Photo by: Liang Changsheng

1. Integrated Flood Management addresses issues of flood management from the perspective of human security and sustainable development, within the overall framework of Integrated Water Resources Management. There are no universal criteria to determine environmentally friendly flood management practices. The presentation highlights some of the basic principles that need to be understood to adopt practices that suit the particular circumstances and follow a rational and balanced approach in addressing environmental issues in flood management.Integrated Flood Management addresses issues of flood management from the perspective of human security and sustainable development, within the overall framework of Integrated Water Resources Management.

2. Flood Plains Historically, flood plains have been the preferred places for socio-economic activity as is evident from the very high densities of human settlement found there due to positive impacts of floods. On the other hands, flood plains and the economic activities therein adversely are recurrently affected by flooding. Some of the adverse impacts are debilitating the achievements of development. Therefore, strategies that largely rely on structural solutions, for example, dams, embankments, diversion works, etc. have been adopted in the past.Historically, flood plains have been the preferred places for socio-economic activity as is evident from the very high densities of human settlement found there due to positive impacts of floods.

3. Consequences These interventions have been successful in accelerating the development process in flood plain. However, strategies that largely rely on structural solutions alter the natural environment of the flood plains by fixing the shape of the rivers, separating river channels from their flood plains and altering natural morphological and ecological processes. This has resulted in loss of habitat, biological diversity, ecosystem productivity, and services provided by such ecosystems.These interventions have been successful in accelerating the development process in flood plain. However, strategies that largely rely on structural solutions alter the natural environment of the flood plains by fixing the shape of the rivers, separating river channels from their flood plains and altering natural morphological and ecological processes. This has resulted in loss of habitat, biological diversity, ecosystem productivity, and services provided by such ecosystems.

4. Flood Control  The need and concerns for sustainable development has highlighted the importance of addressing the negative consequences of such flood control and protection measures on the environment and has led to a paradigm shift from flood control to flood management. Integrated Flood Management includes: Maximizing the net benefits from flood plains Reduce loss of life from flooding Reduce flood vulnerability and risks Preserve ecosystems and their associated biodiversity The need and concerns for sustainable development has highlighted the importance of addressing the negative consequences of such flood control and protection measures on the environment and has led to a paradigm shift from flood control to flood management. Integrated Flood Management includes: Maximizing the net benefits from flood plains Reduce loss of life from flooding Reduce flood vulnerability and risks Preserve ecosystems and their associated biodiversity

5. Environment and Sustainable Development Environmental degradation will threaten human security, for example, life, livelihoods, food and health etc�Ecosystems, such as forests, wetlands and lakes provide enormous services to mankind. If ecosystems are mismanaged and water resources are threatened due to environmental changes, those changes lead to unsustainable development.Environmental degradation will threaten human security, for example, life, livelihoods, food and health etc�

6. Ecosystem Services It is useful to have an insight into the ecosystem services being provided by natures. Ecosystem services are �the benefits that people obtain from ecosystems�. These include supporting services such as provisioning (Food, Freshwater, Wood and fibre, Fuel, etc.), regulating (Climate regulation, Flood regulation, Disease regulation, Water purification, etc.), and cultural services needed to maintain other services. Many of these services are closely inter-linked with the well-being of human beings and nature as shown in the figure.It is useful to have an insight into the ecosystem services being provided by natures. Ecosystem services are �the benefits that people obtain from ecosystems�. These include supporting services such as provisioning (Food, Freshwater, Wood and fibre, Fuel, etc.), regulating (Climate regulation, Flood regulation, Disease regulation, Water purification, etc.), and cultural services needed to maintain other services. Many of these services are closely inter-linked with the well-being of human beings and nature as shown in the figure.

7. Development Dilemma Human ingenuity is presented with a dilemma between development imperatives and environmental degradation. However, it is important to understand various causes of such a degradation. Poverty and consumerism: Inequality in modern societies may foster unsustainable behavior because the poor rely on natural resources, and have no real prospects of gaining access to other types of resources while the rich through higher per capital consumption impact the sustainability of natural resources. Agricultural development: Direct impacts of agricultural development on the environment arise from farming activities, which contribute to soil erosion, loss of fertility, land salinization,etc. Industrialization: Large quantities of industrial and hazardous wastes, created by the chemical industry, have compounded the waste management problem with serious environmental health implications. Urbanization: Rapid and unplanned expansion of cities in developing countries has resulted in degradation of the urban environment. Population growth:Increasing population densities in floodplain areas necessitates huge infrastructure investment to protect people, their livelihoods and property from flooding.Most of the poverty alleviation measures for development and improvement of livelihoods and human security are drivers of environmental and ecosystem degradation. Accordingly, flood management policies and practices have to be viewed within this overall matrix. It should be recognized that, within river systems, flooding is the natural way for the system to discharge the water arising from occasional large rainfall events. There is no problem until people decide to use these natural flood plains for socio-economic activities, and realize that occasional flood inundation is acceptable. However, it is important to balance development imperatives and the risks such flooding is likely to pose. It is important to understand these risks in relation to social and economic vulnerability and sustainable development vis-a �vis the preservation of ecosystem services. Human ingenuity is presented with a dilemma between development imperatives and environmental degradation. However, it is important to understand various causes of such a degradation. Poverty and consumerism: Inequality in modern societies may foster unsustainable behavior because the poor rely on natural resources, and have no real prospects of gaining access to other types of resources while the rich through higher per capital consumption impact the sustainability of natural resources. Agricultural development: Direct impacts of agricultural development on the environment arise from farming activities, which contribute to soil erosion, loss of fertility, land salinization,etc. Industrialization: Large quantities of industrial and hazardous wastes, created by the chemical industry, have compounded the waste management problem with serious environmental health implications. Urbanization: Rapid and unplanned expansion of cities in developing countries has resulted in degradation of the urban environment. Population growth:Increasing population densities in floodplain areas necessitates huge infrastructure investment to protect people, their livelihoods and property from flooding.

8. Understanding Ecosystems: Flood managers should understand what are the basic concepts of the morphology and ecology of rivers and their flood plains and how morphological and ecological processes are driven by the flow regime? It requires understanding of the environmental impacts of flood management measures. This will help their in exploring environmentally sensitive designs. In the following items, essentially, we address issues related to the middle and lower reaches of alluvial rivers, which exhibit flood plain development and where river floodplains processes are decoupled from the adjacent hill slopes.  However, ecosystems also play a vital role in determining the hydrological response of a river basin. Therefore, it is important to understand the various hydrological processes generating floods, and how ecosystems interact with such processes to influence the volume, magnitude and timing of flood events. It is also important to understand the potentials and limitations of ecosystems in providing flood moderation. Structural flood control and protection works (such as dams, detention and retention basins, bypass channels, embankments, channelization, etc.) the flow regime, and the sediment transport, water quality and biodiversity associated with them. Many of the flood management measures have the potential to cause consequential hydrological, morphological and environmental impacts, with further significant impacts on socio-economic development.Flood managers should understand what are the basic concepts of the morphology and ecology of rivers and their flood plains and how morphological and ecological processes are driven by the flow regime? It requires understanding of the environmental impacts of flood management measures. This will help their in exploring environmentally sensitive designs.

9. Firstly, flood managers should understand what are the basic concepts of the morphology and ecology of rivers and their flood plains in rivers and their associated flood plains, and how morphological and ecological processes are driven by the flow regime? Under natural conditions, rivers migrate across their floodplain belt and change the configuration of the landform. Flow and sediment regimes, interacting with bed and bank materials and with riverine vegetation, creat and destroy fluvial features, thereby providing a variety of habitats for diverse biotic communities. It is important to understand fluvial processes in flood plains, then, morphological regime, the biological diversity, they hold and how the morphology is contribution to ecological function.Firstly, flood managers should understand what are the basic concepts of the morphology and ecology of rivers and their flood plains in rivers and their associated flood plains, and how morphological and ecological processes are driven by the flow regime?

10. Fluvial processes and flood plains It is fundamental for flood manager to understand the basic concepts of morphology (landforms) and ecology (distribution of organisms and ecological processes) in rivers and their associated flood plains. It is also important to understand morphological and ecological processes are driven by the flow regime. Floods is simply a part of the natural variation of hydrological processes, allowing water to flow over the banks and inundations the adjacent lands in case of extreme rainfall events. They play a key role in determining the level of biological productivity and diversity of rivers and their flood plains.It is fundamental for flood manager to understand the basic concepts of morphology (landforms) and ecology (distribution of organisms and ecological processes) in rivers and their associated flood plains. It is also important to understand morphological and ecological processes are driven by the flow regime. Floods is simply a part of the natural variation of hydrological processes, allowing water to flow over the banks and inundations the adjacent lands in case of extreme rainfall events. They play a key role in determining the level of biological productivity and diversity of rivers and their flood plains.

11. In the long-term timescale, the independent drivers in a given river basin are its geology and climate. The local temperature and rainfall regimes weather the exposed rocks, determining the character of the soil and the type of vegetation that can grow across the basin. Together, acting through the stream network, all of these variables prescribe the discharge, sediment and wood debris regimes at the catchments� outlet.In the long-term timescale, the independent drivers in a given river basin are its geology and climate. The local temperature and rainfall regimes weather the exposed rocks, determining the character of the soil and the type of vegetation that can grow across the basin. Together, acting through the stream network, all of these variables prescribe the discharge, sediment and wood debris regimes at the catchments� outlet.

12. What is the definition of a flood plain? Ecologists and hydrologists have different understand of a flood plain. According to Ecologists floodplain is �Area that are periodically inundated by lateral overflow of rivers or lakes, or by direct precipitation or even by a rise in ground water level�.Hydrologists on the other hand tend to describe flood plain in more precise manner �Area on both banks of a river inundated by a flood event with a recurrent interval of 100 years�. As such, we can define the extent of a flood plain by �the specific geomorphic and vegetation characteristics� and �the objectives of floodplain management.�What is the definition of a flood plain? Ecologists and hydrologists have different understand of a flood plain. According to Ecologists floodplain is �Area that are periodically inundated by lateral overflow of rivers or lakes, or by direct precipitation or even by a rise in ground water level�.

13. Morphological Regime River landscape is determined by the interactions among water in hydrological regime, sediment concentration and characteristics, the slopes, course woody debris carried by the flows, bed and bank materials, and vegetation, etc. River landscape is modified by the movable sediment boundary through erosion and deposition processes, and creating a range of channel or patterns depending on its stream power or energy.River landscape is determined by the interactions among water in hydrological regime, sediment concentration and characteristics, the slopes, course woody debris carried by the flows, bed and bank materials, and vegetation, etc. River landscape is modified by the movable sediment boundary through erosion and deposition processes, and creating a range of channel or patterns depending on its stream power or energy.

14. Morphological Regime Flood plains have highly heterogeneous ecosystems and a complex assemblage of small channels, depressions, backwaters, hillocks, ridges, etc. Depression wetlands within large flood plains are connected to rivers by small channels, and are bringing flood water and associated fine sediment and nutrients. They are also allowing migration of fish that spwan on the flood plain, and are providing habitats for birds. This figure shows an alluvial river corridor (the river channel along with the flood plain formed through the alluvial process). The fluvial processes of erosion and sedimentation, driven by flooding, sediment transport, woody deposition and vegetation growth, continuously modify the entire river corridor, even though, from a distance, the landscape might seem unchanged. They are in a dynamic equilibrium.Flood plains have highly heterogeneous ecosystems and a complex assemblage of small channels, depressions, backwaters, hillocks, ridges, etc. Depression wetlands within large flood plains are connected to rivers by small channels, and are bringing flood water and associated fine sediment and nutrients. They are also allowing migration of fish that spwan on the flood plain, and are providing habitats for birds. This figure shows an alluvial river corridor (the river channel along with the flood plain formed through the alluvial process). The fluvial processes of erosion and sedimentation, driven by flooding, sediment transport, woody deposition and vegetation growth, continuously modify the entire river corridor, even though, from a distance, the landscape might seem unchanged. They are in a dynamic equilibrium.

15. Morphological Regime There are two kinds of phenomena in morphological regime, e.g., aggradation and degradation. Aggradation is continuously raising bed levels under natural conditions or due to human induced land use change, deforestation, etc. Figure shows the case of hanging river formed as part of aggradation due to natural and man made induced processes. If embanked, to avoid flooding and lateral avulsions, aggradations continue within the narrowed channel, raising the bed levels to higher elevations than the surrounding flood plains. On the other hand, degradation is lowering of the bed levels due to reduction of sediment supply by dam construction, soil protection, reforestation, etc. It can cause serious environmental change along a river corridor, including loss of riverine vegetation due to lowering of the groundwater table, etc.There are two kinds of phenomena in morphological regime, e.g., aggradation and degradation. Aggradation is continuously raising bed levels under natural conditions or due to human induced land use change, deforestation, etc. Figure shows the case of hanging river formed as part of aggradation due to natural and man made induced processes. If embanked, to avoid flooding and lateral avulsions, aggradations continue within the narrowed channel, raising the bed levels to higher elevations than the surrounding flood plains. On the other hand, degradation is lowering of the bed levels due to reduction of sediment supply by dam construction, soil protection, reforestation, etc. It can cause serious environmental change along a river corridor, including loss of riverine vegetation due to lowering of the groundwater table, etc.

16. Biological diversity Biological diversity requires three basic elements: the adequate quality of water, appropriate variability of focus and the diversity of habitat. The later is determined by the spatial heterogeneity and temporal variability. Both of them are grounded by the flow regime and the sediment regime. All the three forms of connectivity helps in keeping these regimes in place. Shifting habitat created by disturbances, are essential components of riverine ecosystems.Biological diversity requires three basic elements: the adequate quality of water, appropriate variability of focus and the diversity of habitat. The later is determined by the spatial heterogeneity and temporal variability. Both of them are grounded by the flow regime and the sediment regime. All the three forms of connectivity helps in keeping these regimes in place. Shifting habitat created by disturbances, are essential components of riverine ecosystems.

17. Morphological and Ecological Connectivity River corridor are understood as three-dimensional systems that change in time and space. As biological diversity depends on a variable flow regime and sediment regime, changes that effect this variability will have impact on the biodiversity of the river corridor. The lateral connectivity between the river channel and its flood plain, if disturbed, will disturb the existing flow and sediment regime. The new regime may not be able to maintain the habitat that is conclusive to the existence of the bio diversity. Similar is the case with longitudinal as well as vertical connectivity.River corridor are understood as three-dimensional systems that change in time and space. As biological diversity depends on a variable flow regime and sediment regime, changes that effect this variability will have impact on the biodiversity of the river corridor. The lateral connectivity between the river channel and its flood plain, if disturbed, will disturb the existing flow and sediment regime. The new regime may not be able to maintain the habitat that is conclusive to the existence of the bio diversity. Similar is the case with longitudinal as well as vertical connectivity.

18. Framework (1/3) In order to translate environmental consideration into decision-making processes in flood management, a environment-friendly decision-making process at each stage is called for. Starting from flood management policy formulation to developing basin plan for flood management and down to designing various measures and their implementation.In order to translate environmental consideration into decision-making processes in flood management, a environment-friendly decision-making process at each stage is called for. Starting from flood management policy formulation to developing basin plan for flood management and down to designing various measures and their implementation.

19. Framework (2/3) A number of public policies not directly linked to flood management also impact flood risks. Basin flood management goals are guided among others by the environmental drivers and the goals.A number of public policies not directly linked to flood management also impact flood risks. Basin flood management goals are guided among others by the environmental drivers and the goals.

20. Framework (3/3) Environmental assessment at various levels of decision-making is important. Strategic Environmental Assessment (SEA) is a proactive approach at the strategic level helps pre identify key issues that should be addressed in the subsequent Environmental Impact Assessment (EIA), which is carried out at the project design and implementation level. SEA supports EIA in screening, scoping and thereby integrating environmental considerations into decision-making processes. Environmental assessment at various levels of decision-making is important. Strategic Environmental Assessment (SEA) is a proactive approach at the strategic level helps pre identify key issues that should be addressed in the subsequent Environmental Impact Assessment (EIA), which is carried out at the project design and implementation level. SEA supports EIA in screening, scoping and thereby integrating environmental considerations into decision-making processes.

21. THE FRAMEWORK In order to minimize subjectivity in decision-making, an environmentally sensitive framework needs to be established following a threefold approach of avoiding, reducing and mitigation the adverse environmental impacts without compromising on flood management objectives.In order to minimize subjectivity in decision-making, an environmentally sensitive framework needs to be established following a threefold approach of avoiding, reducing and mitigation the adverse environmental impacts without compromising on flood management objectives.

22. Environmental Assessment Environmental assessment at various levels of decision-making is important. Strategic Environmental Assessment (SEA) is a proactive approach at the strategic level. It can help pre-identify key issues that should be addressed in the subsequent Environmental Impact Assessment (EIA), which are implemented at the project design and implementation level. SEA supports EIA in screening, scoping and thereby integrating environmental considerations into decision-making processes. The basic objective of the two is to factor environment issues in decision-making. However, the differences is in the levels of detail and assessment of alternatives. However, the two are similar in the procedures, in other words, follow the same stages of screening, scoping, identification, prediction and evaluation of impacts, monitoring. Stakeholder participation is the underlying foundation for all the processes.Environmental assessment at various levels of decision-making is important. Strategic Environmental Assessment (SEA) is a proactive approach at the strategic level. It can help pre-identify key issues that should be addressed in the subsequent Environmental Impact Assessment (EIA), which are implemented at the project design and implementation level. SEA supports EIA in screening, scoping and thereby integrating environmental considerations into decision-making processes. The basic objective of the two is to factor environment issues in decision-making. However, the differences is in the levels of detail and assessment of alternatives. However, the two are similar in the procedures, in other words, follow the same stages of screening, scoping, identification, prediction and evaluation of impacts, monitoring. Stakeholder participation is the underlying foundation for all the processes.

23. Environmentally sensitive economic analysis Cost-benefit analysis (CBA) and Multi criteria analysis (MCA) are useful methodologies that support decision-making when a suite of options have to be analysed in relation to their economic aspects. Cost-benefit analysis (CBA) is used to compare costs versus benefits in monetary terms and has limit actions in evaluating the true costs and benefits of the environmental and societal aspects. Multi Criteria Analysis (MCA) is used to judge the expected performance of each development option against a number of societal and environmental criteria. It is useful in ranking options and short-listing a limited number of options and is carried out with full participation of all stakeholder. A complementary approach using CBA and MCA is most suitable.Cost-benefit analysis (CBA) and Multi criteria analysis (MCA) are useful methodologies that support decision-making when a suite of options have to be analysed in relation to their economic aspects. Cost-benefit analysis (CBA) is used to compare costs versus benefits in monetary terms and has limit actions in evaluating the true costs and benefits of the environmental and societal aspects. Multi Criteria Analysis (MCA) is used to judge the expected performance of each development option against a number of societal and environmental criteria. It is useful in ranking options and short-listing a limited number of options and is carried out with full participation of all stakeholder. A complementary approach using CBA and MCA is most suitable.

24. Adaptive Management (1/2) While understanding of river morphology and ecology is the key to achieving Integrated Flood Management, scientific knowledge about the existing conditions of ecosystems is fragmentary. At the same time, impacts of human interventions on ecosystems are not fully understood. In order to account for this lack of scientific certainly, precautionary principles are recommended. Adaptive management approaches such scientific uncertainties through continuous monitoring and evaluation of applied strategies, incorporating new knowledge as it becomes available.While understanding of river morphology and ecology is the key to achieving Integrated Flood Management, scientific knowledge about the existing conditions of ecosystems is fragmentary. At the same time, impacts of human interventions on ecosystems are not fully understood. In order to account for this lack of scientific certainly, precautionary principles are recommended.

25. Adaptive Management (2/2) Adaptive management has been widely recognized as the appropriate approach to deal with such scientific uncertainties wherein, decisions are made as part of an ongoing science-based process. It involves planning, acting, monitoring and evaluating applied strategies, and incorporating new knowledge as it becomes available into management approaches. The importance of monitoring has been recognized from various perspectives. At the development planning level, the achievement of objectives of the plan can be evaluated and assessed. During and post-implementation, monitoring is important at the project level, in order to assess whether the flood management measures has met the desired objectives. It also can assess whether the extent of the impacts foreseen being manifested and whether the measures are taken to prevent them effective. They can improve the methodology applied in future plans and project designs. .Adaptive management has been widely recognized as the appropriate approach to deal with such scientific uncertainties wherein, decisions are made as part of an ongoing science-based process. It involves planning, acting, monitoring and evaluating applied strategies, and incorporating new knowledge as it becomes available into management approaches. The importance of monitoring has been recognized from various perspectives. At the development planning level, the achievement of objectives of the plan can be evaluated and assessed. During and post-implementation, monitoring is important at the project level, in order to assess whether the flood management measures has met the desired objectives. It also can assess whether the extent of the impacts foreseen being manifested and whether the measures are taken to prevent them effective. They can improve the methodology applied in future plans and project designs. .