scholarly journals The long-term and interannual variability of summer fresh water storage over the eastern Siberian shelf: Implication for climatic change

Author(s):  
Igor A. Dmitrenko ◽  
Sergey A. Kirillov ◽  
L. Bruno Tremblay
2021 ◽  
Author(s):  
William Rickard ◽  
Marcos Paradelo Perez ◽  
Aurelie Bacq-Labreuil ◽  
Andy Neal ◽  
Xiaoxian Zhang ◽  
...  

<p>Soil organic matter is associated with important biological and physical functions. There are many theories to interpret this association, as yet there is not a fully developed understanding linking soil properties to nutritional management in arable systems.</p><p>We used X-ray computed tomography to analyse soil structure at the core and aggregate scale on the Broadbalk long term experiment (Hertfordshire, England). Here we present results of the treatments that have been under continuous wheat for 175 years. Corresponding to treatments that the only difference between the treatments is the nutrient management regime, with the exception of the baseline, or ‘wilderness’ treatment in which the plot was left unmanaged and has returned to mature woodland since 1882. The other nutrient treatments correspond to inorganic fertiliser addition with and without phosphorus, farmyard manure, and no added nutrient.</p><p>At core scale (40 µm resolution) we capture macro pore structures that are responsible for convective flow, while the aggregate scale images (1.5 µm resolution) include structures responsible for retention of water by capillary forces.  Therefore, a comparison of images taken at the two resolutions 1.5 µm and 40 µm provides information on how soil partitions between drainage and storage of water, and therefore on the air water balance under different environmental contexts.</p><p>The results are presented as a state-space plot of simulated permeability vs. porosity for each treatment. We find that nutrient management resulted in two distinct states at aggregate scale corresponding to water storage potential. Inorganic nutrient management resulted in structures of lower porosity and lower simulated permeability. There was no significant difference between each treatment, or between these treatments and the treatment with no nutrient addition. By comparison, the wilderness and manure treatments had higher porosity and higher permeability, with no significant difference between them.</p><p>At core scale, the results are slightly different. Again, the inorganic nutrient management treatments had lower porosity and simulated permeability, with no significant difference between them, and between them and the treatment with no nutrient addition. However, the manure treatment had a significantly lower porosity and permeability than the wilderness treatment. We conclude that long-term cultivation with organic nutrient management results in a similar capacity for water storage and transport to roots than a wilderness control, but that long-term management using a purely inorganic nutrient regime results in a smaller capacity for water storage and a lower transport rate to roots. Organic inputs, roots and plant detritus ploughed into the soil after harvest had no significant impact. Infiltration potential is highest in the wilderness control, lower for the manure treatment, and lowest for the inorganic nutrient management treatment. Again, inputs of organic nutrients from plants had no significant impact. We interpret these findings in terms of a previously hypothesised self-organising feedback loop between microbial activity and soil structure.</p>


2021 ◽  
Vol 48 (8) ◽  
Author(s):  
Fupeng Li ◽  
Jürgen Kusche ◽  
Nengfang Chao ◽  
Zhengtao Wang ◽  
Anno Löcher

1971 ◽  
Vol 36 (3) ◽  
pp. 322-335 ◽  
Author(s):  
Dennis E. Puleston

AbstractExperimental techniques have provided an exciting breakthrough for the functional analysis of Maya chultuns. While deep cistern-like chultuns, common at certain sites in the northern lowlands, have been shown to be functional for water storage, smaller lateral-chambered chultuns characteristic of certain parts of the southern lowlands probably had a very different function. Excavation and examination of the latter features, in light of a whole range of possibilities, suggest that they were constructed to be used for food storage. Experimental studies, however, reveal them to be unsuitable for the storage of most traditional foods, including maize. At least one local food crop, the seed of the ramon (Brosimum alicastrum, Moraceae), appears to be ideally suited for long-term storage under these conditions. Chambers constructed beneath platforms in the northern lowlands may have been used for the storage of maize. A need for more experimental work is indicated.


1981 ◽  
Vol 16 (2) ◽  
pp. 135-145 ◽  
Author(s):  
R. A. Bryson ◽  
A. M. Swain

AbstractTwo reconstructed histories of the monsoon rainfall in Rajasthan show that the monsoon was weak or absent in latest glacial time. With the advent of Holocene climatic patterns, fresh water lakes formed in dune fields and the pollen rain preserved in these reservoirs provides a basis for the reconstruction of the monsoon history. The two reconstructions, separated by only 150 km, have some features in common and some striking differences. Both show maximum monsoon amounts in the early Holocene, with a roughly two-thirds decrease to the present. Both show salinization in sub-Boreal time. Both show long intervals of near complete desiccation in the last four millennia. The shorter term variations, however, are not closely parallel. These shorter term variations may be explained in terms of the behavior of the present day interannual variability.


Author(s):  
Vadim Yapiyev ◽  
Kanat Samarkhanov ◽  
Dauren Zhumabayev ◽  
Nazym Tulegenova ◽  
Saltanat Jumassultanova ◽  
...  

Both climate change and anthropogenic activities contribute to the deterioration of terrestrial water resources and ecosystems worldwide. Central Asian endorheic basins are among the most affected regions through both climate and human impacts. Here, we used a digital elevation model, digitized bathymetry maps and Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia (CA), for the period of 1986 to 2016. Based on the analysis of long-term climatic data from meteorological stations, short-term hydrometeorological network observations, gridded climate datasets (CRU) and global atmospheric reanalysis (ERA Interim), we have evaluated the impacts of historical climatic conditions on the water balance of BNNP lake catchments. We also discuss the future based on regional climate model projections. We attribute the overall decline of BNNP lakes to long-term deficit of water balance with lake evaporation loss exceeding precipitation inputs. Direct anthropogenic water abstraction has a minor importance in water balance. However, the changes in watersheds caused by the expansion of human settlements and roads disrupting water drainage may play a more significant role in lake water storage decline. More precise water resources assessment at the local scale will be facilitated by further development of freely available higher spatial resolution remote sensing products. In addition, the results of this work can be used for the development of lake/reservoir evaporation models driven by remote sensing and atmospheric reanalysis data without the direct use of ground observations.


2016 ◽  
Vol 1 (1) ◽  
pp. 24-35
Author(s):  
G. V. Zuyev ◽  
V. A. Bondarev ◽  
Yu. V. Samotoi

Investigations of the Black Sea sprat intraspecific differentiation are the basis for the scientific substantiation of rational exploitation of its resource potential. This work is devoted to the study of spatial variability of length and age structure of sprat as specific population parameter reflecting its intraspecific differentiation. Our own data and materials of Scientific, Technical and Economic Committee for Fisheries (STECF) of the European Commission have been used. The first time long-term dynamics (2007–2012) and interannual variability of length and age structure of sprat in different geographical regions of the Black Sea (coastal waters of Bulgaria – Romania, Turkey and the Crimea) have been investigated. Differences of the long-term dynamics and interannual variability of length and age structure in these regions have been found. Sprat population from Bulgaria – Romania region is in better conditions (mean length 8.59 ± 0.01 cm; mean age 1.79  year), sprat population from Crimea region is in worse conditions (mean length 7.64 ± 0.01 cm; mean age 1.38 year). It has been shown that the main factor determining the interregional biological heterogeneity of sprat is the different fishery regulations. This fact disagrees with concept of united commercial sprat stock in the Black Sea.


2007 ◽  
Vol 13 (3) ◽  
pp. 577-590 ◽  
Author(s):  
ALLISON L. DUNN ◽  
CAROL C. BARFORD ◽  
STEVEN C. WOFSY ◽  
MICHAEL L. GOULDEN ◽  
BRUCE C. DAUBE

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