A methodology is presented for extracting topographic, topologic, and hydrologic information, from the digital spatial data of a hydrologic system, for hydrologic modeling with HMS. Methods for stream and watershed delineation from digital elevation models are presented. After vectorizing the raster-based stream segments and watersheds, navigation fields are added to their tables to support top...

Anticipated future temperature changes in the mountainous U.S. Pacific Northwest will cause reduced spring snow pack, earlier melt, earlier spring peak flow and lower summer flow in transient rain-snow and snowmelt dominant river basins. In the context of managed flood control, these systematic changes are likely to disrupt the balance between flood control and reservoir refill in existing rese...

The authors propose establishing a hydrologic remote sensing observatory to further advance sensing technologies and their use in scientific inquiry of hydrologic processes. They pose four fundamental questions the answering of which would benefit from a specialized observatory. The questions address issues that range from global needs to monitor changing landscapes and the associate hydrologic...

Distributed, physics-based hydrologic models require spatially explicit specification of parameters related to climate, geology, land-cover, soil, and topography. Extracting these parameters from national geodatabases requires intensive data processing. Furthermore, mapping these parameters to model mesh elements necessitates development of data access tools that can handle both spatial and tem...

The Community Land Model (CLM3) Dynamic Global Vegetation Model (CLMDGVM) is used diagnostically to identify land and atmospheric model biases that lead to biases in the simulated vegetation. The CLM-DGVM driven with observed atmospheric data (offline simulation) underestimates global forest cover, overestimates grasslands, and underestimates global net primary production. These results are con...

Mosquitoes and mosquitoborne disease transmission are sensitive to hydrologic variability. If local hydrologic conditions can be monitored or modeled at the scales at which these conditions affect the population dynamics of vector mosquitoes and the diseases they transmit, a means for monitoring or modeling mosquito populations and mosquitoborne disease transmission may be realized. We review h...

Assignment of soils to hydrologic soil groups has been based on published criteria subjectively interpreted and applied by soil scientists. As a result hydrologic soil group placement for any given soil lacks consistency of method and correlation to the respective soil's physical properties. A method of placing soil into hydrologic soil groups was developed using fuzzy systems techniques. This ...

Recent legislation to initiate vegetation management in the Central Sierra hydrologic region of California includes a focus on corresponding changes in water yield. This served as the impetus for developing a combined geographic information system (GIS) and simulation assessment framework. Using the existing vegetation density condition, together with proposed rules for thinning to reduce fire ...

Some observations are more variable in space and relatively less variable in time or vice versa. Based on the major source of variability, regionalized variable theory is used to construct either spatial or temporal semivariograms. Examples include georeferenced soil data, with primarily spatial variability, and daily weather data, with primarily temporal variability, as input to dynamic simula...