To enable the efficient use of the Hydro-NEXRAD system in hydrologic research, the authors are developing and computing a set of metadata. Vast archives of radar-centric NEXRAD data, the highly variable spatial and temporal characteristics of precipitation events, and the existence of anomalous data complicate the process of selecting subsets of the data for specific investigation. Well-defined, pre-computed, radar-centric, basin-centric and point (for a selected set of rain gauge locations) metadata offer the possibility of efficiently selecting data subsets that meet user-specified criteria. Metadata have to be computed quickly so that they do not slow down the data ingest process, but they do not have to be highly accurate. Separating rainfall from clear air conditions and heavy rainfall from light precipitation is often sufficient. In this paper, the authors discuss the technical challenges of computing metadata for the vast archives of NEXRAD data and basic data quality control incorporated into that process. Users of Hydro-NEXRAD will be able to query the database using different criteria based on the metadata or visually inspect the time series of the metadata.
Big data and hydroinformatics
Big data is popular in the areas of computer science, commerce and bioinformatics, but is in an early stage in hydroinformatics. Big data is originated from the extremely large datasets that cannot be processed in tolerable elapsed time with the traditional data processing methods. Using the analogy from the object-oriented programming, big data should be considered as objects encompassing the data, its characteristics and the processing methods. Hydroinformatics can benefit from the big data technology with...
Analysis of drought characteristics over Luanhe River basin using the joint deficit index
In order to describe the overall drought status objectively, a copula-based joint deficit index (JDI) was adopted for analyses of drought characteristics in Luanhe River basin. Monthly precipitation data from 1958 to 2011 selected from 26 rain-gauge stations were used for calculating the JDI. The JDI, which encompasses multiple deficit statuses over time scales from 1 to 12 months by using the 12-dimensional empirical copula, is shown to be capable of providing a comprehensive and objective assessment of droughts....
Using SWAT to simulate streamflow in Huifa River basin with ground and Fengyun precipitation data
High-resolution satellite precipitation products, which can provide a reasonable depiction of the spatial extent of rainfall, have been increasingly used to model hydrological processes. In this study, we introduced important satellite rainfall data – Fengyun (FY) precipitation product, and evaluated the data through streamflow simulation using the Soil and Water Assessment Tool model in Huifa River basin, China. Three precipitation inputs were conducted to investigate the simulation performance of the FY...
Digging for data on Africa’s climate future
The cardboard box is covered with a layer of dust so thick it must have been tucked away in this Kenyan basement for decades. The researcher wipes off the dust and rummages through the papers stored inside by someone long since retired. Sheet after sheet of neatly typed paper emerges, the faded rows of numbers detailing rainfall, temperature and wind speed. In a way, the researcher is hunting for treasure. And she is not alone. In Sub-Saharan Africa, dozens of her colleagues are searching for weather data...
Effects of rainfall data resolution on watershed-scale model performance in predicting runoff
The hydrologic simulation program-FORTRAN (HSPF) model is widely used to develop management strategies for water resources, but its effectiveness is limited by predictive uncertainties associated with model input data. This study evaluated the effect of rainfall data resolution on the model performance when predicting runoff. We examined hourly, 3-hourly, 12-hourly, and 24-hourly temporal resolutions, and spatial resolutions from seven to one rain gauges. We used a statistical sensitivity analysis to test the...