Download or read book Changes and Trends in Streamflow During Floods and Droughts in the Urbanizing Christina River Basin written by Kimberly C. Cloud and published by ProQuest. This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Christina River Basin is a vital resource to nearly half a million people in three different states that is undergoing rapid growth. The goal of this study is to quantify the changes in land use and population and identify the potential impacts on streamflow in the region. Land use and population data from four different time frames dating back to 1970 are analyzed using a GIS to measure the rate of increase in urbanization and population. Streamflow data from the USGS and precipitation data from the NCDC were examined to look for trends that reflect the impact of urbanization on the Basin. Several variables, including runoff coefficient, maximum instantaneous peak flow and minimum 7-day low flow, the highest 10 discharge and lowest 10 discharge events were all reviewed by water year. The results show that agriculture and forest land use in the Christina River Basin is being converted to residential and other urban land uses at a rate of approximately 5% every ten years. This is causing the impervious cover of the region to increase by 2-3% in the same time frame. At the current rate, impervious cover across the Basin will exceed the threshold of what a watershed can handle without significant impairment in quality and habitat within the next 15 to 20 years. Population is also increasing approximately 10-15% every ten years across the entire Basin and is reflective of the urban sprawl as residents spread out from the most urbanized areas. Seven stream gages were paired with nearby precipitation gages to measure trends in streamflow for the seven discharge areas. The analysis reflects that peak instantaneous discharges are increasing and minimum 7-day low flows (baseflow) are decreasing. The highest 10 discharge events (floods) and lowest 10 streamflow events (droughts) are getting worse over time. Precipitation has not changed significantly over time and the changes do not closely correspond with changes in streamflow, leading to the conclusion that floods and droughts are getting more severe due to urbanization.
Download or read book Urbanization of the Christina River Basin and Subsequent Hydrologic Alteration written by Alexandra Olaya DeWeese and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Christina River Basin is an invaluable source of water for more than half a million people. Thus, sustainable management of the basin is vital for maintaining and improving the health of this resource while addressing projected changes in climate. For this reason, the objectives of this study include examining changes in population density, land use land cover, impervious cover and precipitation, and analyzing the relationship between urbanization, streamflow and water quality. Population data from 1970 onward and land use data from 1990 onward are observed to quantify urbanization of the basin, while precipitation, streamflow and water quality data are analyzed to identify and understand effects of this urbanization on the hydrology of the Basin. ArcGIS and Microsoft Excel are utilized for this study for the analysis and mapping. Results of the analysis show a definite increase in population density across the majority of the basin, with some of the 38 subwatersheds increasing by greater than 1,500 people per square mile on the outskirts of Newark, DE and others increasing by as much as 1,000 people per square mile on the outskirts of Downington, PA. A decrease in population density occurs in the Wilmington and New Castle, DE area with as much as an 800 people per square mile decline. Between 1990 and 2010, a significant portion of agriculture and forest land uses were lost as they converted to urban land uses. Urban uses occupy nearly 9% more of the Basin's area by 2010, while agriculture has decreased by 7% and forest by 4.4%. This has lead to a significant increase in impervious cover across most of the basin as well. Precipitation at two representative precipitation gages show negligible changes over the time frame. The streamflow-precipitation analysis demonstrates very little change in peak flows and highest ten discharge events, or flash floods. While trends are positive at the majority of the five station pairings selected for this aspect of the study, slopes are very small and have weak or no correlation. Likewise, minimum 7-day low flows, or baseflow, and the ten lowest discharge events, or droughts, also demonstrate very little change over the period of study. Trends of these variables are negative at most of the station pairings but slopes are very small and correlation is weak or nonexistent. As precipitation has not changed over the time frame of the study, any of the anticipated changes in these variables indicate undesired alterations in hydrology due to increased urbanization. Despite increases in population density, urban land use and impervious cover, water quality across the basin has demonstrated some improvement since 1995. Inorganic nitrogen has increased basin wide, sometimes with seasonal statistical significance, and bacteria levels have increased at most locations as well (although with no correlation in any watershed). However, total suspended sediments and orthophosphate as phosphorus levels have decreased during most seasons in the majority of the watersheds, with statistical significance for some seasons, and dissolved oxygen has increased with strong correlation and statistical significance, indicating an improvement in the health of the basin. This study illustrates major changes in population, land use and impervious cover of the Christina River Basin since 1990, and unexpectedly little change in streamflow and some improvement of water quality. Recommended future research includes a more in depth analysis of the relationship between land use and water quality.
Download or read book Guide to Geography Programs in the Americas written by and published by . This book was released on 2007 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Data Mining and Spatiotemporal Analysis of Extreme Precipitation written by Josiah Daniel Smith and published by . This book was released on 2005 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The Prairie Pothole Region in the Northern Great Plains (PPR-NGP) of the United States frequently fluctuates from drought to deluge. The historical hydrologic record for this region reveals periods of intense, prolonged drought intermingled with rapid and destructive flooding. Drought or flooding is initiated and sustained by deficit or surplus precipitation, respectively. The weather events that accompany these disasters are characterized by large spatial and temporal variations from normal in the frequency and intensity. The unique hydrology and geology of the region makes the PPR-NGP highly sensitive to these weather perturbations. The future looks to bring more warming and thus more intense precipitation to the region. As the frequency of extreme precipitation events rises, the magnitude and occurrence of floods and droughts will be elevated. The objective of this research was to determine the factors controlling precipitation trends, drought, and flooding in the study area. Also, the weather conditions preceding the disastrous events were observed and characterized. The analysis was focused on the effects of varying precipitation intensity, frequency, and antecedent conditions as they pertain to PPR-NGP drought and Red River flooding. The results may be applied to better predict the future trends of flood and drought response to extreme precipitation. Data mining was performed on available weather station observations to extract significant information and use it to derive valuable insight into PPR-NGP drought and flooding behavior. Hydrometeorological indices calculated over various timescales were applied to assess the intensity and frequency of rainfall, the change in snow depths, and the deviation from normal precipitation. Flood discharge hydrographs were classified based on shape parameters and matched to precipitation characteristics. Spatiotemporal and statistical operations were employed to determine the controlling factors of precipitation trends, drought, summer floods, and spring floods in the PPR-NGP and Red River Basin. Current precipitation and stream flow trends indicate the potential for enhanced flood and drought activity. Precipitation intensity and frequency are ascending, but the intensity is increasing more than the frequency of monthly events. The result is that Red River discharge rates are rising six times faster than total precipitation over the basin. The rise in stream flow rates can be explained by elevated precipitation intensity and to some extent precipitation frequency during key flood months. However, the most critical flood month of April has a decreasing total precipitation trend and yet the highest rise in discharge rate. These trends come about because overall fall and winter precipitation rates are on the rise. The antecedent precipitation is stored on and in the frozen ground until released by the spring thaw, which usually takes place in April. Thus, the risk for larger April floods is affected not by a single month but by a half year's worth of increasing precipitation conditions. Large fluctuations in monthly drought conditions were determined to be equally controlled by both the frequency and intensity of precipitation events. Extreme drought took a minimum of two to three months both to develop and dissipate from a semi-arid state. Though, the biggest shifts in month-to-month conditions were observed when both precipitation intensity and frequency were well above or below normal over the same area. So the onset or end of an extreme drought took place more rapidly when the intensity and frequency changes were great and harmonized. Similarly, the spatial extent of the most intense (on average) drought cells was surprisingly little, because the overlap of large precipitation intensity and frequency shifts typically occurred over a small area. Also, the drought duration usually increased when severity reached a higher level, so that multiple months of moderate drought reduced the overall intensity for all but the most severe parts of the cells. The intensity of precipitation events was the main controlling factor in Red River summer flood occurrence and magnitude. Antecedent conditions were not essential to the development of summer floods. Conditions were often near normal prior to a flood because more of the normal rain fell in a fewer number of more intense events. Conversely, the magnitude and occurrence of spring floods was controlled by antecedent precipitation and fast snow melt rates. A significant snow pack was observed prior to both major and minor floods, while a non-flood year had little snow pack over the basin. Fall soil moisture, winter snowfall, and a fast rate of stored water release all had to be present at sufficient levels to trigger a large flood response.
Download or read book Hydrologic Changes in Two River Basins in Connecticut written by Paul Joseph Albert and published by . This book was released on 1999 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Synoptically Guided Approach to Determining Suburbanization s Impacts on the Hydrology of the Red and White Clay Creeks Pennsylvania and Delaware written by Anne Marina Bagwell and published by . This book was released on 2007 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: An examination of major flooding events in Northern New Castle County, Delaware is presented in the context of the discrimination between flooding due to landuse change and flooding due to anomalous heavy rain events. The Christina River Basin encompasses the Red and White Clay Creek Watersheds. These basins are the focus of this study because of their short response time, shift to suburban landuse types, and impact on approximately 165,000 people in southeastern Pennsylvania and northern Delaware. The Christina basin has recorded many floods since record keeping began approximately 70 years ago, These floods were classified according to the synoptic weather situation that was responsible for the flooding. A qualitative synoptic classification identified four general synoptic types responsible for flooding including tropical storms, frontal systems, coastal storms/nor'easters and convective systems. Stream gages across the Christina Basin have seen an increase in the frequency of flooding and in some cases an increase in the strength of the flooding over time. A detailed hydrologic model (HEC), developed by the Army Corps of Engineers, was used to investigate the role of landuse change from agricultural to single family residential landuse. The GIS-based preprocessor, HEC-GeoHMS, uses a digital elevation model, gage locations, landuse and soil to output basin characteristics to the model. Simulations are run for two diverse atmospheric forcings and various landuse scenarios. The resulting simulations yielded flood hydrographs which closely matched the observed discharge data. When actual hydrographs are compared to a landuse scenario representing pre-European settlement conditions (all forest), recent anomalous heavy precipitation still causes major floods but at levels that are 50-80% lower than that of the current landuse conditions. The results of this research provide a better understanding of the complex interaction between landuse changes and synoptic weather patterns. The results can also be used to forecast future flooding potential based upon changes in landuse across the Christina Basin.
Download or read book Trends in Streamflow Above and Below Dams Across the Columbia River Basin from 1950 to 2012 written by John Christophe Hammond and published by . This book was released on 2014 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change, combined with population growth, is expected to exacerbate water scarcity globally. In the Columbia River basin (CRB), streamflow is managed for multiple objectives with a network of dams and reservoirs distributed throughout the basin that may mitigate climate change effects on water scarcity. This study quantified trends in daily streamflow from 1950-2012 in 28 pairs of gages above and below dams in the CRB, including the U.S. and Canada. Each gage pair consisted of an above-dam gage that is primarily forested and has little apparent human disturbance and minimal flow regulation or diversions, combined with a below-dam gage immediately downstream of a major dam and reservoir. Monthly streamflow and precipitation for a total of 59 sites was correlated with monthly indices of the Pacific Decadal Oscillation (PDO), the Northern Pacific Index (NPI), the Pacific North America pattern (PNA), and the 700-millibar wind speeds (u700) using Pearson's r. Long-term trends and patterns in daily streamflow and climate data were estimated using linear regression, the Mann-Kendall test, and wavelet analysis. Streamflow was generally weakly correlated with NPI, PNA, and PDO, while positively correlated with upper elevation wind speed at low elevations during wet months. Fewer than half of above-dam gages in the CRB have experienced increasing trends in daily streamflow from mid-March to the beginning of May over the period 1950 to 2012, whereas a majority has experienced decreasing trends from the middle of May to the middle of October. These trends in above-dam basins are consistent with trends expected from climate change, but they also may be affected by legacies of past forest harvest or wildfire. Below dams, reservoir management appears to have overwritten the signal of earlier snowmelt, except in the Boise sub-basin, but long-term declines in late summer flows were evident at half of below-dam sites. Declining summer flows below dams were attributable to a variety of factors, including changes in reservoir management as well as reservoir management that propagates signals from above dam catchments, such as climate change or forest-harvest legacy effects on streamflow. There have been very few significant changes in annual flow volume throughout the basin, and these streamflow trends represent a small percentage of annual flow volume; thus, observed trends appear to be shifts in timing rather than shifts in the annual water balance. The magnitude of 60-yr declines in late summer flow in above-dam catchments represents only a few percent of annual yield, and much less than the storage capacity of the dams, but these long-term changes may be quite important for water yield during the late summer low-flow period. These findings are relevant for strategies to adaptively manage water resources in light of the ongoing planning for renegotiation of the U.S.-Canada Columbia River Treaty.
Download or read book Concern Models for the Christina River Basin written by Joachim Toby Tourbier and published by . This book was released on 1972 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spring Meeting written by American Geophysical Union. Meeting and published by . This book was released on 2000 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Managing California s Water written by Ellen Hanak and published by Public Policy Instit. of CA. This book was released on 2011 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Climate Change Impacts in the United States written by U.S. Global Change Research Program and published by Cambridge University Press. This book was released on 2009-08-24 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes the science of climate change and impacts on the United States, for the public and policymakers.
Download or read book The United Nations world water development report 2020 written by UNESCO World Water Assessment Programme and published by UNESCO Publishing. This book was released on 2020-03-23 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 2020 edition of the WWDR, titled 'Water and Climate Change' illustrates the critical linkages between water and climate change in the context of the broader sustainable development agenda. Supported by examples from across the world, it describes both the challenges and opportunities created by climate change, and provides potential responses - in terms of adaptation, mitigation and improved resilience - that can be undertaken by enhancing water resources management, attenuating water-related risks, and improving access to water supply and sanitation services for all in a sustainable manner. It addresses the interrelations between water, people, environment and economics in a changing climate, demonstrating how climate change can be a positive catalyst for improved water management, governance and financing to achieve a sustainable and prosperous world for all. The report provides a fact-based, water-focused contribution to the knowledge base on climate change. It is complementary to existing scientific assessments and designed to support international political frameworks, with the goals of helping the water community tackle the challenges of climate change, and informing the climate change community about the opportunities that improved water management offers in terms of adaptation and mitigation.
Download or read book Floods in a Changing Climate written by Ramesh S. V. Teegavarapu and published by Cambridge University Press. This book was released on 2012-11-22 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurement, analysis and modeling of extreme precipitation events linked to floods is vital in understanding changing climate impacts and variability. This book provides methods for assessment of the trends in these events and their impacts. It also provides a basis to develop procedures and guidelines for climate-adaptive hydrologic engineering. Academic researchers in the fields of hydrology, climate change, meteorology, environmental policy and risk assessment, and professionals and policy-makers working in hazard mitigation, water resources engineering and climate adaptation will find this an invaluable resource. This volume is the first in a collection of four books on flood disaster management theory and practice within the context of anthropogenic climate change. The others are: Floods in a Changing Climate: Hydrological Modeling by P. P. Mujumdar and D. Nagesh Kumar, Floods in a Changing Climate: Inundation Modeling by Giuliano Di Baldassarre and Floods in a Changing Climate: Risk Management by Slodoban Simonović.
Download or read book Climate Change and Indigenous Peoples in the United States written by Julie Koppel Maldonado and published by Springer. This book was released on 2014-04-05 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a long history and deep connection to the Earth’s resources, indigenous peoples have an intimate understanding and ability to observe the impacts linked to climate change. Traditional ecological knowledge and tribal experience play a key role in developing future scientific solutions for adaptation to the impacts. The book explores climate-related issues for indigenous communities in the United States, including loss of traditional knowledge, forests and ecosystems, food security and traditional foods, as well as water, Arctic sea ice loss, permafrost thaw and relocation. The book also highlights how tribal communities and programs are responding to the changing environments. Fifty authors from tribal communities, academia, government agencies and NGOs contributed to the book. Previously published in Climatic Change, Volume 120, Issue 3, 2013.
Download or read book Turn Down the Heat written by A Report for the World Bank by the Potsdam Institute for Climate Impact Research and Analytics. and published by World Bank Publications. This book was released on 2013-06-19 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report focuses on the risks of climate change to development in Sub-Saharan Africa, South East Asia and South Asia. Building on the 2012 report, Turn Down the Heat: Why a 4°C Warmer World Must be Avoided, this new scientific analysis examines the likely impacts of present day, 2°C and 4°C warming on agricultural production, water resources, and coastal vulnerability. It finds many significant climate and development impacts are already being felt in some regions, and that as warming increases from present day (0.8°C) to 2°C and 4°C, multiple threats of increasing extreme heat waves, sea-level rise, more severe storms, droughts and floods are expected to have further severe negative implications for the poorest and most vulnerable. The report finds that agricultural yields will be affected across the three regions, with repercussions for food security, economic growth, and poverty reduction. In addition, urban areas have been identified as new clusters of vulnerability with urban dwellers, particularly the urban poor, facing significant vulnerability to climate change. In Sub-Saharan Africa, under 3°C global warming, savannas are projected to decrease from their current levels to approximately one-seventh of total land area and threaten pastoral livelihoods. Under 4°C warming, total hyper-arid and arid areas are projected to expand by 10 percent. In South East Asia, under 2°C warming, heat extremes that are virtually absent today would cover nearly 60-70 percent of total land area in northern-hemisphere summer, adversely impacting ecosystems. Under 4°C warming, rural populations would face mounting pressures from sea-level rise, increased tropical cyclone intensity, storm surges, saltwater intrusions, and loss of marine ecosystem services. In South Asia, the potential sudden onset of disturbances to the monsoon system and rising peak temperatures would put water and food resources at severe risk. Well before 2°C warming occurs, substantial reductions in the frequency of low snow years is projected to cause substantial reductions in dry season flow, threatening agriculture. Many of the worst climate impacts could still be avoided by holding warming below 2°C, but the window for action is closing rapidly. Urgent action is also needed to build resilience to a rapidly warming world that will pose significant risks to agriculture, water resources, coastal infrastructure, and human health.
Download or read book The History of Hydrology written by Edward Landa and published by . This book was released on 1987 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Anatomy of a Silent Crisis written by Global Humanitarian Forum and published by Global Humanitarian Forum. This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
