Individual and combined effects of land use/cover and climate change on Wolf Bay watershed streamflow in southern Alabama

Self Cite

Abstract:The Soil and Water Assessment Tool 2012 (SWAT2012) offers four sediment routing methods as optional alternatives to the default simplified Bagnold method. Previous studies compared only one of these alternative sediment routing methods with the default method. The proposed study evaluated the impacts of all four alternative sediment transport methods on sediment predictions: the modified Bagnold equation, the Kodoatie equation, the Molinas and Wu equation, and the Yang equation. The Arroyo Colorado Watershed, Texas, USA, was first calibrated for daily flow. The sediment parameters were then calibrated to monthly sediment loads, using each of the four sediment routing equations. An automatic calibration tool-Integrated Parameter Estimation and Uncertainty Analysis Tool (IPEAT)-was used to fit model parameters. The four sediment routing equations yielded substantially different sediment sources and sinks. The Yang equation performed best, followed by Kodoatie, Bagnold, and Molinas and Wu equations, according to greater model goodness-of-fit (represented by higher Nash-Sutcliffe Efficiency coefficient and percent bias closer to 0) as well as lower model uncertainty (represented by inclusion of observed data within 95% confidence interval). Since the default method (Bagnold) does not guarantee the best results, modelers should carefully evaluate the selection of alternative methods before conducting relevant studies or engineering projects.

Section: The Swat Modelmentioning

confidence: 99%

Assessment of Optional Sediment Transport Functions via the Complex Watershed Simulation Model SWAT

Yen

Feng

et al. 2017

Self Cite

“…It is well known that urban hydrologic systems become flashier in response to increasing watershed development [33]. The interaction between climate variability and urbanization can amplify hydrologic pulses and the export of carbon, nutrients, and contaminants in many urban waterways [79,[93][94][95][96].…”

Section: Evolving Hydrology: An Amplified Urban Hydrologic Pulsementioning

confidence: 99%

“…For example, the amplified hydrologic pulse of urban ecosystems is expected to change due to the interactive effects of land use and climate change across different areas of the U.S. and elsewhere [79,[93][94][95][96], and this may trigger urban adaptation and evolution of ecosystem structure and function of urban drainage [44,90]. As another example, the number and concentrations of pharmaceutical and personal care products (PPCPs) in the chemical diet of urban watersheds can be expected to increase in the future, and there are questions regarding urban adaptation from individual organisms and ecosystem responses to environmental regulations globally [128][129][130][131].…”

Section: The Future Of Urban Evolutionmentioning

confidence: 99%

Urban Evolution: The Role of Water

Kaushal

McDowell

Wollheim

et al. 2015

Abstract:The structure, function, and services of urban ecosystems evolve over time scales from seconds to centuries as Earth's population grows, infrastructure ages, and sociopolitical values alter them. In order to systematically study changes over time, the concept of "urban evolution" was proposed. It allows urban planning, management, and restoration to move beyond reactive management to predictive management based on past observations of consistent patterns. Here, we define and review a glossary of core concepts for studying urban evolution, which includes the mechanisms of urban selective pressure and urban adaptation. Urban selective pressure is an environmental or societal driver contributing to urban adaptation. Urban adaptation is the sequential process by which an urban structure, function, or services becomes more fitted to its changing environment or human choices. The role of water is vital to driving urban evolution as demonstrated by historical changes in drainage, sewage flows, hydrologic pulses, and long-term chemistry. In the current paper, we show how hydrologic traits evolve across successive generations of urban ecosystems OPEN ACCESSWater 2015, 7 4064 via shifts in selective pressures and adaptations over time. We explore multiple empirical examples including evolving: (1) urban drainage from stream burial to stormwater management; (2) sewage flows and water quality in response to wastewater treatment; (3) amplification of hydrologic pulses due to the interaction between urbanization and climate variability; and (4) salinization and alkalinization of fresh water due to human inputs and accelerated weathering. Finally, we propose a new conceptual model for the evolution of urban waters from the Industrial Revolution to the present day based on empirical trends and historical information. Ultimately, we propose that water itself is a critical driver of urban evolution that forces urban adaptation, which transforms the structure, function, and services of urban landscapes, waterways, and civilizations over time.

“…Separating the impacts from these various factors on runoff, especially land cover change caused by rapid modernization and urbanization, is important for understanding the mechanisms that cause variations in flow and thus planning for sustainable utilization of water resources. Because of this need, many studies [16][17][18][19] have also quantified the impacts of land cover change on runoff. For example, Guo et al [20] explored the effects of changes in climate and land cover on runoff in a watershed in northern China.…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Impacts of Climate, Land Cover Change and Direct Human Activities on Runoff Variations in the Wei River Basin, China

Li¹,

Chang²,

Wang³

et al. 2016

Previous studies that quantified variations in runoff have mainly focused on the combined impacts of climate and human activities or climate and land cover change. Few have separated land cover change from human activities, which is critical for effective management of water resources. This study aims to investigate the impact of changing environmental conditions on runoff using the Soil and Water Assessment Tool (SWAT) model; we examined three categories: climate, land cover change and direct human activities. The study area was the Wei River Basin, a typical arid to semi-arid basin that was divided into five sub-zones (UZ, MZ, DZ, JZ and BZ). Our results showed the following: (1) the calibrated SWAT model produced satisfactory monthly flow processes over the baseline period from 1978 to 1986; (2) compared to the baseline period, the impact of climatic variations decreased and the impact of direct human activities increased from the 1990s to the 2000s, while the impact of land cover change was generally stable; and (3) climatic variations were the main cause of runoff declines over the entire basin during the 1990s and in the UZ, MZ and JZ areas during the 2000s, while direct human activities were most important in the DZ and BZ areas during the 2000s.