•Ground-radar precip product upscaled spatiotemporally to coarser satellite resolution.•Upscaled products used to simulate discrete flood characteristics.•Satellite uncertainty shown to overpower ...weaker errors from upscaled products.•Upscaled products suffer from negative water balance errors after modeling.•Spatial upscaling adds uncertainty to simulations while temporal upscaling adds bias.
This research focuses on the effects of spatio-temporal resolutions of global satellite precipitation on simulated flood events characteristics. The analysis is carried out by spatially, temporally, and spatiotemporally upscaling fine-scale precipitation forcings from the ground-radar-based Multi-Radar Multi-Sensor system (MRMS) to the resolution of the Integrated Multi-satellitE Retrievals for GPM (IMERG) satellite precipitation product. These upscaled products were then run through the Ensemble Framework for Flash Flood Forecasting hydrologic modeling framework over the U.S. to assess how the different spatial and temporal resolutions impact the simulated outputs of flood event magnitude, duration, and timing. It was found that the quantitative uncertainties generated by the IMERG Early (IMERG-E) simulations overpowered those associated with resolution across all flood characteristics. When compared to native MRMS simulations, however, the upscaled precipitation estimates tended to underestimate peak discharges and event durations, associated with distinct negative water balance errors. It was also found that the upscaled precipitation simulations exhibited a scaling effect with regards to error contribution of peak discharge, with higher contributions at smaller basin sizes and decreasing contributions as basin sizes increased. Looking at how upscaling can affect the modeled output desired allows for improved understanding of which resolutions lead to the greatest changes in simulation accuracy, increasing the potential global use and utility of current or future satellite products, especially in regions where high-resolution ground radars are sparse.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•IMERG satellite and MRMS radar precipitation applied for integrated hydrologic validation.•Discrete flood characteristics assessed with respect to USGS stream gauges.•Hydrologic model impacts on ...flood discharge, duration, and timing are investigated.•IMERG-E discharge errors are higher than MRMS, but IMERG-E duration errors are lower.•Flood timings are better simulated at smaller basin sizes with low systematic error.
This study investigates the hydrologic utility of satellite precipitation estimates from the Global Precipitation Measurement mission by comparing flood signals produced across the Continental United States by a ten-year span of in-situ, ground-based radar and satellite-based precipitation data. The flood characteristics generated with radar and satellite precipitation through a distributed hydrologic model are contrasted against reference stream gauge data as a method of integrated validation to assess and quantify error budgets between precipitation products by highlighting precipitation products’ accuracy, hydrologic scaling effects, and the impact of the hydrologic model. It is found that systematic and random errors associated with flood characteristics behave similarly to trends previously seen in precipitation rate errors between precipitation products, establishing a clear link through propagation of errors into the water cycle. Additionally, behaviors associated with both water balance and routing schemes within the hydrologic model were shown to affect outputs. Errors generated by water balance tend to cause overestimation of peak discharge values, while errors associated with routing tend to cause underestimation of flood durations and push flood timings earlier than the stream gauge reference.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A novel framework is developed for integrated hydrologic validation of satellites.•Assessment focuses on flood characteristics in favor of bulk metrics.•The effects of IMERG resolution are seen on ...flood peak discharge.•Basin size is also found to play a role in over or underestimation of peak discharge.•IMERG simulated floods events start earlier and end later than the MRMS benchmark.
In recent years, a great amount of research has been done towards evaluating precipitation data generated by satellites, but less has focused on how these estimates and their uncertainties manifest further into the water cycle. In this study, ten years of satellite-based and ground-based radar data are used as forcings for a distributed hydrologic model across the Continental United States. They are compared using a methodology designed to assess the flood signals and characteristics generated by the model. By focusing on how well the model reproduces flood characteristics rather than fits traditional bulk statistics, this research provides robust insights into satellite precipitation deficiencies. It is found that satellite data has greater success at resolving lower magnitude flood events while tending to generate floods of longer durations. Additionally, flood managers should note that satellites tend to generate floods that characteristically both begin earlier and end later than the ground radar reference. Subsequent research is recommended into other satellite data products in order to better understand these discrepancies and mitigate or plan for them in the future.
In recent years, satellites have been increasingly used to provide valuable insights on rainfall across the globe, especially in locations where radars are unable to be installed on the ground. By nature, however, the rainfall data provided by satellites has uncertainties. Large amounts of research has gone into the difference in accuracy between satellite radar and ground references, but less has focused on how these differences impact flood simulations, respectively. In this study it was found that the rainfall data from satellites tends to predict floods that are more severe (have higher magnitudes), last longer (have longer durations), and have different timings (start earlier and end later) than the reference. It is also found that satellites struggle with predictions involving extreme rainfall values. Further research is suggested to better understand these issues, as well as compare against other forms of satellite rainfall data.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
In the hydrological sciences, the outstanding challenge of regional modeling requires to capture common and event-specific hydrologic behaviors driven by rainfall spatial variability and ...catchment physiography during floods. The overall objective of this study is to develop robust understanding and predictive capability of how rainfall spatial variability influences flood peak discharge relative to basin physiography. A machine learning approach is used on a high-resolution dataset of rainfall and flooding events spanning 10 years, with rainfall events and basins of widely varying characteristics selected across the continental United States. It overcomes major limitations in prior studies that were based on limited observations or hydrological model simulations. This study explores first-order dependencies in the relationships between peak discharge, rainfall variability, and basin physiography, and it sheds light on these complex interactions using a multi-dimensional statistical modeling approach. Amongst different machine learning techniques, XGBoost is used to determine the significant physiographical and rainfall characteristics that influence peak discharge through variable importance analysis. A parsimonious model with low bias and variance is created which can be deployed in the future for flash flood forecasting. The results confirm that although the spatial organization of rainfall within a basin has a major influence on basin response, basin physiography is the primary driver of peak discharge. These findings have unprecedented spatial and temporal representativeness in terms of flood characterization across basins. An improved understanding of sub-basin scale rainfall spatial variability will aid in robust flash flood characterization as well as with identifying basins which could most benefit from distributed hydrologic modeling.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In the hydrological sciences, the outstanding challenge of regional modeling requires to capture common and event-specific hydrologic behaviors driven by rainfall spatial variability and catchment ...physiography during floods. The overall objective of this study is to develop robust understanding and predictive capability of how rainfall spatial variability influences flood peak discharge relative to basin physiography. A machine-learning approach is used on a high-resolution dataset of rainfall and flooding events spanning 10 years, with rainfall events and basins of widely varying characteristics selected across the continental United States. It overcomes major limitations in prior studies that were based on limited observations or hydrological model simulations. This study explores first-order dependencies in the relationships between peak discharge, rainfall variability, and basin physiography, and it sheds light on these complex interactions using a multidimensional statistical modeling approach. Among different machine-learning techniques, XGBoost is used to determine the significant physiographical and rainfall characteristics that influence peak discharge through variable importance analysis. Aparsimonious model with low bias and variance is created that can be deployed in the future for flash flood forecasting. The results confirm that, although the spatial organization of rainfall within a basin has a major influence on basin response, basin physiography is the primary driver of peak discharge. These findings have unprecedented spatial and temporal representativeness in terms of flood characterization across basins. An improved understanding of subbasin scale rainfall spatial variability will aid in robust flash flood characterization as well as with identifying basins that could most benefit from distributed hydrologic modeling
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The interconnected conceptual areas of teacher knowledge and teacher beliefs (included by some authors under the rubric of teacher cognition) have been debated in the field of language education ...intensively for the last two decades, during which time the terminology used in the discussions has been interpreted in a variety of different ways. However, there have been limited attempts to study the way in which teacher knowledge and beliefs develop in specific cases of language teaching methodology: one area of that has not been studied is that of knowledge/beliefs of communicativeness in language teaching. This paper argues that the conceptual area referred to by the above term is multi-dimensional and dynamic. It first develops a framework which focuses specifically on two of these dimensions, a personal–impersonal dimension, and a theoretical–practical dimension. It then examines the interaction between these two dimensions in the specific case of the knowledge of communicative language teaching of six Turkish teachers of English, using the term “understandings” to refer to this dynamic phenomenon.
► Examined teachers’ understandings of communicativeness in language teaching. ► Demonstrates a dynamic process of interaction of two dimensions of knowledge. ► Teachers reconsidered stated beliefs while observing recorded classroom practice. ► No direct connection between impersonal theoretical knowledge and practice. ► Knowledge personalized through a process of interpretation from teacher’s experience.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
On May 27th, 2021, we met virtually with Devon Woods. We asked him about his studies on beliefs and the relationship between beliefs and emotions and identity. We approached the decision-making ...process and its relationship to BAK (Beliefs, Assumptions and Knowledge). We also, discussed its relevance to English teaching communities, particularly here in Brazil. Devon Woods has always demonstrated to be amazed by the unseen and often unnoticed processes of interpretation that are involved in both personal and pedagogical types of communication. In the 1970s, he engaged in studies of learners’ and teachers’ cognition – their beliefs, interpretations and actions – and the interactions between them in language classrooms. As a product of his 1992 doctoral dissertation, we find his remarkable book “Teacher Cognition in Language Teaching” (1996), several articles, and the focus of the work of a number of graduate students published in the Carleton Papers in Applied Language Studies. The results of this conversation are what we present here in the form of an interview.
A report of research carried out in Tehran & Shiraz, Iran, on English instruction at the Iranian Language Institute describes results of interviews with officials, teachers, & students & classroom ...observations &, in light of the current success of the programs under study, develops a needs analysis for the future evolution of English teaching at the Institute, with recommendations for change & for the involvement of Carleton U in the changes. Issues to be taken into account in considering future changes include recent theoretical advances in the study of second language acquisition, classroom interaction, discourse structure & genre, & learner cognition & models of socially constructed learning; issues of control, program size, & lock-step curricular sequence favor retention of the current system, however. Guidelines for the implementation of possible changes are sketched, & teacher exchange scenarios are envisioned between Carleton U & the Institute for materials development & teacher training. J. Hitchcock
Issue Title: The Ethics Trapeze This article reports on a collective effort to position ethics policies within the context of a specific discipline - Applied Language Studies (ALS). Through a ...discussion of challenges to ALS-specific pedagogical and research practices, this article highlights (1) the need for consistency across institutional Research Ethics Boards in the application of general principles of ethics review, and (2) the recognition of local considerations that are informed by disciplinary approaches not envisioned in current ethics policies. Ethics policies that are driven by substantive ethical intent will recognize pedagogical practices, research methodologies, and epistemological values and traditions that mark a discipline.PUBLICATION ABSTRACT
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
An account of the design & instruction of a graduate-level sociolinguistics course spotlights teaching & learning processes. As a visiting lecturer at the Monterey Institute of International Studies, ...Woods aimed at integrating the previous instructor's approach with his own beliefs, assumptions, & knowledge about teaching; institutional continuity should be preserved while students were encouraged to develop their own interpretations & syntheses of sociolinguistics concepts. Broadening M. Swain's (eg, 1995) theory that increased language output requirements activate deeper processing, the sociolinguistics course was designed to focus on student output. The course structure accounted for student feedback. Examination of student logs & of statistical evaluations required by the university reflects successful application of sociolinguistic understanding, mixed with some frustration over course requirements & assessment. 4 Appendixes, 20 References. E. Taylor
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