Download or read book Ecohydrologic Impacts of Climate and Land Use Changes on Watershed Systems written by Paul A. Ekness and published by . This book was released on 2013 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maintaining flows and quality of water resources is critical to support ecosystem services and consumptive needs. Understanding impacts of changes in climate and land use on ecohydrologic processes in a watershed is vital to sustaining water resources for multiple uses. This study completes a continental and regional scale assessment using statistical and simulation modeling to investigate ecohydrologic impacts within watershed systems. Watersheds across the continental United States have diverse hydrogeomorphic characters, mean temperatures, soil moistures, precipitation and evaporation patterns that influence runoff processes. Changes in climate affect runoff by impacting available soil moisture, evaporation, precipitation and vegetative patterns. A one percent increase in annual soil moisture may cause a five percent increase in runoff in watersheds across the continent. Low soil moisture and high temperatures influence runoff patterns in specific regions. Spring runoff is increased by the influence Spring soil moisture, Winter and Spring evaporation, and Winter and Spring evaporation. Spring runoff is decreased by increases in Winter and Spring temperatures and increases in the vegetation index. Winter runoff is affected by maximum vegetative index, temperature, soil moisture, evaporation and precipitation. Contributing factors to runoff are influenced by geomorphic and seasonal variations requiring strategies that are site-specific and use system-wide information. Regional scale watershed analysis investigates the influence of landscape metrics on temporal streamflow processes in multiple gauged watersheds in Massachusetts, U.S.A. Time of concentration, recession coefficient, base flow index, and peak flow are hydrologic metrics used to relate to landscape metrics derived using FRAGSTAT software. Peak flow increases with increasing perimeter-area fractal dimensions, and Contagion index and decreases as Landscape Shape Index increases. There was an increasing trend in the fractal dimension over time indicative of more complex shape of patches in watershed. Base flow index and recession coefficient fluctuated from low to high decreasing recently. This could be indicative of open space legislation, conservation efforts and reforestation within the state in the last ten years. Coastal systems provide valuable ecosystem services and are vulnerable to impacts of changes in climate and continental land use patterns. Effects of land use and climate change on runoff, suspended sediments, total nitrogen and total phosphorus are simulated for coastal watersheds around the Boston Bay ecosystem. The SWAT (Soil and Water Assessment Tool) model, a continuous-time, semi distributed, process-based model, is used to simulate the watershed ecohydrologic process affecting coastal bodies. Urbanization in watersheds increased runoff by as much as 80% from the baseline. Land use change poses a major threat to water quality impacts affecting coastal ecosystems. Total nitrogen increased average of 53.8% with conservative changes in climate and land use. Total phosphorus increased an average of 57.3% with conservative changes in land use and climate change. Climate change alone causes up to 40% increase in runoff and when combined with a 3.25% increase in urban development runoff increased an average of 114%. Coastal ecosystems are impacted by nutrient runoff from watersheds. Continued urbanization and changes in climate will increase total nitrogen, total phosphorus and suspended sediments in coastal ecosystems. Continental scale runoff is affected by soil moisture and vegetative cover. Cover crops, low tillage farm practices and natural vegetation contribute to less runoff. Developing policies that encourage protection of soil structure could minimize runoff and aid in maintaining sustainable water resources. Best Management Practices and Low impact development at the national level with continued stormwater legislation directed towards sustainable land use policy will improve water quantity and quality. Fragmentation observed in Massachusetts increases the number of urban parcels and decreases the size of forested areas. Faster runoff patterns are observed but recent land management may be changing this runoff pattern. Municipal and state zoning ordinance to preserve open space and large forest patches will restrict urban growth to specific regions of a watershed. This could improve quantities of water available to ecosystems. Increases in total nitrogen, phosphorus and suspended sediments to coastal ecosystems can be minimized with use of riparian buffers and Best Management Practices within coastal watersheds. Urbanization and climate change threatens coastal ecosystems and national policy to preserve and restrict development of coastal areas will preserve coastal ecosystem services.

Download or read book Abrupt Climate Change written by National Research Council and published by National Academies Press. This book was released on 2002-04-23 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The climate record for the past 100,000 years clearly indicates that the climate system has undergone periodic-and often extreme-shifts, sometimes in as little as a decade or less. The causes of abrupt climate changes have not been clearly established, but the triggering of events is likely to be the result of multiple natural processes. Abrupt climate changes of the magnitude seen in the past would have far-reaching implications for human society and ecosystems, including major impacts on energy consumption and water supply demands. Could such a change happen again? Are human activities exacerbating the likelihood of abrupt climate change? What are the potential societal consequences of such a change? Abrupt Climate Change: Inevitable Surprises looks at the current scientific evidence and theoretical understanding to describe what is currently known about abrupt climate change, including patterns and magnitudes, mechanisms, and probability of occurrence. It identifies critical knowledge gaps concerning the potential for future abrupt changes, including those aspects of change most important to society and economies, and outlines a research strategy to close those gaps. Based on the best and most current research available, this book surveys the history of climate change and makes a series of specific recommendations for the future.

Download or read book Impacts of Anthropogenic Activities on Watersheds in a Changing Climate written by Luís Filipe Sanches Fernandes and published by MDPI. This book was released on 2021-04-14 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: The immediate goal of this Special Issue was the characterization of land uses and occupations (LULC) in watersheds and the assessment of impacts caused by anthropogenic activities. The goal was immediate because the ultimate purpose was to help bring disturbed watersheds to a better condition or a utopian sustainable status. The steps followed to attain this objective included publishing studies on the understanding of factors and variables that control hydrology and water quality changes in response to human activities. Following this first step, the Special Issue selected work that described adaption measures capable of improving the watershed condition (water availability and quality), namely LULC conversions (e.g., monocultures into agro-forestry systems). Concerning the LULC measures, however, efficacy was questioned unless supported by public programs that force consumers to participate in concomitant costs, because conversions may be viewed as an environmental service.

Download or read book Climate Change and Land Use Cover Change Impacts on Watershed Hydrology Nutrient Dynamics a Case Study in Missisquoi River Watershed written by Linyuan Shang and published by . This book was released on 2019 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Watershed regulation of water, carbon and nutrient dynamics support food, drinking water and human development. Projected climate changes and land use/cover change (LUCC) have been identified as drivers of watershed nutrient and hydrological processes and are likely to happen jointly in the future decades. Studying climate change and LUCC impacts on watersheds' streamflow and nutrients dynamics is therefore essential for future watershed management. This research aimed to unveil how climate change and LUCC affect water and nutrient dynamics in the Missisquoi River watershed, Vermont. We used 12 scenarios of future climate data (2021 - 2050) generated by three GCMs (ccsm4, mri-cgcm3, and gfdl-esm2m) under four Representative Concentration Pathways (RCPs). For LUCC, we used three different scenarios generated by the Interactive Land Use Transition Agent-Based Model (ILUTABM). The three LUCC scenarios were Business As Usual (BAU), Prefer Forest (proForest), and Prefer Agriculture (proAg). New land use maps were generated every 10 years for the period of 2021 - 2050. Combining each climate change and LUCC scenario resulted in 36 scenarios that were used to drive Regional Hydro-Ecologic Simulation System (RHESSys) ecohydrological model. In chapter 3, we used RHESSys to study streamflow. We found climate was the main driver for streamflow because climate change directly controlled the system water input. For streamflow, climate change scenarios had larger impacts than LUCC, different LUCCs under the same climate change scenario had similar annual flow patterns. In chapter 4, we used RHESSys to study streamflow NO3-N and NH4-N load. Because fertilizer application is the major source for nitrogen export, LUCC had larger impacts; watersheds with more agricultural land had larger nitrogen loads. In chapter 5, we developed RHESSys-P by coupling the DayCent phosphorus module with RHESSys to study climate change and LUCC impacts on Dissolved Phosphorus (DP) load. RHESSys-P was calibrated with observed DP data for 2002 - 2004 and validated with data for 2009 - 2010. In both calibration and validation periods, simulated DP basically captured patterns of observed DP. In the validation period, the R2 of simulated vs observed DP was 0.788. Future projection results indicated BAU and proForest annual loads were around 4.0 x 104 kg under all climate change scenarios; proAg annual loads increased from around 4.0 x 104 kg in 2021 to 1.6 x 105 kg in 2050 under all climate change scenarios. The results showed LUCC was the dominant factor for dissolved phosphorus loading. Overall, our results suggest that, while climate drives streamflow, N and P fluxes are largely driven by land use and management decisions. To balance human development and environmental quality, BAU is a feasible future development strategy.

Download or read book Water and Land Security in Drylands written by Mohamed Ouessar and published by Springer. This book was released on 2017-04-25 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent lessons learned in the context of research and development for various dryland ecosystems, focusing on water resources management, land and vegetation cover degradation and remediation, and socioeconomic aspects, as well as integrated approaches to ensuring water and land security in view of the current and predicted climate change. As water and land are the essential bases of food production, the management of these natural resources is becoming a cornerstone for the development of dryland populations. The book gathers the peer-reviewed, revised versions of the most outstanding papers on these topics presented at the ILDAC2015 Conference in Djerba, Tunisia.

Download or read book Hydrology and the Management of Watersheds written by Kenneth N. Brooks and published by John Wiley & Sons. This book was released on 2012-10-01 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition is a major revision of the popular introductory reference on hydrology and watershed management principles, methods, and applications. The book's content and scope have been improved and condensed, with updated chapters on the management of forest, woodland, rangeland, agricultural urban, and mixed land use watersheds. Case studies and examples throughout the book show practical ways to use web sites and the Internet to acquire data, update methods and models, and apply the latest technologies to issues of land and water use and climate variability and change.

Download or read book Hydro Environmental Impact of Climate and Land Use Change on Watersheds for Sustainable Development written by T. I. Eldho and published by . This book was released on 2024-07 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes the most up-to-date research findings on the topics of climate change impact assessment, land use change impact assessment, mathematical modelling, and field applications presented as case studies in the water resources engineering discipline. The book covers various aspects of hydrological and environmental processes; provides a comprehensive treatment of climate change and land use changes and their impacts, illustrated with case studies; and demonstrates recent modelling techniques for hydrological and environmental impact studies. The book may serve graduate students, engineers, professors, and researchers in providing a concise overview of climate and land use change and its impacts on hydrology, water resources, and the environment.

Download or read book Global Deforestation written by Christiane Runyan and published by Cambridge University Press. This book was released on 2016-04-18 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global Deforestation provides a concise but comprehensive examination of the variety of ways in which deforestation modifies environmental processes, as well as the societal implications of these changes. The book stresses how forest ecosystems may be prone to nearly irreversible degradation. To prevent the loss of important biophysical and socioeconomic functions, forests need to be adequately managed and protected against the increasing demand for agricultural land and forest resources. The book describes the spatial extent of forests, and provides an understanding of the past and present drivers of deforestation. It presents a theoretical background to understand the impacts of deforestation on biodiversity, hydrological functioning, biogeochemical cycling, and climate. It bridges the physical and biological sciences with the social sciences by examining economic impacts and socioeconomic drivers of deforestation. This book will appeal to advanced students, researchers and policymakers in environmental science, ecology, forestry, hydrology, plant science, ecohydrology, and environmental economics.

Download or read book Impacts of Landscape Change on Water Resources written by Manoj K. Jha and published by MDPI. This book was released on 2020-11-13 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in land use and land cover can have many drivers, including population growth, urbanization, agriculture, demand for food, evolution of socio-economic structure, policy regulations, and climate variability. The impacts of these changes on water resources range from changes in water availability (due to changes in losses of water to evapotranspiration and recharge) to degradation of water quality (increased erosion, salinity, chemical loadings, and pathogens). The impacts are manifested through complex hydro-bio-geo-climate characteristics, which underscore the need for integrated scientific approaches to understand the impacts of landscape change on water resources. Several techniques, such as field studies, long-term monitoring, remote sensing technologies, and advanced modeling studies, have contributed to better understanding the modes and mechanisms by which landscape changes impact water resources. Such research studies can help unlock the complex interconnected influences of landscape on water resources in terms of quantity and quality at multiple spatial and temporal scales. In this Special Issue, we published a set of eight peer-reviewed articles elaborating on some of the specific topics of landscape changes and associated impacts on water resources.

Download or read book Water Climate Change and Forests written by Michael J. Furniss and published by DIANE Publishing. This book was released on 2011 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a print on demand edition of a hard to find publication. Water from forested watersheds provides irreplaceable habitat for aquatic and riparian species and supports our homes, farms, industries, and energy production. Yet population pressures, land uses, and rapid climate change combine to seriously threaten these waters and the resilience of watersheds in most places. Forest land managers are expected to anticipate and respond to these threats and steward forested watersheds to ensure the sustained protection and provision of water and the services it provides. Contents of this report: (1) Intro.; (2) Background: Forests and Water; Climate Change: Hydrologic Responses and Ecosystem Services; (3) Moving Forward: Think; Collaborate; Act; (4) Closing; (5) Examples of Watershed Stewardship. Illus.

Download or read book Addressing Climate Change in Long term Water Resources Planning and Management written by Levi D. Brekke and published by DIANE Publishing. This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the water management community¿s needs for climate change info. and tools to support long-term planning. Technical specialists and program managers have worked with their planners, water operators, and environmental compliance managers to identify the information and tools most relevant to their programs. They also have engaged and consulted with other Federal, State, and local agencies and stakeholder groups that have a role in water and water-related resource management to identify complementary priorities and individual perspectives. This report will help focus research and technology efforts to address info. and tools gaps relevant to the water management user community. Charts and tables. This is a print on demand report.

Download or read book Uncertainty in Climatic Change Impacts on Multiscale Watershed Systems written by Olga V. Tsvetkova and published by . This book was released on 2013 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty in climate change plays a major role in watershed systems. The increase in variability and intensity in temperature and precipitation affects hydrologic cycle in spatial and temporal dimensions. Predicting uncertainty in climate change impacts on watershed systems can help to understand future climate-induced risk on watershed systems and is essential for designing policies for mitigation and adaptation. Modeling the temporal patterns of uncertainties is assessed in the New England region for temperature and precipitation patterns over a long term. The regional uncertainty is modeled using Python scripting and GIS to analyze spatial patterns of climate change uncertainties over space and time. The results show that the regional uncertainty is significant in variation for changes in location and climatic scenarios. Watershed response to climate change under future scenarios is assessed using hydrologic simulation modeling for the Connecticut River watershed. Changes in water budgets are assessed for each of the subbasins using spatial analysis and process modeling using GIS and Soil and Water Assessment tool (SWAT). The results show that climate change uncertainty in precipitation and temperature can lead to uncertainty in both quantity and quality in the watershed system. A spatiotemporal, dynamic model was applied to subbasins within the Chicopee River Watershed to estimate climate change uncertainty impacts at a micro scale. These changes were assessed relative to changes in land use and climatic change. The results show that there is a significant potential for climate change to increase evaporation, watershed runoff and soil erosion rates and this varied with climate change uncertainty. Finally, water sustainability gradient analysis was applied to the Volga River watershed in Russia to assess potential climate change impacts by combining with downscaled Global Circulation Model estimates and spatial assessment. Results show that runoff and evapotranspiration are projected to increase with potential for more localized floods and drought events effecting both water resources and food supply. Overall results show that climate change uncertainty can impact watershed systems and spatial and temporal assessments is important for developing strategies for adaptation to climatic change conditions at local and regional scales.

Download or read book Soil Hydrology Land Use and Agriculture written by Manoj Shukla and published by CABI. This book was released on 2011 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agriculture is strongly affected by changes in soil hydrology as well as changes in land use and management practices and the complex interactions between them. This book develops an understanding of these interactions on a watershed scale, using soil hydrology models and addresses the consequences of land use and management changes on agriculture from a research perspective. Case studies illustrate the impact of land use and management on various soil hydrological parameters under different climates and ecosystems.

Download or read book Climate and Land Surface Changes in Hydrology written by Eva Boegh and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on field-based and modelling studies addressing the sensitivity of hydrological and hydrometeorological fluxes of the coupled landatmosphere system to climate and land-use change at local, regional and global scales. The volume includes significant model-based studies evaluating methodologies and impacts of using climate and weather prediction data including downscaling and uncertainty analyses. Hydrological sensitivity and impacts due to spatial and temporal land-use and land-cover variability are reported for a wide variety of environmental settings. Observational and model-based investigations assess the significance of land cover and hydrological dynamics for the development of land surface heat fluxes and regional climate. Several empirical hydroclimatological studies, some from remote and data-scarce regions, and others using long-term multi-variable time series data or Earth Observations to evaluate temporal and spatial variability in precipitation, evapotranspiration and hydrological predictions, are included. The International Association of Hydrological Sciences is the world's premier member-based organization promoting the study and practice of Hydrology. Our books are authored, edited and produced at the highest level of quality, with the most current and thorough research. Our publications and our work advance the science and the professional practice of Hydrology in a variety of Science and Engineering fields around the world.

Download or read book Combined Effects of Land Use Change and Climate Change on Soil Loss and Water Bablance Variables written by Yashar Makhtoumi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in water balance variables such as runoff and evapotranspiration (ET) are essential in planning and management of land and water resources. Two major factors affecting these variables are climate and land use change. There is a need to investigate the combined effects of land use and climate change at local scales. Towards that end, the hydrological processes were modeled using the Soil and Water Assessment Tool (SWAT) to investigate the impacts of climate and land use change in Southeast US (Makhtoumi, Li, Ibeanusi, and Chen, 2020). We integrated land use based on the Shared Socioeconomic Pathways (SSPs) with future climate data (CMIP5) to study the combined effects on hydrological response of Upper Choctawhatchee Watershed (UCW.) Future rainfall and air temperature, for two time periods (2040-2069 and 2070-2099), were obtained using Global Climate Models to provide SWAT with the climatic forcing in order to project water balance variables. The simulation was carried out under two radiative forcing pathways of Representative Concentration Pathways (RCP4.5 and RCP6.0.) Our results indicate that increased imperviousness resulted from urbanization has more impact on runoff than that of projected changes in climate. Impacts on water balance variables (runoff, ET, discharge) differed seasonally. Results showed peak surface runoff experienced changes under both emission scenarios in June up to five times increase. Among the water balance variables, ET as the least dominant pathways for water loss, showed the modest changes with the largest decrease during fall and summer. Projections indicated more frequent extreme behavior regarding precipitation, peak surface runoff, water yield (WY) and ET, during midcentury. Discharge was estimated to increase through the year and the highest changes were expected during summer and fall with 186.3% increase in November under RCP6.0. Relying on rainfall for farming along with reduced agricultural land use (11.8%) and increased urban area (47%) and population growth, would likely make the water use efficiency critical. In our second study, we focused on the combined impact of land use and climate change on soil erosion at local scales. Topsoil loss is a widespread environmental concern causing adverse impacts on natural and human systems. Severe weather accompanied with human activities can exacerbate this issue degrading soil health and consequently accelerating global and regional food insecurity and injustice. Erosion impairs soil physical and chemical properties such as infiltration rate, water holding capacity, loss of nutrients including soil carbon and nitrogen. Although, temporal properties of a rainfall event have meaningful implications for soil erosion, spatial heterogeneity of a rainfall contributes substantially and cannot be overlooked. Therefore, in the third chapter we investigated soil loss using SWAT in Northern Mississippi. First, we built a hydrological model and calibrated it for both flow and sediment discharge. Then we developed land use and climate scenarios. The land use scenarios include farming (soybean and corn) and grazing practices. The climate scenarios comprise of four different precipitation time series, S0 which no concentration is forced, while S1, S2, and S3 have 3%, 6%, and 9% concentration in top four rainy days, respectively. We coupled the land use and climate scenarios and evaluated a small watershed (Hickahala Creek Watershed) in response. We classified the subbasins into different classes of soil loss severity and then determined the hotspots for soil loss at subbasin scale. Our result suggests that the resolution of rainfall data is crucial in studying the soil loss. We found that pasture management by itself can manifold soil loss, and if accompanied with extreme rainfalls, soil loss accelerates impacting different subbasins each time. We found that spatial heterogeneity of extreme rainfalls (ERs) can be more substantial than land use in individual extreme rainfalls; however, over a year, soil moisture and type of the management practices (grazing and farming) could contribute more to soil loss. Soil loss can go as high as 350 (ton/ha/yr) under the ERs. Adding only the management practices can increase erosion 3600%. Under S1 parts of watershed yield more than 150 ton/ha/yr (extremely severe). Under S2 and S3 more soil loss hotspots emerge yielding approximately 200 ton/ha/yr. We found that in the hotspots, up to 10% increase in CI can increase annual soil loss up to 75%. Single ER can generate up to 35% of annual soil loss. Under one ER event hotspot subbasins can lose up to 160 ton/ha/day (subbasin 15). The results reveal that adding grazing and farming (S0) under one ER event can increase soil loss by 95%. 32% and 80% increase in rainfall amount in one ER event can increase soil loss by 94% and 285% respectively. Our results suggested the importance of site-specific managements to mitigate soil loss and all the consequences. It is essential to consider the varying sensitivity of subbasins for the sustainability of agricultural landscapes.

Download or read book Impacts of Urbanization and Climate Change on the Hydrological Cycle written by Lele Shu and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The past one hundred years have seen a tremendous migration to towns and cities worldwide. This population movement exerts serious impacts on surface and ground- water supplies, soil health, and the sustainability of ecosystems. At the same time, climate change has become a decisive influence on water systems as land conversion continues. Historically, urbanization and climate change were two important determinants in the sustainability of water, food and energy supplies, as well as the increasing risk of environmental hazards.At the watershed scale the evolving land use change in urban areas does not only change the flood risk because of increasing impervious areas or by directly reducing the consumption of water by trees and plants, but also fundamentally alters the local water balance and the partitioning of water within the land-atmosphere- ecological system. Both land use change and climate change may influence the urban watershed in ways that reinforce or compensate sustainable management.In this study we applied two spatially explicit models to the problem. One is the Penn State Integrated Hydrologic Model (PIHM), a hydrologic model that partitions the water balance in space and time over the urban catchment. The other is the Cellular Automata Land Use Change Model (CALUC), a land use change model, which simulates the evolution of land use classes based on physical measures associated with population change and land use demand factors.We selected two study sites, one modern and one ancient, to highlight the capability of coupling catchment hydrology with land use change models. The goal is to assess the role of hydrologic change in urbanizing watersheds and to evaluate the contemporaneous impacts of climate change. The modern sites are the Conestoga watershed and the Lancaster PA urban center; the historical site is the ancient Maya city of Tikal in Peten region of Guatemala. In each setting, the essential data was developed and the models were used to evaluate how urbanization and land use change gradually altered the entire water balance often in unexpected ways.Chapter 1 introduces the overall problem and carries out a comprehensive literature review for each of the following chapters. Chapter 2 discusses the relevant models used in the study, and the role of model parameterization, particularly the important role that macropores have on maintaining a healthy soil and supporting soil moisture and recharge to groundwater. Chapter 2 also describes the Cellular Automata Land Use Change model, which is adopted here to simulate land use conditions. Chapter 3 then evaluates the past, present and future land use conditions in the Conestoga watershed and develops quantitative metrics of evaluation. Chapter 4 extends the Conestoga case study to evaluate hydrologic performance when dynamic land use and future climate change scenarios from IPCC are the drivers. An evaluation of the relative importance of land use and climate to hydrologic change is presented. Chapter 5 implements the models in a retrospective scenario of the water history of the ancient Maya city of Tikal and discusses the problem of urbanization-deforestation-agriculture land conversion, and the likely sensitivity of their water supply to extreme climate events. Chapter 6 summarizes the two case studies and makes inferences on the resilience and elasticity of the two study sites to climate and land use change.

Download or read book The Cumulative Impacts of Climate Change and Land Use Change on Water Quantity and Quality in the Narragansett Bay Watershed written by Evan R. Ross and published by . This book was released on 2014 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: Narragansett Bay, Rhode Island, is a valuable natural resource that suffers summer hypoxic events resulting from over a century of cultural eutrophication. Current efforts to reduce nitrogen loading from wastewater treatment facilities discharging into the Bay and its tributaries hold the promise of working towards ecological restoration. But, the efficacy of these efforts may be limited, or undone, if future changes in climate or land use increase nutrient and sediment loads to the Bay. This study developed a SWAT model of the upper Narragansett Bay watershed to simulate water quantity and quality. The baseline model was calibrated and validated to accurately reflect watershed behavior. I then used the model to simulate water quantity and quality under an altered climate, with an IPCC projected increase in temperature of 3°C and a 10% increase in precipitation by 2080. A second scenario incorporated projected 2080 land use in the absence of climate change. The third scenario combined the climate change and land use change alterations to examine cumulative impacts. A comparison of scenario outputs against the baseline simulation highlighted the expected impacts climate change and land use change will have on the watershed. Both climate change and land use change demonstrated impacts on surface runoff, water yield, PET and ET, streamflow, and loading of sediment, organic N, organic P and nitrate. Climate impacts were much greater than land use impacts, but land use impacts displayed greater regional variation. The results of the combined simulation indicate that future climate and land use change will likely negatively impact the Bay and undermine current efforts at restoration. However, the results also highlight the potential to utilize land use to mitigate some of the impacts of climate change.