Please see attached file.
Rivers in Crisis: Mapping Dual Threats to Water Security for Biodiversity and Humans SUS-C-7200 Assignment III Data Analysis of Large Datasets Rivers in Crisis: Mapping Dual Threats to Water Security for Biodiversity and Humans Background Rivers maintain unique biotic resources and provide critical water supplies to people. The Earth's limited supplies of fresh water and irreplaceable biodiversity are vulnerable to human mismanagement of watersheds and waterways. Multiple environmental stressors, such as agricultural runoff, pollution and invasive species, threaten rivers that serve 80 percent of the world’s population. These same stressors endanger the biodiversity of 65 percent of the world’s river habitats putting thousands of aquatic wildlife species at risk. Efforts to abate fresh water degradation through highly engineered solutions are effective at reducing the impact of threats but at a cost that can be an economic burden and often out of reach for developing nations. The Rivers in Crisis dataset includes a global database of 23 drivers of environmental stress, categorized into four themes and organized as digital maps. These drivers reflect numerous pathways to ultimate threats to Human Water Security (HWS) and riverine biodiversity (BD) that can be mapped at the global scale. Each driver and theme was weighted according to its relative influence on threat by surveying expert opinion. The geospatial driver values were converted into standardized driver scores needed to calculate the aggregate HWS and BD threat indices. To account for the beneficial impacts of technological advances in engineering and regulatory approaches to enhance HWS, a distinction was made between the Incident HWS Threat index outlined above and an Adjusted HWS Threat index that accounts for investment in water infrastructure and management such as dams, sustainable water use practices, improved access to water resources, and improvements in clean drinking water supplies. Global Threats to River Biodiversity SUS-C-7200 Assignment III Data Analysis of Large Datasets The Rivers in Crisis dataset to be considered in this assignment represents the first global-scale initiative to quantify the impact of these human-induced stressors on Human Water Security and riverine biodiversity. The map figure above shows the global threat index to River Biodiversity. Reference web site: http://www.riverthreat.net/ C.J. Vorosmarty, P.B. McIntyre, M.O. Gessner, D. Dudgeon, A. Prusevich, P. Green, S. Glidden, S.E. Bunn, C.A. Sullivan, C. Reidy Liermann, and P.M. Davies. Global threats to human water security and river biodiversity Nature 467, 555-561 (30 September 2010) doi:10.1038/nature09440 Assignment This assignment will be carried out in two steps: Step I: Rivers in Crisis Dataset Exploration and Investigations (due October 8) You will explore the Rivers in Crisis dataset and determine and investigate three relationships between the data fields that point to environmental issues associated with human activity. All Rivers in Crisis driver datasets are available on-line at the Rivers in Crisis web site (http://www.riverthreat.net/data.html). Associated on-line documentation includes the Nature publication and explanatory notes. There is also an Interactive Mapping Tool that will facilitate your analysis (http://www.riverthreat.net/maps/). In performing your investigation, you may download the datasets or you may use the Interactive Mapping Tool. Each of your three investigations may combine two or more of the drivers datasets on the web site. Each of your analyses may be global, regional, or cross-regional in scope. For each analysis, prepare PowerPoint-style summary charts (approximately 3-5 charts per analysis). Each analysis should include: (1) The topic area of the investigation, the associated list of drivers, and a BRIEF statement (1-2 sentences) summarizing the motivation of the investigation. Why did you look at this particular issue? Why did you think it may be important? Why did you think there may be an interesting relationship between the drivers datasets? (2) Screen shots or other display of the drivers data, indicating the salient issues associated with your comparison. (3) Conclusions that you draw or hypotheses that you postulate that are associated with your observations. This section should include a discussion of the relationships depicted in the screen shots indicating why you are making your conclusions or hypotheses. The three sets of summary charts will be reviewed in class on October 8. You may work in groups during classtime. The assignment should be carried out individually. Step II: Rivers in Crisis Dataset Correlative Comparisons Step II of the assignment will be given on October 8, and will involve a comparative analysis with datasets external to the Rivers in Crisis datasets. http://www.riverthreat.net/ http://www.riverthreat.net/data.html http://www.riverthreat.net/maps/ Rivers in Crisis: Dams, River Fragmentation, and Anadromous Fish Extent in the Pacific Northwest and California Rivers in Crisis Datasets: Description • Dam Density – Describes the density of large and medium dams – Results in river fragmentation (large dams) – Blocks animal movement, e.g. – Has a relative BD threat weight of 0.25 • River Fragmentation – Describes the actual fragmentation of rivers caused by large dams – Isolates aquatic populations and limits gene flow of aquatic species (Allee effect) – Has a relative BD threat weight of 0.30 Comparison • A higher proportion of large dams should result in increased river fragmentation • This limits the gene pool of aquatic species by isolating populations and limiting migration patterns • Therefore, dam density and river fragmentation should be positively correlated • Both have negative impacts on biodiversity Source: Vorosmarty, e. (2010). Global threats to human water security and river biodiversity. Nature , 467, 555-561. Source: Vorosmarty, e. (2010). Global threats to human water security and river biodiversity. Nature , 467, 555-561. Comparison • The river fragmentation driver is positively correlated with the dam density driver • Therefore, streams with a high number of dams tend to be more fragmented • The U.S. shows a high threat for both drivers • Areas of the U.S. with a large population of anadromous species will have a higher biodiversity risk from river fragmentation Global threats to human water security and river biodiversity ARTICLE doi:10.1038/nature09440 Global threats to human water security and river biodiversity C. J. Vörösmarty1*, P. B. McIntyre2*{, M. O. Gessner3, D. Dudgeon4, A. Prusevich5, P. Green1, S. Glidden5, S. E. Bunn6, C. A. Sullivan7, C. Reidy Liermann8 & P. M. Davies9 Protecting the world’s freshwater resources requires diagnosing threats over a broad range of scales, from global to local. Here we present the first worldwide synthesis to jointly consider human and biodiversity perspectives on water security using a spatial framework that quantifies multiple stressors and accounts for downstream impacts. We find that nearly 80% of the world’s population is exposed to high levels of threat to water security. Massive investment in water technology enables rich nations to offset high stressor levels without remedying their underlying causes, whereas less wealthy nations remain vulnerable. A similar lack of precautionary investment jeopardizes biodiversity, with habitats associated with 65% of continental discharge classified as moderately to highly threatened. The cumulative threat framework offers a tool for prioritizing policy and management responses to this crisis, and underscores the necessity of limiting threats at their source instead of through costly remediation of symptoms in order to assure global water security for both humans and freshwater biodiversity. Water is widely regarded as the most essential of natural resources, yet freshwater systems are directly threatened by human activities1–3 and stand to be further affected by anthropogenic climate change4. Water systems are transformed through widespread land cover change, urb- anization, industrialization and engineering schemes like reservoirs, irrigation and interbasin transfers that maximize human access to water1,5. The benefits of water provision to economic productivity2,6 are often accompanied by impairment to ecosystems and biodiversity, with potentially serious but unquantified costs3,7,8. Devising interventions to reverse these trends, including conventions9 and scientific assessments10 to protect aquatic biodiversity and ensure the sustainability of water delivery systems11, requires frameworks to diagnose the primary threats to water security at a range of spatial scales from local to global. Water issues feature prominently in assessments of economic development6, ecosystem services3, and their combination12–14. However, worldwide assessments of water resources2 rely heavily on fragmented data often expressed as country-level statistics, seriously limiting efforts to prioritize their protection and rehabilitation15. High-resolution spatial analyses have taken understanding of the human impact on the world’s oceans16,17 and the human footprint on land18 to a new level, but have yet to be applied to the formal assessment process for freshwater resources2 despite a recognized need19,20. The success of integrated water management strategies depends on striking a balance between human resource use and ecosystem pro- tection2,9,10,21. To test the degree to which this objective has been advanced globally, and to assess its potential value in the future, requires systematic accounting. An important first step is to develop a spatial picture of contemporary incident threats to human water security and biodiversity, where the term ‘incident’ refers to exposure to a diverse array of stressors at a given location. Many stressors threaten human water security and biodiversity through similar pathways, as for pollution, but they also influence water systems in distinct ways. Reservoirs, for example, convey few negative effects on human water supply, but substantially impact on aquatic biodiversity by impeding the movement of organisms, changing flow regimes and altering habitat. Similarly, non-native species threaten biodiversity but are typically inconsequential to human water security. Here we report the results of a global-scale analysis of threats to fresh water that, for the first time, considers human water security and biodiversity perspectives simultaneously within a spatial accounting framework. Our focus is on rivers, which