Quaternary Deserts and Climatic Change
Quaternary Deserts and Climatic Change

Author: A.S. Alsharhan

Publisher: CRC Press

Published: 2020-08-26

Total Pages: 636

ISBN-13: 1000099873

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These proceedings record the results of climate change in many areas which are hyper-arid deserts today but which, almost cyclically, at intervals of thousands or even hundreds of thousands of years, have had a much more humid climate.

Paleoclimatic Reconstructions from Owens Lake Core OL-92, Southeastern California
Paleoclimatic Reconstructions from Owens Lake Core OL-92, Southeastern California

Author: Kirsten Margaret Menking

Publisher:

Published: 1995

Total Pages: 420

ISBN-13:

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In 1992, the U.S. Geological Survey cored Owens Lake to obtain a continuous paleoclimate record for the Sierra Nevada region. Owens Lake heads a chain of closed-basin lakes which are separated by a series of bedrock sills, received their water primarily from Sierra Nevadan precipitation, and overflowed during wet periods. The core records the histories of cyclic glaciation of the Sierra Nevada and water-balance of Owens Lake over the past 800 kyrs. A variety of paleoclimatic proxies have been studied, details of which may be found in Smith and Bischoff (1993). In this thesis, I report the results and interpretations of 1) grain-size and clay-mineralogical analyses performed on 3.5-m-long channel samples (%7500 years of sedimentation per sample) and point samples, 2) grain size, carbonate content, and oxygen isotopic measurements on 70-cm-long channel samples (%1500 years), and 3) a water-balance model used to infer the magnitude of runoff and evaporation changes necessary to fill the lakes in the Owens Lake system, and to determine the response time of the lake chain to climatic perturbations.

Subsurface Hydrological Responses to Land Cover and Land Use Changes
Subsurface Hydrological Responses to Land Cover and Land Use Changes

Author: Makoto Taniguchi

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 232

ISBN-13: 1461561418

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Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.