scholarly journals Intensified vegetation water use under acid deposition

2019 ◽  
Vol 5 (7) ◽  
pp. eaav5168 ◽  
Author(s):  
Matthew Lanning ◽  
Lixin Wang ◽  
Todd M. Scanlon ◽  
Matthew A. Vadeboncoeur ◽  
Mary B. Adams ◽  
...  
Keyword(s):  
Water Use ◽  
Acid Deposition ◽  
Large Scale ◽  
Water Cycle ◽  
Base Cations ◽  
Surface Energy Flux ◽  
Soil Calcium ◽  
Fossil Fuel Burning ◽  
Calcium Supply ◽  
Vegetation Water

Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. In this study, we reveal a new mechanism of soil biogeochemical control of large-scale vegetation water use. Nitrate and sulfate deposition from fossil fuel burning have caused substantial soil acidification, leading to the leaching of soil base cations. Of these, calcium has a unique role in plant cells by regulating stomatal aperture, thus affecting vegetation water use. We hypothesized that the leaching of the soil calcium supply, induced by acid deposition, would increase large-scale vegetation water use. We present evidence from a long-term whole watershed acidification experiment demonstrating that the alteration of the soil calcium supply by acid deposition can significantly intensify vegetation water use (~10% increase in evapotranspiration) and deplete available soil water. These results are critical to understanding future water availability, biogeochemical cycles, and surface energy flux and to help reduce uncertainties in terrestrial biosphere models.

scholarly journals An analysis of the sensitivity of sap flux to soil and plant variables assessed for an Australian woodland using a soil - plant - atmosphere model

2008 ◽  
Vol 35 (6) ◽  
pp. 509 ◽  
Author(s):  
Melanie Zeppel ◽  
Catriona Macinnis-Ng ◽  
Anthony Palmer ◽  
Daniel Taylor ◽  
Rhys Whitley ◽  
...  
Keyword(s):  
Water Content ◽  
Water Use ◽  
Water Uptake ◽  
Soil Profile ◽  
Sap Flow ◽  
Large Scale ◽  
Seasonal Patterns ◽  
Management Options ◽  
Vegetation Water ◽  
Spa Model

Daily and seasonal patterns of tree water use were measured for the two dominant tree species, Angophora bakeri E.C.Hall (narrow-leaved apple) and Eucalyptus sclerophylla (Blakely) L.A.S. Johnson & Blaxell (scribbly gum), in a temperate, open, evergreen woodland using sap flow sensors, along with information about soil, leaf, tree and micro-climatological variables. The aims of this work were to: (a) validate a soil–plant–atmosphere (SPA) model for the specific site; (b) determine the total depth from which water uptake must occur to achieve the observed rates of tree sap flow; (c) examine whether the water content of the upper soil profile was a significant determinant of daily rates of sap flow; and (d) examine the sensitivity of sap flow to several biotic factors. It was found that: (a) the SPA model was able to accurately replicate the hourly, daily and seasonal patterns of sap flow; (b) water uptake must have occurred from depths of up to 3 m; (c) sap flow was independent of the water content of the top 80 cm of the soil profile; and (d) sap flow was very sensitive to the leaf area of the stand, whole tree hydraulic conductance and the critical water potential of the leaves, but insensitive to stem capacitance and increases in root biomass. These results are important to future studies of the regulation of vegetation water use, landscape-scale behaviour of vegetation, and to water resource managers, because they allow testing of large-scale management options without the need for large-scale manipulations of vegetation cover.

Pressure management in Waitakere City, New Zealand - a case study

2003 ◽  
Vol 3 (1-2) ◽  
pp. 135-141 ◽  
Author(s):  
Z. Pilipovic ◽  
R. Taylor
Keyword(s):  
Water Use ◽  
Water Loss ◽  
Water Cycle ◽  
Demand Management ◽  
Cost Benefit ◽  
Water Shortage ◽  
Design Tool ◽  
Network Computer ◽  
Water Pipeline ◽  
The City

In 1996, as part of Waitakere Council’s Water Cycle Strategy, a pressure standardisation programme to permanently lower the average supply pressure citywide was implemented with the aim of reducing water loss and water use. The experience gained during the 1994/95 Auckland water shortage had confirmed that there was considerable scope to reduce pressures in many areas. Since 1996 water pressures have been reduced in over 60% of the reticulated area of the city, with the average pressure reduced from 710 kPa to 540 kPa. As a result of this programme water loss from the network has been reduced, there has been a reduction in the frequency of mains breaks and it is likely that the life of water pipeline assets has been extended. Furthermore both pressure and demand management initiatives have reduced per capita water use in the city by more than 10%. A network computer model was used as a design tool to check the network under various pressure regimes and cost benefit analyses were carried out for various design scenarios. Fire sprinkler systems were checked as part of the design process. Minimum service standards were not reduced and in some cases pressures were actually increased. This paper covers the various aspects of the design, the implementation and the results of the pressure standardisation programme.

Social interaction in water demand management implementation

2005 ◽  
Vol 5 (3-4) ◽  
pp. 295-301
Author(s):  
J.S. Buckle
Keyword(s):  
Social Interaction ◽  
Water Use ◽  
Water Demand ◽  
Water Cycle ◽  
Demand Management ◽  
Community Members ◽  
Water Demand Management ◽  
Education Project ◽  
Broad Concept ◽  
Efficient Water Use

This article describes a successful awareness and education project undertaken in an East Rand township by the Water Cycle Management Section of Rand Water. The Project's focus was to create awareness in the community of the broad concept of water cycle management within an environment and to transfer skills to community members (facilitators) who could then assist in ensuring effective and efficient water use.

scholarly journals The effect of deforestation on the water cycle in the amazon basin: an attempt reformulate the problem

1985 ◽  
Vol 15 (3-4) ◽  
pp. 307-310 ◽  
Author(s):  
J. R. Gat ◽  
Ε. Matsui ◽  
Ε. Salati
Keyword(s):  
Large Scale ◽  
Amazon Basin ◽  
Water Cycle ◽  
Water Flux ◽  
Atmospheric Stability ◽  
Local Heat ◽  
Physical Geography ◽  
Cloud Formation ◽  
Evaporative Water ◽  
Stability Structure

If widespread deforestation in Amazon results in reduced evaporative water flux, then either a decrease in evaporation is compensated locally by reduced rainfall,or else changed moisture balance expresses itself downwind in the yet undisturbed forest. The question of where rain will occur is crucial. It is suggested that the appearance of clouds and the occurrence of rainout is governed primarily by the interplay of local meteorologic and physical geography parameters with the atmospheric stability structure except for a few well-defined periods when rain is dominated by large scale atmospheric instability. This means that the study of these phenomena (local heat balances,studies on cloud formation mechanism, vertical atmospheric stability, etc.) must be made on the scale of the cloud size, a few tens of kilometers at most.

scholarly journals Groundwater use for irrigation – a global inventory

2010 ◽  
Vol 7 (3) ◽  
pp. 3977-4021 ◽  
Author(s):  
S. Siebert ◽  
J. Burke ◽  
J. M. Faures ◽  
K. Frenken ◽  
J. Hoogeveen ◽  
...  
Keyword(s):  
Water Use ◽  
Irrigation Water ◽  
Water Cycle ◽  
The United States ◽  
Major Step ◽  
Groundwater Use ◽  
Irrigation Water Use ◽  
Global Inventory ◽  
Consumptive Water ◽  
Water Uses

Abstract. Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1 277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha), China (19 million ha) and the United States of America (17 million ha). Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.

scholarly journals MEDICAL AND ENVIRONMENTAL ASPECTS OF THE DEGRADATION OF THE PERMAFROST ZONE: PROBLEM OF PALEOVIRAL CONTAMINATION

2019 ◽  
Vol 96 (8) ◽  
pp. 706-711
Author(s):  
Leonid I. Elpiner ◽  
A. V. Dzyuba
Keyword(s):  
Surface Water ◽  
Groundwater Contamination ◽  
Water Use ◽  
Large Scale ◽  
Permafrost Zone ◽  
Environmental Aspects ◽  
Drinking Purposes

We present the concept of a possible global viral infestation associated with the processes of permafrost melting and probability of groundwater contamination with paleoviruses. The most realistic mechanism of the development of this process is considered, as well as possible ways of forming of a new epidemic situation, depending on characteristics of groundwater and surface water use for drinking purposes by the population of the permafrost zone (permafrost). The necessity of in-depth development of large-scale multi-disciplinary researches in order to clarify the pathogenetic significance of paleoviruses in the permafrost zone and assess the need of the development of the composition and the nature of the complex environmental and anti-epidemic measures is substantiated.

Ocean Salinity changes in the global ocean under global warming conditions Part 1: Mechanisms in a strong warming scenario

2021 ◽  
pp. 1-56
Author(s):  
Anju Sathyanarayanan ◽  
Armin Köhl ◽  
Detlef Stammer
Keyword(s):  
Large Scale ◽  
Water Cycle ◽  
Spatial Scales ◽  
Sea Surface Salinity ◽  
Global Ocean ◽  
Dynamical Response ◽  
Freshwater Flux ◽  
Near Surface ◽  
Salinity Changes ◽  
Circulation Changes

AbstractWe investigate mechanisms underlying salinity changes projected to occur under strong representative concentration pathway (RCP) 8.5 forcing conditions. The study is based on output of the Max Planck Institute Earth System Model Mixed Resolution (MPI-ESM-MR) run with an ocean resolution of 0.4°. In comparison to the present-day oceanic conditions, sea surface salinity (SSS) increases towards the end of the 21st century in the tropical and the subtropical Atlantic. In contrast, a basin-wide surface freshening can be observed in the Pacific and Indian Oceans. The RCP8.5 scenario of the MPI-ESM-MR with a global surface warming of ~2.3°C marks a water cycle amplification of 19 %, which is equivalent to ~8%°C−1 and thus close to the water cycle amplification predicted according to the Clausius–Clapeyron (CC) relationship (~7%°C−1). Large scale global SSS changes are driven by adjustments of surface freshwater fluxes. On smaller spatial scales, it is predominantly advection related to circulation changes that affects near-surface SSS. With respect to subsurface salinity, it is changes in surface freshwater flux that drive their changes over the upper 500 m of the subtropical Pacific and Indian oceans by forcing changes in water mass formation (spice signal). In the subtropical Atlantic Ocean, in contrast, the dynamical response associated with wind stress, circulation changes and associated heaving of isopycnals is equally important in driving subsurface salinity changes over the upper 1000 m.

Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Puerto Rico ◽  
Freshwater Fish ◽  
Water Use ◽  
Large Scale ◽  
River Flow ◽  
Fish Assemblages ◽  
Physical Habitat ◽  
Resource Exploitation ◽  
Ecological Processes ◽  
Tropical Island

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

scholarly journals Soil water cycle and crop water use efficiency after long-term nitrogen fertilization in Loess Plateau

2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Cycle ◽  
Triticum Aestivum L ◽  
Growing Seasons ◽  
Water Recharge ◽  
Use Efficiency ◽  
N Management

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20&ndash;60 cm, increased water recharge by 16&ndash;21 mm, and decreased ASWS by 89&ndash;133 mm in 0&ndash;300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246&ndash;1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was &lt; 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.

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