Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth’s gravity interacts with other objects in space, especially the Sun and the Moon, Earth’s only natural satellite. Earth revolves around the Sunin 365.26 days, a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times.
Earth’s axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth. The gravitational interaction between Earth and the Moon causes ocean tides, stabilizes Earth’s orientation on its axis, and gradually slows its rotation. Earth is the densest planet in the Solar System and the largest of the four terrestrial planets.
Earth’s lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earth’s surface is covered with water, mostly by oceans. The remaining 29% is land consisting of continents and islands that together have many lakes, rivers and other sources of water that contribute to the hydrosphere. The majority of Earth’s polar regions are covered in ice, including the Antarctic ice sheet and the sea ice of the Arctic ice pack. Earth’s interior remains active with a solid iron inner core, a liquid outer core that generates the Earth’s magnetic field, and a convecting mantle that drives plate tectonics.
Within the first billion years of Earth’s history, life appeared in the oceans and began to affect the Earth’s atmosphereand surface, leading to the proliferation of aerobic and anaerobic organisms. Some geological evidence indicates that life may have arisen as much as 4.1 billion years ago. Since then, the combination of Earth’s distance from the Sun, physical properties, and geological history have allowed life to evolve and thrive. In the history of the Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinction events. Over 99% of all species that ever lived on Earth are extinct. Estimates of the number of species on Earth today vary widely; most species have not been described. Over 7.6 billion humans live on Earth and depend on its biosphere and natural resources for their survival. Humans have developed diverse societies and cultures; politically, the world has about 200 sovereign states.
The Challenges faced by more and more countries in their struggle for economic and social development are increasingly related to water. Water shortages, quality deterioration and flood impacts are among the problems which require greater attention and action. Integrated Water Resources Management (IWRM) is a process which can assist countries in their endeavour to deal with water issues in a cost-effective and sustainable way. The concept of IWRM has attracted particular attention following the international conferences on water and environmental issues in Dublin and Rio de Janeiro held during 1992; however IWRM has neither been unambiguously defined nor has the question of how it is to be implemented been fully addressed. There are certain Practical Situations leading to IWRM are:
Resource Under Pressure: The world’s freshwater resources are under increasing pressure. Growth in population, increased economic activity and improved standards of living lead to increased competition for and conflicts over the limited freshwater resource.
Populations under water stress; The world population has increased by a factor of about three during the 20th century whereas water withdrawals have increased by a factor of about seven. It is estimated that currently one third of the world’s population live in countries that experience medium to high water stress. This ratio is expected to grow to two thirds by 2025.
The impact of pollution; Pollution of water is inherently connected with human activities. In addition to serving the basic requirement of biotic life and industrial processes, water also acts as a sink and transport mechanism for domestic, agricultural and industrial waste causing pollution. Deteriorating water quality caused by pollution influences water usability downstream, threatens human health and the functioning of aquatic ecosystems so reducing effective availability and increasing competition for water of adequate quality.
Water governance crisis; The above problems are aggravated by shortcomings in the management of water. Sectoral approaches to water resources management have dominated and are still prevailing; this leads to the fragmented and uncoordinated development and management of the resource. Moreover, water management is usually left to top-down institutions, the legitimacy and effectiveness of which have increasingly been questioned.
Integrated Water Resource Management has certain Goals to Achieve;
Securing Water for People: ; Although most countries give first priority to satisfaction of basic human needs for water, one fifth of the world’s population is without access to safe drinking water and half of the population is without access to adequate sanitation. These service deficiencies primarily affect the poorest segments of the population in developing countries. In these countries, water supply and sanitation for urban and rural areas represents one of the most serious challenges in the years ahead.
Securing water for food production; ; Population projections indicate that over the next 25 years food will be required for another 2-3 billion people. Water is increasingly seen as a key constraint on food production, on a par with, if not more crucial than, land scarcity. Irrigated agriculture is already responsible for more than 70% of all water withdrawals (more than 90% of all consumptive use of water). Even with an estimated need for an additional 15-20% of irrigation water over the next 25 years – which is probably on the low side – serious conflicts are likely to arise between water for irrigated agriculture and water for other human and ecosystem uses. Difficulties will be exacerbated if individual water-short countries strive for food selfsufficiency rather than achieving food security through trade; by importing food countries can in effect import water from more generously endowed areas (the concept of “virtual water”).
Developing other job creating activities; All human activities need water and produce waste, but some of them need more water or produce more waste per job than others. This consideration has to be taken into account in economic development strategies, especially in regions with scarce water resources.
Protecting vital ecosystems; Terrestrial ecosystems in the upstream areas of a basin are important for rainwater infiltration, groundwater recharge and river flow regimes. Aquatic ecosystems produce a range of economic benefits, including such products as timber, fuelwood and medicinal plants, and they also provide wildlife habitats and spawning Global Water Internship. The ecosystems depend on water flows, seasonality and watertable fluctuations and have water quality as a fundamental determinant. Land and water resources management must ensure that vital ecosystems are maintained and that adverse effects on other natural resources.
Dealing with variability of water in time and space; Almost all the freshwater available for human use originates from precipitation, which varies immensely over time and space. Most tropical and sub-tropical regions of the world are characterized by huge seasonal and annual variations in rainfall, often compounded by erratic short-term variations. Such variability manifoldly increases the demand for infrastructure development and the need to manage water demand and supply. The challenge in managing variability is clearly greatest in the poorest countries with the least financial and human resources to cope with the problem. The effects of global climate change may add further to this challenge.
Managing risks; Variations in water flows and groundwater recharge, whether of climatic origin or due to land mismanagement, can add to drought and flood events, which can have catastrophic effects in terms of large scale loss of human life and damage to economic, social and environmental systems. Water pollution creates another set of risks, affecting human health, economic development and ecosystem functions. Economic risks are also important in water resources management and development due to the often large-scale and long-term character of the investments required. Political instability and change represents yet another important risk factor for IWRM. To date, relatively little attention has been paid to the systematic assessment of risk mitigation costs and benefits across the water use sectors and to the consequent evaluation of various risk trade-off options.
Creating popular awareness and understanding; Public awareness is needed in order to mobilize effective support for sustainable water management and induce the changes in behaviour and action required to achieve this. Additionally, public awareness and subsequent pressure for action may be vital in fostering the political will to act.
The Principles of IWRM are as Follows:
I Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment. Integrated Water Resources Management.
II Water development and management should be based on a participatory approach, involving users, planners and policymakers at all levels.
III Women play a central part in the provision, management and safeguarding of water.
IV Water has an economic value in all its competing uses and should be recognized as an economic good.
The important role of reliable data such as water quality measurement is indisputable. This is not only a natural scientific dogma but also largely recognized by various international water management bodies. For example, the theme of the World Water Day in 2010 was in fact ‘water quality’. On this day the International Water Association stressed “the urgent need to step up research, monitoring and assessment of water quality at global, regional, and local levels”. The role of research results as inputs to sound policy formation and implementation was also high-lighted as another core message. Scientific studies have also shown that reliable data that all parties can trust are crucial for the knowledge-based management of water resourcesIn this special issue, Skarbøvik et al. stress the need for reliable data and information as an important basis for integrated water resources management (IWRM). Such data are especially important in transboundary water bodies, as they can represent a common and transparent knowledge-base that all concerned parties can trust and utilise in the management process. Their case study area was the transboundary Lake Macro Prespa (West Balkan). Important results from these include that water quality monitoring can give inadequate or even erroneous information if all steps of the data aquisition are not thoroughly understood and quality assured, and that the lack of accreditation and inter-comparisons between laboratories was the main challenge for obtaining reliable water quality data in this case study.IWRM is the Highly efficient method that can be employed to solve all water problems throughout the World.