Hydrologic metrics have been used extensively in ecology and hydrology to summarize the characteristics of riverine flow regimes at various temporal scales but there has been limited evaluation of the sources and magnitude of uncertainty involved in their computation. Variation in bias, precision and overall accuracy of these metrics influences the ability to correctly describe flow regimes, de...

However, hydrologists and ecologists are still woefully incapable of answering the question, “How much hydrologic alteration is too much for an aquatic or riparian ecosystem?” This is not to say that we haven’t learned a great deal about the influence of hydrologic variation and extreme events on species and natural communities or key ecosystem processes such as nutrient transport and cycling. ...

411 Abstract: Expected effects of wildland fires on hydrologic values have been indexed by 11 hydrologic parameters of floods, sedimentation and water supply. Coefficients and watershed attributes from 10 multiple-regression models are used to distribute measured hydrologic parameters throughout each watershed. Other coefficients are used with present fire condition and fire frequency to estima...

Aggregate annual discharge from the six largest Arctic-draining Eurasian rivers achieved an all-time record high in 2007, accentuating a long-term upward trend that argues for intensification of the Arctic hydrologic cycle. This record discharge was due in part to strong positive anomalies in late winter snow water equivalent across much of northern Eurasia. These anomalies arose in response to...

In recent decades, there has been a tendency toward increased summer floods in south China, increased drought in north China, and moderate cooling in China and India while most of the world has been warming. We used a global climate model to investigate possible aerosol contributions to these trends. We found precipitation and temperature changes in the model that were comparable to those obser...

Climate change is increasing the burden of climate-sensitive health determinants and outcomes worldwide. Acting through increasing temperature, changes in the hydrologic cycle, and sea level rise, climate change is projected to increase the frequency and intensity of heat events and extreme events (floods and droughts), change the geographic range and incidence of climate-sensitive vector-, foo...

Hydrologic models simulate the river flow from the contributing basin for a given river. For the simulation process, the integration domain is discretized into computational cells. The inputs for such models are precipitation ratio and the initial flow. There are many parameters to be determined for an operational model, including the type of soil (porosity field, water flux between the bottom ...

The southern United States is characterized by a humid, subtropical climate and consists of 16 states (Texas, Oklahoma, Arkansas, Louisiana, Mississippi, Tennessee, Kentucky, Alabama, Florida, Georgia, South Carolina, North Carolina, Virginia, West Virginia, Delaware, and Maryland) and Washington DC. Currently this region is experiencing the largest net population growth in the U.S. Over the la...

The objective of this paper is to show that the structure of the spatiotemporal continuum has important implications in practical stochastic hydrology (e.g., geostatistical analysis of hydrologic sites) and is not merely an abstract mathematical concept. We propose that the concept of physical geometry as a spatiotemporal continuum with properties that are empirically de®ned is important in hyd...