نتایج جستجو برای: arid

تعداد نتایج: 18687  

2005
Jin Chen Ming Yuan Zhang Le Wang Hiroto Shimazaki Masayuki Tamura

Tracking the presence, distribution and disappearance of biological soil crusts is important for ecosystem management of desert regions and provides highly valuable information on desertification and climate change studies in arid environments. Based on the analysis of the spectral features of biological soil crusts, we propose a new biological soil crust index (BSCI) for biological soil crusts...

Journal: :Remote Sensing 2013
Anton Vrieling Jan de Leeuw Mohammed Y. Said

The spatial distribution of crops and farming systems in Africa is determined by the duration of the period during which crop and livestock water requirements are met. The length of growing period (LGP) is normally assessed from weather station data—scarce in large parts of Africa—or coarse-resolution rainfall estimates derived from weather satellites. In this study, we analyzed LGP and its var...

1997
MATHIAS VUILLE CASPAR AMMANN

Since 1990 the project ‘Climate Change in the Arid Andes’ has been focusing on past climate and environmental conditions in the high mountain range of the north Chilean Andes (18 S– 28 S). The extreme aridity of this region is shown by the absence of glaciers, even at the highest altitudes above 6700 m a.s.l. More knowledge of the present climatic situation is needed to interpret the proxy data...

2017
Daniela V. Morales Soledad Molares Ana H. Ladio

Ecosystems, their components, processes and functions are all subject to management by human populations, with the purpose of adapting the environments to make them more habitable and ensuring the availability and continuity of subsistence resources. Although a lot of work has been carried out on resources of alimentary or medicinal interest, little has been done on associating processes of dom...

2004
MICHAEL L. RODERICK GRAHAM D. FARQUHAR

Contrary to expectations, measurements of pan evaporation show decreases in many parts of the Northern Hemisphere over the last 50 years. When combined with rainfall measurements, these data show that much of the Northern Hemisphere’s terrestrial surface has become less arid over the last 50 years. However, whether the decrease in pan evaporation is a phenomenon limited to the Northern Hemisphe...

2018
Edward G. J. Stevenson

Since the early 20th century, “desert reclamation” has been synonymous with large-scale waterworks and irrigation. These techniques have made it possible to produce abundant crops in arid or semi-arid environments. The costs have often been externalized, with increased environmental productivity in the new croplands counterbalanced by increased aridity elsewhere. In this paper I consider whose ...

2015
Mariangela Diacono Francesco Montemurro

Excessive salt rate can adversely influence the physical, chemical, and biological properties of soils, mainly in arid and semi-arid world regions. Therefore, salt-affected soils must be reclaimed to maintain satisfactory fertility levels for increasing food production. Different approaches have been suggested to solve these issues. This short review focuses on selected studies that have identi...

2010
John C. Risley Jim Constantz Hedeff Essaid

[1] The relative impact of a large upstream dam versus in‐reach groundwater pumping on stream temperatures was analyzed for humid, semiarid, and arid conditions with long dry seasons to represent typical climate regions where large dams are present, such as the western United States or eastern Australia. Stream temperatures were simulated using the CE‐QUAL‐W2water quality model over a 110 kmmod...

Journal: :Remote Sensing 2017
Ran Goldblatt Alexis Rivera Ballesteros Jennifer Burney

Semi-arid ecosystems play a key role in global agricultural production, seasonal carbon cycle dynamics, and longer-run climate change. Because semi-arid landscapes are heterogeneous and often sparsely vegetated, repeated and large-scale ecosystem assessments of these regions have to date been impossible. Here, we assess the potential of high-spatial resolution visible band imagery for semi-arid...

2015
Jesse R. Raab Samuel Resnick Terry Magnuson Jason D. Lieb

Multiple positions within the SWI/SNF chromatin remodeling complex can be filled by mutually exclusive subunits. Inclusion or exclusion of these proteins defines many unique forms of SWI/SNF and has profound functional consequences. Often this complex is studied as a single entity within a particular cell type and we understand little about the functional relationship between these biochemicall...

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