The United States Geological Survey (USGS) makes hourly measurements of river discharge every day at thousands of stream-gauge stations across the United States. Regular patterns of diurnal variation have been observed in hundreds of these rivers, many of which are primary water sources for cities, industries, and agriculture. Diurnal cycles are evident in many river records (Figure 1, Merced R...

BACKGROUND Models of Foot and Mouth Disease (FMD) transmission have assumed a homogeneous landscape across which Euclidean distance is a suitable measure of the spatial dependency of transmission. This paper investigated features of the landscape and their impact on transmission during the period of predominantly local spread which followed the implementation of the national movement ban during...

The previous chapter discussed the emergence of concerns for diminishing flows in rivers during the 1950s in the USA and the consequential evolution of the concept of environmental flows. Parallel developments occurred worldwide in the understanding of river ecosystems (see chapter 2) and the impacts of flow regulation on ecosystem components other than fish (chapter 4). Accordingly, the method...

[1] Diurnal cycles of streamflow in snow-fed rivers can be used to infer the average time a water parcel spends in transit from the top of the snowpack to a stream gauge in the river channel. This travel time, which is measured as the difference between the hour of peak snowmelt in the afternoon and the hour of maximum discharge each day, ranges from a few hours to almost a full day later. Trav...

The chemical and microbiological properties of Lebanese perennial coastal rivers were studied during the dry season extending from July to September 2004. The results indicate significant levels of pollution in all eight rivers. Although many physical and chemical variables were within WHO guidelines for drinking water, coliform levels were unacceptably high indicating pollution from untreated ...

Contents 1. Introduction 2. Factors determining the development of the hydrographic network and the hydrological regime of rivers during the present period 2.1. Relief 2.2. Climate 2.3. Soils and vegetation 2.4. Economic activity 2.4.1 Water reservoirs 2.4.2 Irrigation 3. Hydrography, hydrological knowledge, river runoff, water use and water availability 3.

We analyzed the impact of increased water temperature on the late-season phenology of the mayfly (Baetis liebenauae). The River Gwda, unlike two other examined rivers (controls), has reservoirs along its length and thus, higher water temperature. Elevated water temperature prolonged summer diapause of the mayfly and shifted its life cycle to the later autumn: the last generation of mayflies sta...

Owing to overflows from combined sewer pipe systems, water quality of receiving waters, including urban rivers, has become worse year by year. Appropriate countermeasures that can mitigate the overflows, therefore, must be developed promptly. The authors have investigated a distributed simulation model of water quality and stormwater runoff in urban sewer pipe systems. First, a surface routing ...

This paper considers the risk of drought and develops drought scenarios for use in the study of severe sustained drought in the southwestern United States. The focus is on the Colorado River basin and regions to which Colorado River water is exported, especially southern California, which depends on water from the Colorado River as well as the four major rivers in northern California. Drought s...