fast moving. This plus its abundant rainfall
leading to strong erosive forces in upstream regions. Alluvial
deltas are formed at the point where the larger rivers flow
out into the ocean. These are formed by the collection of
silt downstream. However, in recent years, the original
characteristics of the river has often been destroyed and
changed completely by the development and pollution of forests
and hillside areas by humans, and the construction of reservoirs
and check dams along the river. These man-made factors pose
a severe threat to the continued survival of many river
species, many of which now face extinction due to the loss
of their habitat.
Furthermore,
almost 70% of the island's total rainfall occurs during
the summer typhoon months (Jul, to September). These short
bursts of torrential rain exacerbate problems of soil conservation
and high natural erosion in hillside areas, often causing
devastating land- and mudslides. Mudslides and other disasters
are even more likely in areas where hillside slopes have
been developed illegally. Most of Taiwan's 151 rivers and
streams are short and the flows are rapid. Riverbeds tend
to be wide and shallow. During heavy rainstorms, the rivers
can become torrential, carrying heavy loads of mud and silt.
By contrast, the water dries up during the dry season and
some rivers become underground streams. Even when precipitation
is extremely high, Taiwan's rivers do not store much water;
therefore, their management and development as water resources
is difficult. According to 1997 statistics, ground water
accounted for approximately 35% of Taiwan's water consumption,
while reservoirs accounted for almost 26%. This places a
great deal of pressure on Taiwan's aquatic ecosystems. Therefore,
it is essential for Taiwan to manage its water resources
reasonably and in a sustainable manner to protect its freshwater
ecology.
In
global terms, Taiwan is biologically important due to its
wide range of climactic and vegetation zones. Taiwan's ecosystems
are not merely distributed according to latitude, they also
vary with elevation. The high altitude of the island's mountains
provides climatic and vegetation zones ranging from tropical
to alpine. Divided into east and west by the Central Mountain
Range, variations in Taiwan's plant species and numbers
occur in a gradual stepped pattern as they spread north
and southwards. therefore, Taiwan has a surprising diversity
of habitat. Each habitat type works within its unique environment
and climate to accommodate many different types of species.
This means that the stock of species found in Taiwan is
extremely diverse and need to be carefully monitored to
help preserve a specific portion of the global biodiversity.
With
the consideration of incorporating meaningful resource and
ecosystem indicators which reflects the special characteristic
of Taiwan's natural environment and resource state, a preliminary
set of 16 indicators belonging to 8 different categories
and calculated with 33 variables were selected. After consultation
with experts specialized in biology, environmental sciences,
resource management and conservation, data searching and
evaluation, only 8 indicators calculated with 14 variables
were kept as the final set of indicators (Table 3.1). These
indictors were further divided into four categories: Land
use, biological resources, biodiversity, and soil and water
resources. The other 8 indicators and 19 variables, including
indicators to measure supply of underground water, size
of polluted agricultural land, areas with potential danger
of landslide or mudslide, were excluded for now due to data
deficiency.
Table
3.1 Definition and data feasibility of natural resources
and ecosystem indicators.
| Category |
Indicator |
Variables |
Data
feasibility* |
| A.
Land use |
SRA1.Ratio
of areas depleted of natural resources |
Total
size of urban area |
A |
| Total
size of industrial area |
| SRA2.Ratio
of natural coastline |
Total
length of natural coastline |
A |
| Total
length of artificial construction along the coast |
| B.Biological
resources |
SRB1.Ratio
of healthy forest |
Total
area of natural forest |
A |
| Total
area of artificial plantation |
| Total
forest area affected by fire, pest , disease and illegal
use |
| SRB2.Ratio
of healthy arable land |
Total
area of arable land |
A |
| Total
arable area affected by pest, disease, natural catastrophe |
| SRB3.Fisheries
yield per unit effort |
Total
catch in inner waters by fishing vessels larger than
50 tones |
A |
| Total
number of netting in inner waters by fishing vessels
larger than 50 tones |
| C.Biodiversity |
SRC1.Ratio
of ecologically sensitive areas |
Degree
of siltation of major rivers |
A |
| D.Water
& Soil |
SRD1.Degree
of erosion |
Degree
of siltation of major rivers |
B |
| SRD2.Supply
of water resources |
%
reduction in total storage volume of reservoirs |
A |
| *
Feasibility: A: Completed data, could be executed and
analyzed, B: incomplete or poor quality data, but could
be analyzed. |
|
3.3
Results of indicator calculation
After
collecting and analyzing data for each indicator between
1988 and 1998, we could examine the trend of change for
each indicator (Table 3.2)
Table 3.2 Summary of trend of resource and ecosystem indicators
| Category
|
Indicator
|
Trend
|
Sustainability
|
| A.
Land use |
SRA1.Ratio
of areas depleted of natural resources |
↑
|
↓
|
| SRA2.Ratio
of natural coastline |
↓
|
↓
|
| B.
Biological resources |
SRB1.Ratio
of healthy forest |
=
|
=
|
| SRB2.ratio
of healthy arable land |
=
|
=
|
| SRB3.Fisheries
yield per unit effort |
↓
|
↓
|
| C.
Biodiversity |
SRC1.Ratio
of ecologically sensitive Areas |
↓
|
↓
|
| SRD1.Degree
of erosion |
=
|
=
|
| SRD2.Supply
of water resources |
↓
|
↓
|
*
Land Use
Changes
in the land use pattern incorporate both changes in the
ratio of areas depleted of natural resources and change
of natural coastline. The former indicator is a measure
of expansion of urban and industrial areas, which reflects
trends of loss of wilderness. The later reflects how ecosystem
function, resources and biodiversity of coastal zone are
affected. Data of the last ten years revealed the trend
of expanding urban and industrial areas and the reduction
of natural coastline, which is due to an increasing population
and pressure of economic development. The proportion of
natural coastline is reduced at a rate of nearly 1 % every
year. Although there was an increase in the percentage of
natural coastline in 1997, it was due to destruction of
old construction along the coast and a change in relevant
data collection. The general trend of loss of natural coastline
continues. Therefore, the overall trend of land use pattern
is heading away from the direction of sustainability.
Ratio
of areas depleted of natural resources
Ration
of natural coastline
*
Biological Resources
Assessment
of changes in biological resources focused on changes in
forest, agricultural land and fisheries, which are important
for providing basic subsistence material and serving important
ecological function. Due to the ban of logging natural forest
for more than a decade, the total forest area in Taiwan
changed a little. Although fire, forest pest, diseases and
illegal development still happen frequently, their impact
is generally limited in small areas. However, since over
95% of the timber used annually in Taiwan is imported, as
international policies on timber policy change, Taiwan may
lift the ban and start logging again, and the ratio of forest
land may change in the future. Therefore, it is important
to continue monitoring the forest policy and its effect
on forest resources. Although data of healthy agriculture
land also changed little, there is an increasing fluctuation
in the amount of crop loss due to pest and natural catastrophe.
Furthermore, there have been more and more incidents of
agriculture land being polluted by heavy metal from industrial
waste. The magnitude of such pollution has not been completed
revealed. Therefore, there may be an overestimate of healthy
arable land. Fisheries resources in the near-shore water
showed a significant reduction in the past years due to
pollution, habitat destruction and over-fishing. Although
government has taken measures, such as setting up fisheries
protected areas and revising fisheries regulation, to ratify
the situation, the effect has been slow.
Ration
of healthy forest
Ratio
of healthy arable land
Catch
per unit effort in near-shore water
*
Biodiversity
Preservation
of natural habitat is the foundation of preserving biological
diversity. Therefore, the percentage of protected area is
often used as an indicator reflecting sustainability of
biological diversity. However, because freshwater biological
diversity is often unable to be fully represented by the
protected areas, we included ratio of natural river bank
as an additional indicator. During the past ten years, six
national parks, 19 nature reserves, 13 wildlife refuges,
and 26 important wildlife habitat have been established.
With the recent announcement of the establishment of the
ecological corridor along the Central Mountain Range, the
total area protected for species and ecosystems became 6992
km2, which is about 19.5% of the land area of Taiwan. On
the other hand, the river systems in Taiwan have been seriously
modified by constructions of dams, check dames, dikes, irrigation
canals, etc., and natural river banks which may constitute
important breeding and nesting habitat of many riparian
species were lost quickly from 85.2% in 1988 to 80.7% in
1997.
Changes
in the ratio of protected area and natural river bank (adjusted
by using data in 1988 as 100%)
*Water
and Soil
Water
and soil are the basis of resource production and sustainable
development. Taiwan is prone to heavy erosion due to its
fragile geology, heavy and concentrated rainfall, as well
as frequent natural and human disturbance. However, due
to infrequent and non-standardized data collection, we were
not able to identify the trend of change in siltation of
major rivers.
Although
Taiwan receives a lot of rain, the distribution and amount
of precipitation usually varies tremendously in time and
space, making water reservation very difficult. Although
many reservoirs were constructed in recent years, siltation
due to heavy erosion upstream have quickly reduce the capacity
of water storage in these reservoirs, making water management
even more difficult. To prevent erosion, many check dames
and dikes were built, and many rivers have been blocked
into several sections. Freshwater species may have difficulty
migrating back and forth between dams and check dams. Their
population distribution and breeding pattern may be affected
by the construction. Blockage of water ways lead to accumulation
of silt and shallowing of rivers, which further reduce the
natural habitat of freshwater organism. Meanwhile, the amount
of sand and silt moving downstream may be affected. It is
further affected by the massive collection of sand and silt
for construction and other purposes. Thus silt and sand
which used to feed into the delta at river mouth decrease,
which may lead to erosion at coastal areas.
Reduction
of reservoir capacity
Degree of siltation
4.4
Conclusion
Although many environmental indicators showed sign of improving
pollution control, the trend of most resource and ecosystem
indicators are heading away from sustainability, which matches
the results of recent survey on the perception of public
to our natural environment. Therefore, policy maker need
to pay attention of such trend and take appropriate measures
to improve resource use and the condition of our vital ecosystem,
particularly the coastal and freshwater ecosystem. Meanwhile,
this study also reveals that further work is need to improve
the current system of assessing trend of resource and ecosystem
state in Taiwan:
1.
The need to collect data for more indicators. Several important
indicators were excluded at present due to data deficiency,
e.g. land subsided areas, erosion-prone slope land, underground
water supply, polluted arable land, etc. Therefore, effort
should be devoted to data collection and accumulation so
that these indicators could be incorporated into the SDI
system in the future.
2.
Scientific basis of the relationship between indicators
and sustainability. The relationship between most indicators
and sustainability in this system was based on subjective
judgement or the experts' opinion. How do changes of indicators
lead to reduction of changes in sustainability and the inter-relationship
between different indicators need to be studied scientifically,
so that the accuracy of prediction and policy-making.
3. Integration of indicators. In this study, an extended
PSR system was used with an idea of linking environment
and resource state indictors with social and economic pressure
indicators, so that the causal relationship of how various
pressure factors affect environment and resource states
can be revealed, and how policy should be decided to ratify
the impact of relevant pressure factors can be identified.
Therefore, the integration between different indicators
needs to be improved so that the goal of linking indicators
of different dimensions can be achieved.
4.
Finally, the purpose of developing this SDI system is to
help examine trend of development in Taiwan and develop
appropriate policy which can direct Taiwan towards sustainability.
Therefore, the linkage between SDI system with policy and
decision-making needs to be strength so that the SDI system
can truly serve its function.
|
|
|
 
|
