Hi World,
The following is a term paper I submitted for my Geography 211 class on the state of the earth. This project I found to be really interesting, as researching it revealed just how interconnected and interdependent all of the human systems are to natural systems, specifically hydrological cycles and their effects on ecosystems. You dont really realize the extent to which you are wrapped up in all of lifes intricate cycles in daily life; technology has a way of taking us out of this down to earth, geographical frame to put us on a sperate, or higher plane. I believe the DPSIR framework is really helpful to putting us back into thinking about these important cycles of nature, and how our daily action may be harming not only other forms of life, but the future of human life. However, with any way of trying analyze interdependencies between incredibly broad, abstract cycles encapsualting all of nature and ecology, it is hard to focus in on specific examples that demonstrate issues in more tangible ways. I would thus hope that what you take away from reading this, is a frame of thunking about the world that increases your awareness of how essential water is in daily life; noticing the little things and understanding their working on a much larger scale in terms of our progress.
Because this is a blog I took the liberty of including some multimedia which help in the visual exploration of the scale of the environmental impacts of dams that I discuss. Feel free to check out the youtube video as well as the NASA site below before reading the paper; both are really helpful in providing some background context from which to start thinking about theses global environmental issues.
Youtube Video on Dams Worldwide 1800-Present:
NASA Site/Database:
http://sedac.ciesin.columbia.edu/data/collection/grand-v1
Thanks for reading,
Sam
Progress of the Dammed: A DPSIR Framework Analysis of Dams and their Environmental Consequences
Environmentalist Patrick Mc Cully states in the opening section of his book, Silenced Rivers: “Dams… are concrete, rock and earth expressions of the dominant ideology of the technological age: icons of economic development and scientific progress” (2). Indeed, they embody humanity’s seemingly complete control over the external environment so integral to life on earth. By controlling our environment, humans are able to use the life forces of such environmental systems to further our progress. Dams play an integral part of this process by controlling arguably the most important force of nature: water. Water connects all living organisms on earth through providing the means for them to grow and adapt, as well as playing an essential role in the shaping of our physical environment. This ecological link of water to land is played out in a system called a watershed (Horner). The UNEP Global Environmental Outlook 5 defines them as “A group of linked water systems that can include rivers, lakes, reservoirs, wetlands, underlying aquifers and downstream marine systems.” (Gaddis, 100). Humans plants and animals are all also included in the watershed in the sense that the water provides a multitude of ecosystem services that are essential to life (Horner). The river is by far the most important to humans inside of the watershed system, as it is point in the water cycle at which humans have the maximum amount of control over the flow of water. Thus, dams serve to control not only the flow of water but more broadly, the ability of the watershed as a system to provide ecosystems services. The amount of control we have, and need over these ecosystem services is determined by a number of “drivers” and is dependent on society’s physical and ideological needs in furthering human progress (Kristensen, 2). However, by attempting to control such large, natural life forces, there are immediate observable consequences to the ecosystem services and the state of the environment, which in turn impact humans. While the control of rivers through large scale dams are beneficial to humans in a number of ways, I will argue that our ideological idea of ‘progress’ involving our ‘control’ of the environment is extremely problematic, and in many cases is actually detrimental to humanity and to life everywhere on earth.
In order to explore this complex human-environment interaction, some sort of system of analysis is needed. One such framework, adopted by the European Environment Agency (EEA) is the Driver-Pressure-State-Impact-Response framework (DPSIR) (Kristensen, 1). This framework separates the causal chain of human-environment relations into five parts. In this paper I will use DPSIR as a guide to trace the web of connection between human action and environmental response in terms of dams. I will first move to a deeper examination of the drivers aspect of DPSIR, as the reason that we build dams and attempt to control the forces of nature is ultimately the reason why we care about how the environment responds. Through this I will show how the magnitude and scale of drivers have accelerated in the recent past, and move into an analysis of the pressures that such development has had on the state of the environment in present day through scholarly research separated into three broad categories in relation to dams: Hydrology/Floods, Biodiversity and Human/Cultural. Through presenting research on how dams impact the state of the environment through pressures, I will also include how the state of the environment connects back to us by discussing what implications these changes have to society, or their impacts. Turning to the future, I will then consider in the Human/Cultural section, the link between our responses to the impacts of environmental degradation (from dams) and how this has affected and will affect our drivers. Through connecting the causal chain of DPSIR I then look towards what needs to be done so as to avoid unrecoverable negative changes to the hydrological system as a whole.
Globally today, there are an estimated 42,000 large scale dams, and an estimated 800,000 smaller scale dams (Rosenberg, McCully and Pringle). While the reason for controlling the flow of water in rivers has been explained, why have we built so many? The answer lies the driving forces of human action on the environment. Peter Kristensen from Denmark’s National Environmental Research Institute defines ‘Drivers’ as the primary (food, shelter) and secondary (culture, entertainment) needs of human societies, which influences how humanity will interact with the surrounding environment (2). Thus, the more a society progresses, the greater the magnitude and complexity of the driving forces becomes, due to the increased needs that have to be fulfilled. Ronald Wright, in his book A Short History of Progress discusses this idea of progress as increasing our needs, through the example of Sumerian civilization. Wright states that for Sumerians, “Arable land had literally to be created….In this case at least, the hierarchies of civilizations grew with the demands of water control.” (68). “Canals were lengthened, fallow periods reduced, population increased, and the economic surplus concentrated on Ur to support grandiose building projects.” (Wright, 79). From this we can see how human progress through the control of the environment (in this case water) ultimately leads to an intensification of driving forces, both primary and secondary.
However, Wright in his book uses these examples to show how such civilizations fell into ‘progress traps’, or problems inadvertently created by the development of a society through exploitation and abuse of its environment. Thus we must not only look at the benefits that our control of the natural world has for us, but also the negative effects it has on the surrounding ecosystems and cycles, which in turn will eventually impact us. As we know, our progress was accelerated through industrialization and the resulting massive technological advances, so that now more than ever, drivers put pressure on the environment around us through our need for resources. Some of the key influential drivers UNEP notes today are population growth, economic development globally, energy use, globalization and urbanization (Levy, 5). Thus we come back to McCully’s quote from the beginning of the paper. The reason we have built such an enormous number of dams is rooted in our ideology of progress as a species; they fulfill our needs in order for us to progress. Dams serve to fulfill multiple needs listed above: they give us flood protection, reliable and predictable water supplies for irrigation and industry, clean water for people and animals, as well as hydroelectric power. (Gaddis, 108). Now that we understand the background of how and why society puts pressures on the environment through dams, I want to turn my focus to the State and Impact section of the DPSIR framework. States are the effects that the pressures of dams have on the quality of the environment services and ecosystems around them. Impacts are the ways in which those changes in environmental quality affect the abilities of ecosystems to function, thus ultimately affecting human health and progress through providing ecosystem services (Kristensen, 3).
The most damaging impact that dams have on ecosystem services is the adaptation of natural hydrological flood cycles to be in tune with human drivers. The ecology of rivers are built on interacting cycles due to the seasons, these cyclical flood flows provide essential ecological functions for the health of the river (FitzHugh, Vogel). Because dams release water to generate hydroelectricity, they do so at times when power is needed the most, creating flow variation different from natural rhythms (Graf, 1308). Unnatural cycles of flooding mean that ecosystems which are dependent on the natural cycles for initiating other cycles such as reproduction, hatching, migration etc. are thrown out of balance, ultimately reducing the ability for those ecosystems to provide their essential services (McCully, 47). Floods also replenish nutrients to soil at specific times of the year which allow for regular growth and development in plants; if this does not happen the habitats of other non-aquatic species can also be affected, as well as the agricultural lands that depend on floodplains for their nutrient rich soils. By trying to control the natural hydrological cycles to fulfill human needs, the result is actually a reduction in the ability of the ecosystems to provide their services, through the creation of unnatural flood cycles. From here, we can see how different pressures that dams put on the state of the environment build on top of each other, creating multivariable impacts for human society. This increased complexity which means solving the problems they create becomes more difficult as they are more intertwined with human drivers.
Due to our ideology, our response to water insecurity is to build more, larger dams to provide more ecosystem services. However, As William Graf finds in his geographic study of U.S. dams, the bigger the ratio of geographical density and storage capacity of dams to the watershed capacity of the ecoregion, the greater the magnitude for potential damage to the surrounding environment through river fragmentation, ecological disruption etc. (1306). Thus the problem of unnatural flow variation multiplies through increased river fragmentation. Moreover, Graf and Mc Cully both point out the hydrological and geomorphological effects inside reservoirs. Reservoirs, by storing the nutrient rich sediment carrying waters from upstream it stops the waters from moving, increasing its temperature. This leads to unnatural chemical reactions, causing increased algal blooms, and bacteria which harm habitats and species within the reservoir as well as downstream (McCully, 38). Furthermore, by stopping essential sediments and nutrients from flowing freely, we are seeing a loss of deltas (McCully, 35). Deltas are areas in where rivers deposit their sediment load before entering the ocean, creating incredibly agriculturally productive areas; by losing them we are also losing the services they provide in terms of agricultural productivity. Also, the increased surface area of reservoirs leads to increased evaporation; “More than 7 percent of the total amount of freshwater consumed by all human activities (evaporates in reservoirs).” (McCully, 40). This leads to the deoxygenation of the water, which means saltier, nutrient stripped water travelling downstream (McCully, 40). Through irrigating the land with this water, you make it less productive over time, meaning smaller crop yields. It also has a direct impact on biodiversity by harming both aquatic and terrestrial life downstream (McCully, 39). Thus we can see how essential natural river cycle flows are to all of the ecological cycles connected to them in the watershed. The changes that dams enact on these ecosystems ultimately impact us through the reduction of ecosystem services.
This leads me to the second broad category which dams have a negative impact on: biodiversity. Biodiversity is negatively impacted through the changes to surrounding ecosystems already discussed, like affecting life cycles of plants and animals and through worsening water quality. However, I want to further this by examining dams effect on biodiversity in terms of migratory species. The one most obvious effect that dams have on species is through river fragmentation. Fragmentation of rivers is simply the function of a dam as a permanent barrier separating the river into ‘upstream’ of the dam and ‘downstream’, thus isolating species from each other and from movement throughout the river system as a whole (McCully, 31). Moreover, this fragmentation has geomorphological effects which reduce biodiversity by destroying the species habitat (McCully, 42). Salmon are an example of migratory species that have been extremely negatively impacted due to dams. Salmon are “anadromous” fish; they are born in the fresh upriver streams and migrate down to the saltwater where they grow up, and eventually migrate back upstream to give birth and die (McCully, 41). By drastically fragmenting rivers, salmon have species has experienced extreme biodiversity loss due to isolation and habitat destruction. Out of 400 species of salmon, only 214 remain, out of which 169 are threatened or extinct (McCully, 42). But why do we as humans care about biodiversity inside of ecosystems? As UNEP points out, biodiversity is essential to ecosystem services; the more biodiversity an ecosystem has, the stronger the ecosystem is, thus increasing the quality and consistency of the ecosystem services it can provide for us. (Gaddis, 135). Furthermore as well as reducing the resilience of the ecosystem, biodiversity loss also means a reduction of total yield for human consumption. The estimated 10 million yearly yield in the Columbia River basin before and dams were built has been reduced to a mere 1.5 million presently; three quarters of which come from hatcheries (McCully, 41). In expanding our frame from just salmon in the Columbia to biodiversity globally, we can see how migratory species worldwide, and indeed ecosystems are affected. Vorosmaty et al. find that 65% of global river discharge and the aquatic habitat it supports is under moderate to high threat. Thus, the degredation of the environmental services discussed above through disrupting hydrological cycles and reducing biodiversity is a diffuse issue, affecting many species, watersheds and peoples globally.
This global focus brings us to the Human/Cultural category of pressures and impacts. While I have made dams out to be evil, they do have benefits in terms of providing water security, or reliable sources of fresh water. Indeed, Vorosmaty et al. echoes this in stating that such technological investment produces globally significant, positive impacts on water security. However, they also find that because of this, highly developed countries have low level water security threats, even if the incident level threat is high. Thus, it is developing countries who have the highest threats to water security, as the only way they are able to receive these technological investments are through western powers such as the IMF or World Bank. Therefore, dams have deep ties to the global flows of bureaucratic, economic and political power (McCully, 241). What does this mean for who decides our progress? And further, what does this mean in terms of the dichotomy of who decides the state of the environment (through the negative environmental impacts of dams) vs those who actually feels the impacts of such environmental degradation?
The reason that wealthy, developed countries have low levels of water security threats is not just technological investment of the dams themselves, but also the technological investments that result from the environmental degradation that the dams cause. The impacts of dams that I have described in terms of hydrology and biodiversity ultimately have an effect on the wealthy countries. However it is in the resulting responses that actually allow for their needs to be met, and thus for progress to continue. As Vorosmaty et al. puts it “Rich countries…reduce their negative impacts by treating symptoms instead of underlying causes of incident threat”. Some examples of this in relation to the States-Impacts part of the DPSIR framework above are the use of chemical fertilizers to counter the loss of nutrients and the increasing salinity in soils, the investment in desalination plants to make said ‘fresh’ water fresh again, as well as the creation of fish hatcheries to make up for the dwindling number observed in yearly yields (McCully, 35, 41). While these technological investments are quick fixes, they don’t focus on the underlying causes and in many cases (specifically hatcheries), actually add to the impact on the ecosystem services. Additionally, by investing in developing countries through building similar dams, they reduce water security levels, but leave said countries to feel the environmental effects without having the money or power to counter these effects.
So, seeing as our current responses are actually creating more problems than they are solutions, what do we need to do to make significant and meaningful change before it’s too late? The scholars cited in this paper all have overlapping ideas as to possible responses which might help reduce water stress, while benefiting the environment. For one, Vorosmaty et al. points out that global water data is fragmented into country based statistic, but because water does not obey political boundaries, this limits efforts to prioritise areas of protection. FitzHugh and Vogel echo this, arguing generating more specific data for river systems could have practical applications in restoring places whose flow variation is affected the most. Graf, as well as Vorosmaty et al. also calls for a reworking of flow variation, stating that changes in dams rules and regulations could promote natural flood flows, and thus an improvement in ecosystem services (Graf, 1309-1310). Overall, the trend is towards a need for both preserving critical habitat regions, as well as moving towards a greater balance of needs of humans and the environment through integrated resource management (Vorosmaty et al.). However, as McCully points out, the outcome of the extensive damming of river systems globally is unknown. Dams are massive, permanent, environmental experiments with no previous studies done, thus their large scale effects will not be felt in this generation, but for generations years to come (McCully, 31).
Works Cited
FitzHugh, Thomas W., and Richard M. Vogel. “The Impact of Dams on Flood Flows in the United States”. River Research and Applications 27.10 (2011): 1192-1215. Web.
Gaddis, Erica B. et al. “Water” Geo 5 Global Environmental Outlook. United Nations Environment Programme, 2012. Chapter 4. 97-133. Web.
Graf, William F. “Dam Nation: A Geographic Census of American dams and their Large-Scale Hydrologic Impacts”. Water Resources Research 34.4 (1999): 1305-1311. Web.
Horner, Kate. International Rivers. N.p. n.d. Web. <https://www.internationalrivers.org/rivers-in-crisis>
Kristensen, Peter. “The DPSIR Framework”. UNEP Headquarters, Nairobi, Kenya. 27-29 Sept. 2004. Paper Presentation. Web.
Levy, Mark A. et al. “Drivers” Geo 5 Global Environmental Outlook. United Nations Environment Programme, 2012. Chapter 1. 3-33. Web.
Mc. Cully, Patrick. Silenced Rivers: The Ecology and Politics of Large Dams. London: Zed Books Ltd., 1996. Print.
Rosenberg, David M., McCully, Patrick and Catherine M. Pringle. “Global–Scale Environmental Effects of Hydrological Alterations: Introduction”. BioScience 50.9 (2000): 746-751. Web.
Vorosmarty, C.J., et al. “Global threats to human water security and river biodiversity.” Nature 467.7315 (2010): 555+. Health Reference Center Academic. Web.
Wright, Ronald. A Short History of Progress. House of Anansi Press Inc., 2004. Print.