wetland assesment
TRANSCRIPT
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An ecosystem assesment needs to provide both an analysis of the natural environment by looking at
the state of biodiversity and ecosystems, and by evaluating the level of ecosystem services provided to
people by that particular ecosystem. It needs to consider both the ecosystem which delivers specific
services and the people who depend on and are affected by those services or by any change in the
provision of those services.
Deriving information on ecosystem services directly from land-use/cover or habitat maps (40).
Such approaches may be appropriate at national or European scales, for areas where the
dominant service relates directly to land use (e.g. crop and timber production) or where data
availability or expertise is limited, and where the focus is on the assumed presence of ecosystem
services rather than on quantification of the supply. This method is often coupled to value
transfer. Ecosystem service values are transferred from existing valuation studies to other areas
using land cover data for value transfer (41). This approach cannot be so easily applied to the
marine environment.
Primary data to map ecosystem services are used for provisioning services where statistics are
available. Examples include timber, food, or water supply. Statistical data usually relate tocertain administrative units. For the EU assessment, valuable socio-economic data may be
extracted from national and EU reports/datasets (e.g. Eurostat, national statistics from MS).
Socio-economic analysis linked to environmental assessments can be also obtained from the
sources of information mentioned in the previous section (e.g. Water Framework Directive Art.
9, visitors to Natura 2000 sites).
Primary data are often not available for regulating and cultural services and we must rely on
proxies for mapping these services. For instance, the regulation of urban air quality by trees
depends much on the size and density of the leaves. A dense canopy is able to capture more
particulate matter or pollutants than sparse canopies. The leaf area index is therefore a possible
indicator to map this ecosystem service.
Recent mapping techniques are based on biological data such as functional traits of plants or
ecosystem structure and habitat data (42). Functional traits, such as vegetation height, leaf dry
matter content, leaf nitrogen and phosphorus concentration, flowering onset, can be used to
map several services (43). Habitat classification, such as the European Nature Information
System (EUNIS) classification include detailed data on the associated biodiversity, which makes
their use reasonable in mapping relationships between biodiversity and ecosystem services.
An outlook or scenario analysis showing the implications for biodiversity and ecosystem services of
different possible futures is an essential component of an ecosystem assessment. Contrasting policy
scenarios with baseline changes that arise from policy measures can be valued in terms of change in
well-being. A combination of methodologies needs to be utilised for data-gathering and the assessment
process, including questionnaires, semi structured interviews, and a literature review.
To be able to create a fair and accurate assessment of a wetland ecosystem we must first define such an
ecosystem with all it biological, chemical and phzsical parameters and their interactions that are
providing ecological and economic functions (Mitsch and Gosselink 2000). A healthz wetland is one
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which can support biological communities and has similar physical and chemical attributes to those of
natural habitats within the same region. Wetlands are distributed by a number of factors which can be
measured directly. For example we can measure the effect of the introduction of a toxin on a specific
indicator species.
Due to the numerous disturbaces which can occur within a wetland ecosystem, and the numerous
pathways in which a single disturbance can occur, measuring all the potential disturbances or potential
responses to a disturbance within a wetland ecosystemis impractical and inconvenient. The challenge is
in finding methods to evaluate wetland health and the extent to which a wetland has been degraded by
measuring a few key parameters or indicators. Ideally, these will then show a cause and effect
response.However, it is important to keep in mind that using this approach will only give us a general
insight into wetland health and for more specific information, more detailed and intensive
measurements are required.
Indicators of wetland health can be divided into 3 main categories:
Biological
Chemical
Physical
Certain problems can arise due to the fact that many of these problems are interrelated and interact
with eachother. For example, if a wetland is chemically disturbed by an increase in the nutrient content
in the water, apart from seeing changes in the nutrient status, we could also see changes in the
biological make up of the wetland communities. Therefore, it seems logical to concentrate on a group of
parameters rather than just one to assess the health and quality of a wetland ecosystem.
Indicator Parameters used Possible responses to
disturbance
Biological Birds
Macro-invertebrates
Amphibians
Zooplankton
Algae
Vegetation
Microbes
Population structure,
diversity, species richness,
health of individuals
Shifts in species
composition, community
structure.
Disturbance tolerant
species dominate
Chemical pH
Turbidity
Dissolved oxygen
Phosphorus and Nitrogen
concentrations
Pesticides
Dissolved organic C
Major ionsCyanotoxins
Acidity, water clarity,
nutrient status of water,
metals, pesticides,
hydrocarbons, salinity,
organic compunds
Changes in water pH,
eutrophication and algal
blooms, anoxic water and
or sediments.
Changes to
biogeochemical cycling
Toxic responses from
organisms
Physical Water depth
Temperature
Hydrology
Sediment composition
Decomposition
Structure
Water availability and
permanence, water
recharge and discharge
capabilities, peat
accumulation, seasonality
of changes in water depth.
Changes in water storage
or discharge
Changes to ground or
water surface connectivitz
Increased or decreased
decomposition.
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When the chemical, physical and or biological aspects of a wetland ecosystem are disrupted, functions
and associated values can also be disrupted or lost. To assess the disturbance or the overallhealth and
quality if an ecosystem, we need to use indicators. Ideally, practical and efficient approaches to indicator
selection are chosen. Because it is is impossible to measure every biological, chemical or physical
indicator of a wetlands quality, and also cost ineffective, we want to measure only those attributes that
will accurately reflect the health of the system as a whole.
Physical indicators can include both structural and process-based measurements. Structural changes can
be easier to measure and link to physical processes. Measuring physical processes to indicate wetland
health can be difficult and time and cost-consuming. hysical changes to a wetland's hydrology may occur
slowly over time and it can be difficult to monitor those changes. Other physical changes are obvious.
Functions such as water storage, flood control, and peat accumulation may be disrupted by physical
disturbances. However disturbances like these may be difficult to actually quantify, especially when
the natural physical conditions and hydrology are variable. Instead, reflections or impacts of physical
disturbances may be more easily quantified in chemical or biological parameters of the system. For
example, changes in water table are often expressed in changes in plant species assemblages.
Water chemistry parameters may be useful for indicating overall wetland health and are typically the
first parameters investigated to assess water quality.
Chemical indicators, especially water chemistry parameters, can be problematic because of cost and
time requirements. Unless there is concern about a specific chemical or contaminant, direct
measurements may not provide a general picture of wetland health. Sediment chemistry may provide
a better and more long-term picture because chemicals can persist in sediment.
Biological indicators are often considered to be the most useful indicators (US EPA 2002d) because it is
generally assumed that the plant and animal communities of wetlands most accurately reflect wetland
health. Biological indicators considered most useful in assessing wetland health include microbes,vascular and non-vascular plants, invertebrates and birds.
Algal and vascular plant communities are very important in wetland ecosystems because they function
as an energy source for higher organisms. Algal community structure can indicate trophic status of a
wetland and therefore nutrient loading.
Changes in community composition, increases in biomass, and changes to plant health are useful
indicators. Invertebrate communities in wetlands are good indicators of wetland trophic status. ome
invertebrate species are specialized for feeding on certain types of aquatic plants (Murkin et al. 1991)
and as aquatic plant biomass increases so do the numbers of invertebrates.
Several indicators within a wetland system can be combined to form a multimetric index of the overall
health or condition of a wetland site. These metrics may be expressed as a number which is a rating that
indicates the amount of deviation of the system from the same values measured in undisturbed systems
(Karr and Chu 1999). Combining multiple indicators is useful because it encompasses sensitivity of the
system to a wider range of disturbances.
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Wetland functions evaluated by wetland values and assessment methods
Groundwater Water Quality Protection Sediment/Shoreli
ne
Wetlan
d
metho
d
Ground
water
recharge
Ground
water
discharg
e
Flood
flow
attenua
tion
Sediment/to
xicant
retention
Nutrient
removal/transfo
rmation
Sedime
nt
stabiliya
tion
Shoreli
ne
protec
tion
Produc
tion
export
Floral
diver
sity
Fish
and
shelf
ish
habit
at
Descrip
tive
approa
ch
X X X X X X X X X
WIRAM X X X X X X X XVIMS X X X X XWET X X X X X X X XMDE X X X X X XNC
Guidance
X X X X X
Public use/aesthetics/recreation/education
Wetland
method
Wildlife
habitat
Endangered
species habitat
Public
use
Recreation Educational/Scientific
value
Heritage Visual
quality
Descriptive
approachX x X x x X
WIRAM X X X xVIMS X xWET X X xMDE X
NC Guidance x x X
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Economic Value of Wetlands
and Valuation Methods
2.1. Economic Value of Wetlands
The economic value of wetland eco-systems can be divided into four categoriesbased on thebenefits/functions/services provided by the ecosystem: direct (DV), indirect (IV), option (OV) and
existence (EV) values (Figure 2-1). Direct value (DV) refers to physical use of resources such as wild fish
capture, timber, firewood, NTFP, etc. Indirect values (IV) refer to ecosystem services such as watershed
protection, carbon sequestration, water quality attenuation and supply. Option values (OV) refer to
future economic options such as industrial, pharmaceutical, recreational applications. Existence values
(EV) refer to intrinsic worth, regardless of use such as biodiversity, landscape, aesthetic, heritage,
bequest and culture (IUCN, 2006). However, most policy makers/planners consider only the direct value
of ecosystems and neglect the other values which leads to an underestimation of the true economic
value of the wetland.
Total Economic Value (TEV) = DV + IV+ OV + EV
Total Economic Values of Wetlands
Direct Values Indirect Values Option Values Existence Values
Physical use of
services
Wild foods Timber
Firewood
Ecosystem
Services
Watershedprotection
Carbon
sequestering
Water quality
attenuation and
supply
Future Economic
Option
Industrial Agricultural
Pharmaceutical
Recreational
Applications
Intrinsic worth
regardless of use
Biodiversity Landscape
Aesthetic
Heritage
Bequest
Cultural
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Table 2-1. Summarizing the methodology for estimating economic values of wetland
Valuation Direct Use Indirect Use Nonuse
Method Values Values Values
MarketAnalysis
(Productivity
Losses)
(Production
Function)
Public Pricing)
Hedonic Price
Method (HPM)
Travel Cost
Method (TCM)
Contingent
Valuation
(CVM)
Damage
Costs Avoided
Defensive
Expenditures
(Relocation
Costs)
Replacement/
Substitute Cost
Restoration
Costs
Source: Turner, van de Bergh, Barendregt, (1997).
Costs of returning the degraded wetland to its
original state. A total value approach; improtant
ecological, temporal and cultural dimensions.
Expenditures involved in relocation of affected
agents or facilities:: a particular form of defensive
expenditure.
Potential expenditures incurred in replacing the
function that is lost; for instance by the use of
substitute facilities or ‘shadow projects’.
potential biases.The costs that would be incurred if the wetland
function were not present; eg flood prevention.
Costs incurred in mitigating the effects of reduced
environmental quality. Represent a minimum value
which incorporate particular environmental
characteristics.
for the environmental function.
Costs incurred in reaching a recreation site as a
proxy for the value of recreation. Expenses differ
between sites ( or for the same site over time) with
different environmental attributes.
Construction of a hypothetical market by direct
surveying of a sample of individuals and aggregation
market analysis.
Public investment, for instance via land purchase
or monetary incentives, as a surrogate for market
transaction.
Derive an implicit price for an environmental goodsfrom analysis of goods for which markets exist and
Description
Where market prices of outputs (and inputs) are
available. Marginal productivity net of humaneffort/cost. Could approximate with market price
of close substitute. Requires shadow pricing.
to encompass the relevant population. Problems of
Change in net return from marketed goods: a form
of (does-response) market analysis.
Wetlands treated as one input into the production
of other goods: based on ecological linkages and
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STEP 1
Define the scope of the Wetland (type and area) to be
valued
You may need help from a wetland expert for this Step
STEP 2
Identify the principle wetland benefits/functions /services to
be valued
See Figure 2.1 & Table 3.1
STEP 3
Identify principal wetland beneficiaries and stakeholders for
each benefit/function/service being valued
You may need help from a wetland expert for this Step
STEP 4Identify the Constraints to completing the valuation (time,
funding, experience and available data on wetland
characteristics)
Identify the level of perceived constraint (see
Table 3.2)
STEP 5 Select the appropriate valuation method for each wetland
value/benefit/service based on constraints/resources
available.
STEP 6
LWP TOTAL ECONOMIC WETLAND VALUATION MEHODOLOGY
Follow Steps for selected method(s)
enefit Transfer Method (BTM) Chapter 4
arket Price Approach Chapter 5
ontin ent Valuation Method CVM Cha ter 6
STEP 7Sum the estimated value obtained for each principle
wetland benefit/function/service to obtain a Total Economic
Value for the Wetland
Figure 3.1 LWP Total Economic Wetland Valuation Methodology
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3.2 Step 3- Identify wetland beneficiaries and stakeholders
The stakeholders and beneficiaries of wetlands will vary depending on the type of wetland and
the benefit/function/service being valued. E.g. the people who get a direct benefit from wild
fisheries in a wetland may be limited to the people living around the wetland. However, a large
number of people who benefit from the flood control function of the wetland may live some
distance down stream of the wetland.
In addition, stakeholders and beneficiaries may be located both upstream and downstream of
the actual wetland. E.g. those benefiting from the water cleansing value of a wetland may live
upstream in a town that discharges waste water to the wetland while those living downstream
may benefit from the flood control function of a wetland.
Some stakeholders and beneficiaries may not live in the vicinity of the wetland at all. This is
particularly true when considering beneficiaries of the intrinsic/existence benefits of a wetland
such as biodiversity or cultural heritage. These aspects of a wetland benefit the wider public.
Thus it is important to identify you target group of benificaries and stakeholders for each of thewetland benefits/functions/services you want to value.
3.3
Step 4 –Identify the constraints under which the valuation will be carried out
This manual has been developed for estimating the economic value of wetlands when the time
and budget available to complete the valuation is constrainted. It is important to consider the
time, budget, capacity of the person(s) carrying out the valuation and data (basic informationon wetland) available before selecting a of valuation . The criteria for constraints in time,
budget, capacity (staffs capacity), and basic information of wetland is identified as ‘highly
constrainted’, ‘medium constraints’, and ‘small constraints’ in Table 3-1.
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The following steps should be undertaken to identify the most appropriate method of valuation
based on the constraints on time budget and staff capacity;
Define constrains
It is important to identify the constraints for time, budget, capacity (staffs capacity), and basic
information of wetland. See criteria for each option in Table 3-2
Table 3-2 Criteria for each constraint option
Choose a constraint option
Based on your constraints perception, you will have 4 options for selecting an appropriate
valuation method.. Please choose an option in Table 3-3.
Highly constraints Medium constraints Small constraints
Time 2-5 days 3- 5 months More than 6 months
Budget No budget about 80US$/questionnaire* about 120 US$/questionnaire*
Capacity
No basic of naural
resouces economics
Bachalor/master on
environmental economics Ph.D in Economics
Do not have experience in
valuation
Some expriences in
valuation Have Expererience in valuation
Basic information No information of wetland Have some basic data Have all information
Note: *This base on author's experiences. However, it is important to note that cost of survey depend on
geographical condition and type of questionnaire.
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Table 3-3. Constraint Option and appropriate valuation method
Constraint Option 1 Option 2 Option 3 Option 4
Time 000 000 0 0
Budget 000 000 00 0
Capacity 000 000 00 0
Basic Information 000 0 0 0
Appropriate
Method
Benefit
Transfer
Method
Benefit Transfer
Method
Marked Price
Approach
Contingent Value
Method
Go to Chapter
Note 000; Highly constrained
00; Medium constraints
0; Low constraints
3.6 Step 5 - Choosing a valuation method
An appropriate valuation method is indicated in Table 3.2 for each of the 4 Options listed. After
choosing the relevant option base on perceived constraints, we could then go to the chapter
detailing the methodology indicated for that option; e.g. Option – Benefit Transfer Method
(BTM).
However, we can combine four options together based on our constraints. For example, we
might choose the BTM for valuing the flood control function of a wetland, the Market Price
Approach for estimating direct benefits of a wetland such as wild fish capture and the CTV for
estimating the biodiversity value of the wetland.
3.7 Step 6 Calculating the Total Economic Value
This step simply requires the addition of all the values estimated for each of the wetland
benefits/functions/services considered to produce a Total Economic Value for the wetland.
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4.0 Benefit Transfer Method
The Benefit transfer method (BTM) is a popular method when time and cost are constraints. BTM is
using previous study results for estimating the value of the current study site.
There are four steps to follow in order to implement BTM.
Step 1. Review studies on wetlands
Step 2. Select relevant papers and studies to conduct BTM
Step 3. Estimate economic value of wetland
Step 4. Adjust value
5.0. Market Price Approach
Market price approach is the simplest and most straight forward way of finding out the value of
wetland goods because we can find out directly what wetland goods such as sish and other
aquatic animals are consumed and sold.
This method uses a questionnaire to collect data about the market price of buying and selling
wetland goods. For example, catching fish from the wetland for sale in local markets. We can
estimate the economic value of a direct benefit/value (such as fish) by the amount of fish
consumed and sold based on the sale price of the fish.
There are six steps for conducting market base approach as follows.
Step 1. Setting scope of wetland valuation
Step 2. Design questionnaire
Step 3. Decide on sample size
Step 4. Preparing for the survey
Step 5. Input data
Step 6. Estimating a direct value of a wetland
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6.0. Contingent Valuation Method (CVM) or Willingness To Pay (WTP)
This approach, implemented by means of surveys, aims to assess how individuals would
hypothetically react to changes in environmental quality. In particular, it elicits from
respondents how much they would be willing to pay to access improved environmental quality
or avoid a hypothetical reduction in environmental quality. There are many approaches to
estimating “willingness to pay” (WTP), we use an open-end questionnaire which asks people
directly how much they are willing to pay to conserve a particular benefit/function/service of a
wetland. For example, “What is the maximum amount you would be willing to pay to preserve
the biodiversity of a particular wetland?”
There are seven steps for conducting Contingent Valuation Method (CVM) as follows.
Step 1. Select the wetland benefit you wish to value
Step 2 Select the relevant stakeholders/beneficiaries
Step 3. Questionnaire Design
Step 4. Decide sampling size and composition
Step 5. Preparing for the survey
Step 6. Input data
Step 7. Estimating Willingness to pay (WTP)
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