Susceptibility of Water Supply Reservoirs to Drought Conditions

1998 ◽  
Vol 3 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Antonino Cancelliere ◽  
Alessandro Ancarani ◽  
Giuseppe Rossi
Fact Sheet ◽  
1997 ◽  
Author(s):  
Michael L. Pomes ◽  
W.R. Green ◽  
E.M. Thurman ◽  
W.H. Orem ◽  
H.T. Lerch

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jose J. De Vega ◽  
Abel Teshome ◽  
Manfred Klaas ◽  
Jim Grant ◽  
John Finnan ◽  
...  

Abstract Background Miscanthus is a commercial lignocellulosic biomass crop owing to its high biomass productivity, resilience and photosynthetic capacity at low temperature. These qualities make Miscanthus a particularly good candidate for temperate marginal land, where yields can be limited by insufficient or excessive water supply. Differences in response to water stress have been observed among Miscanthus species, which correlated to origin. In this study, we compared the physiological and molecular responses among Miscanthus species under excessive (flooded) and insufficient (drought) water supply in glasshouse conditions. Results A significant biomass loss was observed under drought conditions in all genotypes. M. x giganteus showed a lower reduction in biomass yield under drought conditions compared to the control than the other species. Under flooded conditions, biomass yield was as good as or better than control conditions in all species. 4389 of the 67,789 genes (6.4%) in the reference genome were differentially expressed during drought among four Miscanthus genotypes from different species. We observed the same biological processes were regulated across Miscanthus species during drought stress despite the DEGs being not similar. Upregulated differentially expressed genes were significantly involved in sucrose and starch metabolism, redox, and water and glycerol homeostasis and channel activity. Multiple copies of the starch metabolic enzymes BAM and waxy GBSS-I were strongly up-regulated in drought stress in all Miscanthus genotypes, and 12 aquaporins (PIP1, PIP2 and NIP2) were also up-regulated in drought stress across genotypes. Conclusions Different phenotypic responses were observed during drought stress among Miscanthus genotypes from different species, supporting differences in genetic adaption. The low number of DEGs and higher biomass yield in flooded conditions supported Miscanthus use in flooded land. The molecular processes regulated during drought were shared among Miscanthus species and consistent with functional categories known to be critical during drought stress in model organisms. However, differences in the regulated genes, likely associated with ploidy and heterosis, highlighted the value of exploring its diversity for breeding.


2009 ◽  
Vol 376 (1-2) ◽  
pp. 261-274 ◽  
Author(s):  
Lisa D. Lowe ◽  
J. Angus Webb ◽  
Rory J. Nathan ◽  
Teri Etchells ◽  
Hector M. Malano

2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Juliana Nazareth de Lana ◽  
Márcio de Oliveira ◽  
Vanessa Romario de Paula ◽  
Cézar Henrique Barra Rocha

Changes in the land use and land cover in areas adjacent to water reservoirs directly affect the quality of this water. This research presents a study on the water quality in the basin of one of the most important public water supply reservoirs in the city of Juiz de Fora, Minas Gerais. The main objective of this study was to analyze the behavior of limnological parameters and the correlation with land use and land cover in the contribution basin of the Doutor João Penido reservoir (CBJPR). The methodology was based on the analysis of water quality parameters, related to water samples collected from 2012 to 2015. Six sampling points were chosen from different locations: spring, medium course, main tributaries of the reservoir and the reservoir catchment. The parameters analyzed were turbidity, total solids (TS), oxygen consumed (OC), dissolved oxygen (DO), electrical conductivity, total nitrogen (TN), total phosphorus (TP), E. Coli, temperature, pH and total dissolved solids (TDS). The Kendall’s tau test was used to analyze the correlations between the parameters of water quality, land use and land cover in the CBJPR. In general, measured parameters showed better results in spring and in reservoir catchment, showing a worse quality of the water along the tributaries and the dilution power of the reservoir. The correlations pointed to the need for protection and preservation of forests in strategic locations to ensure good water quality.


2006 ◽  
Vol 4 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Justin D. Brookes ◽  
Cheryl M. Davies ◽  
Matthew R. Hipsey ◽  
Jason P. Antenucci

Artificial cow pats were seeded with Cryptosporidium oocysts and subjected to a simulated rainfall event. The runoff from the faecal pat was collected and different particle size fractions were collected within settling columns by exploiting the size-dependent settling velocities. Particle size and Cryptosporidium concentration distribution at 10 cm below the surface was measured at regular intervals over 24 h. Initially a large proportion of the total volume of particles belonged to the larger size classes (>17 μm). However, throughout the course of the experiment, there was a sequential loss of the larger size classes from the sampling depth and a predominance of smaller particles (<17 μm). The Cryptosporidium concentration at 10 cm depth did not change throughout the experiment. In the second experiment samples were taken from different depths within the settling column. Initially 26% of particles were in the size range 124–492 μm. However, as these large particles settled there was an enrichment at 30 cm after one hour (36.5–49.3%). There was a concomitant enrichment of smaller particles near the surface after 1 h and 24 h. For Pat 1 there was no difference in Cryptosporidium concentration with depth after 1 h and 24 h. In Pat 2 there was a difference in concentration between the surface and 30 cm after 24 h. However, this could be explained by the settling velocity of a single oocyst. The results suggested that oocysts are not associated with large particles, but exist in faecal runoff as single oocysts and hence have a low (0.1 m d−1) settling velocity. The implications of this low settling velocity on Cryptosporidium risk reduction within water supply reservoirs was investigated through the application of a three-dimensional model of oocyst fate and transport to a moderately sized reservoir (26 GL). The model indicated that the role of settling on oocyst concentration reduction within the water column is between one and three orders of magnitude less than that caused by advection and dilution, depending on the strength of hydrodynamic forcing.


2014 ◽  
Vol 30 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Andrew Smolders ◽  
Kate Smolders ◽  
Andrew Watkinson ◽  
Darren Ryder

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