A substance, factor, change, living being or a system that quantifies and simplifies phenomena and helps in understanding complex realities, is called as indicator. It tells us something about changes in a system.
There are many types of indicators some of which are- Financial Indicators, Poverty Indicators, Health Indicators, Environmental Indicators, and Indicators of Sustainable Development.
Financial Indicators describe changes in the state of individual, local and national economies. Poverty Indicators describe poverty whereas health indicators describe changes in the health conditions.
Environmental Indicators expose realities relating to good or bad health of environment of a particular area and status of interactions among its components. These are selected to provide information about the functioning of a specific system to support decision making and management.
Indicators quantify and aggregate data that can be measured and monitored to determine whether some changes are taking place. The indicators need to help the decision makers understand why the change is taking place so as to make the environmental managers able to understand the actual process of changes.
Here we are principally concerned with the indicators of environment. These indicators show the condition of environment, for example the level of pollution, health of ecosystem etc.
A number of factors are considered for the assessment and prediction of the health of environment and balance among its various components that are feared to be affected due to anthropogenic activities.
The effective and reliable monitoring systems that are required for assessing, recognizing and predicting adverse impacts of anthropogenic activities on the health of environment are called as environmental indicators.
There are a number of environmental indicators. These may be bio-indicators or Ecological indicators. Some of the indicators of this type may be the Indicators of Land Productivity, Agriculture, Climate, soil type, fire, petroleum deposits, concentration of gases, pollutions etc., micro-organisms, plants, animals, cell organelles, organs, individuals, populations, biotic communities and ecosystems that show different levels of sensitivities towards impacts of anthropogenic origin are some indicators. These can be considered and impacts can be analysed to asses and predict environmental changes in periodic manner
Organisation for Economic Co-operation and Development (OECD) has designed DPSIR or “drivers, pressures, state, impact, response” framework for environmental indicators.
OECD is a multidisciplinary international body made up of 30 member countries that offers a forum for governments to consult and co-operate with each other in order to develop and refine economic and social policy.
In this abbreviation of environmental indicators drivers and pressures are indicators of the human activities and resulting pressures on the environment in the form of pollution or land-use change. State and impact indicators are the resulting conditions in the environment and the implications for the health of ecosystems and humans.
The varying conditions of ecosystems and its critical state are indicators of the system’s health. The response indicators measure the reaction of human society to the environmental issue. Criteria tend to focus on three key areas – scientific credibility, policy/social relevance and practical monitoring and data requirements.
Uses of Environmental Indicators
• Use of Environmental Indicators is made by Governmental and Non- governmental Organisations, community groups and research institutions to observe if objectives of environmental conservation are met properly
• These indicators are also used and to communicate the state of the environment to the general public and decision makers
• Environmental Indicators are also used as a diagnostic tool for detecting trends in the environment
Important Points to remember while using Environmental Indicators
While making use of indicators, the environmental managers should bear following facts in mind –
(i) It is not possible to develop indicators without the stock of sufficient information and accurate data,
(ii) Appropriate targets should be set to measure performance,
(iii) Indicators should take into account different locations, communities, cultures and institutions etc. because different people living in different locations have different values.
(iv) Different sets of indicators are evolved overtime, and these are seldom, if ever complete,
(v) The measurement of indicators has tendencies to eliminate the conditions of uncertainty, but it does not eliminate these conditions,
(vi) Making changes in indicators can change the system.
Basic Functions Environmental Indicators
The Environmental Indicators have some basic functions like – simplification, quantification and communication. The environmental indicators indicate environmental conditions in simple ways that remain easy to understand. They should show the extent of the environmental conditions in clear terms and they must communicate the message or the indication of particular environmental conditions.
The environmental indicators should meet the following criteria-
(i) These should be sound scientifically,
(ii) These should be easy to understand,
(iii) These should show trends overtime,
(iv) These should be sensitive to the changes that these are intended to measure,
(v) These should be measurable and capable of being updated regularly, and
The data and information from environmental indicators should be easily available