[1] Lake sediments are ‘‘hot spots’’ of methane production in the landscape. However, regional and global lake methane emissions, contributing to the greenhouse effect, are poorly known. We developed predictions of methane emissions from easily measured lake characteristics based on measurements for 11 North American and 13 Swedish lakes, and literature values from 49 lakes. Results suggest tha...

A bulk O2 budget for Lake Hoare, Antarctica, is presented. Five years of seasonal data show the lake to be persistently supersaturated with O2. Oxygen is carried into the lake in glacial meltstreams and is left behind when this water is removed as ice by ablation and sublimation. A diffusive loss of O2 from the lake through the summer moat is suggested. Measured values of the total O2 in the...

The Mississippi Delta Management Systems Evaluation Area (MD-MSEA) project was established in 1994 in three small watersheds (202 to 1,497 ha) that drain into oxbow lakes (Beasley, Deep Hollow, and Thighman). The primary research objective was to assess the implications of management practices on water quality. Monthly monitoring of herbicide concentrations in lake water was conducted from 2000...

The 6’*0 content of streamflow discharge entering Pyramid Lake is a simple mixture of isotopically enriched Lake Tahoe discharge and isotopically depleted snowmelt. The aI80 value of Pyramid Lake water varies continuously, as isotopically depleted water evaporates from the epilimnion and isotopically depicted water enters the lake as streamflow discharge and on-lake precipitation. In a normal w...

The Qehan Lake Basin (QLB) and its system of lakes are located in a marginal monsoon zone and are extremely sensitive to global climate change. In this paper, using aerial photographs from different periods, in addition to MSS, TM, and ETM images, and combining these with regional topographic maps, we analyze lake area changes from 1958 to 2010 and the relation between Qehan Lake (QL) and clima...

Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. H...

-The interactions between organic matter, bacterial biomass, enzyme activities and environmental factors were studied during bank filtration of humus-rich lake water. The exoenzymatic //-glucosidase, phosphatase and alanine-aminopeptidase activities in water were measured in vitro as release of fluorescing degradation products from methylumbelliferyl substrates. The total enzymatic decompositio...

Holocene paleoclimate records from Greenland help us understand the response of the Greenland Ice Sheet and regional oceanic and atmospheric circulation systems to natural climate variability in order to place recent changes in a longer-term perspective. Here biogeochemical analysis of a lake sediment core from southeast Greenland is used to define changes in moisture balance and runoff during ...

A method developed to evaluate the cumulative effect of wetland mosaics on water quality was applied to 33 lake watersheds in the seven-county region surrounding Minneapolis-St. Paul, Minnesota. A geographic information system (GIS) was used to record and measure landscape variables derived from aerial photos. Twenty-seven watershed land-use and land-cover variables were reduced to eight princi...

The nutrient-water color paradigm is a framework to characterize lake trophic status by relating lake primary productivity to both nutrients and water color, the colored component of dissolved organic carbon. Total phosphorus (TP), a limiting nutrient, and water color, a strong light attenuator, influence lake chlorophyll a concentrations (CHL). But, these relationships have been shown in previ...