Water Stocks Research Articles

Environmental determinants of zooplankton assemblages during summer hypoxia in the Changjiang Estuary and its adjacent waters, China

An extensive area (6800 km2) of bottom hypoxia (dissolved oxygen concentration <2.86 mg L−1), which could be ascribed to strong stratification of the water column and bottom organic carbon oxidation, was observed in the Changjiang Estuary and its adjacent waters in July–August 2006. The relationship between environmental conditions and zooplankton community structure was studied based on samples collected from a total of 72 stations. The zooplankton community was dominated by copepods, and could be divided into five groups by CLUSTER analysis. Spatial patterns in zooplankton community were structured by a combination of sampling depth, temperature, salinity and bottom dissolved oxygen. The most dominant species Centropages dorsispinatus maintained its high abundance in the hypoxic area, perhaps due to its adaptive strategies to hypoxia. While the abundance of other taxa such as the copepod Acartia pacifica showed a positive relation to bottom oxygen levels at hypoxic stations. In general, the total amount of zooplankton biomass and diversity present in the water column were high in hypoxic areas, which was probably due to the presence of large phytoplankton stock in the surface water.

Natural and anthropogenic signatures on sedimentary organic matters across varying intertidal habitats in the Korean waters

Sedimentary organic matters in the typical intertidal areas were investigated to address year-round monthly distributions and site-specific sources. Target areas included four natural tidal flats (Ganghwa, Garolim, Sinan, and Suncheon) and one artificially closed estuary (Nakdong River), South Korea (in 2018). Among the parameters monitored, mud content was a key factor controlling organic matter contents, across varying habitats, with significant positive correlations to total organic carbon (TOC, r = 0.66, p < 0.001) and total nitrogen (TN, r = 0.44, p < 0.001). The elevated TOC and TN contents and heavier carbon stable isotope ratios (δ13C) in sediments of Garolim and Suncheon from February to April reflected the winter microphytobenthos blooms, receiving prevailed marine sources. Whilst, the depleted δ13C and δ15N values in sediments of Nakdong River estuary were observed during flood season (September–October), indicating direct influence of terrestrial organic input through freshwater discharge. Overall, distributions and sources of sedimentary organic matters in the Korean coastal waters suggested variabilities in season and space, with anthropogenic alteration. The data accumulated in this study would provide baseline information for sediment organic carbon stocks in the Korean coastal waters and elsewhere.

Cartographical Perspectives on the Evolution of Fisheries in Newfoundland’s Grand Banks Area and Adjacent North Atlantic Waters in the Sixteenth and Seventeenth Centuries

At the turn of the sixteenth century, John Cabot and his successors discovered abundant fish stocks in the north west Atlantic waters near Newfoundland. This article accounts for how sixteenth- and seventeenth-century mapping provide another strand of evidence that supplement our knowledge of the subsequent Iberian, French, and British fisheries. Such cartography exhibited significant mutations and innovations in rendering fishing locations, and illustrating fishing practices and fish species. Fishermen’s knowledge must have informed such mapping. The innovation of hydrographical indicators in esthetically appealing maps recognized from an early stage the status of the Grand Banks as a globally important feature of submarine topography. More refined and accurate delineations of its submarine plateaus and other adjacent continental shelves closely followed the development of fishing activities, encompassing both Newfoundland’s nearshore and the Grand Banks themselves. Furthermore, such cartography reflected transformative and reciprocal relationships with commerce and inter-state politics across the North Atlantic.

The Effects of Irrigation and Climate on the High Plains Aquifer: A County‐Level Econometric Analysis

AbstractThe High Plains Aquifer (HPA) underlies parts of eight states and 208 counties in the central area of the United States (U.S.). This region produces more than 9% of U.S. crops sales and relies on the aquifer for irrigation. However, these withdrawals have diminished the stock of water in the aquifer. In this paper, we investigate the aggregate county‐level effect on the HPA of groundwater withdrawal for irrigation, of climate variables, and of energy price changes. We merge economic theory and hydrological characteristics to jointly estimate equations describing irrigation behavior and a generalized water balance equation for the HPA. Our simple water balance model predicts, at average values for irrigation and precipitation, an HPA‐wide average decrease in the groundwater table of 0.47 feet per year, compared to 0.48 feet per year observed on average across the HPA during this 1985–2005 period. The observed distribution and predicted change across counties is in the (−3.22, 1.59) and (−2.24, 0.60) feet per year range, respectively. The estimated impact of irrigation is to decrease the water table by an average of 1.24 feet per year, whereas rainfall recharges the level by an average of 0.76 feet per year. Relative to the past several decades, if groundwater use is unconstrained, groundwater depletion would increase 50% in a scenario where precipitation falls by 25% and the number of degree days above 36°C doubles. Editor’s note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.

Wind Field Influences on the Spatial Distribution of Cyanobacterial Blooms and Nutrients in Meiliang Bay of Lake Taihu, China

Wind field is a very important physical factor controlling the formation of cyanobacteria blooms. A surface particle tracking drift experiment was carried out to study the influence of wind field on the surface current in Meiliang Bay of Lake Taihu during the algal bloom season. For this, chlorophyll-a, nitrogen, phosphorus, the permanganate index, dissolved organic carbon (DOC), and dissolved oxygen (DO) were measured in surface, middle, and bottom waters of the Meiliang Bay during the cyanobacteria bloom period to test how wind field affects the temporal and spatial distribution of cyanobacterial blooms and biomass stock in the water column. The results showed that the average drift velocities of surface particles were 3.0 cm·s-1 and 5.0 cm·s-1 when wind speed averaged 1.9 m·s-1 and 2.3 m·s-1, respectively. The wind field determined the spatial distribution of cyanobacterial blooms in surface waters and led to a high spatial heterogeneity of cyanobacterial blooms. The spatial redistribution of cyanobacterial blooms exerted an important influence on water quality indexes such as particulate nitrogen, phosphorus, organic matter, and dissolved oxygen. The concentrations of particulate nitrogen, phosphorus, the permanganate index, and chlorophyll-a showed a similar vertical distribution pattern. Cyanobacterial blooms were less influenced by the distribution of dissolved nitrogen and dissolved organic carbon from external pollution, while long-term legacy loading played a more important role. This meant that the spatial distributions of dissolved nitrogen and dissolved organic carbon were different from that of chlorophyll-a. Because the redistribution of cyanobacterial blooms, as affected by wind fields, has a complex effect on the dissolved oxygen in the water column, the dissolved oxygen concentration decreased with depth, which may affect the release of soluble nutrients from the sediment. The cyanobacterial biomass stock in the surface water was estimated according to the survey of high-density sites. The dry matter of cyanobacteria in the surface 20 cm of Meiliang Bay was approximately 396 tons on the day of sampling. The results from the present study indicated that the factors influencing cyanobacterial blooms should be considered in sampling methods and the analysis of lake water quality due to the significant influence of wind fields on bloom drift. The collection of cyanobacteria has limited effect on the removal of the algal bloom biomass in whole lake, only being effective at prevention of the event of black spots in lake shore.

Fungal diversity and its functions in tropical peatlands as plant growth promoting microorganism or associated with green house emission

Peat land deterioration is global issue. Exploitation of peatland ecosystem, especially extreme drainage has caused severe environmental problem. Among other destruction of fresh water stock, emission of greenhouse gas in the form of carbon dioxide, methane, and nitrous oxide. The objective study was to assess the influence of land use type on fungal diversity and its activity which indirectly contribute plant growth promotion or associated with greenhouse emission from peatland in Central Kalimantan. Four land use types: Nearly-pristine peat swamp forest (n-PSF), Un-drained deforested peatlands (UDP), Drained deforested peatlands (DDP), and Degraded peatlands under agriculture (DPA) were evaluated representing the disturb and less disturb peatland ecosystem. The hydrolytic enzymes assessment, particularly those linking to polymeric substances mineralization, was conducted to estimate microbial activities which contribute to greenhouse gas emission. The result indicates that fungal diversity and its activities of less disturb peatland was quite distinctive from exploited areas, which implies that higher greenhouse gas emission in exploited areas. It is recommended that exploitation of peatland ecosystem should consider water regimes through managing oxic and anaerobic environment to limit greenhouse gas emission. The presence of IAA, phosphatase producing fungi could be important for genetic resources for the growth promotion in peatland ecosystem.

ANALYSIS OF IMPACT OF INJECTION WELL CAPACITY ON SELF-INDUCED HYDRAULIC FRACTURE DEVELOPMENT

As experience in field development shows, unplanned growth of injection well cracks does not always have a positive effect on the development of oil reserves, but, on the contrary, causes premature flooding of producing wells. Currently, most of the fields are at the final stages of development, and an increase in reservoir coverage by flooding is an important task of developing oil fields. The article discusses and analyzes the effect of injection well capacity on the growth of self-induced fracturing fractures and the relationship with oil production on the example of one of the fields in Western Siberia. Using the hydrodynamic simulator and the geomechanical module, the best option was chosen and the positive effect was evaluated. An example is a production well of a highly watered stock. The reasons for the premature well flooding are considered by analyzing the graphical dynamics of capacity and flow rate of injection and production wells. As confirmation of the fracture growth or closing, the results of the adaptation of a single-layer two-phase model using the automatic hydraulic fracture are presented. The analysis of the geomechanical properties of the layers was carried out, during which the dependence of the crack length on the bottomhole pressure was determined. This dependence is compared with the results of the model adaptation. According to this adaptation of the hydrodynamic model, several variants of calculations were made in order to identify the optimal bottomhole pressure and compare this variant with the actual one. According to the data obtained, it was found that with optimal injectivity, a positive effect was observed already in the first month. The information obtained during the analysis of actual data and calculation on the hydrodynamic and geomechanical module, confirms the need to control bottomhole pressure at injection wells. Calculations show that there is a significant loss of oil production after the crack has opened. Using a calculation on the geomechanical module, optimal bottomhole pressures were given for a given injection well, at which there would be no increase in the crack of the injection well followed by watering of the production well. Calculations to determine the optimal values of the bottomhole pressure of the selected injection well can be applied to the wells of other fields.

PSVI-17 Evaluation of a nutritional water supplement on growth performance of nursery pigs

Abstract One-hundred forty weanling pigs (5.26 kg; 20 d of age) were used to determine the effects of a nutritional water supplement (WB; Water Boost, Furst-McNess, Freeport, IL) on growth performance of nursery pigs. Pigs were randomly allotted to two water treatments (7 pens/treatment; 10 pigs/pen). The water treatments were 0 and 62.5 mL WB/L of water (stock solution) supplied by water medicators (1:100 dilution). Pigs were fed simple, corn soybean meal diets (no plasma or crystalline lactose utilized) in four dietary phases (Phase 1: d 0-7, Phase 2: d 7-14, Phase 3: d 14-21, and Phase 4: d 21-42). The water treatments were provided on d 0 through d 3. Pigs and feeders were weighed weekly to determine ADG, ADFI, and G:F. Water meters were used to record and calculate water disappearance. Data were analyzed as a randomized complete block design with pen serving as the experimental unit. Water disappearance (L/pig/d) was not affected from d 0-21, but it increased (P &lt; 0.01) for pigs provided WB for d 21-42 (1.71 vs 2.12) and d 0-42 (1.11 vs 1.35). Growth performance was not affected by WB during d 0-21. However, from d 21-42, WB tended to increase (P &lt; 0.10) ADG (483 vs 528 g/d) and ADFI (706 vs 767 g/d), but it had no effect on G:F. For the overall period, pigs provided WB from d 0-3 tended to have improved G:F (0.671 vs 0.684) and numerical increases in ADG (P = 0.14) and ADFI (P = 0.17) were observed. Final ending body weight tended to be increased (P &lt; 0.10) for pigs provided WB (18.6 vs 19.9 kg). These results suggest providing WB for the first three days in the nursery to pigs fed corn soybean meal-based diets increased water disappearance and tended to improve growth performance of nursery pigs.

Light absorption, light use efficiency and productivity of 16 contrasted genotypes of several Eucalyptus species along a 6-year rotation in Brazil

Stemwood productivity in forest ecosystems depends on the amount of light absorbed by the trees (APAR) and on the Light Use Efficiency (LUE), i.e. the amount of stemwood produced per amount of absorbed light. In fertilized Eucalyptus plantations of Brazil, growth is expected to be strongly limited by light absorption in the first years after planting, when trees can benefit from high soil water stocks, recharged after clearcutting the previous stand. Other limiting factors, such as water or nutrient shortage are thought to increase in importance after canopy closure, and changes in allocation patterns are expected, affecting the LUE.Studying changes in APAR and LUE along a complete rotation is paramount for gaining insight into the mechanisms that drive the inter- and intra-genotype variabilities of productivity and stemwood biomass at the time of harvest. Here, we present a 6-year survey of productivity, APAR and LUE of 16 Eucalyptus genotypes of several species used in commercial plantations and planted in 10 randomized replications in the São Paulo Region, Brazil. APAR was estimated using the MAESTRA tridimensional model parameterized at tree scale for each tree in each plot (a total of 16,000 trees) using local measurements of leaf and canopy properties. Stand growth was estimated based on allometric relationships established through successive destructive biomass measurements at the study site.Allometric relationships predicting biomass of tree components, leaf surface, crown dimension and leaf inclination angle distribution throughout the rotation for the 16 productive genotypes are shown. Results at stand scale showed that (1) LUE increased with stand age for all genotypes, from 0.15 at age 1 yr to 1.70 g MJ−1 at age 6 yrs on average; (2) light absorption was a major limiting factor over the first year of growth (R2 between APAR and stand biomass ranging from 0.5 to 0.95), explaining most of the inter- and intra-genotype growth variability; (3) at rotation scale, the variability of final stemwood biomass among genotypes was in general attributable to other factors than average APAR; (4) differences in stemwood productions among genotypes remained large throughout the rotation; (5) LUEs over the second half of the rotation, rather than initial growth or APAR, was the major driver of stemwood biomass at the time of harvest.

Forecasting Model of Wheat Yield in Relation to Rainfall Variability in North Africa Countries

The study investigated the effect of rainfall variations on wheat yield in Morocco as a representative case study of North Africa region. The data were collected for the period 2004– 2015 from 12 meteorological stations. The wheat yield variability range was 79.5%-38.0%. It increased in poor-rain years and the regions of precipitation ≤ 350 mm. The wheat yield showed more significant response to monthly perception changes than the annual. The estimated forecasting model showed that March's rain was the critical month for wheat yield as the elasticity of production was 0.587. April and May showed an elasticity of 0.011 and 0.023, respectively. The estimated response of wheat farm price to grain yield showed that 10% increase in wheat yield would decrease the farm gate price by 4.1%, i.e. poor rainy seasons mean income foregone with the loss of inputs expenses and expansion in imported wheat. A country buffer stock, a regional strategic stock of wheat and supplementary water for irrigation in poor precipitation years are required.

Does Caragana korshinskii plantation increase soil carbon continuously in a water‐limited landscape on the Loess Plateau, China?

AbstractAlthough afforestation of nitrogen‐fixing shrubs, especially Caragana korshinskii in semiarid areas, is expected to improve ecosystem restoration and carbon sequestration, water shortage induced by these thirsty shrubs may negate potential benefits. Yet there is poor understating of the persistence of soil carbon sequestration in nitrogen‐fixing shrub plantations. Here, we selected three C. korshinskii plantations with different ages (10, 20, and 30 years) on the Loess Plateau to evaluate the persistence of soil carbon sink. We examined dynamics of soil carbon, total nitrogen, and soil water, as well as their relationships along the plantation ages. The results showed that soil organic carbon (SOC) and soil total nitrogen (STN) were tightly coupled. SOC, STN, and soil water stocks (0–100 cm) were significantly decreased by 23.9%, 19.9%, and 29.2% from 10 to 30 years, respectively. The reduction of SOC and STN was likely caused by lowered intercanopy herbaceous productivity due to soil drying and intensified competition from shrubs. We present evidence that the positive carbon sequestration by afforestation of leguminous shrub in short term may be further weakened by water shortage, making our ability to restore degraded land in semiarid regions more challenging than previously thought. Therefore, it is essential to improve management of afforestation land such as thinning for maintaining SOC sequestration persistently in water‐limited areas.

Human domination of the global water cycle absent from depictions and perceptions

Human water use, climate change and land conversion have created a water crisis for billions of individuals and many ecosystems worldwide. Global water stocks and fluxes are estimated empirically and with computer models, but this information is conveyed to policymakers and researchers through water cycle diagrams. Here we compiled a synthesis of the global water cycle, which we compared with 464 water cycle diagrams from around the world. Although human freshwater appropriation now equals half of global river discharge, only 15% of the water cycle diagrams depicted human interaction with water. Only 2% of the diagrams showed climate change or water pollution—two of the central causes of the global water crisis—which effectively conveys a false sense of water security. A single catchment was depicted in 95% of the diagrams, which precludes the representation of teleconnections such as ocean–land interactions and continental moisture recycling. These inaccuracies correspond with specific dimensions of water mismanagement, which suggest that flaws in water diagrams reflect and reinforce the misunderstanding of global hydrology by policymakers, researchers and the public. Correct depictions of the water cycle will not solve the global water crisis, but reconceiving this symbol is an important step towards equitable water governance, sustainable development and planetary thinking in the Anthropocene.

Total water storage variability from GRACE mission and hydrological models for a 50,000 km2 temperate watershed: the Garonne River basin (France)

Study RegionGaronne Basin, France. Study FocusThis study analyses water mass variations for the whole Garonne basin (50,000 km2 drainage area). To do so, Total Water Storage Anomalies (TWSA) from seven global solutions based on the Gravity Recovery And Climate Experiment (GRACE) satellite mission measurements (˜300 km spatial resolution) are inter-compared with TWSA from two hydrological models, SAFRAN-ISBA-MODCOU (SIM) and Soil and Water Assessment Tool (SWAT), between January 2003 and December 2010. New Hydrological Insights for the RegionDespite the small size of the Garonne basin compared to GRACE spatial resolution, good agreement between GRACE solutions and hydrological model TWSA has been found (maximum correlation coefficient ˜0.9 and Nash-Sutcliffe Efficiency, NSE, ˜0.7). These datasets showed that TWSA in the Garonne basin is mainly due to water stored in the first dozen meters of soil and in the shallow aquifer. To a smaller extent, snow also influences Garonne TWSA. Open surface water TWSA is quite small and TWSA from deep aquifer is negligible. The most important drought period occurred in 2011/2012, due to low precipitation during the two hydrological years and ETR close to previous years. Important precipitation in 2013/2014 helps to refill the water stocks. This study also showed that GRACE and models mismatches should be due to GRACE poor spatial resolution, but also to its monthly time resolution (rarely shown in previous studies).

Elucidating controls of the variability of deep soil bulk density

Information on the variability of bulk density (BD) in deep soil is critical to understand the hydrological dynamics of the deep unsaturated zone (USZ), but studies have mainly focused on quantifying BD in shallow soils (<1 m). The objective of this study was to quantify the spatial variability of soil BD in deep USZ and their controls at multiple scales. Three undisturbed soil cores (98.0, 18.4, 22.8 m) were collected from three land-use areas (grassland, orchard, and farmland) from the Changwu tableland of the Chinese Loess Plateau; then, BD, magnetic susceptibility, particle size and organic carbon were determined in the laboratory. The spatial patterns and scale- and location-specific controls of BD variability were quantified using traditional statistics and wavelet analyses. BD distribution in the deep USZ was consistent across the cores indicating the minimal influence of land-use. For the vertical distribution of the USZ BD, the coefficient of variation (CV) in the upper 0–40 m was higher (8%) compared to the broadly steady BD (CV = 3%) in the lower 40–90 m depth. BD with depth mainly exhibited two-type variations: an exponentially increasing trend at the large scale (13–30 m) and a cyclical trend at the medium scale (3–13 m). While soil depth was the major factor contributing to BD variability at the large scale, magnetic susceptibility contributed at the medium scale and exhibited a stronger effect than organic carbon and particle size composition. This information on the deep USZ BD is distinctly different than that of the shallow soil from previous studies and enhanced our understanding of BD spatial patterns with depth and identified the dominant factor(s) to improve predictability. This can provide an objective evaluation of soil characteristics, accurate estimation of soil water, nutrients and carbon stocks and fluxes, and the simulation of related hydraulic processes in the deep USZ.

Can water level management, stock enhancement, and fishery restriction offset negative effects of hydrological changes on the four major Chinese carps in China’s largest freshwater lake?

Habitat degradation and fragmentation have been the leading cause of reduced fishery yields in many freshwater ecosystems around the world. In Poyang Lake, the largest freshwater lake in China, recent hydrological changes driven by the operation of Three Gorges Dam (TGD) and drought have caused a drastic loss of fishery resources. In response, managers have planned to build a sluice at Poyang Lake's outlet to manage the lake's water level and, as the sluice will unavoidably limit the river–lake migration of many fishery species, managers have also proposed implementing stock enhancement programs and restricting fisheries to sustain fisheries in the lake. In this study, we built and implemented a Poyang Lake Ecopath with Ecosim model to evaluate effects of water level management, stock enhancement, and fishery restriction on biomass of the four major Chinese carps: grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix), bighead carp (H. nobilis), and black carp (Mylopharyngodon piceus), of which all are river–lake migratory and important to fisheries. Results showed that the total biomass of the four major Chinese carps could increase with increases in water level, increases in stocking biomass, and decreases in fishing pressure. However, even in the best management effort scenario (i.e., highest water level, highest stocking biomass, and no fishing), simulated total biomass of the four major Chinese carps was still 16% lower than the biomass estimate in 2000, three years before the operation of TGD. These results suggest that a combination of managing water level, stocking, and restricting fisheries can substantially offset negative effects of hydrological changes on the four major Chinese carps, but may not be enough to restore the biomass of the four major Chinese carps to high levels that had occurred before the operation of TGD, because of the blockage of river–lake connectivity by the Poyang Lake sluice.

Analisa Karakteristik Dan Distribusi Hujan Pada Kawasan DAS Batang Hari Kabupaten Dharmasraya

Batang Hari is the 2nd biggest DAS in Indonesia. About 76% of Batang Hari DAS is located in Jambi Province, the entire 24%is in West Sumatera Province. Batang Hari dam which was built on 1997 is one of infrastrcture at Public Work ministery under management at Balai Wilayah Sungai Sumatera V (BWSS V) his high potential of water stock. Optimum discharge of Batang Hari Dam is about 86 m3/sec. In the recently years DAS Batang Hari has been disturbed by some changes like catchment area utilized fot other purpose, change on global climate done to greenhouse effectwhich causingintensity of rain as well as flood. This climate change then will affected standard for engineering design for making a water control buiding which may injuireaccurate waterfall intensity data. Study of rainfall intensity obtained from 3 (three) nearby stations will show the characteristic dam trend of distribution with reperted period. Cousistency of data using Mass Curve method and local rain analysis to be done by Arithmatic &amp; Thiessen Polygon method. To analysis trend of rainfall distribution. We use : Normal, Log Normal, Log Person type III and Gumbel methods. For complaince test of distribution, we use Chi-Kuadrat and Smirnov-Kolmogorov methods. Refer to result of distribution using Chi-Kuadrat and Smirnov-Kolmogorov methods for Arithmatic methods it is adviced to use Gumbel method to evaluate distribution trend; because critical deviation is smell comparing to available in table, with rainfall with repeating period 2,5,10,25,50 and 100 years are 124,08 mm, 1168,56 mm, 198,01 mm, 235,22 mm, 262,83 mm, 290,23 mm and Thiessen Polygon 106,93 mm, 138,22 mm, 158,94 mm, 185,11 mm, 204,53 mm, 223,81 mm

Assessment of Physical Water Scarcity in Africa Using GRACE and TRMM Satellite Data

The critical role of water in enabling or constraining human well-being and socioeconomic activities has led to an interest in quantitatively establishing the status of water (in)sufficiency over space and time. Falkenmark introduced the first widely accepted measure of water status, the Water Scarcity Index (WSI), which expressed the status of the availability of water resources in terms of vulnerability, stress, and scarcity. Since then, numerous indicators have been introduced, but nearly all adopt the same basic formulation; water status is a function of “available water” resource—by the demand or use. However, the accurate assessment of “available water” is difficult, especially in data-scarce regions, such as Africa. In this paper, therefore, we introduce a satellite-based Potential Available Water Storage indicator, PAWS. The method integrates GRACE (Gravity Recovery and Climate Experiment) satellite Total Water Storage (TWS) measurements with the Tropical Rainfall Measuring Mission (TRMM) precipitation estimates between 2002 and 2016. First, we derived the countries’ Internal Water Storage (IWS) using GRACE and TRMM precipitation data. Then, the IWS was divided by the population density to derive the PAWS per capita. Following the Falkenmark thresholds, 54% of countries are classified in the same water vulnerability status as the AQUASTAT Internal Renewable Water Resources (IRWR) method. Of the remaining countries, PAWS index leads to one or two categories shift (left or right) of water status. The PAWS index shows that 14% (~160 million people) of Africa’s population currently live under water scarcity status. With respect to future projections, PAWS index suggests that a 10% decrease in future water resources would affect ~37% of Africa’s 2025 population (~600 million people), and 57% for 2050 projections (~1.4-billion people). The proposed approach largely overcomes the constraints related to the data needed to rapidly and robustly estimate available water resources by incorporating all stocks of water within the country, as well as underscores the recent water storage dynamics. However, the estimates obtained concern potential available water resources, which may not be utilizable for practical, economic, and technological issues.

Fin spine chemistry as a non-lethal alternative to otoliths for stock discrimination in an endangered catfish

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 614:147-157 (2019) - DOI: https://doi.org/10.3354/meps12895 Fin spine chemistry as a non-lethal alternative to otoliths for stock discrimination in an endangered catfish Esteban Avigliano1,*, Barbara Maichak de Carvalho2, Nathan Miller3, Sofía Córdoba Gironde4, Andrea Tombari4, Karin Limburg5, Alejandra V. Volpedo1 1Instituto de Investigaciones en Producción Animal (INPA-CONICET-UBA), Facultad de Ciencias Veterinarias, Universidad de Buenos Aires (UBA), Av. Chorroarín 280 (C1427CWO), Ciudad Autónoma de Buenos Aires C1427CWO, Argentina 2Programa de Pós-Graduação em Zoologia, Departamento de Zoologia - UFPR, Centro Politécnico, Caixa Postal 19.020, CEP 81.531-980, Bairro Jardim das Américas, Curitiba, Paraná 19.020/CEP 81.531-980, Brazil 3Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA 4Laboratorio de Tecnología de Alimentos y Biotecnología, Sede Atlántica, Universidad Nacional de Río Negro, Ruta Provincial N° 1 y Rotonda Cooperación (R8500FAL), Viedma, Río Negro R8500FAL, Argentina 5Department of Environmental and Forest Biology, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA *Corresponding author: estebanavigliano@conicet.gov.ar ABSTRACT: Trace element:Ca (Ba:Ca, Mg:Ca, Mn:Ca and Sr:Ca) ratios in water and last growth intervals (outer 45 µm) of dorsal spine and otolith edges from Genidens barbus collected in 3 study areas (Brazil, Argentina-Uruguay and Patagonia) were compared to determine whether the spine can provide a non-lethal natural marker alternative to otoliths for this endangered species. We found an association between calcified structures and the availability of some element:Ca ratios in water. Among the measured element:Ca ratios, a strong correlation in Ba:Ca between outer edges of fin spines and otoliths was found (r2 = 0.87, p = 0.0001), whereas Mg:Ca, Mn:Ca and Sr:Ca ratios were weakly correlated between structures (0.09 < r2 < 0.20, 0.0006 < p < 0.02). Several ratios were significantly different among sites for otolith and spine edge (p < 0.05). Permutational multivariate ANOVA (p < 0.05) and quadratic discriminant analysis (QDA) proved highly effective for characterizing differences in otolith and spine edge compositions between sampling sites (mean classification rates: 84.2 and 90.1% for otolith and spine edge, respectively), suggesting that both structures can be used as habitat markers. To identify the possible contribution of multiple stocks to the different areas, we performed QDA for the complete last year of a fish’s life. Classification rates were high for both structures, averaging 79.6 and 81.2% for otolith and spine, respectively, suggesting the existence of new stocks in Patagonian waters. Spine chemistry seems to be an acceptable non-lethal advantage over otoliths to study different biological aspects of catfish. KEY WORDS: Genidens barbus · Anadromous · Microchemistry · Southwestern Atlantic · Calcified structures · Indicator · Segregation · LA-ICP-MS · SXFM Full text in pdf format PreviousNextCite this article as: Avigliano E, Maichak de Carvalho B, Miller N, Córdoba Gironde S, Tombari A, Limburg K, Volpedo AV (2019) Fin spine chemistry as a non-lethal alternative to otoliths for stock discrimination in an endangered catfish. Mar Ecol Prog Ser 614:147-157. https://doi.org/10.3354/meps12895 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 614. Online publication date: April 04, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Deep soil water extraction by apple sequesters organic carbon via root biomass rather than altering soil organic carbon content

Soil water and carbon stocks have always been research hotspots. However, the interaction between soil water and carbon in deep soil (>1 m below surface) remains poorly understood. The present study used the chronosequence approach to investigate water extraction and carbon input by roots to a depth of 25.2 m in 8-, 11-, 15-, 18-, and 22-year-old afforested apple (Malus pumila Mill.) orchard stands in a sub-humid region of the Chinese Loess Plateau. Three long-term cultivated farmlands were used as a benchmark of soil water and carbon status before land use change. Measurements showed that the apple trees accessed deep soil water reserves by growing deep roots, with the resulting desiccated soil possibly stimulating apple trees to extend their roots into deeper, moister soil. Accordingly, soil water content in the root zone decreased progressively with increasing stand age. For example, the roots of apple trees in the 22-year-old stand extended to 23.2 m below the soil surface and extracted 1530 ± 43 mm deep soil water. Consequently, carbon input from root biomass correlated well with the water storage loss in deep soil (R2 = 0.88). Deep roots accounted for 49 ± 22% of the total root biomass and contributed 0.44 ± 0.15 Mg C ha−1 yr−1 to the deep soil. However, the roots of apple trees did not significantly change the soil organic carbon content in the root zone possibly because there was limited root biomass per unit soil depth and because soil water content in the root zone gradually decreased. These findings demonstrate the importance of deep soil in regulating water and carbon cycles, advancing our understanding of interactions among water, roots, and carbon in this zone.

The control expenditure and quality urban water by NMR flowmeter: relaxometer.

The diminution of pure fresh water stocks and increase the payment for her is demandiny from people rational use her. For this necessaring of urban water expenditure control accurate devices. The many people wants to control the quality urban water of besides the expenditure. This's important for residents at big city. In this city often the different damages occurred in the water - main which result the different chemical elements hit in the clearing water. In the world make many type devices for measuring the expenditure, the concentration different substances in the urban water. This devices use independently. The NMR flowrneter - relaxometer allowed to make the control expenditure and quality urban water of uncontact method by one device.