Satellite-driven downscaling of global reanalysis precipitation products for hydrological applications

Deriving flood hazard maps for ungauged basins typically requires simulating a long record of annual maximum discharges. To improve this approach, precipitation from global reanalysis systems must be downscaled to a spatial and temporal resolution applicable for flood modeling. This study evaluates such downscaling and error correction approaches for improving hydrologic applications using a combination of NASA's Global Land Data Assimilation System (GLDAS) precipitation data set and a higher resolution multi-satellite precipitation product (TRMM). The study focuses on 437 flood-inducing storm events that occurred over a period of ten years (2002–2011) in the Susquehanna River basin located in the northeastern United States. A validation strategy was devised for assessing error metrics in rainfall and simulated runoff as function of basin area, storm severity, and season. The WSR-88D gauge-adjusted radar-rainfall (stage IV) product was used as the reference rainfall data set, while runoff simulations forced with the stage IV precipitation data set were considered as the runoff reference. Results show that the generated rainfall ensembles from the downscaled reanalysis product encapsulate the reference rainfall. The statistical analysis consists of frequency and quantile plots plus mean relative error and root-mean-square error statistics. The results demonstrated improvements in the precipitation and runoff simulation error statistics of the satellite-driven downscaled reanalysis data set compared to the original reanalysis precipitation product. Results vary by season and less by basin scale. In the fall season specifically, the downscaled product has 3 times lower mean relative error than the original product; this ratio increases to 4 times for the simulated runoff values. The proposed downscaling scheme is modular in design and can be applied on any gridded satellite and reanalysis data set

Additive Discourse Markers in English Journal Articles Written by Kurdish and English Native Speakers: A Corpus-Based Study

This paper reports a study that examines the use of additive discourse markers written by Kurdish scholars of English and compares their use with English native speakers. In this study, five discourse markers of 'and, or, for example, for instance, thus' are specifically analyzed. It aimed to investigate functions, frequency, and sentence positions of additive discourse markers. To achieve this, the researchers utilized two language corpora of 34 research articles published by Kurdish scholars in different journals of Iraqi Kurdistan Region Universities and international journals, and a corpus of 27 research articles published by English native scholars in different English Journals. Quantitative as well as qualitative research methods were employed. The results of this study showed that Kurdish scholars overused 'and' and 'for instance' in their writing; however, they underused 'or, for example, and thus'. Moreover, it showed that in both types of writings, there is a similarity in the frequent use of the medial position of additive discourse markers

Additive Discourse Markers in English Journal Articles Written by Kurdish and English Native Speakers: A Corpus-Based Study

This paper reports a study that examines the use of additive discourse markers written by Kurdish scholars of English and compares their use with English native speakers. In this study, five discourse markers of 'and, or, for example, for instance, thus' are specifically analyzed. It aimed to investigate functions, frequency, and sentence positions of additive discourse markers. To achieve this, the researchers utilized two language corpora of 34 research articles published by Kurdish scholars in different journals of Iraqi Kurdistan Region Universities and international journals, and a corpus of 27 research articles published by English native scholars in different English Journals. Quantitative as well as qualitative research methods were employed. The results of this study showed that Kurdish scholars overused 'and' and 'for instance' in their writing; however, they underused 'or, for example, and thus'. Moreover, it showed that in both types of writings, there is a similarity in the frequent use of the medial position of additive discourse markers