WorldWideScience

Sample records for water balance components

  1. Trends in water balance components across the Brazilian Cerrado

    Science.gov (United States)

    Oliveira, Paulo Tarso S.; Nearing, Mark A.; Moran, M. Susan; Goodrich, David C.; Wendland, Edson; Gupta, Hoshin V.

    2014-09-01

    We assess the water balance of the Brazilian Cerrado based on remotely sensed estimates of precipitation (TRMM), evapotranspiration (MOD16), and terrestrial water storage (GRACE) for the period from 2003 to 2010. Uncertainties for each remotely sensed data set were computed, the budget closure was evaluated using measured discharge data for the three largest river basins in the Cerrado, and the Mann-Kendall test was used to evaluate temporal trends in the water balance components and measured river discharge. The results indicate an overestimation of discharge data, due mainly to the overestimation of rainfall by TRMM version 6. However, better results were obtained when the new release of TRMM 3B42 v7 was used instead. Our results suggest that there have been (a) significant increases in average annual evapotranspiration over the entire Cerrado of 51 ± 15 mm yr-1, (b) terrestrial water storage increases of 11 ± 6 mm yr-1 in the northeast region of the Brazilian Cerrado, and (c) runoff decreases of 72 ± 11 mm yr-1 in isolated spots and in the western part of the State of Mato Grosso. Although complete water budget closure from remote sensing remains a significant challenge due to uncertainties in the data, it provides a useful way to evaluate trends in major water balance components over large regions, identify dry periods, and assess changes in water balance due to land cover and land use change.

  2. Modelling raster-based monthly water balance components for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ulmen, C.

    2000-11-01

    The terrestrial runoff component is a comparatively small but sensitive and thus significant quantity in the global energy and water cycle at the interface between landmass and atmosphere. As opposed to soil moisture and evapotranspiration which critically determine water vapour fluxes and thus water and energy transport, it can be measured as an integrated quantity over a large area, i.e. the river basin. This peculiarity makes terrestrial runoff ideally suited for the calibration, verification and validation of general circulation models (GCMs). Gauging stations are not homogeneously distributed in space. Moreover, time series are not necessarily continuously measured nor do they in general have overlapping time periods. To overcome this problems with regard to regular grid spacing used in GCMs, different methods can be applied to transform irregular data to regular so called gridded runoff fields. The present work aims to directly compute the gridded components of the monthly water balance (including gridded runoff fields) for Europe by application of the well-established raster-based macro-scale water balance model WABIMON used at the Federal Institute of Hydrology, Germany. Model calibration and validation is performed by separated examination of 29 representative European catchments. Results indicate a general applicability of the model delivering reliable overall patterns and integrated quantities on a monthly basis. For time steps less then too weeks further research and structural improvements of the model are suggested. (orig.)

  3. Impact of climate forcing uncertainty and human water use on global and continental water balance components

    Science.gov (United States)

    Müller Schmied, Hannes; Adam, Linda; Eisner, Stephanie; Fink, Gabriel; Flörke, Martina; Kim, Hyungjun; Oki, Taikan; Portmann, Felix Theodor; Reinecke, Robert; Riedel, Claudia; Song, Qi; Zhang, Jing; Döll, Petra

    2016-10-01

    The assessment of water balance components using global hydrological models is subject to climate forcing uncertainty as well as to an increasing intensity of human water use within the 20th century. The uncertainty of five state-of-the-art climate forcings and the resulting range of cell runoff that is simulated by the global hydrological model WaterGAP is presented. On the global land surface, about 62 % of precipitation evapotranspires, whereas 38 % discharges into oceans and inland sinks. During 1971-2000, evapotranspiration due to human water use amounted to almost 1 % of precipitation, while this anthropogenic water flow increased by a factor of approximately 5 between 1901 and 2010. Deviation of estimated global discharge from the ensemble mean due to climate forcing uncertainty is approximately 4 %. Precipitation uncertainty is the most important reason for the uncertainty of discharge and evapotranspiration, followed by shortwave downward radiation. At continental levels, deviations of water balance components due to uncertain climate forcing are higher, with the highest discharge deviations occurring for river discharge in Africa (-6 to 11 % from the ensemble mean). Uncertain climate forcings also affect the estimation of irrigation water use and thus the estimated human impact of river discharge. The uncertainty range of global irrigation water consumption amounts to approximately 50 % of the global sum of water consumption in the other water use sector.

  4. Estimating Water Balance Components of Lakes and Reservoirs Using Various Open Access Satellite Databases

    NARCIS (Netherlands)

    Duan, Z.

    2014-01-01

    There are millions of lakes and ten thousands of reservoirs in the world. The number of reservoirs is still increasing through the construction of large dams to meet the growing demand for water resources, hydroelectricity and economic development. Accurate information on the water balance component

  5. Estimating Water Balance Components of Lakes and Reservoirs Using Various Open Access Satellite Databases

    NARCIS (Netherlands)

    Duan, Z.

    2014-01-01

    There are millions of lakes and ten thousands of reservoirs in the world. The number of reservoirs is still increasing through the construction of large dams to meet the growing demand for water resources, hydroelectricity and economic development. Accurate information on the water balance component

  6. AWRA-G: A continental scale groundwater component linked to a land surface water balance model

    Science.gov (United States)

    Joehnk, Klaus; Crosbie, Russell; Peeters, Luk; Doble, Rebecca

    2013-04-01

    The Australian Water Resources Assessment (AWRA) system is a combination of models, data sources and analysis techniques that together will describe the water balance of Australia's landscapes, rivers and groundwater systems. It is a grid based water balance model that has lumped representation of the water balance of the soil, groundwater and surface water stores for each cell. The purpose of AWRA is to operationally provide up to date, credible, comprehensive, and accurate information about the history, present state and future trajectory of the water balance across Australia with sufficient spatial and temporal detail and enable water resources management for undertaking annual water resource assessments and national water accounts. AWRA is developed to link three major components: a landscape water balance model (AWRA-L), a river routing model (AWRA-R), and a groundwater component model (AWRA-G). These three component models combined are expected to be able to model the fluxes and stores of water throughout the landscape. The groundwater component (AWRA-G) addresses an improved representation of groundwater in the AWRA system to describe basic aquifer dynamics and groundwater-surface water processes. While most continental scale land surface models do not have the capacity to allow water to flow between cells and thus ignore this element of the water balance, AWRA-G does account for lateral flows. In general, AWRA-G provides estimates of groundwater fluxes that are not incorporated into either AWRA-L and its modifications to in-cell soil and groundwater processes, or AWRA-R. The processes integrated into AWRA-G thus are lateral groundwater flow between cells in regional and intermediate groundwater flow systems, groundwater discharge to the ocean, groundwater extraction and infiltration, river losses to groundwater, recharge from overbank flooding, and interactions between deep confined systems and surficial groundwater systems. Basis of AWRA-G is a good

  7. Assessing Variation in Water Balance Components in Mountainous Inland River Basin Experiencing Climate Change

    Directory of Open Access Journals (Sweden)

    Zhenliang Yin

    2016-10-01

    Full Text Available Quantification of the changes of water balance components is significant for water resource assessment and management. This paper employed the Soil and Water Assessment Tool (SWAT model to estimate the water balance in a mountainous watershed in northwest China at different spatial scales over the past half century. The results showed that both Nash-Sutcliffe efficiency (NSE and determination coefficient (R2 were over 0.90 for the calibration and validation periods. The water balance components presented rising trends at the watershed scale, and the total runoff increased by 30.5% during 1964 to 2013 period. Rising surface runoff and rising groundwater flow contributed 42.7% and 57.3% of the total rising runoff, respectively. The runoff coefficient was sensitive to increasing precipitation and was not significant to the increase of temperature. The alpine meadow was the main landscape which occupied 51.1% of the watershed and contributed 55.5% of the total runoff. Grass land, forest land, bare land, and glacier covered 14.2%, 18.8%, 15.4%, and 0.5% of the watershed and contributed 8.5%, 16.9%, 15.9%, and 3.2% of the total runoff, respectively. The elevation zone from 3500 to 4500 m occupied 66.5% of the watershed area, and contributed the majority of the total runoff (70.7%. The runoff coefficients in the elevation zone from 1637 to 2800 m, 2800 to 3500 m, 3500 to 4000 m, 4000 to 4500 m, and 4500 to 5062 m were 0.20, 0.27, 0.32, 0.43, and 0.78, respectively, which tend to be larger along with the elevation increase. The quantities and change trends of the water balance components at the watershed scale were calculated by the results of the sub-watersheds. Furthermore, we characterized the spatial distribution of quantities and changes in trends of water balance components at the sub-watershed scale analysis. This study provides some references for water resource management and planning in inland river basins.

  8. Determining water balance components at a lysimeter site in north-eastern Austria

    Science.gov (United States)

    Nolz, Reinhard; Kammerer, Gerhard; Cepuder, Peter

    2014-05-01

    The water balance of a certain soil profile in a certain time interval is subjected to changes of soil water content within the respective profile, and fluxes at its upper and lower boundary such as evapotranspiration and percolation, respectively. Weighing lysimeters are valuable instruments for water balance studies. Typically, mass changes - thus, changes of soil profile water content - are detected by a weighing system, while percolating water is measured by a tipping bucket or a weighed storage tank, and precipitation is measured by a rain gauge. Consequently, evapotranspiration can be determined by solving a simple water balance equation. However, a typical problem is that using separately measured precipitation data may cause implausible (negative) evapotranspiration. As a solution, the quantities can be determined directly from lysimeter mass changes, which are assumed to be positive due to precipitation and negative due to evapotranspiration. This method requires short measuring intervals and precise data. In this regard, data management of primarily older lysimeter facilities may be improved to fulfil these criteria. At an experimental site in north-eastern Austria hourly water balance components were determined using a reference lysimeter that was installed 1983 and equipped with lever-arm-counterbalance weighing system. A disadvantage of such systems is their sensitivity to external disturbances, mainly forces exerted by wind, which can significantly decrease measuring accuracy. Hence, we firstly studied the mechanical performance of the system regarding wind effects and oscillation behavior, and tested averaging procedures on noisy raw data to enhance measurement accuracy. The measurement accuracy for a wind velocity dew formation was measured, though its total amount was small. Evapotranspiration calculated on daily and hourly base according to ASCE standards indicated good correlation with measured data, but measured values were considerably smaller

  9. The water balance components of undisturbed tropical woodlands in the Brazilian cerrado

    Science.gov (United States)

    Oliveira, P. T. S.; Wendland, E.; Nearing, M. A.; Scott, R. L.; Rosolem, R.; da Rocha, H. R.

    2015-06-01

    Deforestation of the Brazilian cerrado region has caused major changes in hydrological processes. These changes in water balance components are still poorly understood but are important for making land management decisions in this region. To better understand pre-deforestation conditions, we determined the main components of the water balance for an undisturbed tropical woodland classified as "cerrado sensu stricto denso". We developed an empirical model to estimate actual evapotranspiration (ET) by using flux tower measurements and vegetation conditions inferred from the enhanced vegetation index and reference evapotranspiration. Canopy interception, throughfall, stemflow, surface runoff, and water table level were assessed from ground measurements. We used data from two cerrado sites, Pé de Gigante (PDG) and Instituto Arruda Botelho (IAB). Flux tower data from the PDG site collected from 2001 to 2003 were used to develop the empirical model to estimate ET. The other hydrological processes were measured at the field scale between 2011 and 2014 at the IAB site. The empirical model showed significant agreement (R2 = 0.73) with observed ET at the daily timescale. The average values of estimated ET at the IAB site ranged from 1.91 to 2.60 mm day-1 for the dry and wet seasons, respectively. Canopy interception ranged from 4 to 20 % and stemflow values were approximately 1 % of the gross precipitation. The average runoff coefficient was less than 1 %, while cerrado deforestation has the potential to increase that amount up to 20-fold. As relatively little excess water runs off (either by surface water or groundwater), the water storage may be estimated by the difference between precipitation and evapotranspiration. Our results provide benchmark values of water balance dynamics in the undisturbed cerrado that will be useful to evaluate past and future land-cover and land-use changes for this region.

  10. Water Balance Components in Covered and Uncovered Soil Growing Irrigated Muskmelon

    Directory of Open Access Journals (Sweden)

    Paulo Leonel Libardi

    2015-10-01

    Full Text Available ABSTRACT Knowledge of the terms (or processes of the soil water balance equation or simply the components of the soil water balance over the cycle of an agricultural crop is essential for soil and water management. Thus, the aim of this study was to analyze these components in a Cambissolo Háplico (Haplocambids growing muskmelon (Cucumis melo L. under drip irrigation, with covered and uncovered soil, in the municipality of Baraúna, State of Rio Grande do Norte, Brazil (05º 04’ 48” S, 37º 37’ 00” W. Muskmelon, variety AF-646, was cultivated in a flat experimental area (20 × 50 m. The crop was spaced at 2.00 m between rows and 0.35 m between plants, in a total of ten 50-m-long plant rows. At points corresponding to ⅓ and ⅔ of each plant row, four tensiometers (at a distance of 0.1 m from each other were set up at the depths of 0.1, 0.2, 0.3, and 0.4 m, adjacent to the irrigation line (0.1 m from the plant row, between two selected plants. Five random plant rows were mulched using dry leaves of banana (Musa sp. along the drip line, forming a 0.5-m-wide strip, which covered an area of 25 m2 per of plant row with covered soil. In the other five rows, there was no covering. Thus, the experiment consisted of two treatments, with 10 replicates, in four phenological stages: initial (7-22 DAS - days after sowing, growing (22-40 DAS, fruiting (40-58 DAS and maturation (58-70 DAS. Rainfall was measured with a rain gauge and water storage was estimated by the trapezoidal method, based on tensiometer readings and soil water retention curves. For soil water flux densities at 0.3 m, the tensiometers at the depths of 0.2, 0.3, and 0.4 m were considered; the tensiometer at 0.3 m was used to estimate soil water content from the soil water retention curve at this depth, and the other two to calculate the total potential gradient. Flux densities were calculated through use of the Darcy-Buckingham equation, with hydraulic conductivity determined by

  11. Variations of global and continental water balance components as impacted by climate forcing uncertainty and human water use

    Science.gov (United States)

    Müller Schmied, Hannes; Adam, Linda; Eisner, Stephanie; Fink, Gabriel; Flörke, Martina; Kim, Hyungjun; Oki, Taikan; Portmann, Felix Theodor; Reinecke, Robert; Riedel, Claudia; Song, Qi; Zhang, Jing; Döll, Petra

    2016-07-01

    When assessing global water resources with hydrological models, it is essential to know about methodological uncertainties. The values of simulated water balance components may vary due to different spatial and temporal aggregations, reference periods, and applied climate forcings, as well as due to the consideration of human water use, or the lack thereof. We analyzed these variations over the period 1901-2010 by forcing the global hydrological model WaterGAP 2.2 (ISIMIP2a) with five state-of-the-art climate data sets, including a homogenized version of the concatenated WFD/WFDEI data set. Absolute values and temporal variations of global water balance components are strongly affected by the uncertainty in the climate forcing, and no temporal trends of the global water balance components are detected for the four homogeneous climate forcings considered (except for human water abstractions). The calibration of WaterGAP against observed long-term average river discharge Q significantly reduces the impact of climate forcing uncertainty on estimated Q and renewable water resources. For the homogeneous forcings, Q of the calibrated and non-calibrated regions of the globe varies by 1.6 and 18.5 %, respectively, for 1971-2000. On the continental scale, most differences for long-term average precipitation P and Q estimates occur in Africa and, due to snow undercatch of rain gauges, also in the data-rich continents Europe and North America. Variations of Q at the grid-cell scale are large, except in a few grid cells upstream and downstream of calibration stations, with an average variation of 37 and 74 % among the four homogeneous forcings in calibrated and non-calibrated regions, respectively. Considering only the forcings GSWP3 and WFDEI_hom, i.e., excluding the forcing without undercatch correction (PGFv2.1) and the one with a much lower shortwave downward radiation SWD than the others (WFD), Q variations are reduced to 16 and 31 % in calibrated and non

  12. Characterising water balance dynamics and different runoff components in a poorly gauged tropical catchment, Nicaragua

    Science.gov (United States)

    Calderon, Heyddy; Uhlenbrook, Stefan

    2014-05-01

    The water balance dynamics, groundwater flow systems and the runoff components of a tropical forested small catchment (46 km2) is the southwestern Pacific coast of Nicaragua were studied by a combination of hydrometry (observation of rainfall, runoff, evaporation and groundwater levels), geological characterisation (hydrogeological mapping, flow systems, characterization and Piper diagrams) and hydrochemical and isotopic tracers (chemograph analysis, 2- and 3-component hydrograph separation, discharge-hydrochemical hysteresis effects, and MWL). Although some methods can be considered standard in runoff generation research in temperate climate regions; to the best of our knowledge, this is one of the few studies that used the combination of these techniques in a tropical catchment of Central America. Runoff components were studied at different spatial and temporal scales, finding that different sources and temporal contributions are controlled by geology, catchment size, and dominant landscape elements. Two major groundwater flow systems were identified with different chemical and isotopic characteristics. Indication of moisture recycling in the upper catchment area was found based on d-excess analysis. Runoff components were studied at different spatial and temporal scales, demonstrating that different sources and temporal contributions are controlled by dominant landscape elements and precipitation distribution. Evidence of strong river-aquifer interactions in the lower part of the catchment was found. The results provide an in-depth understanding of the surface and groundwater contributions to stream flow and its temporal and spatial distribution, which indicate the importance of runoff generation areas upstream in the catchment and also the vulnerability of the alluvial aquifer to contamination. This provides the basis to develop realistic, evidence-based water management plans for this developing region.

  13. How to constrain multi-objective calibrations using water balance components for an improved realism of model results

    Science.gov (United States)

    Pfannerstill, Matthias; Bieger, Katrin; Guse, Björn; Bosch, David; Fohrer, Nicola; Arnold, Jeffrey G.

    2017-04-01

    Accurate discharge simulation is one of the most common objectives of hydrological modeling studies. However, a good simulation of discharge is not necessarily the result of a realistic simulation of hydrological processes within the catchment. To enhance the realism of model results, we propose an evaluation framework that considers both discharge and water balance components as evaluation criteria for hydrological models. In this study, we integrated easily available expert knowledge such as average annual values of surface runoff, groundwater flow, and evapotranspiration in the model evaluation procedure to constrain the selection of good model runs. For evaluating water balance and discharge dynamics, the Nash-Sutcliffe efficiency (NSE) and percent bias (PBIAS) were used. In addition, the ratio of root mean square error and standard deviation of measured data (RSR) was calculated for individual segments of the flow duration curve to identify the best model runs in terms of discharge magnitude. Our results indicate that good statistics for discharge do not guarantee realistic simulations of individual water balance components. Therefore, we recommend constraining the ranges of water balance components to better capture internal and external fluxes of the hydrological system, even if trade-offs between good statistics for discharge simulations and reasonable amounts of the water balance components are unavoidable.

  14. Variability of Hydrological Parameters and Water Balance Components in Small Catchment in Croatia

    Directory of Open Access Journals (Sweden)

    Lidija Tadić

    2016-01-01

    Full Text Available Analysis of small catchment area in Croatian lowland with its hydrological characteristics in the period between 1981 and 2014 was carried out in order to define significance of change in hydrological and meteorological parameters (precipitation, air temperatures, and discharges and water balance components (deep percolation and potential evapotranspiration. There was no significant land use change in the observed period, so all changes in hydrological processes can be considered to be without human impact in the last 35 years. Application of RAPS (Rescaled Adjusted Partial Sums on all data series distinguished two subperiods with different length but the same behaviour. The first subperiod was a period characterised by the decrease, starting in 1980 and finishing between 1991 and 1995, while the second one was a period characterised by the increase of parameters in all analyses, starting between 1991 and 1995 and finishing in 2001. In comparison to the analysis of climate change impacts per decade, this approach is much more appropriate and gives insight into variations throughout the entire observed period. The most variable but not significant parameters are precipitation and discharges, especially in the second subperiod which has a major impact on occurrence of hydrological hazards such as droughts and floods and makes great pressure and responsibility on water management system.

  15. Improved drought indicators based on Gravity Recovery and Climate Experiment (GRACE), water balance components and soil moisture

    Science.gov (United States)

    Saemian, Peyman; Tourian, Mohammad J.; Sneeuw, Nico

    2017-04-01

    Drought, as a natural recurring hazard, can occur in virtually all climate zones. In recent years, severe large scale droughts have been detected in all continents including large areas in Europe. A change in water storage, which is the combination of groundwater, snow, and soil moisture, can indicate deficiencies in water storage in general. Such deficiencies may be related to any of its components or even a combination of them. We present here a new water storage deficiency index that has been developed using the terrestrial water storage (TWS) change from the Gravity Recovery and Climate Experiment (GRACE) and global water balance components data (Precipitation, Evapotranspiration and Runoff). First, for each monthly time series of TWS we calculate differences of water storage from a climatology that has been obtained from the long term water balance components time series. We then turn the differences into meaningful indices with the help of soil moisture data that characterizes agricultural drought. Our indexes identifies variation in water storage in general and characterizes groundwater drought including onset, severity, and duration of drought periods. Our results highlight the ability of GRACE TWS in combination with global water balance fluxes as an invaluable source to detect and monitor groundwater and groundwater drought which is a vital step for the planning and management of water resources both at local and global scales.

  16. Impacts of deforestation on water balance components of a watershed on the Brazilian East Coast

    Directory of Open Access Journals (Sweden)

    Donizete dos Reis Pereira

    2014-08-01

    Full Text Available The Brazilian East coast was intensely affected by deforestation, which drastically cut back the original biome. The possible impacts of this process on water resources are still unknown. The purpose of this study was an evaluation of the impacts of deforestation on the main water balance components of the Galo creek watershed, in the State of Espírito Santo, on the East coast of Brazil. Considering the real conditions of the watershed, the SWAT model was calibrated with data from 1997 to 2000 and validated for the period between 2001 and 2003. The calibration and validation processes were evaluated by the Nash-Sutcliffe efficiency coefficient and by the statistical parameters (determination coefficient, slope coefficient and F test of the regression model adjusted for estimated and measured flow data. After calibration and validation of the model, new simulations were carried out for three different land use scenarios: a scenario in compliance with the law (C1, assuming the preservation of PPAs (permanent preservation areas; an optimistic scenario (C2, which considers the watershed to be almost entirely covered by native vegetation; and a pessimistic scenario (C3, in which the watershed would be almost entirely covered by pasture. The scenarios C1, C2 and C3 represent a soil cover of native forest of 76, 97 and 0 %, respectively. The results were compared with the simulation, considering the real scenario (C0 with 54 % forest cover. The Nash-Sutcliffe coefficients were 0.65 and 0.70 for calibration and validation, respectively, indicating satisfactory results in the flow simulation. A mean reduction of 10 % of the native forest cover would cause a mean annual increase of approximately 11.5 mm in total runoff at the watershed outlet. Reforestation would ensure minimum flows in the dry period and regulate the maximum flow of the main watercourse of the watershed.

  17. BALANCE OF ENERGY AND COMPONENTS OF VOLTAGE DURING THE ELECTROTECHNICAL MODIFICATION OF PHYSICOCHEMICAL PARAMETERS OF WATER

    Directory of Open Access Journals (Sweden)

    Stiopka O.G

    2006-04-01

    Full Text Available The paper is dealing with results of theoretical and experimental investigations related to the balance of energy and voltage distribution in units for electrochemical units for water treatment. The electrical energy conversion mechanism in electrochemical units equipped with ionic selective membrane is analyzed. The obtained results could be used for design of electrochemical units for the water conditioning for diverse technological processes in agriculture and biotechnology.

  18. The Effect of Climate Change on Water Balance Components in the Senegal River Basin

    Science.gov (United States)

    Sandholt, I.; Ridler, M.; Stisen, S.; MacKellar, N.; Christensen, J. H.; Nielsen, C.; Rasmussen, K.

    2009-12-01

    West Africa has undergone some of the most dramatic recorded changes in climate during the last decades, having affected people directly due to large impact on food production and water resources. The livelihood of future generations in this very vulnerable region of the World is dependent on access to water, influenced directly by changes in climate and land cover. The goal of this study is thus to investigate the relative effects of future changes in climate and land cover in one of the large river basins in the region, the transnational Senegal Basin, from a water resource perspective. Based on predictions from an ensemble of up to nine regional climate models over West Africa and associated land cover change scenarios, the effect on components of the water balance in the Senegal Basin is analysed. We apply a distributed hydrological model based on the MIKE SHE code to simulate changes in stream flow and in the partitioning of evapotranspiration for the years 2030-2050. The model is calibrated on a control period spanning from 1951 to 1990. The results from RCMs and their associated uncertainties derived in the ENSEMBLES project are used as input to the hydrological model. Climate change effects on land cover are introduced via a simple relation between remotely sensed vegetation cover and precipitation. The simulations enable us to assess the relative importance of changes in climate and land cover constrained by model results and realistic land cover changes. Stream flow and evapotranspiration in four sub-basins each with distinct characteristics with regards to land cover and precipitation are subject to more detailed analyses. We acknowledge the ENSEMBLES project (http://ensembles-eu.metoffice.com), funded by the European Commission's 6th Framework Programme and the AMMA Project (http://www.amma-international.org). Based on a French initiative, AMMA was built by an international scientific group and is currently funded by a large number of agencies

  19. High-resolution estimation of the water balance components from high-precision lysimeters

    Directory of Open Access Journals (Sweden)

    M. Hannes

    2015-01-01

    Full Text Available Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater-recharge with high accuracy. In contrast to other techniques, like Eddy-flux systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration from a clearly defined surface area at the scale of a soil profile via the built-in weighing system. In particular the estimation of precipitation can benefit from the much higher surface area compared to typical raingauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an appropriate data processing with respect to various error sources. Most lysimeter studies account for noise in the data by averaging. However, the effects of smoothing by averaging on the accuracy of the estimated water balance is rarely investigated. In this study, we present a filtering scheme, which is designed to deal with the various kinds of possible errors. We analyze the influence of averaging times and thresholds on the calculated water balance. We further investigate the ability of two adaptive filtering methods (the Adaptive Window and Adaptive Threshold filter (AWAT-filter (Peters et al., 2014 and the consecutively described synchro-filter in further reducing the filtering error. On the basis of the data sets of 18 simultanously running lysimeters of the TERENO SoilCan research site in Bad Lauchstädt, we show that the estimation of the water balance with high temporal resolution and good accuracy is possible.

  20. Application of a technique for scenario prediction of climate change impact on the water balance components of northern river basins

    Directory of Open Access Journals (Sweden)

    Gusev Yeugeniy M.

    2014-09-01

    Full Text Available The scenario forecasting technique for assessing changes of water balance components of the northern river basins due to possible climate change was developed. Three IPCC global emission scenarios corresponding to different possible scenarios for economic, technological, political and demographic development of the human civilization in the 21st century were chosen for generating climate change projections by an ensemble of 16 General Circulation Models with a high spatial resolution. The projections representing increments of monthly values of meteorological characteristics were used for creating 3-hour meteorological time series up to 2063 for the Northern Dvina River basin, which belongs to the pan-Arctic basin and locates at the north of the European part of Russia. The obtained time series were applied as forcing data to drive the land surface model SWAP to simulate possible changes in the water balance components due to different scenarios of climate change for the Northern Dvina River basin

  1. Application of Tank Model for Predicting Water Balance and Flow Discharge Components of Cisadane Upper Catchment

    Directory of Open Access Journals (Sweden)

    Nana Mulyana Arifjaya

    2012-01-01

    Full Text Available The concept of hydrological tank model was well described into four compartments (tanks. The first tank (tank A comprised of one vertical (qA0 and two lateral (qA1 and qA2 water flow components and tank B comprised of one vertical (qB0 and one lateral (qB1 water flow components. Tank C comprised of one vertical (qC0 and one lateral (qC1 water flow components, whereas tank D comprised of one lateral water flow component (qD1.  These vertical water flows would also contribute to the depletion of water flow in the related tanks but would replenish tanks in the deeper layers. It was assumed that at all lateral water flow components would finally accumulate in one stream, summing-up of the lateral water flow, much or less, should be equal to the water discharge (Qo at specified time concerns. Tank A received precipitation (R and evapo-transpiration (ET which was its gradientof (R-ET over time would become the driving force for the changes of water stored in the soil profiles and thosewater flows leaving the soil layer.  Thus tank model could describe th vertical and horizontal water flow withinthe watershed. The research site was Cisadane Upper Catchment, located at Pasir Buncir Village of CaringinSub-District within the Regency of Bogor in West Java Province.  The elevations ranged 512 –2,235 m above sealevel, with a total drainage area of 1,811.5 ha and total length of main stream of 14,340.7 m.  The land cover wasdominated by  forest  with a total of 1,044.6 ha (57.67%,  upland agriculture with a total of 477.96 ha (26.38%,mixed garden with a total of 92.85 ha(5.13% and semitechnical irigated rice field with a total of 196.09 ha (10,8%.  The soil was classified as hydraquent (96.6% and distropept (3.4%.  Based on the calibration of tank model application in the study area, the resulting coefficient of determination (R2 was 0.72 with model efficiency (NSEof= 0.75, thus tank model could well illustrate the water flow distribution of

  2. Water Balance of the Eğirdir Lake and the Influence of Budget Components, Isparta,Turkey

    Directory of Open Access Journals (Sweden)

    Ayşen DAVRAZ

    2014-09-01

    Full Text Available Water budget of lakes must be determined regarding to their sustainable usage as for all water resources. One of the major problems in the management of lakes is the estimation of water budget components. The lack of regularly measured data is the biggest problem in calculation of hydrological balance of a lake. A lake water budget is computed by measuring or estimating all of the lake’s water gains and losses and measuring the corresponding changes in the lake volume over the same time period. Eğirdir Lake is one of the most important freshwater lakes in Turkey and is the most important surface water resources in the region due to different usages. Recharge of the Eğirdir Lake is supplied from especially precipitation, surface and subsurface water inflow. The discharge components of the lake are evaporation and water intake for irrigation, drinking and energy purposes. The difference between recharge and discharge of the lake was calculated as 7.78 hm3 for 1970-2010 period. According to rainfall, evaporation and the lake water level relations, rainfall is dominantly effective on the lake water level such as direct recharge to the lake and indirect recharge with groundwater flow

  3. Scenario forecasting changes in the water balance components of the Olenek and Iindigirka river basins due to possible climate change

    Directory of Open Access Journals (Sweden)

    Ye. M. Gusev

    2015-06-01

    Full Text Available Scenario projections of the dynamics of meteorological characteristics for the basins of the Olenek and Indigirka rivers (the Republic of Sakha in the XXI century have been obtained for four IPCC global climate change scenarios of SRES family which correspond to specified scenarios of economic, technological, political, and demographic development of human civilization. The projections have been used to calculate scenarios of possible changes in water balance components for the basins under consideration up to the year of 2063. The calculation procedure involves a physically-based model for heat and mass exchange between the land surface and the atmosphere SWAP and climate scenario generator MAGICC/SCENGEN.

  4. Analysis of climate change impacts on surface energy balance of Lake Huron (estimation of surface energy balance components: Remote sensing approach for water -- atmosphere parameterization)

    Science.gov (United States)

    Petchprayoon, Pakorn

    The purpose of this thesis was to investigate the physical processes of energy exchange between the water surface and atmosphere of Lake Huron in order to explain the processes behind such changes in long-term water levels and to monitor their spatial and temporal fluctuations. The lake surface water temperature and the four components of surface energy balance, including net radiation, latent heat, sensible heat, and heat storage, as well as evaporation rate, were estimated using the daily remotely sensed data from eleven years (2002--2012) with a multi-spatial resolution of 1 km to 5 km using the Moderate Resolution Imaging Spectroradiometer (MODIS) on board Terra satellite, together with in-situ measurements. The regression analysis of the entire lake daily mean water surface temperature revealed a positive trend of 0.1 °C per year, indicating that the lake surface temperature increased by 1.1°C during the period 2002-2012. The warming rate was found to be greatest in the deepest areas of the lake, with a statistically-significant correlation between warming rate and depth. The four components of surface energy balance showed temporal and spatial heterogeneities. There were strong seasonal patterns for all of the components, which were very high in summer and low in winter for net radiation and heat storage. In contrast, the latent heat and sensible heat were very high in the winter and very low in the summer. Approximately 70% of the annual mean 30 min evaporation occurred during the fall and winter seasons, whereas the lowest evaporation rate occurred in March, which was only 3% of the annual mean of 30 min evaporation. There was an increase in the evaporation rate of approximately 1.4 mm m-2 over the 2005--2012 observation period, the water level decreased by 0.04 m during the period 2002--2012, and there was a decrease in total water storage by 1.18 cm during the entire study period (2004--2012). There was obviously a negative correlation between lake

  5. Differences in the water-balance components of four lakes in the southern-central Tibetan Plateau

    Science.gov (United States)

    Biskop, S.; Maussion, F.; Krause, P.; Fink, M.

    2016-01-01

    The contrasting patterns of lake-level fluctuations across the Tibetan Plateau (TP) are indicators of differences in the water balance over the TP. However, little is known about the key hydrological factors controlling this variability. The purpose of this study is to contribute to a more quantitative understanding of these factors for four selected lakes in the southern-central part of the TP: Nam Co and Tangra Yumco (increasing water levels), and Mapam Yumco and Paiku Co (stable or slightly decreasing water levels). We present the results of an integrated approach combining hydrological modeling, atmospheric-model output and remote-sensing data. The J2000g hydrological model was adapted and extended according to the specific characteristics of closed-lake basins on the TP and driven with High Asia Refined analysis (HAR) data at 10 km resolution for the period 2001-2010. Differences in the mean annual water balances among the four basins are primarily related to higher precipitation totals and attributed runoff generation in the Nam Co and Tangra Yumco basins. Precipitation and associated runoff are the main driving forces for inter-annual lake variations. The glacier-meltwater contribution to the total basin runoff volume (between 14 and 30 % averaged over the 10-year period) plays a less important role compared to runoff generation from rainfall and snowmelt in non-glacierized land areas. Nevertheless, using a hypothetical ice-free scenario in the hydrological model, we indicate that ice-melt water constitutes an important water-supply component for Mapam Yumco and Paiku Co, in order to maintain a state close to equilibrium, whereas the water balance in the Nam Co and Tangra Yumco basins remains positive under ice-free conditions. These results highlight the benefits of linking hydrological modeling with atmospheric-model output and satellite-derived data, and the presented approach can be readily transferred to other data-scarce closed lake basins, opening new

  6. Evaluation of water balance components in the Elbe river catchment simulated by the regional climate model CCLM

    Directory of Open Access Journals (Sweden)

    Jan Volkholz

    2014-12-01

    Full Text Available For investigations of feedbacks between the hydrological cycle and the climate system, we assess the performance of the regional climate model CCLM in reconstructing the water balance of the Elbe river catchment. To this end long-term mean precipitation, evapotranspiration and runoff are evaluated. Extremes (90th percentile are also considered in the case of precipitation. The data are provided by a CCLM present-day simulation for Europe that was driven by large-scale global reanalyses. The quality of the model results is analyzed with respect to suitable reference data for the period 1970 to 1999. The principal components of the hydrological cycle and their seasonal variations were captured well. Basin accumulated, averaged daily precipitation, evapotranspiration and runoff differ by no more than 10 % from observations. Larger deviations occur mainly in summer, and at specific areas.

  7. Impact of climate change on water balance components in Mediterranean rainfed olive orchards under tillage or cover crop soil management

    Science.gov (United States)

    Rodríguez-Carretero, María Teresa; Lorite, Ignacio J.; Ruiz-Ramos, Margarita; Dosio, Alessandro; Gómez, José A.

    2013-04-01

    The rainfed olive orchards in Southern Spain constitute the main socioeconomic system of the Mediterranean Spanish agriculture. These systems have an elevated level of complexity and require the accurate characterization of crop, climate and soil components for a correct management. It is common the inclusion of cover crops (usually winter cereals or natural cover) intercalated between the olive rows in order to reduce water erosion. Saving limited available water requires specific management, mowing or killing these cover crops in early spring. Thus, under the semi-arid conditions in Southern Spain the management of the cover crops in rainfed olive orchards is essential to avoid a severe impact to the olive orchards yield through depletion of soil water. In order to characterize this agricultural system, a complete water balance model has been developed, calibrated and validated for the semi-arid conditions of Southern Spain, called WABOL (Abazi et al., 2013). In this complex and fragile system, the climate change constitutes a huge threat for its sustainability, currently limited by the availability of water resources, and its forecasted reduction for Mediterranean environments in Southern Spain. The objective of this study was to simulate the impact of climate change on the different components of the water balance in these representative double cropping systems: transpiration of the olive orchard and cover crop, runoff, deep percolation and soil water content. Four climatic scenarios from the FP6 European Project ENSEMBLES were first bias corrected for temperatures and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) and, subsequently, used as inputs for the WABOL model for five olive orchard fields located in Southern Spain under different conditions of crop, climate, soils and management, in order to consider as much as possible of the variability detected in the Spanish olive orchards. The first results indicate the significant effect of the cover

  8. Senstitivity of water balance components to environmental changes in a mountainous watershed: uncertainty assessment based on models comparison

    Directory of Open Access Journals (Sweden)

    E. Morán-Tejeda

    2013-10-01

    Full Text Available This paper evaluates the response of stream flow and other components of the water balance to changes in climate and land-use in a Pyrenean watershed. It further provides a measure of uncertainty in water resources forecasts by comparing the performance of two hydrological models: Soil and Water Assessment Tool (SWAT and Regional Hydro-Ecological Simulation System (RHESSys. Regional Climate Model outputs for the 2021–2050 time-frame, and hypothetical (but plausible land-use scenarios considering re-vegetation and wildfire processes were used as inputs to the models. Results indicate an overall decrease in river flows when the scenarios are considered, except for the post-fire vegetation scenario, in which stream flows are simulated to increase. However the magnitude of these projections varies between the two models used, as SWAT tends to produce larger hydrological changes under climate change scenarios, and RHESSys shows more sensitivity to changes in land-cover. The final prediction will therefore depend largely on the combination of the land-use and climate scenarios, and on the model utilized.

  9. RECONSTRUCTION AND PREDICTION OF WATER BALANCE COMPONENTS FROM DENDROCHRONOLOGICAL DATA FOR THE NARYN RIVER BASIN (KYRGYZSTAN

    Directory of Open Access Journals (Sweden)

    V. G. Konovalov

    2012-01-01

    Full Text Available Suggested new method for reconstruction of runoff includes: 1. Search informative points based weather observations for dependence runoff = f(climate index. Climate index consists of normalized anomalies of annual precipitation and air temperature, together with water vapor pressure and total cloud amount in the June–September. 2. The selection of sites that represent local relationship between the index of climate and tree rings. 3. Getting the multivariate linear regression equation between the runoff V and tree rings D. Basic climatic period 1961–1990 is used as a calibration interval of time. Verification of the equations for 1940–1960 identified the need to use other arguments in addition to the width of tree rings. For this purpose, two climate index: PDSI and SPEI were tested. It is established that the empirical formulae V = f(D, PDSI and V = f(D, SPEI are suitable for assessing the annual flow of the Naryn in 1901–2006. In the report is described a process of  reconstruction of flow for the years 1700–2005 based on the data of the width of the tree rings, and taking into account the temporal variability of parameters of regression equations.Chronologies of the width and density of tree rings in the thirty-two tree ring sites were used to reconstruct long-term series of average summer air temperature Ts at meteorological stations of the Pamir and Tien Shan. The calibration interval of time was 1961–1990 to find equations Ts = f(D of third-order multiple regression, and independent control of their quality, done in 1932–1960. Combined correlation coefficient in 10 cases out of 15 was more than 0.80, a relative error of calculation Ts in 19611990 ranged from 0.13 to 4.73%, and in 1932–1960 from 0.23 to 8.10%. Duration of the reconstructed series Ts ranged from 100 to 278 years. Positive results were received for predicting a common and glacial runoff of Naryn river, a long-term range of density of tree rings. 

  10. Differences in the water-balance components of four lakes in the southern-central Tibetan Plateau

    OpenAIRE

    Biskop, S.; Maussion, F.; Krause, P; Fink, M.

    2016-01-01

    The contrasting patterns of lake-level fluctuations across the Tibetan Plateau (TP) are indicators of differences in the water balance over the TP. However, little is known about the key hydrological factors controlling this variability. The purpose of this study is to contribute to a more quantitative understanding of these factors for four selected lakes in the southern-central part of the TP: Nam Co and Tangra Yumco (increasing water levels), and Mapam Yumco and Paiku Co ...

  11. The Impact of Para Rubber Expansion on Streamflow and Other Water Balance Components of the Nam Loei River Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Winai Wangpimool

    2016-12-01

    Full Text Available At present, Para rubber is an economical crop which provides a high priced product and is in demand by global markets. Consequently, the government of Thailand is promoting the expansion of Para rubber plantations throughout the country. Traditionally, Para rubber was planted and grown only in the southern areas of the country. However, due to the Government’s support and promotion as well as economic reasons, the expansion of Para rubber plantations in the northeast has increased rapidly. This support has occurred without accounting for suitable cultivation of Para rubber conditions, particularly in areas with steep slopes and other factors which have significant impacts on hydrology and water quality. This study presents the impacts of Para rubber expansion by applying the Soil and Water Assessment Tool (SWAT hydrological model on the hydrology and water balance of the Nam Loei River Basin, Loei Province. The results showed that the displacement of original local field crops and disturbed forest land by Para rubber production resulted in an overall increase of evapotranspiration (ET of roughly 3%. The major factors are the rubber canopy and precipitation. Moreover, the water balance results showed an annual reduction of about 3% in the basin average water yield, especially during the dry season.

  12. MONITORING OF STRUCTURAL COMPONENTS AND WATER BALANCE AS AN AID TO WETLAND MANAGEMENT USING GEOSPATIAL TECHNIQUES – A CASE STUDY FOR NALSAROVAR LAKE, GUJARAT

    OpenAIRE

    Murthy, T. V. R.; Panigrahy, S.

    2012-01-01

    The hydrologic variability greatly influences the structural components of wetlands that have a great bearing on habitats for avifauna, aquatic fauna including fish etc. This paper highlights the results of a study carried out to derive changes in open-water and vegetation, and also water balance for Nalsarovar Lake, Gujarat. MODIS 8-day composite data for three consecutive years viz 2002/03, 2003/04 and 2004/05 were used to study the seasonal and inter annual dynamics of water regime in the ...

  13. Lake El'gygytgyn water and sediment balance components overview and its implications for the sedimentary record

    Directory of Open Access Journals (Sweden)

    G. Fedorov

    2012-08-01

    Full Text Available Modern process studies of the hydrologic balance and sediment flux into and out of Lake El'gygytgyn, central Chukotka, provide important quantitative estimates for better understanding the lacustrine paleoclimate record from this basin. Formed ca. 3.6 Ma as a result of a meteorite impact, the basin contains one of the longest paleoclimate records in the Arctic. Fluvial activity into the basin today is concentrated over the short snowmelt period. Recent lake-level changes have a slow regressive character due to active underground runoff, even during winter. The residence time of the lake-water is estimated to be about 100 yr. The main source of clastic material are incoming steams. The amount of sediment discharge through the outflow river is insignificant and completely compensated even by little aeolian input.

  14. Impacts of climatic changes on carbon and water balance components of boreal forest ecosystems in central part of European Russia

    Science.gov (United States)

    Olchev, A.; Novenko, E.; Desherevskaya, O.; Kurbatova, J.

    2009-04-01

    Within the framework of the study the possible impacts of climatic changes on carbon and water balances of boreal forest ecosystems of the central part of European Russia for period up to 2100 was estimated using results of model simulations and field measurements. The boreal forests of the Central Forest State Natural Biosphere Reserve (CFSNBR) were selected for the study. They are located at the southern boundary of south taiga zone in the European part of Russia (Tver region) and it can be expected that they will be very sensitive to modern climate warming. Expected future pattern of climatic parameters in the study area was derived using the global climatic model ECHAM5 (MPI Hamburg, Germany) and climatic scenarios B1, A1B and A2 (IPCC 2007). The possible scenarios of species composition changes of the boreal forests were developed using reconstructions of Holocene vegetation cover and climatic conditions on the base of pollen and plant macrofossil analysis of peat profiles in CFSNBR. The annual future pattern of CO2 and H2O fluxes of the forests were simulated using a process-based Mixfor-SVAT model (Olchev et al. 2002, 2008). The main advantage of Mixfor-SVAT is that it allows us to describe CO2 and H2O fluxes both in mono-specific and mixed forest stands. It is able to quantify both total ecosystem fluxes and flux partitioning among different tree species and canopy layers. It is obvious that it can be very helpful to describe accurately effects of species composition changes on structure of dynamics of carbon and water balance of forest ecosystems. Results of modeling experiments show that expected climatic and vegetation changes can have significant impact on evapotranspiration, transpiration, Net Ecosystem Exchange (NEE), Gross (GPP) and Net (NPP) Primary Productivities of boreal forest ecosystems. These changes have a clear seasonal trend and they are depended on species composition of a forest stand. This study was supported by the Russian Foundation

  15. Spatial‑temporal variability of water balance components in the North area of the Zailiisky Alatau Range

    Directory of Open Access Journals (Sweden)

    V. G. Konovalov

    2016-01-01

    Full Text Available Analysis of changes in WB components (precipitation, evaporation, glacier runoff, dynamical water resources on the Northern slope of the Zailiisky Alatau was performed for the 1946–2005 time divided into two periods: 1946–1975 and 1976–2005. The territory under investigation included basins of the following rivers: Bolshaya Almatinka, Malaya Almatinka, Talgar, Turgen, Issyk, Chemolgan, Kaskelen, Kargalinka, Prohodnaya, and Uzunkargaly. Their total area down to the closing gauge points amounts to 2644 km2. Summarized glacier areas in these basins and annual runoff were equal, respectively, to: 306.6 km2 and 39.05 km3in 1946–1975, and 253.0 km2 and 38.35 km3 in 1975–2005. In 1946–2005, typical features of regional glaciation dynamics were increasing area of the moraine cover on glaciers and reducing area of bare ice that results in decreasing of the glacial runoff volume, all other factors being the same. The method to calculate the WB components consists of the following constituents: model of seasonal runoff from melted snow and ice in the areas of accumulation and ablation of glaciers; complex of formulas to calculate precipitation, air temperature and humidity, intensity of ice melting under the moraine, bare ice and evaporation within the height intervals corresponding to the main types of surfaces on the glaciers. On the basis of our method, we could reconstruct for the 1876–2015 period long‑term series of data on a runoff, separately annual values and sums for the vegetation periods. They can be used for regional scientific and applied analyses of the river stream discharges. The data on runoff in the Malaya Almatinka River basin and observational data on the meteorological station Almaty (Hydrometeorological Observatory had been quantitatively substantiated as the representative information for modeling and calculation of water resources on the Northern slope of the Zailiisky Alatau Range.

  16. An approach to improve direct runoff estimates and reduce uncertainty in the calculated groundwater component in water balances of large lakes

    Science.gov (United States)

    Wiebe, Andrew J.; Conant, Brewster; Rudolph, David L.; Korkka-Niemi, Kirsti

    2015-12-01

    Groundwater is important in the overall water budget of a lake because it affects the quantity and quality of surface water and the ecological health of the lake. The water balance equation is frequently used to estimate the net groundwater flow for small lakes but is seldom used to determine net groundwater flow components for large lakes because: (1) errors accumulate in the calculated groundwater term, and (2) there is an inability to accurately quantify the direct runoff component. In this water balance study of Lake Pyhäjärvi (155 km2) in Finland, it was hypothesized a hydrograph separation model could be used to estimate direct runoff to the lake and, when combined with a rigorous uncertainty analyses, would provide reliable net groundwater flow estimates. The PART hydrograph separation model was used to estimate annual per unit area direct runoff values for the watershed of the inflowing Yläneenjoki River (a subwatershed of the lake) which were then applied to other physically similar subwatersheds of the lake to estimate total direct runoff to the lake. The hydrograph separation method provided superior results and had lower uncertainty than the common approach of using a runoff coefficient based method. The average net groundwater flow into the lake was calculated to be +43 mm per year (+3.0% of average total inflow) for the 38 water years 1971-2008. It varied from -197 mm to 284 mm over that time, and had a magnitude greater than the uncertainty for 17 of the 38 years. The average indirect groundwater contribution to the lake (i.e., the groundwater part of the inflowing rivers) was 454 mm per year (+32% of average total inflow) and demonstrates the overall importance of groundwater. The techniques in this study are applicable to other large lakes and may allow small net groundwater flows to be reliably quantified in settings that might otherwise be unquantifiable or completely lost in large uncertainties.

  17. Modeling the monthly mean soil-water balance with a statistical-dynamical ecohydrology model as coupled to a two-component canopy model

    Directory of Open Access Journals (Sweden)

    J. P. Kochendorfer

    2010-10-01

    Full Text Available The statistical-dynamical annual water balance model of Eagleson (1978 is a pioneering work in the analysis of climate, soil and vegetation interactions. This paper describes several enhancements and modifications to the model that improve its physical realism at the expense of its mathematical elegance and analytical tractability. In particular, the analytical solutions for the root zone fluxes are re-derived using separate potential rates of transpiration and bare-soil evaporation. Those potential rates, along with the rate of evaporation from canopy interception, are calculated using the two-component Shuttleworth-Wallace (1985 canopy model. In addition, the soil column is divided into two layers, with the upper layer representing the dynamic root zone. The resulting ability to account for changes in root-zone water storage allows for implementation at the monthly timescale. This new version of the Eagleson model is coined the Statistical-Dynamical Ecohydrology Model (SDEM. The ability of the SDEM to capture the seasonal dynamics of the local-scale soil-water balance is demonstrated for two grassland sites in the US Great Plains. Sensitivity of the results to variations in peak green leaf area index (LAI suggests that the mean peak green LAI is determined by some minimum in root zone soil moisture during the growing season. That minimum appears to be close to the soil matric potential at which the dominant grass species begins to experience water stress and well above the wilting point, thereby suggesting an ecological optimality hypothesis in which the need to avoid water-stress-induced leaf abscission is balanced by the maximization of carbon assimilation (and associated transpiration. Finally, analysis of the sensitivity of model-determined peak green LAI to soil texture shows that the coupled model is able to reproduce the so-called "inverse texture effect", which consists of the observation that natural vegetation in dry climates tends

  18. Modeling the monthly mean soil-water balance with a statistical-dynamical ecohydrology model as coupled to a two-component canopy model

    Directory of Open Access Journals (Sweden)

    J. P. Kochendorfer

    2008-03-01

    Full Text Available The statistical-dynamical annual water balance model of Eagleson (1978 is a pioneering work in the analysis of climate, soil and vegetation interactions. This paper describes several enhancements and modifications to the model that improve its physical realism at the expense of its mathematical elegance and analytical tractability. In particular, the analytical solutions for the root zone fluxes are re-derived using separate potential rates of transpiration and bare-soil evaporation. Those potential rates, along with the rate of evaporation from canopy interception, are calculated using the two-component Shuttleworth-Wallace (1985 canopy model. In addition, the soil column is divided into two layers, with the upper layer representing the dynamic root zone. The resulting ability to account for changes in root-zone water storage allows for implementation at the monthly timescale. This new version of the Eagleson model is coined the Statistical-Dynamical Ecohydrology Model (SDEM. The ability of the SDEM to capture the seasonal dynamics of the local-scale soil-water balance is demonstrated for two grassland sites in the US Great Plains. Sensitivity of the results to variations in peak green Leaf Area Index (LAI suggests that the mean peak green LAI is determined by some minimum in root zone soil moisture during the growing season. That minimum appears to be close to the soil matric potential at which the dominant grass species begins to experience water stress and well above the wilting point, thereby suggesting an ecological optimality hypothesis in which the need to avoid water-stress-induced leaf abscission is balanced by the maximization of carbon assimilation (and associated transpiration. Finally, analysis of the sensitivity of model-determined peak green LAI to soil texture shows that the coupled model is able to reproduce the so-called "inverse texture effect", which consists of the observation that natural vegetation in dry climates tends

  19. MONITORING OF STRUCTURAL COMPONENTS AND WATER BALANCE AS AN AID TO WETLAND MANAGEMENT USING GEOSPATIAL TECHNIQUES – A CASE STUDY FOR NALSAROVAR LAKE, GUJARAT

    Directory of Open Access Journals (Sweden)

    T. V. R. Murthy

    2012-09-01

    Full Text Available The hydrologic variability greatly influences the structural components of wetlands that have a great bearing on habitats for avifauna, aquatic fauna including fish etc. This paper highlights the results of a study carried out to derive changes in open-water and vegetation, and also water balance for Nalsarovar Lake, Gujarat. MODIS 8-day composite data for three consecutive years viz 2002/03, 2003/04 and 2004/05 were used to study the seasonal and inter annual dynamics of water regime in the lake. Digital elevation model derived using Shuttle Radar Topographic Mission data with interpolated bottom topography was used to generate elevation contours and compute water volume from water spread data. The reference data of 2002 (drought year shows the maximum extent of wetland to be 8.06 km2 with emergent vegetation of recorded as 2.36 km2 and open-water as 5.70 km2. The rainfall has an impact on the preferred habitat availability for various species of avifauna and it is noted that emergent vegetation present in the lake completely dried up by summer 2002, a rainfall deficit year but revived again in the preceding year i.e. 2003 which was a good rainfall year with 46.68 km2 under emergent vegetation and 61.96 km2 under open-water. The 2002 being a drought year has shown very low reference storage (0.256 MCM, which has shown a gradual decrease in the storage to 0.00019 MCM in March 2003. The reference storage also registered a steep increase to 18.165 MCM in October 2003 and decreased 1.264 MCM in March 2004. From this study it is evident that water level of about 9 m elevation at the end of the rainy season is found to be optimal for maintaining various habitats that in turn support the avifauna for the rest of the lean period.

  20. Monitoring of Structural Components and Water Balance as AN Aid to Wetland Management Using Geospatial Techniques - a Case Study for Nalsarovar Lake, Gujarat

    Science.gov (United States)

    Murthy, T. V. R.; Panigrahy, S.

    2011-09-01

    The hydrologic variability greatly influences the structural components of wetlands that have a great bearing on habitats for avifauna, aquatic fauna including fish etc. This paper highlights the results of a study carried out to derive changes in open-water and vegetation, and also water balance for Nalsarovar Lake, Gujarat. MODIS 8-day composite data for three consecutive years viz 2002/03, 2003/04 and 2004/05 were used to study the seasonal and inter annual dynamics of water regime in the lake. Digital elevation model derived using Shuttle Radar Topographic Mission data with interpolated bottom topography was used to generate elevation contours and compute water volume from water spread data. The reference data of 2002 (drought year) shows the maximum extent of wetland to be 8.06 km2 with emergent vegetation of recorded as 2.36 km2 and open-water as 5.70 km2. The rainfall has an impact on the preferred habitat availability for various species of avifauna and it is noted that emergent vegetation present in the lake completely dried up by summer 2002, a rainfall deficit year but revived again in the preceding year i.e. 2003 which was a good rainfall year with 46.68 km2 under emergent vegetation and 61.96 km2 under open-water. The 2002 being a drought year has shown very low reference storage (0.256 MCM), which has shown a gradual decrease in the storage to 0.00019 MCM in March 2003. The reference storage also registered a steep increase to 18.165 MCM in October 2003 and decreased 1.264 MCM in March 2004. From this study it is evident that water level of about 9 m elevation at the end of the rainy season is found to be optimal for maintaining various habitats that in turn support the avifauna for the rest of the lean period.

  1. Asia's water balance

    NARCIS (Netherlands)

    Immerzeel, W.W.; Bierkens, M.F.P.

    The availability of water for human consumption and agriculture can no longer be taken for granted. Various facets of water stress at different spatial scales, such as groundwater depletion1,2, climate change and population increase3, and glacier and snow melt4,5, have been recognized as

  2. Quantifying catchment water balances and their uncertainties by expert elicitation

    Science.gov (United States)

    Sebok, Eva; Refsgaard, Jens Christian; Warmink, Jord J.; Stisen, Simon; Høgh Jensen, Karsten

    2017-04-01

    The increasing demand on water resources necessitates a more responsible and sustainable water management requiring a thorough understanding of hydrological processes both on small scale and on catchment scale. On catchment scale, the characterization of hydrological processes is often carried out by calculating a water balance based on the principle of mass conservation in hydrological fluxes. Assuming a perfect water balance closure and estimating one of these fluxes as a residual of the water balance is a common practice although this estimate will contain uncertainties related to uncertainties in the other components. Water balance closure on the catchment scale is also an issue in Denmark, thus, it was one of the research objectives of the HOBE hydrological observatory, that has been collecting data in the Skjern river catchment since 2008. Water balance components in the 1050 km2 Ahlergaarde catchment and the nested 120 km2 Holtum catchment, located in the glacial outwash plan of the Skjern catchment, were estimated using a multitude of methods. As the collected data enables the complex assessment of uncertainty of both the individual water balance components and catchment-scale water balances, the expert elicitation approach was chosen to integrate the results of the hydrological observatory. This approach relies on the subjective opinion of experts whose available knowledge and experience about the subject allows to integrate complex information from multiple sources. In this study 35 experts were involved in a multi-step elicitation process with the aim of (1) eliciting average annual values of water balance components for two nested catchments and quantifying the contribution of different sources of uncertainties to the total uncertainty in these average annual estimates; (2) calculating water balances for two catchments by reaching consensus among experts interacting in form of group discussions. To address the complex problem of water balance closure

  3. Functional model of water balance variability at the catchment scale: 2. Elasticity of fast and slow runoff components to precipitation change in the continental United States

    NARCIS (Netherlands)

    Harman, C.J.; Troch, P.A.; Sivapalan, M.

    2011-01-01

    Assessing the sensitivity of annual streamflow to precipitation is challenging due to the complexity of the processes that control the water balance. A low-dimensional model can be useful to interrogate data in regional assessments of a large number of catchments, and can provide insights into the b

  4. Functional model of water balance variability at the catchment scale: 2. Elasticity of fast and slow runoff components to precipitation change in the continental United States

    NARCIS (Netherlands)

    Harman, C.J.; Troch, P.A.; Sivapalan, M.

    2011-01-01

    Assessing the sensitivity of annual streamflow to precipitation is challenging due to the complexity of the processes that control the water balance. A low-dimensional model can be useful to interrogate data in regional assessments of a large number of catchments, and can provide insights into the b

  5. THE WATER BALANCE OF LAKE LEŞU (ROMANIA

    Directory of Open Access Journals (Sweden)

    Csaba HORVÁTH

    2008-06-01

    Full Text Available Lake Leşu is one of the reservoirs that form the hidrotechnical complex Drăgan-Iad in the upper basin of the Crişul Repede River. The water balance of the lake is closely linked, to the primary functions of the lake. In this paper, we present each of the components that characterize the water balance, to understand which are the most significant ones. We will see how the different components of the water balance equation effect the change of volume in the reservoir. Every component is calculated separately, so precipitation, evaporation, runoff of the basin and the discharge of the dam.

  6. Water and sodium balance in space

    DEFF Research Database (Denmark)

    Drummer, C; Norsk, P; Heer, M

    2001-01-01

    , cumulative water balance and total body water content are stable during flight if hydration, nutritional energy supply, and protection of muscle mass are at an acceptable level. Recent water balance data disclose that the phenomenon of an absolute water loss during space flight, which has often been reported...

  7. Modeling water and heat balance components of large territory for vegetation season using information from polar-orbital and geostationary meteorological satellites

    Science.gov (United States)

    Muzylev, Eugene; Startseva, Zoya; Uspensky, Alexander; Volkova, Elena; Kukharsky, Alexander; Uspensky, Sergey

    2015-04-01

    To date, physical-mathematical modeling processes of land surface-atmosphere interaction is considered to be the most appropriate tool for obtaining reliable estimates of water and heat balance components of large territories. The model of these processes (Land Surface Model, LSM) developed for vegetation period is destined for simulating soil water content W, evapotranspiration Ev, vertical latent LE and heat fluxes from land surface as well as vertically distributed soil temperature and moisture, soil surface Tg and foliage Tf temperatures, and land surface skin temperature (LST) Ts. The model is suitable for utilizing remote sensing data on land surface and meteorological conditions. In the study these data have been obtained from measurements by scanning radiometers AVHRR/NOAA, MODIS/EOS Terra and Aqua, SEVIRI/geostationary satellites Meteosat-9, -10 (MSG-2, -3). The heterogeneity of the land surface and meteorological conditions has been taken into account in the model by using soil and vegetation characteristics as parameters and meteorological characteristics as input variables. Values of these characteristics have been determined from ground observations and remote sensing information. So, AVHRR data have been used to build the estimates of effective land surface temperature (LST) Ts.eff and emissivity E, vegetation-air temperature (temperature at the vegetation level) Ta, normalized vegetation index NDVI, vegetation cover fraction B, the leaf area index LAI, and precipitation. From MODIS data the values of LST Tls, Å, NDVI, LAI have been derived. From SEVIRI data there have been retrieved Tls, E, Ta, NDVI, LAI and precipitation. All named retrievals covered the vast territory of the part of the agricultural Central Black Earth Region located in the steppe-forest zone of European Russia. This territory with coordinates 49°30'-54°N, 31°-43°E and a total area of 227,300 km2 has been chosen for investigation. It has been carried out for years 2009

  8. DEVELOPMENT FOR HIGH PRECISION SIX COMPONENT STRAIN GAUGE BALANCE

    Institute of Scientific and Technical Information of China (English)

    ZHANGZhao-ming; HANBu-zhang

    2004-01-01

    The measurement accuracy of a wind tunnel balance is the key factor to improve the measurement accuracy for a test model in the wind tunnel. In order to improve the measurement accuracy of the wind tunnel balance, a great deal of investigation is carried out in China. This paper summarizes a program to improve the measurement accuracy of wind tunnel balances. In the program, the investigation is carried out in three aspects (1) designing a drag component of the balance in low interactions (2) choosing high quality foil strain gauges with temperature self-compensation (3) choosing the excellent gauges and mounting them meticulously. As an example, these research achievements are applied in a φ18 six component balance. The measurement accuracy of a GB-04 standard model in a transonic wind tunnel with the φ18 six component balance comes up to the advanced world standard.

  9. Analyzing Hydrological Sustainability Through Water Balance

    Science.gov (United States)

    Menció, Anna; Folch, Albert; Mas-Pla, Josep

    2010-05-01

    The objective of the Water Framework Directive (2000/60/EC) is to assist in the development of management plans that will lead to the sustainable use of water resources in all EU member states. However, defining the degree of sustainability aimed at is not a straightforward task. It requires detailed knowledge of the hydrogeological characteristics of the basin in question, its environmental needs, the amount of human water demand, and the opportunity to construct a proper water balance that describes the behavior of the hydrological system and estimates available water resources. An analysis of the water balance in the Selva basin (Girona, NE Spain) points to the importance of regional groundwater fluxes in satisfying current exploitation rates, and shows that regional scale approaches are often necessary to evaluate water availability. In addition, we discuss the pressures on water resources, and analyze potential actions, based on the water balance results, directed towards achieving sustainable water management in the basin.

  10. Variability of water balance components in a coffee crop in Brazil Variabilidade dos componentes do balanço hídrico de uma cultura de café no Brasil

    Directory of Open Access Journals (Sweden)

    Adriana Lúcia da Silva

    2006-04-01

    Full Text Available Establishing field water balances is difficult and costly, the variability of their components being the major problem to obtain reliable results. This component variability is presented herein for a coffee crop grown in the Southern Hemisphere, on a tropical soil with 10% slope. It was observed that: rainfall has to be measured with an appropriate number of replicates; irrigation can introduce great variability into calculations; evapotranspiration, calculated as a remainder of the water balance equation, has exceedingly high coefficients of variation; the soil water storage component is the major contributor in error propagation calculations to estimate evapotranspiration; and that runoff can be satisfactorily controlled on the 10% slope through crop management practices.O estabelecimento de balanços hídricos no campo é difícil e dispendioso, sendo a variabilidade de seus componentes o maior problema para se obter resultados confiáveis. Esta variabilidade dos componentes é aqui apresentada para uma cultura de café desenvolvida no hemisfério sul, em um solo tropical com 10% de declividade. Foi observado que a chuva deve ser medida com número apropriado de repetições; a irrigação pode introduzir grande variabilidade dos cálculos; a evapotranspiração calculada a partir da equação do balanço hídrico tem coeficientes de variação muito altos; o componente armazenamento de água no solo é o que mais contribui na propagação dos erros; e que a enxurrada pode ser satisfatoriamente controlada nesse declive de 10% por meio de práticas de manejo.

  11. Management of the water balance and quality in mining areas

    Science.gov (United States)

    Pasanen, Antti; Krogerus, Kirsti; Mroueh, Ulla-Maija; Turunen, Kaisa; Backnäs, Soile; Vento, Tiia; Veijalainen, Noora; Hentinen, Kimmo; Korkealaakso, Juhani

    2015-04-01

    systematically integrate all water balance components (groundwater, surface water, infiltration, precipitation, mine water facilities and operations etc.) into overall dynamic mine site considerations. After coupling the surface and ground water models (e.g. Feflow and WSFS) with each other, they are compared with Goldsim. The third objective is to integrate the monitoring and modelling tools into the mine management system and process control. The modelling and predictive process control can prevent flood situations, ensure water adequacy, and enable the controlled mine water treatment. The project will develop a constantly updated management system for water balance including both natural waters and process waters.

  12. Balancing the Energy-Water Nexus

    Energy Technology Data Exchange (ETDEWEB)

    Dell, Jan

    2010-09-15

    Optimizing the complex tradeoffs in the Energy-Water Nexus requires quantification of energy use, carbon emitted and water consumed. Water is consumed in energy production and is often a constraint to operations. More global attention and investment has been made on reducing carbon emissions than on water management. Review of public reporting by the largest 107 global power producers and 50 companies in the oil/gas industry shows broad accounting on carbon emissions but only partial reporting on water consumption metrics. If the Energy-Water Nexus is to be balanced, then water must also be measured to be optimally managed with carbon emissions.

  13. Renal aquaporins and water balance disorders

    DEFF Research Database (Denmark)

    Kortenoeven, Marleen; Fenton, Robert A.

    2013-01-01

    BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, A......-solute diet and diuretics. GENERAL SIGNIFICANCE: In recent years, our understanding of the underlying mechanisms of water balance disorders has increased enormously, which has opened up several possible new treatment strategies.......BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP......2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW: This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS: Dysfunctions of AQPs are involved in disorders...

  14. Plant water balance with tritiated water-tracing dynamical method

    Institute of Scientific and Technical Information of China (English)

    曾文炳; 颉红梅; 魏宝文; 陈荷生; 冯金朝; 董家伦

    1996-01-01

    The conception of "metabolic pool" is introduced and an ecosystem model consisting of sand body metabolic pool, plant metabolic pool, atmospheric pool and their corresponding channels is established. In addition, the input and output terms of water balance including plant transpiration etc. are measured by tritiated water-tracing dynamical method, etc. and thus a water balance table is obtained. Finally, the plant water balance in the steppified desert environment of the Shapotou area at southeastern fringe of Tengger Desert in China is comprehensively analysed.

  15. Regulation of water balance in mangroves

    OpenAIRE

    Reef, Ruth; Lovelock, Catherine E.

    2014-01-01

    Background Mangroves are a group of highly salt-tolerant woody plants. The high water use efficiency of mangroves under saline conditions suggests that regulation of water transport is a crucial component of their salinity tolerance.

  16. Water balance for Crater Lake, Oregon

    Science.gov (United States)

    Nathenson, Manuel

    1992-01-01

    A water balance for Crater Lake, Oregon, is calculated using measured lake levels and precipitation data measured at Park Headquarters and at a gage on the North Rim. Total water supply to the lake from precipitation and inflow from the crater walls is found to be 224 cm/y over the area of the lake. The ratio between water supply to the lake and precipitation at Park Headquarters is calculated as 1.325. Using leakage determined by Phillips (1968) and Redmond (1990), evaporation from the lake is approximately 85 cm/y. Calculations show that water balances with precipitation data only from Park Headquarters are unable to accurately define the water-level variation, whereas the addition of yearly precipitation data from the North Rim reduces the average absolute deviation between calculated and modeled water levels by one half. Daily precipitation and water-level data are modeled assuming that precipitation is stored on the rim as snow during fall and winter and released uniformly during the spring and early summer. Daily data do not accurately define the water balance, but they suggest that direct precipitation on the lake is about 10 % higher than that measured at Park Headquarters and that about 17 % of the water supply is from inflow from the rim.

  17. Renal aquaporins and water balance disorders

    DEFF Research Database (Denmark)

    Kortenoeven, Marleen; Fenton, Robert A.

    2013-01-01

    associated with disturbed water homeostasis. Hyponatremia with increased AQP levels can be caused by diseases with low effective circulating blood volume, such as congestive heart failure, or osmoregulation disorders such as the syndrome of inappropriate secretion of antidiuretic hormone. Treatment consists......BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP......2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW: This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS: Dysfunctions of AQPs are involved in disorders...

  18. Virtual water balance estimation in Tunisia

    Science.gov (United States)

    Stambouli, Talel; Benalaya, Abdallah; Ghezal, Lamia; Ali, Chebil; Hammami, Rifka; Souissi, Asma

    2015-04-01

    The water in Tunisia is limited and unevenly distributed in the different regions, especially in arid zones. In fact, the annual rainfall average varies from less than 100 mm in the extreme South to over 1500 mm in the extreme North of the country. Currently, the conventional potential of water resources of the country is estimated about 4.84 billion m³ / year of which 2.7 billion cubic meters / year of surface water and 2.14 billion cubic meters / year of groundwater, characterizing a structural shortage for water safety in Tunisia (under 500m3/inhabitant/year). With over than 80% of water volumes have been mobilized for agriculture. The virtual water concept, defined by Allan (1997), as the amount of water needed to generate a product of both natural and artificial origin, this concept establish a similarity between product marketing and water trade. Given the influence of water in food production, virtual water studies focus generally on food products. At a global scale, the influence of these product's markets with water management was not seen. Influence has appreciated only by analyzing water-scarce countries, but at the detail level, should be increased, as most studies consider a country as a single geographical point, leading to considerable inaccuracies. The main objective of this work is the virtual water balance estimation of strategic crops in Tunisia (both irrigated and dry crops) to determine their influence on the water resources management and to establish patterns for improving it. The virtual water balance was performed basing on farmer's surveys, crop and meteorological data, irrigation management and regional statistics. Results show that the majority of farmers realize a waste of the irrigation water especially at the vegetable crops and fruit trees. Thus, a good control of the cultural package may result in lower quantities of water used by crops while ensuring good production with a suitable economic profitability. Then, the virtual water

  19. International Space Station Water Balance Operations

    Science.gov (United States)

    Tobias, Barry; Garr, John D., II; Erne, Meghan

    2011-01-01

    In November 2008, the Water Regenerative System racks were launched aboard Space Shuttle flight, STS-126 (ULF2) and installed and activated on the International Space Station (ISS). These racks, consisting of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA), completed the installation of the Regenerative (Regen) Environmental Control and Life Support Systems (ECLSS), which includes the Oxygen Generation Assembly (OGA) that was launched 2 years prior. With the onset of active water management on the US segment of the ISS, a new operational concept was required, that of water balance . In November of 2010, the Sabatier system, which converts H2 and CO2 into water and methane, was brought on line. The Regen ECLSS systems accept condensation from the atmosphere, urine from crew, and processes that fluid via various means into potable water, which is used for crew drinking, building up skip-cycle water inventory, and water for electrolysis to produce oxygen. Specification (spec) rates of crew urine output, condensate output, O2 requirements, toilet flush water, and drinking needs are well documented and used as the best guess planning rates when Regen ECLSS came online. Spec rates are useful in long term planning, however, daily or weekly rates are dependent upon a number of variables. The constantly changing rates created a new challenge for the ECLSS flight controllers, who are responsible for operating the ECLSS systems onboard ISS from Mission Control in Houston. This paper reviews the various inputs to water planning, rate changes, and dynamic events, including but not limited to: crew personnel makeup, Regen ECLSS system operability, vehicle traffic, water storage availability, and Carbon Dioxide Removal Assembly (CDRA), Sabatier, and OGA capability. Along with the inputs that change the various rates, the paper will review the different systems, their constraints, and finally the operational challenges and means by which flight controllers

  20. Water balance and irrigation water pumping of Lake Merdada for potato farming in Dieng Highland, Indonesia.

    Science.gov (United States)

    Fadlillah, Lintang N; Widyastuti, M

    2016-08-01

    Lakes provide water resources for domestic use, livestock, irrigational use, etc. Water availability of lakes can be estimated using lake water balance. Lake water balance is calculated from the water input and output of a lake. Dieng Highland has several volcanic lakes in its surroundings. Lake Merdada in Dieng Highland has been experiencing extensive water pumping for several years more than other lakes in the surrounding area. It provides irrigation water for potato farming in Dieng Highland. The hydrological model of this lake has not been studied. The modeled water balance in this research uses primary data, i.e., bathymetric data, soil texture, and outflow discharge, as well as secondary data, i.e., rainfall, temperature, Landsat 7 ETM+ band 8 image, and land use. Water balance input components consist of precipitation on the surface area, surface (direct) runoff from the catchment area, and groundwater inflow and outflow (G net), while the output components consist of evaporation, river outflow, and irrigation. It shows that groundwater is the dominant input and output of the lake. On the other hand, the actual irrigation water pumping plays the leading role as human-induced alteration of outflow discharge. The maximum irrigation pumping modeling shows that it will decrease lake storage up to 37.14 % per month and may affect the ecosystem inside the lake.

  1. Water Balance Covers For Waste Containment: Principles and Practice

    Science.gov (United States)

    Water Balance Covers for Waste Containment: Principles and Practices introduces water balance covers and compares them with conventional approaches to waste containment. The authors provided detailed analysis of the fundamentals of soil physics and design issues, introduce appl...

  2. Improving the performance of water balance equation using fuzzy logic approach

    Science.gov (United States)

    Khazaei, Bahram; Hosseini, Seyed Mahmood

    2015-05-01

    It is a common practice to conduct the water budget or water balance analysis in a given area within a specified time in order to investigate the balance between the inputs and outputs of the water system. Such an analysis can be used for water management and water allocation in a designated study area. Due to appearance of an error in water balance equation because of difficulty in accurate estimation of its individual components, the main objective of the current paper was to apply a set of fuzzy coefficients to the components of the water balance equation in order to reduce this error. The fuzzy coefficients reflect the uncertainty and imprecision in evaluating each component, and minimize the overall error of the water balance equation. These coefficients are adjusted by an error minimization procedure, based on fuzzy regression concepts and using available recorded data for a given study area within a specified time scale. The adjusted coefficients can effectively estimate the water balance components in the future. In this study, four different models, representing different types of fuzzy coefficients, were considered and used for annual water balance of Azghand catchment in Khorasan Razavi Province, Iran as a case study. Analysis of results showed that all models were effective in reducing water balance error in Azghand catchment. The best model reduced the error up to 79% in terms of mean absolute error compared with error in water balance equation when conventional (with no correction coefficients) water balance analysis was conducted. Moreover, the results indicated that the performance of the proposed fuzzy models was not significantly sensitive to selection of confidence level in data (h) and improved slightly as h increased.

  3. Monthly Water Balance Model Hydrology Futures

    Science.gov (United States)

    Bock, Andy; Hay, Lauren E.; Markstrom, Steven; Atkinson, R. Dwight

    2016-01-01

    A monthly water balance model (MWBM) was driven with precipitation and temperature using a station-based dataset for current conditions (1950 to 2010) and selected statistically-downscaled general circulation models (GCMs) for current and future conditions (1950 to 2099) across the conterminous United States (CONUS) using hydrologic response units from the Geospatial Fabric for National Hydrologic Modeling (http://dx.doi.org/doi:10.5066/F7542KMD). Six MWBM output variables (actual evapotranspiration (AET), potential evapotranspiration (PET), runoff (RO), streamflow (STRM), soil moisture storage (SOIL), and snow water equivalent (SWE)) and the two MWBM input variables (atmospheric temperature (TAVE) and precipitation (PPT)) were summarized for hydrologic response units and aggregated at points of interest on a stream network. Results were then organized into the Monthly Water Balance Hydrology Futures database, an open-access database using netCDF format (http://cida-eros-mows1.er.usgs.gov/thredds/dodsC/nwb_pub/).  Methods used to calibrate and parameterize the MWBM are detailed in the Hydrology and Earth System Sciences (HESS)  paper "Parameter regionalization of a monthly water balance model for the conterminous United States" by Bock and others (2016).  See the discussion paper link in the "Related External Resources" section for access.  Supplemental data files related to the plots and data analysis in Bock and others (2016) can be found in the HESS-2015-325.zip folder in the "Attached Files" section.  Detailed information on the files and data can be found in the ReadMe.txt contained within the zipped folder. Recommended citation of discussion paper:Bock, A.R., Hay, L.E., McCabe, G.J., Markstrom, S.L., and Atkinson, R.D., 2016, Parameter regionalization of a monthly water balance model for the conterminous United States: Hydrology and Earth System Sciences, v. 20, 2861-2876, doi:10.5194/hess-20-2861-2016, 2016

  4. Regulation of water balance in mangroves.

    Science.gov (United States)

    Reef, Ruth; Lovelock, Catherine E

    2015-02-01

    Mangroves are a group of highly salt-tolerant woody plants. The high water use efficiency of mangroves under saline conditions suggests that regulation of water transport is a crucial component of their salinity tolerance. This review focuses on the processes that contribute to the ability of mangroves to maintain water uptake and limit water loss to the soil and the atmosphere under saline conditions, from micro to macro scales. These processes include: (1) efficient filtering of the incoming water to exclude salt; (2) maintenance of internal osmotic potentials lower than that of the rhizosphere; (3) water-saving properties; and (4) efficient exploitation of less-saline water sources when these become available. Mangroves are inherently plastic and can change their structure at the root, leaf and stand levels in response to salinity in order to exclude salt from the xylem stream, maintain leaf hydraulic conductance, avoid cavitation and regulate water loss (e.g. suberization of roots and alterations of leaf size, succulence and angle, hydraulic anatomy and biomass partitioning). However, much is still unknown about the regulation of water uptake in mangroves, such as how they sense and respond to heterogeneity in root zone salinity, the extent to which they utilize non-stomatally derived CO2 as a water-saving measure and whether they can exploit atmospheric water sources. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. The Water Balance Portal in Saxony - An interactive web application concerning the impact of climate change on the water balance

    Science.gov (United States)

    Hauffe, Corina; Schwarze, Robert; Röhm, Patric; Müller, Ruben; Dröge, Werner; Gurova, Anastasia; Winkler, Peter; Baldy, Agnes

    2016-04-01

    Changes in weather and climate lead to increasing discussions about reasons and possible future impacts on the hydrological cycle. The question of a changed distribution of water also concerns the federal state of Saxony in the eastern part of Germany. Especially with a look at the different and increased requirements for water authorities, water economy and the public. To define and prepare these future requirements estimations of the future development of the natural water resources are necessary. Therefore data, information, and forecast concerning the development of the several components of the water balance are needed. And to make the obtained information easily available for experts and the public, tools like the internet have to be used. Under these frame conditions the water balance portal Saxony (www.wasserhaushaltsportal.sachsen.de) was developed within the project KliWES. The overall approach of the project was devided into the so-called „3 pillars".The first pillar focused on the evaluation of the status quo water balance from 1951-2005 by using a complex area-wide analysis of measured data. Also it contained the generating of a database and the development of a physically based parameter model. Furthermore an extensive model evaluation has been conducted with a number of objective assessment criteria, to select an appropriate model for the project. The second pillar included the calibration of the water balance model and the impact study of climate and land use change (1961-2100) on the water balance of Saxonian catchments. In this context 13 climate scenarios and three land use scenarios were simulated. The web presence of these two pillars represents a classical information service, which provides finalized results at the spatial resolution of sub-catchments using GIS-based webpages. The third pillar focused on the development of an interactive expert system. It allows the user (public, officials and consulting engineers) to simulate the water

  6. Simulation of Assembly Line Balancing in Automotive Component Manufacturing

    Science.gov (United States)

    Jamil, Muthanna; Mohd Razali, Noraini

    2016-02-01

    This study focuses on the simulation of assembly line balancing in an automotive component in a vendor manufacturing company. A mixed-model assembly line of charcoal canister product that is used in an engine system as fuel's vapour filter was observed and found that the current production rate of the line does not achieve customer demand even though the company practices buffer stock for two days in advance. This study was carried out by performing detailed process flow and time studies along the line. To set up a model of the line by simulation, real data was taken from a factory floor and tested for distribution fit. The data gathered was then transformed into a simulation model. After verification of the model by comparing it with the actual system, it was found that the current line efficiency is not at its optimum condition due to blockage and idle time. Various what-if analysis were applied to eliminate the cause. Proposed layout shows that the line is balanced by adding buffer to avoid the blockage. Whereas, manpower is added the stations to reduce process time therefore reducing idling time. The simulation study was carried out using ProModel software.

  7. Sensible heat balance measurements of soil water evaporation beneath a maize canopy

    Science.gov (United States)

    Soil water evaporation is an important component of the water budget in a cropped field. Few methods are available for continuous and independent measurement of soil water evaporation. A sensible heat balance (SHB) approach has recently been demonstrated for continuously determining soil water evapo...

  8. Modeling of Water balance in semiarid region of Mexico

    Science.gov (United States)

    González-Sosa, E.; Mastachi-Loza, C.; Medina-frutos, C.; Ramos-Salinas, N. M.

    2012-04-01

    Around the world water is becoming scarce, especially in the semiarid regions where there is a high inter-annual variability in the amount and distribution of the rainfall. Studies on this kind of environments would allow us to understand the mechanisms that determine the spatial and temporal distribution of the water balance components. The present study was carried out from October 2005 to October 2008 in three semiarid sites located in the south of the Mexican Plateau: El Carmen in Guanajuato State and Amazcala and Cadereyta in the State of Queretaro. The work aim was to provide a better understanding of the hydrological processes that occur in the semiarid ecosystems, specifically through two objectives (1) to quantify and to model the rainfall interception process (EI) employing an adequate sampling strategy and an evaluation of the models developed by Rutter et al. (1975) and Gash (1979) in two shrubs species: huisache (Acacia farnesisna) and mesquite (Prosopis laevigata) both, in situ and ex situ and (2) to quantify and model the water balance in order to define the distribution of the water and energy balance components in El Carmen and Cadereyta. For this purpose, the SiSPAT (Simple Soil Plant Atamosphere Transfer) model was used based on a parametrisation of the soil, plants and atmosphere components. It was found that EI represented between 20% and 22% of the total rainfall (PG). Gash's model reproduced EI with satisfactory efficiency (E>0.6), wind's speed and maximum intensity have a local effect on EI. It was also found that, using SiSPAT, the water balance components were particularly sensitive to parameters associated with the soil and the leaf area index. The model results showed that during the studied period, the annual evapotranspiration in Cadereyta was less than PG (-10 and -5%) and above PG for El Carmen (10 y 30%). Runoff and percolation at 5m were null. Finally in both sites there was a simulated loss of water stored in the soil. This, was

  9. Soil Water Balance Measurement in Field Scale

    Institute of Scientific and Technical Information of China (English)

    CHENZHI-XIONG

    1992-01-01

    A 5-year experiment on water balance has been conducted in a flat rainfed wheat field with an area of 66×100m2 in Fengqiu,Henan Province in China.Based on the analysis of semi-variance functions conducted with soil moisture samples taken from 77 nodes of a 10×10m2 grid,the soil moisture distribution in the field was structural with a temporal stability.According to the autocorrelation range of the semi-variance function,6 sites were selected for the determination of soil water conditions.The characteristic of probability density function of the differences of water storage in two sets of measurements showed that the distribution of these variables in the field was a normal one.The error in the estimation of the average of 5 random samples was 14% (α=0.10),and the errors of water consumption by wheat during the experiments were estimated to be 6-13%.Sime the experimental field was large enough to avoid any edge effect,the results obtained should tally with the actual situation.Yet the soil system was heterogeneous,so we must follow the principles of statistics and geostatistics when describing the system's status with the average of the samples.

  10. Evaluating Water Conservation and Reuse Policies Using a Dynamic Water Balance Model

    Science.gov (United States)

    Qaiser, Kamal; Ahmad, Sajjad; Johnson, Walter; Batista, Jacimaria R.

    2013-02-01

    A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley's water demands through 2035.

  11. [Influence of weightlessness on water and electrolytes balance in body].

    Science.gov (United States)

    Shen, X Y

    2000-02-01

    The balance of water and electrolytes plays an important role in enabling the human body to adapt to spaceflight. This paper introduced the research methods, and changes in water and electrolytes balance during and after space flight. The mechanism and the hazard of the disorder of water and electrolytes caused by weightlessness were discussed.

  12. A probabilistic approach for estimating monthly catchment water balances from satellite and ground data

    Science.gov (United States)

    Schoups, Gerrit

    2017-04-01

    A probabilistic model is developed to estimate monthly basin-scale precipitation, evaporation, storage and river discharge from open-source data and water balance constraints. Both random and systematic deviations between observed and "true" water balance components are included in the model to account for measurement/processing errors and differences in scale. Model parameters comprise data standard deviations (random noise) and scaling factors (systematic bias). Water balance terms and parameters are estimated using Bayesian inference, yielding posterior distributions for all unknowns. The model is applied to MOPEX basins across the continental US using the following data sources: TRMM-3B43 (precipitation), SSEBop (evaporation), GRACE (storage), and USGS stream gauges (river discharge). Results provide optimal estimates and uncertainty of water balance components and data errors across a range of basin characteristics (size, wetness, etc).

  13. [Comment on “GEWEX: The Global Energy and Water Cycle Experiment”] More global water balance uncertainty

    Science.gov (United States)

    Rodda, John C.

    I concur strongly with Chahine's January 14, 1992, Eos article on GEWEX and support his response to Dincer's letter (Eos, June 16, 1992) emphasizing that “our quantitative knowledge of the hydrological cycle remains surprisingly poor.” This is despite the magnificent report on the world water balance to which Dincer refers and his allusion that the existence of a low residual in closing the water balance indicates low errors of measurement of the global budget components.

  14. Evaluation of a mass-balance approach to determine consumptive water use in northeastern Illinois

    Science.gov (United States)

    Mills, Patrick C.; Duncker, James J.; Over, Thomas M.; Marian Domanski,; ,; Engel, Frank

    2014-01-01

    A principal component of evaluating and managing water use is consumptive use. This is the portion of water withdrawn for a particular use, such as residential, which is evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. The amount of consumptive use may be estimated by a water (mass)-balance approach; however, because of the difficulty of obtaining necessary data, its application typically is restricted to the facility scale. The general governing mass-balance equation is: Consumptive use = Water supplied - Return flows.

  15. Comparative water balance study of forest and fallow plots

    Directory of Open Access Journals (Sweden)

    Móricz N

    2012-08-01

    Full Text Available Increasing pressure on groundwater due to land use change (e.g., afforestation and future climate change will alter the recharge of groundwater aquifers, causing shifts in water table levels and hence influencing the avai­lable groundwater resources. The effect of land use change on groundwater resources has initiated a major scientific debate during the last decades between foresters and experts in water management in Hungary and in several other countries. The aim of this study was to compare water balances of two different vegetation covers, a groundwater dependent oak forest and a nearby fallow area in the Hungarian Lowland. Water balance components for an oak and a fallow plots, exposed to similar weather conditions and with similar soils, were estimated and compared by calibrating the Hydrus 1-D model using mea­sured soil water content and groundwater levels. The difference in the groundwater consumption was analyzed in details during dry and wet growing seasons. Transpiration at the fallow plot was only about two-thirds of that in the oak forest, while groundwater consumption was three times higher in the forest than at the fallow plot throughout the two-year study. During the dry growing season, the proportion of groundwater use from the total transpiration reached up to 90% at the oak plot. According to the model, in the dry growing season in 2007 both vegetation covers relied significantly on groundwater resources, while in 2008 the consumption of groundwater was notably reduced due to the wet weather at both plots.

  16. Fuzzy-probabilistic calculations of water-balance uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Faybishenko, B.

    2009-10-01

    Hydrogeological systems are often characterized by imprecise, vague, inconsistent, incomplete, or subjective information, which may limit the application of conventional stochastic methods in predicting hydrogeologic conditions and associated uncertainty. Instead, redictions and uncertainty analysis can be made using uncertain input parameters expressed as probability boxes, intervals, and fuzzy numbers. The objective of this paper is to present the theory for, and a case study as an application of, the fuzzyprobabilistic approach, ombining probability and possibility theory for simulating soil water balance and assessing associated uncertainty in the components of a simple waterbalance equation. The application of this approach is demonstrated using calculations with the RAMAS Risk Calc code, to ssess the propagation of uncertainty in calculating potential evapotranspiration, actual evapotranspiration, and infiltration-in a case study at the Hanford site, Washington, USA. Propagation of uncertainty into the results of water-balance calculations was evaluated by hanging he types of models of uncertainty incorporated into various input parameters. The results of these fuzzy-probabilistic calculations are compared to the conventional Monte Carlo simulation approach and estimates from field observations at the Hanford site.

  17. Resolving hydrologic water balances through a novel error analysis approach, with application to the Tahoe basin

    Science.gov (United States)

    Trask, James C.; Fogg, Graham E.; Puente, Carlos E.

    2017-03-01

    We introduce a new approach for improving estimates of water balance components, applicable to a multi-period water balance series for a lake, watershed, or other area of any size. It consists of making use of statistical relationships between a component series estimate and the residual errors of the water mass balance series. Through this approach, two novel specific techniques are developed. The first, 'precipitation-decorrelation', entails implementing a criterion of decorrelation of residual errors from precipitation estimates. The second, 'residual-redistribution', consists of redistributing each residual error over initial water balance component estimates, in accord with an error minimization criterion for each component series. Efficacy is tested using series of annual water balances for the Tahoe Basin. Upon implementation of precipitation-decorrelation, a tightly bounded statistical estimate of mean annual Lake Tahoe evaporation is obtained, which closely matches independent measurement-based estimates. Residual-redistribution yields revised estimates of annual series of Tahoe areal precipitation and watershed runoff, which are each shown to have substantially reduced random error variance. Highly precise revised estimates of inter-annual variations in Tahoe precipitation have enabled resolution of the watershed multi-year 'memory' of precipitation, and more reliable separation of inter-annual changes in watershed storage from inter-annual variations in atmospheric loss.

  18. The liquid water balance of the Greenland ice sheet

    Science.gov (United States)

    Steger, Christian; Reijmer, Carleen; van den Broeke, Michiel

    2017-04-01

    pronounced in the south-eastern area of the GrIS, where the refreezing fraction is comparably high (˜ 0.75) due to large amounts of available pore space. This area also indicates the highest increase in the modelled areal firn aquifer extent (+343km2 a-1). Generally, many components of the liquid water balance reveal distinctively different magnitudes and temporal patterns on a local, basin-wide scale.

  19. Comparative Analysis of Seepage Losses From Nighttime Water Level Changes and Water Balance Methods

    Science.gov (United States)

    Shukla, A.; Shukla, S.; Wu, C.

    2013-12-01

    Several techniques including Darcy's theory of one and two dimensional groundwater flow, seepage meters, and water balance have been used in the past to estimate seepage from impoundments such as reservoirs, ponds, and constructed wetlands. These methods result in varying level of errors in seepage estimates depending on method and biogeophysical setting to which they are applied. In this study, we explore a simple yet effective method of estimating groundwater fluxes for two stormwater impoundments (SIs) and a partially drained wetland located in agricultural areas using diurnal changes in surface water levels inside these systems. Days with no inflow, outflow, and rainfall were selected to minimize the effect of the error associated water balance components on seepage estimation. Difference in water levels between 20:00 hrs and 5:00 hrs was calculated for the selected days. Only nighttime change was considered keeping in mind the fact that evapotranspiration is negligible during night and hence, the change in water levels can be attributed to seepage alone. Seepage from the analysis of night-time change in the water levels was compared to the estimates from the water balance method with seepage being the residual component of the balance. Results show that seepage constitutes a large part of total outflow from the impoundments (29% and 17% for SI1 during 2008-2009 and 2009-2010 respectively, 30% for SI2 during 2009-2010 and seepage was greater than the total surface water outflow from SI2 during 2010-2011). Accuracy of this method varied from 5% to 41% for first and 4% to 29% for the second SI. Considering that errors as high as 100% have been reported with the use of Darcy's approach, the errors from our method are lower. The lower errors combined with ease of application without using the hydraulic conductivity values makes our approach feasible for other similar systems. Improved seepage estimate from the proposed method will result in quantification of

  20. Evaluating water conservation and reuse policies using a dynamic water balance model.

    Science.gov (United States)

    Qaiser, Kamal; Ahmad, Sajjad; Johnson, Walter; Batista, Jacimaria R

    2013-02-01

    A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley's water demands through 2035.

  1. Modeling water balance distribution in a natural semiarid region of central Mexico using a SVAT model

    Science.gov (United States)

    Mastachi-Loza, C. A.; Braud, I.; Gonzalez-Sosa, E.; Centro de Investigaciones Del Agua de Querétaro

    2010-12-01

    Around the world water is becoming insufficient, especially in the semiarid regions where there is a high inter-annual variability in the amount and distribution of the rainfall. Studies on this kind of environments would allow us to understand the mechanisms that determine the spatial and temporal distribution of the water balance components. The study was carried out from October 2005 to October 2008 in two semiarid sites located in the south of the Mexican Plateau: El Carmen in Guanajuato State and Cadereyta in Queretaro State. The work aim was to provide a better understanding of the hydrological processes that occur in semiarid ecosystems, quantifying and modeling the water balance in order to define the distribution of the water and energy balance components in El Carmen and Cadereyta. For this purpose, the SiSPAT (Simple Soil Plant Atmosphere Transfer) model was used based on a parameterization of the soil, plants and atmosphere components. It was found that, using SiSPAT, the water balance components were particularly sensitive to parameters associated with the soil and the leaf area index. The model results showed that during the studied period, the annual evapotranspiration in Cadereyta was less than PG (-10 and -5%) and above PG for El Carmen (10 y 30%). Runoff and percolation at 5m were null. Finally in both sites there was a simulated loss of water stored in the soil.

  2. Studying surface water balance in Kurdistan province using GIS

    Directory of Open Access Journals (Sweden)

    Nader Fallah

    2016-06-01

    Full Text Available The study of water exchange in a region or area, which emphasizes the principle of conservation of matter in the water cycle, is called balance. Investigating their balance is the basis for managing the rivers’ water management, the results of which refer to the change rate in surface water supply and can efficiently be used in decision making and optimal use of water resources. The present study was carried out in order to investigate the surface water balance in Kurdistan province using GIS. In so doing, digital topographic maps, soil map of the area, and meteorological data retrieved from the regional stations were used to prepare layers of precipitation, evaporation and infiltration of rainwater into the soil. Discharge-arearegion comparative method was employed to measure the amount of runoff and base flow for each sub-basin in raster form saved per unit area which was subsequently overlapped based on balance equation, and the balance of the region was displayed in a graphical mode. The results indicated that more surface water is wasted in the southeast and central area of the province.

  3. Virtual water flows and Water Balance Impacts of the U.S. Great Lakes Basin

    Science.gov (United States)

    Ruddell, B. L.; Mayer, A. S.; Mubako, S. T.

    2014-12-01

    To assess the impacts of human water use and trade on water balances, we estimate virtual water flows for counties in the U.S. portion of the Great Lakes basin. This is a water-rich region, but one where ecohydrological 'hotspots' are created by water scarcity in certain locations (Mubako et al., 2012). Trade shifts water uses from one location to another, causing water scarcity in some locations but mitigating water scarcity in other locations. A database of water withdrawals was assembled to give point-wise withdrawals by location, source, and use category (commercial, thermoelectric power, industrial, agricultural, mining). Point-wise consumptive use is aggregated to the county level, giving direct, virtual water exports by county. A county-level trade database provides import and export data for the various use categories. We link the annual virtual water exported from a county for a given use category to corresponding annual trade exports. Virtual water balances for each county by use category are calculated, and then compared with the renewable annual freshwater supply. Preliminary findings are that overall virtual water balances (imports - exports) are positive for almost all counties, because urban areas import goods and services that are more water intensive than the exported goods and services. However, for some agriculturally-intensive counties, the overall impact of virtual water trade on the water balance is close to zero, and the balance for agricultural sector virtual water trade is negative, reflecting a net impact of economic trade on the water balance in these locations. We also compare the virtual water balance to available water resources, using annual precipitation less evapotranspiration as a crude estimate of net renewable water availability. In some counties virtual water exports approach 30% of the available water resources, indicating the potential for water scarcity, especially from an aquatic ecosystem standpoint.

  4. Soil water content and water balance simulation of Caragana korshinskii Kom. in the semiarid Chinese Loess Plateau

    Directory of Open Access Journals (Sweden)

    Jian Shengqi

    2014-06-01

    Full Text Available In this paper, to evaluate the hydrological effects of Caragana korshinskii Kom., measured data were combined with model-simulated data to assess the C. korshinskii soil water content based on water balance equation. With measured and simulated canopy interception, plant transpiration and soil evaporation, soil water content was modeled with the water balance equation. The monthly variations in the modeled soil water content by measured and simulated components (canopy interception, plant transpiration, soil evaporation were then compared with in situ measured soil water content. Our results shows that the modeled monthly water loss (canopy interception + soil evaporation + plant transpiration by measured and simulated components ranges from 43.78 mm to 113.95 mm and from 47.76 mm to 125.63 mm, respectively, while the monthly input of water (precipitation ranges from 27.30 mm to 108.30 mm. The relative error between soil water content modeled by measured and simulated components was 6.41%. To sum up, the net change in soil water (ΔSW is negative in every month of the growing season. The soil moisture is approaching to wilting coefficient at the end of the growth season, and the soil moisture recovered during the following season.

  5. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  6. Water balance of rice plots under three different water treatments: monitoring activity and experimental results

    Science.gov (United States)

    Chiaradia, Enrico Antonio; Romani, Marco; Facchi, Arianna; Gharsallah, Olfa; Cesari de Maria, Sandra; Ferrari, Daniele; Masseroni, Daniele; Rienzner, Michele; Battista Bischetti, Gian; Gandolfi, Claudio

    2014-05-01

    In the agricultural seasons 2012 and 2013, a broad monitoring activity was carried out at the Rice Research Centre of Ente Nazionale Risi (CRR-ENR) located in Castello d'Agogna (PV, Italy) with the purpose of comparing the water balance components of paddy rice (Gladio cv.) under different water regimes and assessing the possibility of reducing the high water inputs related to the conventional practice of continuous submergence. The experiments were laid out in six plots of about 20 m x 80 m each, with two replicates for each of the following water regimes: i) continuous flooding with wet-seeded rice (FLD), ii) continuous flooding from around the 3-leaf stage with dry-seeded rice (3L-FLD), and iii) surface irrigation every 7-10 days with dry-seeded rice (IRR). One out of the two replicates of each treatment was instrumented with: water inflow and outflow meters, set of piezometers, set of tensiometers and multi-sensor moisture probes. Moreover, an eddy covariance station was installed on the bund between the treatments FLD and IRR. Data were automatically recorded and sent by a wireless connection to a PC, so as to be remotely controlled thanks to the development of a Java interface. Furthermore, periodic measurements of crop biometric parameters (LAI, crop height and rooting depth) were performed in both 2012 and 2013 (11 and 14 campaigns respectively). Cumulative water balance components from dry-seeding (3L-FLD and IRR), or flooding (FLD), to harvest were calculated for each plot by either measurements (i.e. rainfall, irrigation and surface drainage) or estimations (i.e. difference in the field water storage, evaporation from both the soil and the water surface and transpiration), whereas the sum of percolation and capillary rise (i.e. the 'net percolation') was obtained as the residual term of the water balance. Incidentally, indices of water application efficiency (evapotranspiration over net water input) and water productivity (grain production over net water

  7. Investigation of the Impacts of Measured and Calculated Radiation Balance Components on Evapotranspiration

    Science.gov (United States)

    Akataş, Nilcan; Yeşilköy, Serhan; Şaylan, Levent

    2016-04-01

    Determination of surface energy balance over agricultural lands plays a crucial role to better investigation of sustainable agriculture and food security which are related to evapotranspiration. Surface energy balance components that include net shortwave and longwave radiation depend on surface conditions like surface albedo and climate of a region. Surface albedo is ratio between reflected longwave radiation and incoming shortwave radiation. There are many different crops in agriculture ecosystem. Thus, surface energy balance components vary by vegetation surfaces. Net radiation is most important component of surface energy balance which is difference between net shortwave and longwave radiation. These are calculated by commonly used equations and applied to the FAO Penman& Monteith equation using meteorological stations' data located in cities. However, there are differences between urban areas and agricultural ecosystems. This situation causes to the calculation errors. In this research, it is aimed to investigate the changes between estimated and measured surface energy balance components which are estimated by meteorological stations' data in the urban area and measurements from an rural area over winter wheat surface 2014-2015 growing season in Thrace Region located in the Northwestern part of Turkey, Kırklareli city. Keywords: Surface energy balance, winter wheat, FAO Penman-Monteith, Kırklareli/Turkey

  8. Seasonal Water Balance Forecasts for Drought Early Warning in Ethiopia

    Science.gov (United States)

    Spirig, Christoph; Bhend, Jonas; Liniger, Mark

    2016-04-01

    Droughts severely impact Ethiopian agricultural production. Successful early warning for drought conditions in the upcoming harvest season therefore contributes to better managing food shortages arising from adverse climatic conditions. So far, however, meteorological seasonal forecasts have not been used in Ethiopia's national food security early warning system (i.e. the LEAP platform). Here we analyse the forecast quality of seasonal forecasts of total rainfall and of the meteorological water balance as a proxy for plant available water. We analyse forecast skill of June to September rainfall and water balance from dynamical seasonal forecast systems, the ECMWF System4 and EC-EARTH global forecasting systems. Rainfall forecasts outperform forecasts assuming a stationary climate mainly in north-eastern Ethiopia - an area that is particularly vulnerable to droughts. Forecasts of the water balance index seem to be even more skilful and thus more useful than pure rainfall forecasts. The results vary though for different lead times and skill measures employed. We further explore the potential added value of dynamically downscaling the forecasts through several dynamical regional climate models made available through the EU FP7 project EUPORIAS. Preliminary results suggest that dynamically downscaled seasonal forecasts are not significantly better compared with seasonal forecasts from the global models. We conclude that seasonal forecasts of a simple climate index such as the water balance have the potential to benefit drought early warning in Ethiopia, both due to its positive predictive skill and higher usefulness than seasonal mean quantities.

  9. Microclimatic models. Estimation of components of the energy balance over land surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Heikinheimo, M.; Venaelaeinen, A.; Tourula, T. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.

    1996-12-31

    Climates at regional scale are strongly dependent on the interaction between atmosphere and its lower boundary, the oceans and the land surface mosaic. Land surfaces influence climate through their albedo, and the aerodynamic roughness, the processes of the biosphere and many soil hydrological properties; all these factors vary considerably geographically. Land surfaces receive a certain portion of the solar irradiance depending on the cloudiness, atmospheric transparency and surface albedo. Short-wave solar irradiance is the source of the heat energy exchange at the earth`s surface and also regulates many biological processes, e.g. photosynthesis. Methods for estimating solar irradiance, atmospheric transparency and surface albedo were reviewed during the course of this project. The solar energy at earth`s surface is consumed for heating the soil and the lower atmosphere. Where moisture is available, evaporation is one of the key components of the surface energy balance, because the conversion of liquid water into water vapour consumes heat. The evaporation process was studied by carrying out field experiments and testing parameterisation for a cultivated agricultural surface and for lakes. The micrometeorological study over lakes was carried out as part of the international `Northern Hemisphere Climatic Processes Experiment` (NOPEX/BAHC) in Sweden. These studies have been aimed at a better understanding of the energy exchange processes of the earth`s surface-atmosphere boundary for a more accurate and realistic parameterisation of the land surface in atmospheric models

  10. Calculation of available water supply in crop root zone and the water balance of crops

    Science.gov (United States)

    Haberle, Jan; Svoboda, Pavel

    2015-12-01

    Determination of the water supply available in soils for crops is important for both the calculation of water balance and the prediction of water stress. An approach to calculations of available water content in layers of the root zone, depletion of water during growth, and water balance, with limited access to data on farms, is presented. Soil water retention was calculated with simple pedotransfer functions from the texture of soil layers, root depth, and depletion function were derived from observed data; and the potential evapotranspiration was calculated from the temperature. A comparison of the calculated and experimental soil water contents showed a reasonable fit.

  11. Water--Problems and Solutions. A Report Concerning the Problems and Solutions of Negative Water Balance.

    Science.gov (United States)

    Ewert, Alan

    Outdoor leaders constantly face problems created by water shortage and, to act effectively, must thoroughly understand the body's use of water and the ways to delay dehydration when water shortage occurs. Dehydration begins when there is a negative water balance, or more water lost than ingested, and progresses from the stage of dryness, to the…

  12. Sustainable Hydro Assessment and Groundwater Recharge Projects (SHARP) in Germany - Water Balance Models

    Science.gov (United States)

    Niemand, C.; Kuhn, K.; Schwarze, R.

    2010-12-01

    management actions. The model comparisons within reference areas showed significant differences in outcome. The values of water balance components calculated with different models partially fluctuate by a multiple of their value. The SHARP project was prepared in several previous projects that were testing suitable water balance models and is now able to assist the knowledge transfer.

  13. Two strategies by epiphytic orchids for maintaining water balance: thick cuticles in leaves and water storage in pseudobulbs.

    Science.gov (United States)

    Yang, Shi-Jian; Sun, Mei; Yang, Qiu-Yun; Ma, Ren-Yi; Zhang, Jiao-Lin; Zhang, Shi-Bao

    2016-01-01

    Epiphytes are an important component of tropical and subtropical flora, and serve vital ecological functions in forest hydrology and nutrient fluxes. However, they often encounter water deficits because there is no direct contact between their roots and the soil. The strategies employed by epiphytes for maintaining water balance in relatively water-limited habitats are not completely understood. In the present study, we investigated the anatomical traits, water loss rates, and physiology of leaves and pseudobulbs of four Dendrobium species with different pseudobulb morphologies to understand the roles of leaf and pseudobulb in maintaining water balance of epiphytic orchids. Our results showed that two species (D. chrysotoxum and D. officinale), with lower rates of water loss, have thicker leaves and upper cuticles, but lower epidermal thickness and leaf dry mass per area. In contrast, the other two species (D. chrysanthum and D. crystallinum) with thinner cuticles and higher rates of water loss, have less tissue density and greater saturated water contents in their pseudobulbs. Therefore, our results indicate that these latter two species may resist drought by storing water in the pseudobulbs to compensate for their thin cuticles and rapid water loss through the leaves. Under the same laboratory conditions, excised pseudobulbs with attached leaves had lower rates of water loss when compared with samples comprising only excised leaves. This implies that epiphytic orchids utilize two different strategies for sustaining water balance: thick cuticles to conserve water in leaves and water storage in pseudobulbs. Our results also show that Dendrobium species with thin cuticles tend to have pseudobulbs with high water storage capacity that compensates for their faster rates of water loss. These outcomes contribute to our understanding of the adaptive water-use strategies in Dendrobium species, which is beneficial for the conservation and cultivation of epiphytic orchids.

  14. Water balance disorders after neurosurgery: The triphasic response revisited

    NARCIS (Netherlands)

    E.J. Hoorn (Ewout); R. Zietse (Robert)

    2010-01-01

    textabstractWater balance disorders after neurosurgery are well recognized, but detailed reports of the triphasic response are scarce. We describe a 55-year-old woman, who developed the triphasic response with severe hyper- and hyponatraemia after resection of a suprasellar meningioma. The case illu

  15. Balancing water resources conservation and food security in China

    OpenAIRE

    2014-01-01

    China’s economic growth is expected to continue into the next decades, accompanied by sustained urbanization and industrialization. The associated increase in demand for land, water resources, and rich foods will deepen the challenge of sustainably feeding the population and balancing agricultural and environmental policies. We combine a hydrologic model with an economic model to project China’s future food trade patterns and embedded water resources by 2030 and to analyze the effects of targ...

  16. Recasting catchment water balance for water allocation between human and environmental purposes

    Directory of Open Access Journals (Sweden)

    S. Zhou

    2015-01-01

    Full Text Available Rebalancing water allocation between human consumptive uses and the environment in water catchments is a global challenge. The conventional water balance approach which partitions precipitation into evapotranspiration (ET and surface runoff supports the optimization of water allocations among different human water use sectors under the cap of water supply. However, this approach is unable to support the emerging water management priority issue of allocating water between societal and ecological systems. This paper recast the catchment water balance by partitioning catchment total ET into ET for the society and ET for the natural ecological systems, and estimated the impacts of water allocation on the two systems in terms of gross primary productivity (GPP, in the Murray–Darling Basin (MDB of Australia over the period 1900–2010. With the recast water balance, the more than 100 year water management in the MDB was divided into four periods corresponding to major changes in basin management: period 1 (1900–1956 expansion of water and land use by the societal system, period 2 (1956–1985 maximization of water and land use by the societal system, period 3 (1985–2002 maximization of water diversion for the societal system, and period 4 (2002–present rebalancing of water and land use between the societal and ecological systems. The recast water balance provided new understandings of the water and land dynamics between societal and ecological systems in the MDB, and it highlighted the experiences and lessons of catchment water management in the MDB over the last more than 100 years. The recast water balance could serve as the theoretical foundation for water allocation to keep a dynamic balance between the societal and ecological systems within a basin for sustainable catchment development. It provides a new approach to advance the discipline of socio-hydrology.

  17. Application of the hydrophile-lipophile balance concept to the classification of demulsifiers and bituminous froth and its components

    Energy Technology Data Exchange (ETDEWEB)

    Vander Kloet, Jana; Schramm, Laurier L.; Shelfantook, Bill [Chemistry Department, University of Calgary, Calgary, Alberta (Canada)

    2002-01-18

    The hydrophile-lipophile balance (HLB) was used to characterize several naphtha-diluted bituminous froth and bitumen phases, extracted froth components, and commercial demulsifiers used to resolve the froth emulsions. The requirements for emulsification of the diluted froth and bitumen phases could be classified by the HLB system in terms of required HLB values. Although such classification was not effective in detecting gross changes in the interfacial components of the diluted froth and bitumen phases, meaningful HLB values were obtained for the water soluble natural surfactants (HLB 16{+-}1) and asphaltenes (HLB 11{+-}1) isolated from the froth. The HLB values for three commercial demulsifiers were found to change depending on the delivery medium, from 12{+-}1 if the demulsifier was dissolved in naphtha to 7{+-}1 if the demulsifier was dissolved in water. This difference in apparent HLB may arise from differences in interfacially active components in the diluent. It appears that demulsifier components delivered in naphtha and the water-soluble natural surfactants will seek to form O/W emulsions and, therefore, act to destabilize the W/O froth emulsions. Conversely, demulsifier components delivered in water and naturally occurring asphaltenes will act to stabilize the W/O froth emulsions.

  18. Water and heat balances in Doñana wetlands

    Directory of Open Access Journals (Sweden)

    A. Ramos-Fuertes

    2016-10-01

    Full Text Available This paper presents the main results of the study of water balance and surface heat balance in the Doñana marshlands. The study was based on a broad base of hydrometeorological data taken at 10 minute intervals from 2006 to 2011 by a network of six measuring stations located in areas of vegetation-free marsh. This information is used to characterize, at different time scales, the thermal behavior of the marsh by analyzing its hydrometeorology centering on the surface heat fluxes. Thus, we have modeled and analyzed the heat flux between the water and flooded soil and the processes of heat transfer between the water surface and the atmosphere. Special attention has been paid to evaporation, on which the marsh draining process depends.

  19. Water balance of an earth fill built of organic clay

    Directory of Open Access Journals (Sweden)

    Birle Emanuel

    2016-01-01

    Full Text Available The paper presents investigations on the water balance of an earth fill built of organic clay in humid climate. As the organic soil used for the fill contains geogenetically elevated concentrations of arsenic, particular attention is paid on the seepage flow through the fill. The test fill is 5 m high, 30 m long and 25 m wide. The fill consists of the organic clay compacted at water contents wet and dry of Proctor Optimum covered by a drainage mat and a 60 cm thick top layer. For the determination of the water balance extensive measuring systems were installed. The seepage at the bottom measured so far was less than 2 % of the precipitation. The interflow in the drainage mat above the compacted organic clay was of similar magnitude. The estimated evapotranspiration reached approx. 84 % of the precipitation. According to these measurements the percolation is much lower than the percolation of many landfill covers in humid climates.

  20. Design and development of an experimental six component wind tunnel block balance using optical fibre sensors.

    CSIR Research Space (South Africa)

    De Ponte

    2014-05-01

    Full Text Available and manufacturing technologies. These are required to not only improve performance, but also to reduce production costs and lead times. This paper outlines the conceptual design of a six component block balance that uses Optical Fibre Bragg Grating (OFBG) sensors...

  1. Calibration of an experimental six component wind tunnel block balance using optical fibre sensors

    CSIR Research Space (South Africa)

    de Ponte

    2016-05-01

    Full Text Available and manufacturing technologies. These are required to not only improve performance, but also to reduce production costs and lead times. This paper outlines the design and evaluation of a six component block balance that uses Optical Fibre Bragg Grating (OFBG...

  2. Fundamentals of the spatially distributed simulation of the water balance of forest sites in a low-range mountain area

    Directory of Open Access Journals (Sweden)

    K. Schwärzel

    2007-05-01

    Full Text Available For a sustainable forest management, a site-specific knowledge on the water balance is a prerequisite. A simple and popular field method for assessing the water balance of forest sites is based on overlaying relief and soil information. Furthermore, climatic influence on the water balance is often restricted to longtime average values of precipitation and air temperature (whole year and/or growing season. However, the impacts of climate change and climatic extremes, as well as silvicultural changes, are inadequately considered. To overcome these short-comings, we integrated the 1D-SVAT model BROOK90 and a radiation model in a GIS to simulate the spatially distributed components of water balance of forest sites. In this paper, we present the model concept and show an approach to describe the influence of a complex terrain on parameters controlling the spatial distribution of energy and water fluxes.

  3. Is snow sublimation important in the alpine water balance?

    Directory of Open Access Journals (Sweden)

    U. Strasser

    2007-09-01

    Full Text Available In alpine terrain, snow sublimation as a component of the winter moisture budget represents a proportion of precipitation which does not contribute to melt. To quantify its amount we analyze the spatial pattern of snow sublimation at the ground, from a canopy and from turbulent suspension during wind-induced snow transport for a high alpine area in the Berchtesgaden National Park (Germany, and we discuss the efficiency of these processes with respect to seasonal snowfall. Therefore, we utilized hourly meteorological recordings from a network of automatic stations, and a distributed simulation framework comprising validated, physically based models. Meteorological data records were spatially distributed over the simulation domain by means of a quasi-physically based interpolation scheme that accounts for topographic influences on the distributed fields. The applied simulation tools were: a detailed model for shortwave and longwave radiative fluxes, a mass and energy balance model for the ground snow cover, a model for the microclimatic conditions within a forest canopy and related snow-vegetation interactions including snow sublimation from the surface of the trees, and a model for the simulation of wind-induced snow transport and related sublimation from suspended snow particles. For each of the sublimation processes, mass rates were quantified and aggregated over an entire winter season. Sublimation from the ground and from most canopy types are spatially relatively homogeneous and sum up to about 100 mm of snow water equivalent (SWE over the winter period. Accumulated seasonal sublimation due to turbulent suspension is small in the valley areas, but can locally, at very wind-exposed mountain ridges, add up to more than 1000 mm of SWE. The fraction of these sublimation losses of winter snowfall is between 10 and 90%.

  4. GlobWat – a global water balance model to assess water use in irrigated agriculture

    Directory of Open Access Journals (Sweden)

    J. Hoogeveen

    2015-01-01

    Full Text Available GlobWat is a freely distributed, global soil water balance model that is used by FAO to assess water use in irrigated agriculture; the main factor behind scarcity of freshwater in an increasing number of regions. The model is based on spatially distributed high resolution datasets that are consistent at global level and calibrated against values for Internal Renewable Water Resources, as published in AQUASTAT, FAO's global information system on water and agriculture. Validation of the model is done against mean annual river basin outflows. The water balance is calculated in two steps: first a "vertical" water balance is calculated that includes evaporation from in situ rainfall ("green" water and incremental evaporation from irrigated crops. In a second stage, a "horizontal" water balance is calculated to determine discharges from river (sub-basins, taking into account incremental evaporation from irrigation, open water and wetlands ("blue" water. The paper describes methodology, input and output data, calibration and validation of the model. The model results are finally compared with other global water balance models.

  5. Atmospheric Water Balance and Variability in the MERRA-2 Reanalysis

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, Franklin R.; Takacs, Lawrence; Molod, Andrea; Mocko, David

    2017-01-01

    Closing and balancing Earths global water cycle remains a challenge for the climate community. Observations are limited in duration, global coverage, and frequency, and not all water cycle terms are adequately observed. Reanalyses aim to fill the gaps through the assimilation of as many atmospheric water vapor observations as possible. Former generations of reanalyses have demonstrated a number of systematic problems that have limited their use in climate studies, especially regarding low-frequency trends. This study characterizes the NASA Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) water cycle relative to contemporary reanalyses and observations. MERRA-2 includes measures intended to minimize the spurious global variations related to in homogeneity in the observational record. The global balance and cycling of water from ocean to land is presented, with special attention given to the water vapor analysis increment and the effects of the changing observing system. While some systematic regional biases can be identified,MERRA-2 produces temporally consistent time series of total column water and transport of water from ocean to land. However, the interannual variability of ocean evaporation is affected by the changing surface-wind-observing system, and precipitation variability is closely related to the evaporation. The surface energy budget is also strongly influenced by the interannual variability of the ocean evaporation. Furthermore, evaluating the relationship of temperature and water vapor indicates that the variations of water vapor with temperature are weaker in satellite data reanalyses, not just MERRA-2, than determined by observations, atmospheric models, or reanalyses without water vapor assimilation.

  6. Atmospheric Water Balance and Variability in the MERRA-2 Reanalysis

    Science.gov (United States)

    Bosilovich, Michael G.; Robertson, Franklin R.; Takacs, Lawrence; Molod, Andrea; Mocko, David

    2017-01-01

    Closing and balancing Earths global water cycle remains a challenge for the climate community. Observations are limited in duration, global coverage, and frequency, and not all water cycle terms are adequately observed. Reanalyses aim to fill the gaps through the assimilation of as many atmospheric water vapor observations as possible. Former generations of reanalyses have demonstrated a number of systematic problems that have limited their use in climate studies, especially regarding low-frequency trends. This study characterizes the NASA Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) water cycle relative to contemporary reanalyses and observations. MERRA-2 includes measures intended to minimize the spurious global variations related to in homogeneity in the observational record. The global balance and cycling of water from ocean to land is presented, with special attention given to the water vapor analysis increment and the effects of the changing observing system. While some systematic regional biases can be identified,MERRA-2 produces temporally consistent time series of total column water and transport of water from ocean to land. However, the interannual variability of ocean evaporation is affected by the changing surface-wind-observing system, and precipitation variability is closely related to the evaporation. The surface energy budget is also strongly influenced by the interannual variability of the ocean evaporation. Furthermore, evaluating the relationship of temperature and water vapor indicates that the variations of water vapor with temperature are weaker in satellite data reanalyses, not just MERRA-2, than determined by observations, atmospheric models, or reanalyses without water vapor assimilation.

  7. Momentum balance in the shallow water equations on bottom discontinuities

    Science.gov (United States)

    Valiani, A.; Caleffi, V.

    2017-02-01

    This work investigates the topical problem of balancing the shallow water equations over bottom steps of different heights. The current approaches in the literature are essentially based on mathematical analysis of the hyperbolic system of balance equations and take into account the relevant progresses in treating the non-conservative form of the governing system in the framework of path-conservative schemes. An important problem under debate is the correct position of the momentum balance closure when the bottom elevation is discontinuous. Cases of technical interest are systematically analysed, consisting of backward-facing steps and forward-facing steps, tackled supercritical and subcritical flows; critical (sonic) conditions are also analysed and discussed. The fundamental concept governing the problem and supported by the present computations is that the energy-conserving approach is the only approach that is consistent with the classical shallow water equations formulated with geometrical source terms and that the momentum balance is properly closed if a proper choice of a conventional depth on the bottom step is performed. The depth on the step is shown to be included between the depths just upstream and just downstream of the step. It is also shown that current choices (as given in the literature) of the depth on (or in front of) the step can lead to unphysical configurations, similar to some energy-increasing solutions.

  8. Power loss measurement of implantable wireless power transfer components using a Peltier device balance calorimeter

    Science.gov (United States)

    Leung, Ho Yan; Budgett, David M.; Taberner, Andrew; Hu, Patrick

    2014-09-01

    Determining heat losses in power transfer components operating at high frequencies for implantable inductive power transfer systems is important for assessing whether the heat dissipated by the component is acceptable for implantation and medical use. However, this is a challenge at high frequencies and voltages due to limitations in electronic instrumentation. Calorimetric methods of power measurement are immune to the effects of high frequencies and voltages; hence, the measurement is independent of the electrical characteristics of the system. Calorimeters have been widely used to measure the losses of high power electrical components (>50 W), however it is more difficult to perform on low power components. This paper presents a novel power measurement method for components dissipating anywhere between 0.2 W and 1 W of power based on a heat balance calorimeter that uses a Peltier device as a balance sensor. The proposed balance calorimeter has a single test accuracy of ±0.042 W. The experimental results revealed that there was up to 35% difference between the power measurements obtained with electrical methods and the proposed calorimeter.

  9. Quantifying the catchment salt balance: An important component of salinity assessments

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2015-06-01

    Full Text Available been attributed to the manifestation of dryland salinity. Dryland salinity occurs as a result of changes in land use (indigenous vegetation to agriculture and/or pasture), which cause a change in the water and salt balance of the landscape, consequently...

  10. Study on the Balance of Agricultural Water and Land Resources on Ningxia Plain

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing; Feng Zhiming; Yang Yanzhao

    2006-01-01

    The article puts forward the process and means of regional water and land balance research, and then from two scenarios which are the balances under natural regulation and human intervention, calculated and analysed the balance between water and land on Ningxia Plain. For the balance under natural regulation named farmland water balance, using farmland water resource balance equation, the research estimated the monthly farmland water balance of 8 major crops for all of the 12 counties on Ningxia Plain in the period of 1960-2001; for the balance under human intervention,the research estimated land-use water balance equation of the counties in 2000, and calculated the balance between land use and water resources including irrigating water of all the 12 counties on Ningxia Plain. Results showed that ①precipitation can not meet the water demand of the crops for growth and development on Ningxia Plain, and water shortage is the primary character of farmland water balance under natural regulation. ②the diversity of water and land balance of different counties is distinctly influenced by the crop structure, water quantity for irrigation and irrigation level. ③Irrigation water could meet the crop water demand on Ningxia Plain in 2000,but there was not much space to expand irrigating cultivated land.

  11. Soil Water Balance and Irrigation Strategies in an Agricultural District of Southern Italy

    Directory of Open Access Journals (Sweden)

    Domenico Ventrella

    2010-06-01

    Full Text Available An efficient management of water resources is considered very important for Mediterranean regions of Italy in order to improve the economical and environmental sustainability of the agricultural activity. The purpose of this study is to analyze the components of soil water balance in an important district included in the regions of Basilicata and Puglia and situated in the Jonical coastal area of Southern Italy and mainly cropped with horticultural crops. The study was performed by using the spatially distributed and physically based model SIMODIS in order to individuate the best irrigation management maximizing the water use efficiency and minimizing water losses by deep percolation and soil evaporation. SIMODIS was applied taking in to account the soil spatial variability and localization of cadastral units for two crops, durum wheat and water melon. For water melon recognition in 2007 a remote sensed image, from SPOT5 satellite, at the spatial resolution of 10 m, has been used. In 2008, a multi-temporal data set was available, from SPOT5 satellite to produce a land cover map for the classes water melon and durum wheat. Water melon cultivation was simulated adopting different water supply managements: rainfed and four irrigation strategies based on (i soil water availability and (ii plant water status adopting a threshold daily stress value. For each management, several water management indicators were calculated and mapped in GIS environment. For seasonal irrigation depth, actual evapotranspiration and irrigation efficiency were also determined. The analysis allowed to individuate the areas particularly sensitive to water losses by deep percolation because of their hydraulic functions characterized by low water retention and large values of saturated hydraulic conductivity. For these areas, the irrigation based on plant water status caused very high water losses by drainage. On the contrary, the irrigation scheduled on soil base allowed to

  12. Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes

    Science.gov (United States)

    Serrano-Ortiz, P.; Sánchez-Cañete, E. P.; Olmo, F. J.; Metzger, S.; Pérez-Priego, O.; Carrara, A.; Alados-Arboledas, L.; Kowalski, A. S.

    2016-03-01

    The consistency of eddy-covariance measurements is often evaluated in terms of the degree of energy balance closure. Even over sloping terrain, instrumentation for measuring energy balance components is commonly installed horizontally, i.e. perpendicular to the geo-potential gradient. Subsequently, turbulent fluxes of sensible and latent heat are rotated perpendicular to the mean streamlines using tilt-correction algorithms. However, net radiation (Rn) and soil heat fluxes ( G) are treated differently, and typically only Rn is corrected to account for slope. With an applied case study, we show and argue several advantages of installing sensors surface-parallel to measure surface-normal Rn and G. For a 17 % south-west-facing slope, our results show that horizontal installation results in hysteresis in the energy balance closure and errors of up to 25 %. Finally, we propose an approximation to estimate the surface-normal Rn, when only vertical Rn measurements are available.

  13. Application of remote sensing-based two-source energy balance model for mapping field surface fluxes with composite and component surface temperatures

    Science.gov (United States)

    Operational application of a remote sensing-based two source energy balance model (TSEB) to estimate evaportranspiration (ET) and the components evaporation (E), transpiration (T) at a range of space and time scales is very useful for managing water resources in arid and semiarid watersheds. The TSE...

  14. Water balance and soil losses in an irrigated catchment under conservation tillage in Southern Spain

    Science.gov (United States)

    Cid, Patricio; Mateos, Luciano; Taguas, Encarnación V.; Gómez-Macpherson, Helena

    2013-04-01

    Conservation tillage based on permanent beds with crop-residue retention and controlled traffic has been recently introduced in irrigated annual crops in Southern Spain as one way to improve water infiltration, reduce soil losses, and save energy. The water balance and soil losses in water runoff have been monitored during 4 years in a 28-ha catchment within a production farm where this kind of soil conservation practice was established in 2004 for a maize-cotton-wheat rotation. The catchment average slope is 6 %. Soils are Typic Calcixerept and Typic Haploxerert. The water balance components that were measured include: applied irrigation water, rainfall, and runoff. Runoff was measured at the outlet of the catchment by means of a hydrological station that consisted of long-throated flume, ultrasonic water level sensor, automatic water sampler, data logger and transmission system, weather station, and ancillary equipment. We present here results from three hydrological seasons (October to September): 2009-10, 2010-11, and 2011-12. The first season the catchment was grown with wheat, thus the irrigation depth was small (25 mm); rainfall above average, 1103 mm; and the runoff coefficient was 26 %. In the season 2010-11, the catchment was grown with cotton, the irrigation depth was 503 mm, rainfall was 999 mm, and the seasonal runoff coefficient was 7 %. The last season, the crop was maize, rainfall was below average (368 mm), irrigation 590 mm, and the runoff coefficient as the previous year, 7 %. Soil losses were very small: 0.05, 1.26, and 1.33 t per ha and year, the first, second, and third monitored seasons, respectively. A simple water balance model allowed simulating evapotranspiration, deep percolation and runoff. The Curve Number for the catchment was calibrated using the balance model.

  15. Water balance of goats in Jeneponto - South Sulawesi under sunlight exposure and water restriction

    Directory of Open Access Journals (Sweden)

    Djoni Prawira Rahardja

    2007-10-01

    Full Text Available Water balance of 5 does of Kacang goat of Jeneponto was studied under the condition of sunlight exposure and water restriction. The study was conducted in dry season with 4 consecutive treatments of 10 d with 4-5 d of adjustment period between two consecutive treatments: (1 indoor and unrestricted water; (2 indoor and restricted water; (3 10 h outdoor–and unrestricted water; (4 10 h outdoor – restricted water. The maximum air temperature of outdoor was 39.3OC, and it was 30OC in the indoor environment. In all treatments, the animals were placed in the individual crates. The plasma volume of the goats was higher under sunlight exposure, but it decreased by water restriction, while hematocrite value indicated a reverse responses. Sunlight exposure did not significantly decrease the intake and digestion of organic matter, but water restriction affected significantly and this effect was higher under sunlight exposre. The proportions of water loss through every avenue were maintained relatively constant either under water restriction or sunlight exposure in which the respration rate increased significantly. The findings suggest that sunlight exposure with unrestricted water resulted in a positive water balance without a significant change in organic matter intake and utilization. Water restriction resulted in a negative water balance, reducing organic matter intake and utilization. As the adaptive mechanisms, the goat appeared to be able to withstand in the harsh environment of Jeneponto by expanding plasma volume, increasing body temperature and respiration rate.

  16. Balancing water resource conservation and food security in China.

    Science.gov (United States)

    Dalin, Carole; Qiu, Huanguang; Hanasaki, Naota; Mauzerall, Denise L; Rodriguez-Iturbe, Ignacio

    2015-04-14

    China's economic growth is expected to continue into the next decades, accompanied by sustained urbanization and industrialization. The associated increase in demand for land, water resources, and rich foods will deepen the challenge of sustainably feeding the population and balancing agricultural and environmental policies. We combine a hydrologic model with an economic model to project China's future food trade patterns and embedded water resources by 2030 and to analyze the effects of targeted irrigation reductions on this system, notably on national agricultural water consumption and food self-sufficiency. We simulate interprovincial and international food trade with a general equilibrium welfare model and a linear programming optimization, and we obtain province-level estimates of commodities' virtual water content with a hydrologic model. We find that reducing irrigated land in regions highly dependent on scarce river flow and nonrenewable groundwater resources, such as Inner Mongolia and the greater Beijing area, can improve the efficiency of agriculture and trade regarding water resources. It can also avoid significant consumption of irrigation water across China (up to 14.8 km(3)/y, reduction by 14%), while incurring relatively small decreases in national food self-sufficiency (e.g., by 3% for wheat). Other researchers found that a national, rather than local, water policy would have similar effects on food production but would only reduce irrigation water consumption by 5%.

  17. Water balance measurements and simulations of maize plants on lysimeters

    Science.gov (United States)

    Heinlein, Florian; Biernath, Christian; Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2016-04-01

    In Central Europe expected major aspects of climate change are a shift of precipitation events and amounts towards winter months, and the general increase of extreme weather events like heat waves or summer droughts. This will lead to strongly changing regional water availability and will have an impact on future crop growth, water use efficiency and yields. Therefore, to estimate future crop yields by growth models accurate descriptions of transpiration as part of the water balance is important. In this study, maize was grown on weighing lysimeters (sowdate: 24 April 2013). Transpiration was determined by sap flow measurement devices (ICT International Pty Ltd, Australia) using the Heat-Ratio-Method: two temperature probes, 0.5 cm above and below a heater, detect a heat pulse and its speed which allows the calculation of sap flow. Water balance simulations were executed with different applications of the model framework Expert-N. The same pedotransfer and hydraulic functions and the same modules to simulate soil water flow, soil heat and nitrogen transport, nitrification, denitrification and mineralization were used. Differences occur in the chosen potential evapotranspiration ETpot (Penman-Monteith ASCE, Penman-Monteith FAO, Haude) and plant modules (SPASS, CERES). In all simulations ETpot is separated into a soil and a plant part using the leaf are index (LAI). In a next step, these parts are reduced by soil water availability. The sum of these parts is the actual evapotranspiration ETact which is compared to the lysimeter measurements. The results were analyzed from Mid-August to Mid-September 2013. The measured sap flow rates show clear diurnal cycles except on rainy days. The SPASS model is able to simulate these diurnal cycles, overestimates the measurements on rainy days and at the beginning of the analyzed period, and underestimates transpiration on the other days. The main reason is an overestimation of potential transpiration Tpot due to too high

  18. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  19. Drinking and water balance during exercise and heat acclimation

    Science.gov (United States)

    Greenleaf, J. E.; Brock, P. J.; Keil, L. C.; Morse, J. T.

    1983-01-01

    The interactions between fluid intake and balance, and plasma ion, osmotic, and endocrine responses during dehydration produced by exercise in cool and warm environments during acclimation are explored. Two groups of five male subjects performed 8 days of ergometer exercise in hot and thermoneutral conditions, respectively. The exercise trials lasted 2 hr each. Monitoring was carried out on the PV, osmotic, sodium, and endocrine concentrations, voluntary fluid intake, fluid balances, and fluid deficits. A negative correlation was observed between the plasma sodium and osmolality during acclimation. The presence of hypervolemia during acclimation is suggested as a cause of drinking, while the vasopressin concentration was not found to be a significant factor stimulating drinking. Finally, the predominant mechanism in fluid intake during exercise and heat exposure is concluded to be the renin-angiotensin II system in the presence of reductions in total body water and extracellular plasma volumes.

  20. Instantaneous phasor method for obtaining instantaneous balanced fundamental components for power quality control and continuous diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.S.

    1997-07-01

    This paper introduces an instantaneous phasor method that considers three phases simultaneously. This method produces the instantaneous fundamental balanced components of the polluted voltages or currents. A figure shows three-phase voltages that contain 5% of fundamental magnitude for each order of the 3rd, 5th, 7th, 9th and the 11th harmonics, respectively. Additionally, the voltages have 5% unbalance for all voltage components. A 10% fundamental-frequency zero-sequence component, as well as a 10% fundamental-frequency negative-sequence component are also added to the phase voltages. Furthermore, certain high-frequency pulses arbitrarily given at 5% of a 35th order to represent a possible carrier frequency of power electronic circuits are also included.

  1. Characteristics of water and carbon balance in moso bamboo forests

    Science.gov (United States)

    Kume, T.; Laplace, S.; Tseng, H.; Hsieh, Y.; Wey, T.; Komatsu, H.

    2013-12-01

    Water and carbon cycles in mountainous areas can have considerable impacts on our available nature resources such as water resources and timber production. Thus, it is indispensable to clarify the difference of water and carbon balances between different types of forested ecosystems. Recently, bamboo forests have been expanding by replacing surrounding vegetation such as coniferous and broad-leaved forests in eastern Asian countries. It has been speculated that the replacements by bamboo forests could alter the vegetation water and carbon cycles. However, our knowledge for the bamboo forests was still limited due to lack of applicable methodology based on a field measurement. To clarify the potential impacts of bamboo expansion on water and carbon cycles, our previous study established optimal and effective design for assessing bamboo forest water use (ie, transpiration) based on sap flux measurements. Using the method, we quantified stand-scale transpiration in bamboo forests and coniferous forests in Taiwan. Consequently, we found significantly larger transpiration in bamboo forests compared with those of surrounding vegetation due to larger canopy conductance in bamboo forests. The unique characteristics of the water use accompanied larger carbon assimilation and soil CO2 efflux in bamboo forests.

  2. What are the key drivers of regional differences in the water balance on the Tibetan Plateau?

    Science.gov (United States)

    Biskop, S.; Maussion, F.; Krause, P.; Fink, M.

    2015-04-01

    Lake-level fluctuations in closed basins on the Tibetan Plateau (TP) indicate climate-induced changes in the regional water balance. However, little is known about the region's key hydrological parameters, hampering the interpretation of these changes. The purpose of this study is to contribute to a more quantitative understanding of these controls. Four lakes in the south-central part of the TP were selected to analyze the spatiotemporal variations of water-balance components: Nam Co and Tangra Yumco (indicating increasing water levels), and Mapam Yumco and Paiku Co (indicating stable or slightly decreasing water levels). We present the results of an integrated approach combining hydrological modeling, atmospheric-model output and remote-sensing data. The hydrological model J2000g was adapted and extended according to the specific characteristics of closed lake basins on the TP and driven with "High Asia Refined analysis (HAR)" data at 10 km resolution for the period 2001-2010. Our results reveal that because of the small portion of glacier areas (1 to 7% of the total basin area) the contribution of glacier melt water accounts for only 14-30% of total runoff during the study period. Precipitation is found to be the principal factor controlling the water-balance in the four studied basins. The positive water balance in the Nam Co and Tangra Yumco basins was primarily related to larger precipitation amounts and thus higher runoff rates in comparison with the Paiku Co and Mapam Yumco basins. This study highlights the benefits of combining atmospheric and hydrological modeling. The presented approach can be readily transferred to other ungauged lake basins on the TP, opening new directions of research. Future work should go towards increasing the atmospheric model's spatial resolution and a better assessment of the model-chain uncertainties, especially in this region where observational data is missing.

  3. Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response.

    Science.gov (United States)

    Osler, Callum J; Tersteeg, M C A; Reynolds, Raymond F; Loram, Ian D

    2013-10-01

    Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance.

  4. A metabolism perspective on alternative urban water servicing options using water mass balance.

    Science.gov (United States)

    Farooqui, Tauheed A; Renouf, Marguerite A; Kenway, Steven J

    2016-12-01

    Urban areas will need to pursue new water servicing options to ensure local supply security. Decisions about how best to employ them are not straightforward due to multiple considerations and the potential for problem shifting among them. We hypothesise that urban water metabolism evaluation based a water mass balance can help address this, and explore the utility of this perspective and the new insights it provides about water servicing options. Using a water mass balance evaluation framework, which considers direct urban water flows (both 'natural' hydrological and 'anthropogenic' flows), as well as water-related energy, we evaluated how the use of alternative water sources (stormwater/rainwater harvesting, wastewater/greywater recycling) at different scales influences the 'local water metabolism' of a case study urban development. New indicators were devised to represent the water-related 'resource efficiency' and 'hydrological performance' of the urban area. The new insights gained were the extent to which alternative water supplies influence the water efficiency and hydrological performance of the urban area, and the potential energy trade-offs. The novel contribution is the development of new indicators of urban water resource performance that bring together considerations of both the 'anthropogenic' and 'natural' water cycles, and the interactions between them. These are used for the first time to test alternative water servicing scenarios, and to provide a new perspective to complement broader sustainability assessments of urban water.

  5. Dynamic balance changes within three weeks of fitting a new prosthetic foot component.

    Science.gov (United States)

    Kent, Jenny A; Stergiou, Nicholas; Wurdeman, Shane R

    2017-07-05

    Balance during walking is of high importance to prosthesis users and may affect walking during baseline observation and evaluation. The aim of this study was to determine whether changes in walking balance occurred during an adaptation period following the fitting of a new prosthetic component. Margin of stability in the medial-lateral direction (MOSML) and an anterior instability margin (AIM) were used to quantify the dynamic balance of 21 unilateral transtibial amputees during overground walking. Participants trialled two prosthetic feet presenting contrasting movement/balance constraints; a Higher Activity foot similar to that of their own prosthesis, and a Lower Activity foot. Participants were assessed before (Visit 1) and after (Visit 2) a 3-week adaptation period on each foot. With the Higher Activity component, MOSML decreased on the prosthetic side, and increased on the sound side from Visit 1 to Visit 2, eliminating a significant inter-limb difference apparent at Visit 1 (Visit 1-sound=0.062m, prosthetic=0.075m, p=0.018; Visit 2-sound=0.066m, prosthetic=0.074m, p=0.084). No such change was seen with the Lower Activity foot (Visit 1-sound=0.064m, prosthetic=0.077m, p=0.007; Visit 2-sound=0.063m, prosthetic=0.080m, pbalance during walking can occur following the initial receipt of a device regardless of whether the component is of the same functional category as the one an individual is accustomed to using. Copyright © 2017. Published by Elsevier B.V.

  6. Botswana water and surface energy balance research program. Part 1: Integrated approach and field campaign results

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Vugts, H. F.; Ramothwa, G. K.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. Results of the first part of the program (Botswana 1) which ran from 1 Jan. 1988 - 31 Dec. 1990 are summarized. Botswana 1 consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components in general are described and activities performed during the surface energy modeling component including the extensive field campaign are summarized. The results of the passive microwave component are summarized. The key of the field campaign was a multilevel approach, whereby measurements by various similar sensors were made at several altitudes and resolution. Data collection was performed at two adjacent sites of contrasting surface character. The following measurements were made: micrometeorological measurements, surface temperatures, soil temperatures, soil moisture, vegetation (leaf area index and biomass), satellite data, aircraft data, atmospheric soundings, stomatal resistance, and surface emissivity.

  7. Carbon and water vapor balance in a subtropical pine plantation

    Directory of Open Access Journals (Sweden)

    Posse G

    2016-10-01

    Full Text Available Afforestation has been proposed as an effective tool for protecting primary and/or secondary forests and for mitigating atmospheric CO2. However, the dynamics of primary productivity differs between plantations and natural forests. The objective of this work was to evaluate the potential for carbon storage of a commercial pine plantation by determining its carbon balance. Measurements started when trees were aged 6 and ended when they were older than 8 years. We measured CO2 and water vapor concentrations using the Eddy covariance method. Gross primary productivity in 2010 and 2011 was 4290 ± 473 g C m-2 and 4015 ± 485 g C m-2, respectively. Ecosystem respiration ranged between 7 and 20 g C m-2 d-1, reaching peaks in all Februaries. Of the 30 months monitored, the plantation acted as carbon source for 21 months and as carbon sink for 6 months, while values close to neutrality were obtained during 3 months. The positive balance representing CO2 loss by the system was most likely due to the cut branches left on the ground following pruning activities. The plantation was subjected to pruning in January and September 2008 and to sanitary pruning in October 2010. In all cases, cut branches were not removed but remained on the ground. Residue management seems to have a very important impact on carbon balance.

  8. Water balance trumps ion balance for early marine survival of juvenile pink salmon (Oncorhynchus gorbuscha).

    Science.gov (United States)

    Sackville, M; Wilson, J M; Farrell, A P; Brauner, C J

    2012-08-01

    Smolting salmonids typically require weeks to months of physiological preparation in freshwater (FW) before entering seawater (SW). Remarkably, pink salmon (Oncorhynchus gorbuscha) enter SW directly following yolk absorption and gravel emergence at a size of 0.2 g. To survive this exceptional SW migration, pink salmon were hypothesized to develop hypo-osmoregulatory abilities prior to yolk absorption and emergence. To test this, alevins (pre-yolk absorption) and fry (post-yolk absorption) were transferred from FW in darkness to SW under simulated natural photoperiod (SNP). Ionoregulatory status was assessed at 0, 1 and 5 days post-transfer. SW alevins showed no evidence of hypo-osmoregulation, marked by significant water loss and no increase in gill Na⁺/K⁺-ATPase (NKA) activity or Na⁺:K⁺:2Cl⁻ cotransporter (NKCC) immunoreactive (IR) cell frequency. Conversely, fry maintained water balance, upregulated gill NKA activity by 50 %, increased the NKA α1b/α1a mRNA expression ratio by sixfold and increased NKCC IR cell frequency. We also provide the first evidence of photoperiod-triggered smoltification in pink salmon, as fry exposed to SNP in FW exhibited preparatory changes in gill NKA activity and α1 subunit expression similar to fry exposed to SNP in SW. Interestingly, fry incurred larger increases in whole body Na⁺ than alevins following both SW and FW + SNP exposure (40 and 20 % in fry vs. 0 % in alevins). The ability to incur and tolerate large ion loads may underlie a novel mechanism for maintaining water balance in SW prior to completing hypo-osmoregulatory development. We propose that pink salmon represent a new form of anadromy termed "precocious anadromy".

  9. Four-component relativistic theory for nuclear magnetic shielding: magnetically balanced gauge-including atomic orbitals.

    Science.gov (United States)

    Cheng, Lan; Xiao, Yunlong; Liu, Wenjian

    2009-12-28

    It is recognized only recently that the incorporation of the magnetic balance condition is absolutely essential for four-component relativistic theories of magnetic properties. Another important issue to be handled is the so-called gauge problem in calculations of, e.g., molecular magnetic shielding tensors with finite bases. It is shown here that the magnetic balance can be adapted to distributed gauge origins, leading to, e.g., magnetically balanced gauge-including atomic orbitals (MB-GIAOs) in which each magnetically balanced atomic orbital has its own local gauge origin placed on its center. Such a MB-GIAO scheme can be combined with any level of theory for electron correlation. The first implementation is done here at the coupled-perturbed Dirac-Kohn-Sham level. The calculated molecular magnetic shielding tensors are not only independent of the choice of gauge origin but also converge rapidly to the basis set limit. Close inspections reveal that (zeroth order) negative energy states are only important for the expansion of first order electronic core orbitals. Their contributions to the paramagnetism are therefore transferable from atoms to molecule and are essentially canceled out for chemical shifts. This allows for simplifications of the coupled-perturbed equations.

  10. Effects of Water Management Strategies on Water Balance in a Water Scarce Region: A Case Study in Beijing by a Holistic Model

    Directory of Open Access Journals (Sweden)

    Zhigong Peng

    2016-08-01

    Full Text Available Irrigation is facing increasing pressure from other competitive water users to reduce water consumption in a water scarce region. Based on the Basin-wide Holistic Integrated Water Assessment (BHIWA model, the effects of water management strategies on water balance in the dry regions of North China were analyzed. The results show that, with the decrease of irrigation water supply reliability (IWSR and the increase of irrigation water use efficiency (WUE, irrigation water use decreased significantly, leading to reduced agriculture water consumption, and sustained ground water levels. Compared with the increase of WUE, the decrease of IWSR contributes more to reducing irrigation water consumption and protecting groundwater. Sensitivity tests show that among various water cycle components, irrigation water use is most sensitive to changes, followed by agriculture water consumption, and then groundwater level. Reducing IWSR is an effective strategy to reduce irrigation water consumption and promote sustainable water resources management, which could be the support of basic data and theory for regional water resources planning.

  11. The U.S. Geological Survey Monthly Water Balance Model Futures Portal

    Science.gov (United States)

    Bock, Andrew R.; Hay, Lauren E.; Markstrom, Steven L.; Emmerich, Christopher; Talbert, Marian

    2017-05-03

    The U.S. Geological Survey Monthly Water Balance Model Futures Portal (https://my.usgs.gov/mows/) is a user-friendly interface that summarizes monthly historical and simulated future conditions for seven hydrologic and meteorological variables (actual evapotranspiration, potential evapotranspiration, precipitation, runoff, snow water equivalent, atmospheric temperature, and streamflow) at locations across the conterminous United States (CONUS).The estimates of these hydrologic and meteorological variables were derived using a Monthly Water Balance Model (MWBM), a modular system that simulates monthly estimates of components of the hydrologic cycle using monthly precipitation and atmospheric temperature inputs. Precipitation and atmospheric temperature from 222 climate datasets spanning historical conditions (1952 through 2005) and simulated future conditions (2020 through 2099) were summarized for hydrographic features and used to drive the MWBM for the CONUS. The MWBM input and output variables were organized into an open-access database. An Open Geospatial Consortium, Inc., Web Feature Service allows the querying and identification of hydrographic features across the CONUS. To connect the Web Feature Service to the open-access database, a user interface—the Monthly Water Balance Model Futures Portal—was developed to allow the dynamic generation of summary files and plots  based on plot type, geographic location, specific climate datasets, period of record, MWBM variable, and other options. Both the plots and the data files are made available to the user for download 

  12. Assessment of availability water at Boi Branco watershed through the water climate balance and growing

    Science.gov (United States)

    Alexandre de Lima Sales, Mariana; Máximo Sanchez-Román, Rodrigo; Rodríguez-Sinobas, Leonor; Ribeiro da Silva de Souza, Joao Victor; Nonato Farias Monteiro, Raimundo

    2015-04-01

    The water resources are fundamental to the development of several economic activities. Concerning the agriculture production, the water can represent close to 90% of the physical constitution of the plant. The low water supply during the growing stage of vegetables can make the agricultural production not viable and can even seriously affect the balance of the ecosystem. One way to calculate the amount of water in a determined system is by means of the water balance, that is an important tool for the assessment process of the water cycle in a specific region. The main goal of this work was to establish the water balance in the watershed Boi Branco-SP, so that it can be used as a tool for the hydro-agricultural and environmental planning of the region. For the water climate balance, it was used data of the historical series of the region (1971 - 1995). The data of evapotranspiration were estimated by the method Thornthwaite. The water climate balance showed low water supply total annual of 10.1 mm, and exceeding of 319.7 mm, wherein in month January an exceeding of 92.6 to the average monthly precipitation; given the effective monthly precipitation with probability of 75% low water supply in the soil it is 238.8 mm and the exceeding 56.8 mm. When these data are added to the ones of the crop, as a crop coefficient and availability factor of water in the soil, it is observed that all crops which are inserted in the watershed present low water supply in all the months they are in the field. As the water balance is an important assessment of a specific region, further studies are recommended, with data collected in the region, so that the update in the results is obtained. Thus, it is also recommended the establishment of a system for agrometerological collecting data to help the irrigation management and other agricultural activities. Keyword: Water agricultural planning, water capability available in the soil, evapotranspiration.

  13. Water quality assessment using SVD-based principal component ...

    African Journals Online (AJOL)

    Water quality assessment using SVD-based principal component analysis of hydrological data. ... value decomposition (SVD) of hydrological data was tested for water quality assessment. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  14. Components and Treatments of Oilfield Produced Water

    Directory of Open Access Journals (Sweden)

    Essam Abdul-Jalil Saeed

    2010-01-01

    Full Text Available In this study, a review of variety of processes that are used in the treatment produced water prior to reuse or to responsible disposal are presented with their environmental issues and economical benefits. Samples of produced water from five locations in Rumaila oilfield/in south of Iraq were taken and analyzed for their contents of brine, some heavy metals, total suspended solids and oil and grease. Moreover, two samples of water were treated using reverse osmosis technique which showed its ability to treat such contaminated water. The results showed that the environmental impact of produced water arises from its chemical composition; i.e., its salt content, its heavy metals, and hydrocarbon contents.

  15. A worldwide analysis of trends in water-balance evapotranspiration

    Directory of Open Access Journals (Sweden)

    A. M. Ukkola

    2013-10-01

    Full Text Available Climate change is expected to alter the global hydrological cycle, with inevitable consequences for freshwater availability to people and ecosystems. But the attribution of recent trends in the terrestrial water balance remains disputed. This study attempts to account statistically for both trends and interannual variability in water-balance evapotranspiration (ET, estimated from the annual observed streamflow in 109 river basins during "water years" 1961–1999 and two gridded precipitation data sets. The basins were chosen based on the availability of streamflow time-series data in the Dai et al. (2009 synthesis. They were divided into water-limited "dry" and energy-limited "wet" basins following the Budyko framework. We investigated the potential roles of precipitation, aerosol-corrected solar radiation, land use change, wind speed, air temperature, and atmospheric CO2. Both trends and variability in ET show strong control by precipitation. There is some additional control of ET trends by vegetation processes, but little evidence for control by other factors. Interannual variability in ET was overwhelmingly dominated by precipitation, which accounted on average for 54–55% of the variation in wet basins (ranging from 0 to 100% and 94–95% in dry basins (ranging from 69 to 100%. Precipitation accounted for 45–46% of ET trends in wet basins and 80–84% in dry basins. Net atmospheric CO2 effects on transpiration, estimated using the Land-surface Processes and eXchanges (LPX model, did not contribute to observed trends in ET because declining stomatal conductance was counteracted by slightly but significantly increasing foliage cover.

  16. Simulation of the water balance of boreal watersheds of northeastern British Columbia, Canada using MIKE SHE, an integrated hydrological model

    Science.gov (United States)

    Abadzadesahraei, S.; Déry, S.; Rex, J. F.

    2016-12-01

    Northeastern British Columbia (BC) is undergoing rapid development for oil and gas extraction, largely depending on subsurface hydraulic fracturing (fracking), which relies on available freshwater. Even though this industrial activity has made substantial contributions to regional and provincial economies, it is important to ensure that sufficient and sustainable water supplies are available for all those dependent on the resource, including ecological systems. Further, BC statistics predict that the northeastern region's population will increase by 30% over the next 25 years, thereby amplifying the demands of domestic and industrial water usage. Hence, given the increasing demands for surface water in the complex wetlands of northeastern BC, obtaining accurate long-term water balance information is of vital importance. Thus, this study aims to simulate the 1979-2014 water balance at two boreal watersheds using the MIKE SHE model. More specifically, this research intends to quantify the historical, and regional, water budgets and their associated hydrological processes at two boreal watersheds—the Coles Lake and Tsea Lake watersheds—in northeastern BC. The development of coupled groundwater and surface water model of these watersheds are discussed. The model setup, calibration process, and results are presented, focusing on the water balance of boreal watersheds. Hydrological components within these watersheds are quantified through a combination of intensive fieldwork, observational data, analysis and numerical modeling. The output from the model provides important information for decision makers to manage water resources in northeastern BC. Keywords: Northeastern BC; boreal watershed; water balance; MIKE SHE hydrological model.

  17. Impact of Water Recovery from Wastes on the Lunar Surface Mission Water Balance

    Science.gov (United States)

    Fisher, John W.; Hogan, John Andrew; Wignarajah, Kanapathipi; Pace, Gregory S.

    2010-01-01

    Future extended lunar surface missions will require extensive recovery of resources to reduce mission costs and enable self-sufficiency. Water is of particular importance due to its potential use for human consumption and hygiene, general cleaning, clothes washing, radiation shielding, cooling for extravehicular activity suits, and oxygen and hydrogen production. Various water sources are inherently present or are generated in lunar surface missions, and subject to recovery. They include: initial water stores, water contained in food, human and other solid wastes, wastewaters and associated brines, ISRU water, and scavenging from residual propellant in landers. This paper presents the results of an analysis of the contribution of water recovery from life support wastes on the overall water balance for lunar surface missions. Water in human wastes, metabolic activity and survival needs are well characterized and dependable figures are available. A detailed life support waste model was developed that summarizes the composition of life support wastes and their water content. Waste processing technologies were reviewed for their potential to recover that water. The recoverable water in waste is a significant contribution to the overall water balance. The value of this contribution is discussed in the context of the other major sources and loses of water. Combined with other analyses these results provide guidance for research and technology development and down-selection.

  18. Fresh water balance of the Gulf Stream system in a regional model study

    Energy Technology Data Exchange (ETDEWEB)

    Gerdes, R. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Biastoch, A. [California Univ., San Diego, La Jolla, CA (United States). Scripps Inst. of Oceanography; Redler, R. [SCAI Inst. for Algorithms and Scientific Computing, German National Research Center for Information Technology, Sankt Augustin (Germany)

    2001-11-01

    We investigate the dependence of surface fresh water fluxes in the Gulf Stream and North Atlantic Current (NAC) area on the position of the stream axis which is not well represented in most ocean models. To correct this shortcoming, strong unrealistic surface fresh water fluxes have to be applied that lead to an incorrect salt balance of the current system. The unrealistic surface fluxes required by the oceanic component may force flux adjustments and may cause fictitious long-term variability in coupled climate models. To identify the important points in the correct representation of the salt balance of the Gulf Stream a regional model of the northwestern part of the subtropical gyre has been set up. Sensitivity studies are made where the westward flow north of the Gulf Stream and its properties are varied. Increasing westward volume transport leads to a southward migration of the Gulf Stream separation point along the American coast. The salinity of the inflow is essential for realistic surface fresh water fluxes and the water mass distribution. The subpolar-subtropical connection is important in two ways: The deep dense flow from the deep water mass formation areas sets up the cyclonic circulation cell north of the Gulf Stream. The surface and mid depth flow of fresh water collected at high northern latitudes is mixed into the Gulf Stream and compensates for the net evaporation at the surface. (orig.)

  19. Energy balance components in persons with paraplegia: daily variation and appropriate measurement duration.

    Science.gov (United States)

    Nightingale, Tom E; Williams, Sean; Thompson, Dylan; Bilzon, James L J

    2017-09-26

    Despite obesity being highly prevalent in persons with spinal cord injury (SCI), our current understanding of the interactions between energy balance components, which may contribute to this, is limited. The primary aim of this study is to identify the intra-individual variability of physical activity dimensions across days and suggest an appropriate monitoring time frame for these constructs in adults with SCI. The secondary aim is to examine these parameters with regard to energy intake and dietary macronutrient composition. Participants [33 men and women with chronic (> 1 year post injury) paraplegia; age = 44 ± 9 years (mean ± S.D.] wore an Actiheart™ PA monitor and completed a weighed food diary for 7 consecutive days. Spearman-Brown Prophecy Formulae, based on Intraclass Correlations of .80 (acceptable reliability), were used to predict the number of days required to measure energy balance components. Linear mixed-effects analyses and magnitude-based inferences were performed for all energy intake, expenditure and physical activity dimensions. Adjustments were made for age, injury level, wear time, sex, day of the week and measurement order as fixed effects. To reliably measure energy expenditure components; 1 day [total energy expenditure (TEE)], 2 days [physical activity energy expenditure (PAEE), light-intensity activity, moderate-to-vigorous PA (MVPA)], 3 days [physical activity level (PAL)] and 4 days (sedentary behaviour) are necessary. Device wear time (P energy expenditure components. Four and ≤24 days are required to reliably measure total energy intake (kcal) and diet macronutrient composition (%), respectively. Measurement order (from day 1-7) was a covariate for total energy intake (P = 0.01). This is the first study to demonstrate the variability of energy intake and expenditure components in free-living persons with chronic (> 1 year) paraplegia and propose suitable measurement durations to achieve acceptable reliability

  20. A conceptual model of daily water balance following partial clearing from forest to pasture

    Directory of Open Access Journals (Sweden)

    M. A. Bari

    2006-01-01

    Full Text Available A simple conceptual water balance model representing the streamflow generation processes on a daily time step following land use change is presented. The model consists of five stores: (i Dry, Wet and Subsurface Stores for vertical and lateral water flow, (ii a transient Stream zone Store (iii a saturated Goundwater Store. The soil moisture balance in the top soil Dry and Wet Stores are the most important components of the model and characterize the dynamically varying saturated areas responsible for surface runoff, interflow and deep percolation. The Subsurface Store describes the unsaturated soil moisture balance, extraction of percolated water by vegetation and groundwater recharge. The Groundwater Store controls the baseflow to stream (if any and the groundwater contribution to the stream zone saturated areas. The daily model was developed following a downward approach by analysing data from Ernies (control and Lemon (53% cleared catchments in Western Australia and elaborating a monthly model. The daily model performed very well in simulating daily flow generation processes for both catchments. Most of the model parameters were incorporated a priori from catchment attributes such as surface slope, soil depth, porosity, stream length and initial groundwater depth, and some were calibrated by matching the observed and predicted hydrographs. The predicted groundwater depth, and streamflow volumes across all time steps from daily to monthly to annual were in close agreement with observations for both catchments.

  1. Global Energy and Water Balances in the Latest Reanalyses

    Science.gov (United States)

    Ahn, Joong-Bae; Kang, Suchul; Park, Hye-Jin

    2016-04-01

    The recently released Japanese 55-year Reanalysis (JRA-55) data are evaluated and compared with three other global reanalyses, namely Interim version of the next European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERRA-Interim), Modern Era Retrospective-Analysis for Research and Applications (MERRA) and Climate Forecast System Reanalysis (CFSR), in terms of global energy and water balances. All four reanalyses show an energy imbalance at TOA and surface. Especially, clouds in JRA-55 are optically weaker than those in the three other reanalyses, leading to excessive outgoing longwave radiation, which in turn causes negative net energy flux at TOA. Moreover, JRA-55 has a negative imbalance at surface and at TOA, which is attributed to systematic positive biases in latent heat flux over the ocean. As for the global water balance, all reanalyses present a similar spatial pattern of the difference between evaporation and precipitation (E-P). However, JRA-55 has a relatively strong negative (positive) E-P in the Intertropical Convergence Zone and South Pacific Convergence Zone (extratropical regions) due to overestimated precipitation (evaporation), in spite of the global net being close to zero. In time series analysis, especially in E-P, significant stepwise changes occur in MERRA, CFSR and ERA-Interim due to the changes occur in MERRA, CFRS and ERA-Interim due to the changes in the satellite observing system used in the data assimilation. Both MERRA and CFSR show a strong downward E-P shift in 1998, simultaneously with the start of the assimilation of AMSU-A sounding radiances. ERA-Interim exhibits an upward E-P shift in 1992 due to changes in observations from the SSM/I of new DMSP satellites. On the contrary, JRA-55 exhibits less trends and remains stable over time, which may be caused by newly available, homogenized observations and advances in data assimilation technique. Acknowledgements This work was funded by the Korea Meteorological

  2. Design and development of major balance of plant components in solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

    2013-07-01

    The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

  3. Surface water management: a user's guide to calculate a water balance using the CREAMS model

    Energy Technology Data Exchange (ETDEWEB)

    Lane, L.J.

    1984-11-01

    The hydrologic component of the CREAMS model is described and discussed in terms of calculating a surface water balance for shallow land burial systems used for waste disposal. Parameter estimates and estimation procedures are presented in detail in the form of a user's guide. Use of the model is illustrated with three examples based on analysis of data from Los Alamos, New Mexico and Rock Valley, Nevada. Use of the model in design of trench caps for shallow land burial systems is illustrated with the example applications at Los Alamos.

  4. Infiltration and water balance modeling along a toposequence in a rubber tree plantation of NE Thailand

    Science.gov (United States)

    Hammecker, Claude; Seltacho, Siwaporn; Suvanang, Nopmanee; Do, Frederic; Angulo-Jaramillo, Rafael

    2015-04-01

    Northeast of Thailand, is a plateau at 200 m AMSL with a typical undulating landscape. Traditionally the lowlands were dedicated to paddy fields and the uplands covered by Dipterocarpus forest. However development of cash crops during the last decades has led to intensive land clearing in the uplands and to modifications at a regional scale of the water balance in the critical zone with increasing runoff and soil erosion. Recent international demand increase for natural rubber motivated many local farmers to shift from these cash crops towards rubber-tree (Heva Brasiliensis) plantations. However these land use changes have been undertaken without considering the climatic and edaphic specificity of the region, which are not well adapted to the growth of rubber tree (rainfall lower than recommended and sandy soils with low fertility). Therefore, in order to assess and try to predict the environmental consequences (water resources, water-table, ..) of the development of rubber tree plantations in this area, a small watershed in the region ok Khon Kaen has been selected to follow the infiltration and to monitor the different components of the water balance along a toposequence. A six years monitoring of the main components of water balance along a toposequence associated to numerical simulation were used to quantify and try to forecast the evolution of the water use and water resources. Unsaturated soil properties were determined at different depths, in various positions along the toposequence. Experimental results supported by modeling of 2D water flow with HYDRUS3D show clearly that infiltration is blocked by a clayey layer on top of the bedrock and conditioned the occurrence of a perched watertable during the rainy seasons. Most of the soil water flow was found to be directed laterally during the rainy season. The deep groundwater was found to be fed from the lower part of toposequence in the thalweg. The transpiration rate measured on the trees at this stage of

  5. Comparison of Characteristic of Water Balance between Evergreen Coniferous and Deciduous Broad-leaved Forests

    Science.gov (United States)

    Hisada, Shigeta; Senge, Masateru; Ito, Kengo; Maruyama, Toshisuke

    Hydrological observation was carried out at two basins occupied mainly by evergreen coniferous forest of Chamaecyparis obtusa and deciduous broad-leaved forest of Quercus crispula in order to clarify the influences of different forest type on water balance. The analysis of short-time period water-budget method showed that the evapotranspiration of coniferous forest was more than broad-leaved one. By calculating transpiration from Priestley-Taylor equation, intercepted evaporation was separated from evapotranspiration. The result of comparison of intercepted evaporation between two basin was that intercepted evaporation of coniferous basin was more than that of broad-leaved basin. From separating total runoff into direct and base flow components; it was shown that there was no difference in direct runoff of two basins, so the differences of total runoff of two basins were caused due to the difference of base flow. From the above analysis of water balance components, it is clarified that the different forest type influences the amount of intercepted evaporation and base flow.

  6. Water Balance in a Mid-Latitude, Mixed Grass Prairie

    Science.gov (United States)

    Billesbach, D.; Arkebauer, T.

    2003-12-01

    Covering more than 50,000 square kilometers, the Nebraska Sand Hills are the largest stabilized dune field in the world. A unique feature of this region is the close proximity of the land surface to the vast High Plains Aquifier. The land-surface is classified as a mixed grass prairie, and except for a few very small instances, has never been put under the plow. The region is currently home to most of the rangeland cattle industry in Nebraska, and prior to European settlement, was the primary home-range for large herds of North American bison. The co-location of an extensive sub-surface water resource and an inherently semi-arid climate produces an interesting ecosystem, which affords many unique opportunities to study plant-water relationships. We are currently operating a pair of Energy Balance/Bowen Ratio (EBBR) systems to measure evapotranspiration and other ecosystem parameters within key land surface types. We now have 2 growing seasons or more than 20 months of data. We will discuss this data and compare the two seasons in terms of water inputs and outputs.

  7. A catchment scale water balance model for FIFE

    Science.gov (United States)

    Famiglietti, J. S.; Wood, E. F.; Sivapalan, M.; Thongs, D. J.

    1992-01-01

    A catchment scale water balance model is presented and used to predict evaporation from the King's Creek catchment at the First ISLSCP Field Experiment site on the Konza Prairie, Kansas. The model incorporates spatial variability in topography, soils, and precipitation to compute the land surface hydrologic fluxes. A network of 20 rain gages was employed to measure rainfall across the catchment in the summer of 1987. These data were spatially interpolated and used to drive the model during storm periods. During interstorm periods the model was driven by the estimated potential evaporation, which was calculated using net radiation data collected at site 2. Model-computed evaporation is compared to that observed, both at site 2 (grid location 1916-BRS) and the catchment scale, for the simulation period from June 1 to October 9, 1987.

  8. A catchment scale water balance model for FIFE

    Science.gov (United States)

    Famiglietti, J. S.; Wood, E. F.; Sivapalan, M.; Thongs, D. J.

    1992-01-01

    A catchment scale water balance model is presented and used to predict evaporation from the King's Creek catchment at the First ISLSCP Field Experiment site on the Konza Prairie, Kansas. The model incorporates spatial variability in topography, soils, and precipitation to compute the land surface hydrologic fluxes. A network of 20 rain gages was employed to measure rainfall across the catchment in the summer of 1987. These data were spatially interpolated and used to drive the model during storm periods. During interstorm periods the model was driven by the estimated potential evaporation, which was calculated using net radiation data collected at site 2. Model-computed evaporation is compared to that observed, both at site 2 (grid location 1916-BRS) and the catchment scale, for the simulation period from June 1 to October 9, 1987.

  9. Operational Experience of Cooling Water Systems for Accelerator Components at PLS

    CERN Document Server

    Kim, Kyungryul; Kim, Young-Chan; Lee, Bongho; Sik Han, Hong; Soo Ko In; Wha Chung, Chin

    2005-01-01

    The cooling water system has been utilized for absorbing heat generated by a multitude of electromagnetic power delivering networks at PLS. The separate cooling water distribution systems for the storage ring, beam transport line and linear accelerator have been operated with a different operating temperature of supplying water. All water used for heat removal from the accelerator components are deionised and filtered to provide with over 2 MO-cm specific resistance. The operating pressures and flows of input water are also controlled with flow balancing scheme at a specified range. The operating temperature of components in the accelerator is sustained as tight as below ±0.1 deg C to minimize the influence of temperature fluctuation on the beam energy and stability. Although the PLS cooling systems were initially installed with a high degree of flexibility to allow for easy maintenance, a number of system improvements have been employed to enhance operational reliability and to incorporate the newly...

  10. What balance do countries exhibit between the central human resources: water, energy and food

    Science.gov (United States)

    Kossak, Julian; Reusser, Dominik E.; Kropp, Jürgen P.

    2013-04-01

    Sufficient water, food and energy is a precondition for human activities. The water, energy and food nexus states that to some extend, these resources can replace each another: land can be used to produce food or energy crops; water can be used as direct water supply, to produce energy or for irrigation; and energy supports water treatment and agricultural yield. We present an overview of the major components of the trade-off together with a set of indicators and data sources to assess these components. The different indicators of the trade-off are summarized and plotted in a novel way on a triangle, which we discuss in view of the resource availability of different countries. Comparing different countries in view of their balance between water, food and energy will inform the discussion about the transition towards more sustainable societies and highlighting alternative strategies for development. This is important in view of possible synergies between the different sectors and as a tool for better coordinated governance approaches.

  11. Componentes do balanço de água no solo com cana-de-açúcar, com e sem adubação nitrogenada Water balance components in soils cropped to sugarcane, with and without nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Alexsandro dos Santos Brito

    2009-04-01

    drenagem interna e a ascensão capilar foram de -110,9 e 0,67 mm, respectivamente, e a eficiência de uso da água 13 kg m-3. Portanto, pode-se concluir que (a nos períodos de alta pluviosidade, a drenagem interna foi significativa, alertando para possíveis problemas no manejo em relação a uma potencial de contaminação do lençol freático, e (b tanto a evapotranspiração real quanto à eficiência do uso da água foram da mesma ordem de grandeza, independentemente da adubação nitrogenada, e a armazenagem de água no solo foi praticamente a mesma no início e no fim do ciclo estudado.The water balance study in soils with sugarcane, cropped in large areas in Brazil, is essential for the agricultural management to increase the crop productivity and to reduce pollution risks. The objective of this research was to evaluate soil water balance equation components of two Oxisols under sugar-cane (first crop, in the counties of Jaboticabal and Pirassununga, State of São Paulo, Brazil. The study was carried out in an experimental area in Pirassununga (21 º 55 ' 54 '' S, 47 º 10 ' 54 '' W, 650 m, for only one level (120 kg ha-1 of nitrogen, in four replications. In Jaboticabal (21 º 19 ' 98 '' S, 48 º 19 ' 03 '' W, 600 m, two nitrogen levels were used: 0 kg ha-1 (treatment 1-T1 and 120 kg ha-1 (treatment 2-T2. In Pirassununga, the experiments were evaluated between September 28, 2005 and June 08, 2006 and, in Jaboticabal, between September 30, 2005 and July 12, 2006. The upper limit of the control volume used for the water balance was the soil surface and the lower limit a surface at a soil depth of 0.90 m, parallel to the soil surface. Soil water storage variations, soil water inputs (rain and capillary rise and soil water outputs (internal drainage and actual evapotranspiration were determined in 13 and 10 monitoring periods, in Jaboticabal and Pirassununga, respectively. Both studied areas were plane and non irrigated. In the area in Jaboticabal, both internal

  12. BALANCE OF WATER AND ENERGY FOR EUCALYPTUS PLANTATIONS WITH PARTIAL SOIL COVER

    Directory of Open Access Journals (Sweden)

    Mariana Gonçalves dos Reis

    2014-03-01

    Full Text Available http://dx.doi.org/10.5902/1980509813329Eucalyptus plots with initial development ages presented discontinuity in soil cover, resulting in greaterexposure of the leaves to wind and solar radiation, which alters soil-plant-atmosphere interactions. Theobjective of this study was to study the components of the water and energy balances along the first yearof eucalyptus development in the Brazilian coastal plain region. The experimental site is located in anarea belonging to the company Fibria in the municipality of Aracruz, Espírito Santo state, Brazil. Thespace between the planted eucalyptus trees in the area studied was 3 x 3 m and the data of planting wason August 15th , 2004. The period of study lasted from the planting date until the plot reached an ageof 19 months. It was verified that there was a greater availability of energy during the summer and theprecipitation directly influenced the energy balance where during the period of study the energy available necessary for evapotranspiration was always greater than the fraction necessary for heating the soil-plantatmospheresystem, presenting a λE/Rn ratio of 59.57%. It was also observed that the water balance with themodeled evapotranspiration showed a good correspondence with the observed moisture content, presentinga determination coefficient of 0,94. In the majority of trees, greater indices of leaf and root system areasfavored evapotranspiration, indicating that most energy available was utilized for changing the phase ofwater

  13. Water shortage affects the water and nitrogen balance in Central European beech forests.

    Science.gov (United States)

    Gessler, A; Keitel, C; Nahm, M; Rennenberg, H

    2004-05-01

    Whilst forest policy promotes cultivation and regeneration of beech dominated forest ecosystems, beech itself is a highly drought sensitive tree species likely to suffer from the climatic conditions prognosticated for the current century. Taking advantage of model ecosystems with cool-moist and warm-dry local climate, the latter assumed to be representative for future climatic conditions, the effects of climate and silvicultural treatment (different thinning regimes) on water status, nitrogen balance and growth parameters of adult beech trees and beech regeneration in the understorey were assessed. In addition, validation experiments with beech seedlings were carried out under controlled conditions, mainly in order to assess the effect of drought on the competitive abilities of beech. As measures of water availability xylem flow, shoot water potential, stomatal conductance as well as delta (13)C and delta (18)O in different tissues (leaves, phloem, wood) were analysed. For the assessment of nitrogen balance we determined the uptake of inorganic nitrogen by the roots as well as total N content and soluble N compounds in different tissues of adult and young trees. Retrospective and current analysis of delta (13)C, growth and meteorological parameters revealed that beech growing under warm-dry climatic conditions were impaired in growth and water balance during periods with low rain-fall. Thinning affected water, N balance and growth mostly of young beech, but in a different way under different local climatic conditions. Under cool, moist conditions, representative for the current climatic and edaphic conditions in beech forests of Central Europe, thinning improves nutrient and water status consistent to published literature and long-term experience of forest practitioners. However, beech regeneration was impaired as a result of thinning at higher temperatures and under reduced water availability, as expected in future climate.

  14. Mechanism for negative water balance during weightlessness An hypothesis

    Science.gov (United States)

    Greenleaf, J. E.

    1986-01-01

    The mechanism for the apparent decrease in body fluid volume in astronauts during spaceflight remains obscure. The widespread postulate that the hypohydration is the result of the Henry-Gauer reflex, a diuresis caused by inhibition of vasopressin secretion resulting from increased left and perhaps right atrial (central) venous pressure, has not been established with direct measurements on astronauts. An hypothesis is proposed to account for fluid-electrolyte shifts during weightlessness. A moderate but transient increase in central venous pressure occurs when orbit is entered that is insufficient to activate the Henry-Gauer reflex but sufficient to stimulate the release of atrial natriuretic peptides. Increased sodium excretion would facilitate some increased urinary water loss. The resulting relatively dilute plasma and interstitial fluids would cause fluid to shift into the cellular space, resulting in edema in the head and trunk and inhibition of thirst and drinking. Thus, the negative water balance in astronauts would be caused by a gradual natriuresis and diuresis coupled with reduced fluid intake.

  15. A continuous high resolution water isotope dataset to constrain Alpine water balance estimates

    Science.gov (United States)

    Michelon, Anthony; Ceperley, Natalie; Beria, Harsh; Larsen, Josh; Schaefli, Bettina

    2017-04-01

    Water delivered from Alpine environments is a crucial resource for many countries around the world. Precipitation accumulated during cold seasons as snowpack or glaciers is often an important source of water during warm (dry) season but also a dominant contributor to the annual water balance. In Switzerland, water from high Alpine, glacier-fed catchments provides a large portion of both the hydroelectric power and water supply. However, large uncertainties regarding changes in glacier volume and snow accumulation can have significant impacts on hydrologic, biologic, physical and economic understanding, modeling, and predictions. Accurately quantifying these water resources is therefore an on-going challenge. Given the well-known difficulty observing solid precipitation (snowfall), it can be assumed that most of the uncertainty in water balance estimates for snow-dominated environments is due to: 1) Poor measurement of winter precipitation and 2) A poor estimation of timing and amount of snow melt. It is noteworthy that the timing of melt plays a crucial role even for annual water balance estimates since it might significantly influence melt runoff flow paths and thereby groundwater recharge. We use continuous monitoring of water stable isotopes over the entire annual cycle in an Alpine catchment to shed light on how such observations can constrain water balance estimates. The selected catchment is the experimental Vallon de Nant catchment in the Vaud Alps of Switzerland, where detailed hydrologic observations have recently started in addition to the existing vegetation and soil investigations. The Vallon de Nant (14 km2, and an altitude ranging from 1200 to 3051 m) is a narrow valley that accumulates large amounts of snow during winter. In spring and summer, the river discharge is mainly supplied by snowmelt, with additional inputs from a small glacier and rainfall. Continuous monitoring of water stable isotopes (δO18 and δD) is combined with measurements of

  16. Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

    Science.gov (United States)

    Cuthbert, M.O.; Mackay, R.; Nimmo, J.R.

    2012-01-01

    Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is developed and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via macropore flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in the macropore system due to seasonal ploughing of the topsoil, and a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

  17. Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

    Directory of Open Access Journals (Sweden)

    M. O. Cuthbert

    2013-03-01

    Full Text Available Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is presented and tested using a range of numerical models, including a modified soil moisture balance model (SMBM for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via preferential flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in preferential flow pathways due to seasonal ploughing of the topsoil and to a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010 is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

  18. Water balance of the Lepenci river basin, Kosova

    Science.gov (United States)

    Osmanaj, L.; Avdullahi, S.

    2009-04-01

    Republic of Kosova lines on the highlands (500-600 m above sea level) surrounded by the mountains reaching the altitude of more than 2000m. Lower mountains divide the highland plain into four watershed areas, from where waters flow to there different seas, namely to the Adriatic Sea, the Aegean Sea and the Black Sea. Kosova has four water basins, such as the Basin of river Drini i Bardhe, Ibri, Morava e Binqes and Lepenci. The Basin of river Lepenci is located in South-eastern part of Kosova with surface of 650 km2, belongs to Axios river basin discharging into Aegean Sea. The annual rainfall is 670-1.000 mm and specific runoff 8 - 20 l/s/km2. There are also steep mountains in this area. In this case study we have calculate the water balance of the river Lepenc Basin. The Basin of river Lepenc we have divided in to 3 catchments: of Nerodima river, and upper and lower part of river Lepenci. This basin is covered by three municipalities such as municipality of Ferizaj, Kaçanik and Shterpc. The data on precipitation are obtained from three metering stations, such as the metering station of Ferizaj, Kaçanik and Jazhnice. The obtained records are elaborated. For evapotranspiration measurement we have applied four methods: the method of BLANEY - CRIDDLE, radiation, SCHENDELE and Turk. In a basin of river Lepenci we have four stations for measuring the discharges and levels: in Ferizaj, and Kaçanik - Nerodime river and in Hani i Elezit - Lepenc river. The river basin Lepenc has two inflowing points, where are Lepenci river in the border with the FYR of Macedonia and Sazli village near Ferizaj. Key works: precipitation, evaporation, flow, river, discharges,

  19. Modelling the water balance of a mesoscale catchment basin using remotely sensed land cover data

    Science.gov (United States)

    Montzka, Carsten; Canty, Morton; Kunkel, Ralf; Menz, Gunter; Vereecken, Harry; Wendland, Frank

    2008-05-01

    SummaryHydrological modelling of mesoscale catchments is often adversely affected by a lack of adequate information about specific site conditions. In particular, digital land cover data are available from data sets which were acquired on a European or a national scale. These data sets do not only exhibit a restricted spatial resolution but also a differentiation of crops and impervious areas which is not appropriate to the needs of mesoscale hydrological models. In this paper, the impact of remote sensing data on the reliability of a water balance model is investigated and compared to model results determined on the basis of CORINE (Coordination of Information on the Environment) Land Cover as a reference. The aim is to quantify the improved model performance achieved by an enhanced land cover representation and corresponding model modifications. Making use of medium resolution satellite imagery from SPOT, LANDSAT ETM+ and ASTER, detailed information on land cover, especially agricultural crops and impervious surfaces, was extracted over a 5-year period (2000-2004). Crop-specific evapotranspiration coefficients were derived by using remote sensing data to replace grass reference evapotranspiration necessitated by the use of CORINE land cover for rural areas. For regions classified as settlement or industrial areas, degrees of imperviousness were derived. The data were incorporated into the hydrological model GROWA (large-scale water balance model), which uses an empirical approach combining distributed meteorological data with distributed site parameters to calculate the annual runoff components. Using satellite imagery in combination with runoff data from gauging stations for the years 2000-2004, the actual evapotranspiration calculation in GROWA was methodologically extended by including empirical crop coefficients for actual evapotranspiration calculations. While GROWA originally treated agricultural areas as homogeneous, now a consideration and differentiation

  20. Combined approach of isotope mass balance and hydrological water balance methods to constrain the sources of lake water as exemplified on the small dimictic lake Silbersee, northern Germany.

    Science.gov (United States)

    Elmarami, Hatem; Meyer, Hanno; Massmann, Gudrun

    2017-05-01

    Stable isotopes of hydrogen and oxygen are often used for water balance calculations of lakes. We present an approach combining the lake water balance with an isotope mass balance to constrain the sources and sinks of the water of a small dimictic lake subjected to eutrophication. Meteorological and hydraulic data in combination with measured isotope signatures of the different water compartments enabled to assess the degree of surface water/groundwater interaction and the amount of overland flow into the lake. Groundwater could be excluded as a lake water source, as its water level was always below the lake water level. In the absence of a channelled inflow, precipitation and overland flow were the remaining options, whereby the latter was only active during periods of exceptionally high rainfall. While the groundwater signatures adjacent to the lake showed an influence of lake water, the lake water balance itself indicated that the associated volumetric water loss to groundwater is rather negligible. In the present case, only a combined assessment of hydrological and isotopic data allowed for an accurate characterization of the studied lake and a quantification of its water sources and sinks, highlighting the importance of using more than one methodological approach for such a purpose.

  1. The U.S. Geological Survey Monthly Water Balance Model Futures Portal

    Science.gov (United States)

    Bock, Andy

    2017-03-16

    Simulations of future climate suggest profiles of temperature and precipitation may differ significantly from those in the past. These changes in climate will likely lead to changes in the hydrologic cycle. As such, natural resource managers are in need of tools that can provide estimates of key components of the hydrologic cycle, uncertainty associated with the estimates, and limitations associated with the climate forcing data used to estimate these components. To help address this need, the U.S. Geological Survey Monthly Water Balance Model Futures Portal (https://my.usgs.gov/mows/) provides a user friendly interface to deliver hydrologic and meteorological variables for monthly historic and potential future climatic conditions across the continental United States.

  2. Water flow pathways and the water balance within a head-water catchment containing a dambo: inferences drawn from hydrochemical investigations

    Directory of Open Access Journals (Sweden)

    M. P. McCartney

    1999-01-01

    Full Text Available Dambos, seasonally saturated wetlands, are widespread in headwater catchments in sub-Saharan Africa. It is widely believed that they play an important role in regional hydrology but, despite research conducted over the last 25 years, their hydrological functions remain poorly understood. To improve conceptualisation of hydrological flow paths and investigate the water balance of a small Zimbabwean catchment containing a single dambo, measurements of alkalinity and chloride in different water types within the catchment have been used as chemical markers. The temporal variation in alkalinity is consistent with the premise that all stream water, including the prolonged dry season recession, is derived predominantly from shallow sources. The proposition that dry season recession flows are maintained by water travelling at depth within the underlying saprolite is not substantiated. There is evidence that a low permeability clay lens, commonly present in many dambos, acts as a barrier for vertical water exchange. However, the highly heterogeneous chemical composition of different waters precludes quantitative hydrograph split-ting using end member mixing analysis. Calculation of the chloride mass-balance confirms that, after rainfall, evaporation is the largest component of the catchment water budget. The study provides improved understanding of the hydrological functioning of dambos. Such understanding is essential for the development and implementation of sustainable management strategies for this landform.

  3. Meteorological estimates for the water balance of a sparse vine crop growing in semiarid conditions

    Science.gov (United States)

    Sene, K. J.

    1996-05-01

    Estimates are presented for the long-term water balance of a sparse vine crop growing under semiarid conditions. The annual water losses are estimated using a simple soil moisture accounting model combined with a two-component energy combination model representing the separate but coupled evaporation fluxes from plants and bare soil. The models we calibrated using data collected during the European Field Experiment in a Desertification-threatened Area (EFEDA) field experiment in the summer of 1991 in southern Spain. The hourly averaged meteorological conditions required as input to the model were derived both from field observations and using a stochastic model. For the year of the field experiment, the simulations suggested that the plant water consumption was close to the long-term average but that the groundwater recharge was substantially below normal. The sensitivity of this balance was examined using the stochastic model both for current conditions and for various hypothetical changes in the average rainfall, plant spacing and plant species.

  4. Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

    Directory of Open Access Journals (Sweden)

    M. J. Savage

    2010-01-01

    Full Text Available The relatively recently developed scintillometry method, with a focus on the dual-beam surface layer scintillometer (SLS, allows boundary layer atmospheric turbulence, surface sensible heat and momentum flux to be estimated in real-time. Much of the previous research using the scintillometer method has involved the large aperture scintillometer method, with only a few studies using the SLS method. The SLS method has been mainly used by agrometeorologists, hydrologists and micrometeorologists for atmospheric stability and surface energy balance studies to obtain estimates of sensible heat from which evaporation estimates representing areas of one hectare or larger are possible. Other applications include the use of the SLS method in obtaining crucial input parameters for atmospheric dispersion and turbulence models. The SLS method relies upon optical scintillation of a horizontal laser beam between transmitter and receiver for a separation distance typically between 50 and 250 m caused by refractive index inhomogeneities in the atmosphere that arise from turbulence fluctuations in air temperature and to a much lesser extent the fluctuations in water vapour pressure. Measurements of SLS beam transmission allow turbulence of the atmosphere to be determined, from which sub-hourly, real-time and in situ path-weighted fluxes of sensible heat and momentum may be calculated by application of the Monin-Obukhov similarity theory. Unlike the eddy covariance (EC method for which corrections for flow distortion and coordinate rotation are applied, no corrections to the SLS measurements, apart from a correction for water vapour pressure, are applied. Also, path-weighted SLS estimates over the propagation path are obtained. The SLS method also offers high temporal measurement resolution and usually greater spatial coverage compared to EC, Bowen ratio energy balance, surface renewal and other sensible heat measurement methods. Applying the shortened surface

  5. Water balance analysis for efficient water allocation in agriculture. A case study: Balta Brailei, Romania

    Science.gov (United States)

    Chitu, Zenaida; Villani, Giulia; Tomei, Fausto; Minciuna, Marian; Aldea, Adrian; Dumitrescu, Alexandru; Trifu, Cristina; Neagu, Dumitru

    2017-04-01

    Balta Brailei is one of the largest agriculture area in the Danube floodplain, located in SE of Romania. An impressive irrigation system, that covered about 53.500 ha and transferred water from the Danube River, was carried out in the period 1960-1980. Even if the water resources for agriculture in this area cover in most of the cases the volumes required by irrigation water users, the irrigation infrastructure issues as the position of the pumping stations against the river levels hinder the use of the water during low flows periods. An efficient optimization of water allocation in agriculture could avoid periods with water deficit in the irrigation systems. Hydrological processes are essentials in describing the mass and energy exchanges in the atmosphere-plant-soil system. Furthermore, the hydrological regime in this area is very dynamic with many feedback mechanisms between the various parts of the surface and subsurface water regimes. Agricultural crops depend on capillary rise from the shallow groundwater table and irrigation. For an effective optimization of irrigation water in Balta Brailei, we propose to analyse the water balance taking into consideration the water movement into the root zone and the influence of the Danube river, irrigation channel system and the shallow aquifer by combining the soil water balance model CRITERIA and GMS hydrogeological model. CRITERIA model is used for simulating water movement into the soil, while GMS model is used for simulating the shallow groundwater level variation. The understanding of the complex feedbacks between atmosphere, crops and the various parts of the surface and subsurface water regimes in the Balta Brailei will bring more insights for predicting crop water need and water resources for irrigation and it will represent the basis for implementing Moses Platform in this specific area. Moses Platform is a GIS based system devoted to water procurement and management agencies to facilitate planning of

  6. Evapotranspiration and water balance of an anthropogenic coastal desert wetland: responses to fire, inflows and salinities

    Science.gov (United States)

    Glenn, Edward P.; Mexicano, Lourdes; Garcia-Hernandez, Jaqueline; Nagler, Pamela L.; Gomez-Sapiens, Martha M.; Tang, Dawei; Lomeli, Marcelo A.; Ramírez-Hernández, Jorge; Zamora-Arroyo, Francisco

    2013-01-01

    Evapotranspiration (ET) and other water balance components were estimated for Cienega de Santa Clara, an anthropogenic brackish wetland in the delta of the Colorado River in Mexico. The marsh is in the Biosphere Reserve of the Upper Gulf of California and Delta of the Colorado River, and supports a high abundance and diversity of wildlife. Over 95% of its water supply originates as agricultural drain water from the USA, sent for disposal in Mexico. This study was conducted from 2009 to 2011, before, during and after a trial run of the Yuma Desalting Plant in the USA, which will divert water from the wetland and replace it with brine from the desalting operation. The goal was to estimate the main components in the water budget to be used in creating management scenarios for this marsh. We used a remote sensing algorithm to estimate ET from meteorological data and Enhanced Vegetation Index values from the Moderate Resolution Imaging Spectrometer (MODIS) sensors on the Terra satellite. ET estimates from the MODIS method were then compared to results from a mass balance of water and salt inflows and outflows over the study period. By both methods, mean annual ET estimates ranged from 2.6 to 3.0 mm d−1, or 50 to 60% of reference ET (ETo). Water entered at a mean salinity of 2.6 g L−1 TDS and mean salinity in the wetland was 3.73 g L−1 TDS over the 33 month study period. Over an annual cycle, 54% of inflows supported ET while the rest exited the marsh as outflows; however, in winter when ET was low, up to 90% of the inflows exited the marsh. An analysis of ET estimates over the years 2000–2011 showed that annual ET was proportional to the volume of inflows, but was also markedly stimulated by fires. Spring fires in 2006 and 2011 burned off accumulated thatch, resulting in vigorous growth of new leaves and a 30% increase in peak summer ET compared to non-fire years. Following fires, peak summer ET estimates were equal to ETo, while in non-fire years peak ET was

  7. Water balance modeling of Upper Blue Nile catchments using a top-down approach

    NARCIS (Netherlands)

    Tekleab, S.; Uhlenbrook, S.; Mohamed, Y.; Savenije, H.H.G.; Temesgen, M.; Wenninger, J.

    2011-01-01

    The water balances of twenty catchments in the Upper Blue Nile basin have been analyzed using a top-down modeling approach based on Budyko’s hypotheses. The objective of this study is to obtain better understanding of water balance dynamics of upper Blue Nile catchments on annual and monthly time sc

  8. Student Misconceptions in Writing Balanced Equations for Dissolving Ionic Compounds in Water

    Science.gov (United States)

    Naah, Basil M.; Sanger, Michael J.

    2012-01-01

    The goal of this study was to identify student misconceptions and difficulties in writing symbolic-level balanced equations for dissolving ionic compounds in water. A sample of 105 college students were asked to provide balanced equations for dissolving four ionic compounds in water. Another 37 college students participated in semi-structured…

  9. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and... ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and...

  10. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and... ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and...

  11. Identifying dominant controls on the water balance of partly sealed surfaces

    Science.gov (United States)

    Schuetz, Tobias; Schübl, Marleen; Siebert, Caroline; Weiler, Markus

    2017-04-01

    It is the challenge of modern urban development to obtain a near natural state for the urban water balance. For this purpose permeable alternatives to conventional surface sealing have been established during the last decades. A wealth of studies - under laboratory as well as field conditions - has emerged around the globe to examine the hydrological characteristics of different types of pavements. The main results of these studies - measured infiltration and evaporation rates, vary to a great extent between single studies and pavement types due to methodological approaches and local conditions. Within this study we analyze the controls of water balance components of partly sealed urban surfaces derived from an extensive literature review and a series of infiltration experiments conducted on historical and modern pavements within the city of Freiburg, Germany. Measured values published in 48 studies as well as the results of 30 double-ring infiltration experiments were compiled and sorted according to the measured parameter, the pavement type, pavement condition, age of the pavement, porosity of the pavement material and joint filling material as well as joint proportion of joint pavements. The main influencing factors on infiltration / hydraulic conductivity, evaporation rates and groundwater recharge of permeable pavements were identified and quantified using multiple linear regression methods. The analysis showed for both the literature study and our own infiltration experiments that condition and age of the pavement have the major influence on the pavement's infiltration capacity and that maintenance plays an important role for the long-term effectiveness of permeable pavements. For pavements with joints, the porosity of the pavement material seemed to have a stronger influence on infiltration capacity than the proportion of joint surface for which a clear influence could not be observed. Evaporation rates were compared for different surface categories as not

  12. The Pattern as a Reusable Component to Adaptive Framework for Load Balancing Mobile Agent in Internet Banking

    Directory of Open Access Journals (Sweden)

    A. Meiappane

    2012-03-01

    Full Text Available In recent years, the Software Architecture (SA of an Internet banking has become one of the most challengeable and risky fields of modern technology. The advent of the Internet has revolutionized the way banking is being done. In Internet banking, we analyzed some attributes such as usage, security, availability, load balancing and so on. Among those attributes Load Balancing is a serious problem in the Internet and it is necessary to build new systems incorporating load balancing as integral part of their design. The use of patterns, which is of a reusable component, is a good tool to help designers build load balancing systems. In this paper we are going to propose cluster load balancing technique by using mobile agent.

  13. The springs of Lake Patzcuaro: chemistry, salt-balance, and implications for the water balance of the lake

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, James L.; Israde-Alcantara, Isabel; Garduno-Monroy, Victor H.; Shanks III, Wayne C

    2004-11-01

    Lake Patzcuaro, the center of the ancient Tarascan civilization located in the Mexican altiplano west of the city of Morelia, has neither river input nor outflow. The relatively constant lake-salinity over the past centuries indicates the lake is in chemical steady state. Springs of the south shore constitute the primary visible input to the lake, so influx and discharge must be via sub-lacustrine ground water. The authors report on the chemistry and stable isotope composition of the springs, deeming them representative of ground-water input. The springs are dominated by Ca, Mg and Na, whereas the lake is dominated by Na. Combining these results with previously published precipitation/rainfall measurements on the lake, the authors calculate the chemical evolution from spring water to lake water, and also calculate a salt balance of the ground-water-lake system. Comparing Cl and {delta}{sup 18}O compositions in the springs and lake water indicates that 75-80% of the spring water is lost evaporatively during evolution toward lake composition. During evaporation Ca and Mg are lost from the water by carbonate precipitation. Each liter of spring water discharging into the lake precipitates about 18.7 mg of CaCO{sub 3}. Salt balance calculations indicate that ground water input to the lake is 85.9 x 10{sup 6} m{sup 3}/a and ground water discharge from the lake is 23.0 x 10{sup 6} m{sup 3}/a. Thus, the discharge is about 27% of the input, with the rest balanced by evaporation. A calculation of time to reach steady-state ab initio indicates that the Cl concentration of the present day lake would be reached in about 150 a.

  14. The springs of Lake Pátzcuaro: chemistry, salt-balance, and implications for the water balance of the lake

    Science.gov (United States)

    Bischoff, James L.; Israde-Alcántara, Isabel; Garduno-Monroy, Victor H.; Shanks, Wayne C.

    2004-01-01

    Lake Pa??tzcuaro, the center of the ancient Tarascan civilization located in the Mexican altiplano west of the city of Morelia, has neither river input nor outflow. The relatively constant lake-salinity over the past centuries indicates the lake is in chemical steady state. Springs of the south shore constitute the primary visible input to the lake, so influx and discharge must be via sub-lacustrine ground water. The authors report on the chemistry and stable isotope composition of the springs, deeming them representative of ground-water input. The springs are dominated by Ca, Mg and Na, whereas the lake is dominated by Na. Combining these results with previously published precipitation/rainfall measurements on the lake, the authors calculate the chemical evolution from spring water to lake water, and also calculate a salt balance of the ground-water-lake system. Comparing Cl and ??18O compositions in the springs and lake water indicates that 75-80% of the spring water is lost evaporatively during evolution toward lake composition. During evaporation Ca and Mg are lost from the water by carbonate precipitation. Each liter of spring water discharging into the lake precipitates about 18.7 mg of CaCO3. Salt balance calculations indicate that ground water input to the lake is 85.9??106 m3/a and ground water discharge from the lake is 23.0??106 m3/a. Thus, the discharge is about 27% of the input, with the rest balanced by evaporation. A calculation of time to reach steady-state ab initio indicates that the Cl concentration of the present day lake would be reached in about 150 a. ?? 2004 Elsevier Ltd. All rights reserved.

  15. Estimation of GRACE water storage components by temporal decomposition

    Science.gov (United States)

    Andrew, Robert; Guan, Huade; Batelaan, Okke

    2017-09-01

    The Gravity Recovery and Climate Experiment (GRACE) has been in operation since 2002. Water storage estimates are calculated from gravity anomalies detected by the operating satellites and although not the true resolution, can be presented as 100 km × 100 km data cells if appropriate scaling functions are applied. Estimating total water storage has shown to be highly useful in detecting hydrological variations and trends. However, a limitation is that GRACE does not provide information as to where the water is stored in the vertical profile. We aim to partition the total water storage from GRACE into water storage components. We use a wavelet filter to decompose the GRACE data and partition it into various water storage components including soil water and groundwater. Storage components from the Australian Water Resources Assessment (AWRA) model are used as a reference for the decompositions of total storage data across Australia. Results show a clear improvement in using decomposed GRACE data instead of raw GRACE data when compared against total water storage outputs from the AWRA model. The method has potential to improve GRACE applications including a means to test various large scale hydrological models as well as helping to analyse floods, droughts and other hydrological conditions.

  16. Development of a Water and Enthalpy Budget-based Glacier mass balance Model (WEB-GM) and its preliminary validation

    Science.gov (United States)

    Ding, Baohong; Yang, Kun; Yang, Wei; He, Xiaobo; Chen, Yingying; Lazhu; Guo, Xiaofeng; Wang, Lei; Wu, Hui; Yao, Tandong

    2017-04-01

    This paper presents a new water and energy budget-based glacier mass balance model. Enthalpy, rather than temperature, is used in the energy balance equations to simplify the computation of the energy transfers through the water phase change and the movement of liquid water in the snow. A new parameterization for albedo estimation and state-of-the-art parameterization schemes for rainfall/snowfall type identification and surface turbulent heat flux calculations are implemented in the model. This model was driven with meteorological data and evaluated using mass balance and turbulent flux data collected during a field experiment implemented in the ablation zone of the Parlung No. 4 Glacier on the Southeast Tibetan Plateau during 2009 and 2015-2016. The evaluation shows that the model can reproduce the observed glacier ablation depth, surface albedo, surface temperature, sensible heat flux, and latent heat flux with high accuracy. Comparing with a traditional energy budget-based glacier mass balance model, this enthalpy-based model shows a superior capacity in simulation accuracy. Therefore, this model can reasonably simulate the energy budget and mass balance of glacier melting in this region and be used as a component of land surface models and hydrological models.

  17. Water balance and ad libitum water intake in football players during a training session

    Directory of Open Access Journals (Sweden)

    Juan Diego Hernández-Camacho

    2016-01-01

    Full Text Available Introduction: It is known that hydration plays a crucial performance in sports performance. But a great number of studies assessing hydration during football practice have shown that many players have a dehydration state prior to this sport and that most players are not able to replace water loss by sweating with ad libitum water intake. Objectives: To analyze ad libitum water consumption, water balance, thirst sensation and rate of perceived exertion on a sample of young football players during a training session. Material and Methods: A total of 57 players from three teams in the youth category voluntary participated in this study. Weight was collected at the beginning and at the end of training; thirst sensation, rate of perceived exertion and quantification of ingested water were assessed. We used descriptive statistics, correlational and ratio analysis. Results: Mean global intake of players studied was 844.74±351.95mL and an average loss of body water 1274.56±385.82mL. Average rate of dehydration of the initial weight was 0.63%. Average score of 2.81±1.32 on the scale of thirst sensation was obtained. Discussion and conclusions: Rate of loss of body water similar to previous studies is obtained. The players were not able to replace water loss by drinking liquid ad libitum, so the intake of an amount previously scheduled could become helpful.

  18. Estimation of components of energy balance on drifting ice over Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    卞林根; 陆龙骅; 高志球; 程彦杰; 逯昌贵; 李诗明

    2001-01-01

    Estimation and simulation were carried out for the components of ice-surface energy balance and tur bulent exchange parameters using the flux-profile method and the sinple biosphere model version 2 (SiB2, hereinafter) respectively based on the measured results for the atmosphere in the near-ice-surface layer, which were observed by the First Arctic Scientific Expedition of China in August, 1999 at a joint ice-research station (75°02′N, 160°51′W) on the drifting ice of Arctic Ocean. Evidence suggests that during the melting period of drifting ice the sum of the ice-released sensible heat and effective melting-consumed heat is greater than the net ice-absorbed radiation on the surface, with the excess heat coming via heat conduction from the deep layers of the ice mass. The simulated net radiation is systematical lv 18% greater than the measured results, while the simulated sensible heat flux is systematically 3% lower than the measured ones; and the simulated ice-surface heat flux differs noticeably from its calculation. Hence, we see that al though the measured sequences are short, the simulations of net radiation and sensible heat fluxes by the SiB2 model are comparatively good, the simulation of other forms of fluxes still needs to be improved.

  19. Potential groundwater recharge for the State of Minnesota using the Soil-Water-Balance model, 1996-2010

    Science.gov (United States)

    Smith, Erik A.; Westenbroek, Stephen M.

    2015-01-01

    Groundwater recharge is one of the most difficult components of a water budget to ascertain, yet is an important boundary condition necessary for the quantification of water resources. In Minnesota, improved estimates of recharge are necessary because approximately 75 percent of drinking water and 90 percent of agricultural irrigation water in Minnesota are supplied from groundwater. The water that is withdrawn must be supplied by some combination of (1) increased recharge, (2) decreased discharge to streams, lakes, and other surface-water bodies, and (3) removal of water that was stored in the system. Recent pressure on groundwater resources has highlighted the need to provide more accurate recharge estimates for various tools that can assess the sustainability of long-term water use. As part of this effort, the U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency, used the Soil-Water-Balance model to calculate gridded estimates of potential groundwater recharge across Minnesota for 1996‒2010 at a 1-kilometer (0.621-mile) resolution. The potential groundwater recharge estimates calculated for Minnesota from the Soil-Water Balance model included gridded values (1-kilometer resolution) of annual mean estimates (that is, the means for individual years from 1996 through 2010) and mean annual estimates (that is, the mean for the 15-year period 1996−2010).

  20. Signal to noise ratio in water balance maps with different resolution

    Science.gov (United States)

    Yan, Ziqi; Gottschalk, Lars; Wang, Jianhua

    2016-12-01

    What is the best resolution of annual water balance maps for a correct balance between the basic spatial signal in the observations of precipitation, actual evapotranspiration and runoff across a larger drainage basin and the error in estimates for grid cells in the map to avoid giving a false impression of accuracy? To answer this question an approach based a signal to noise ratio is proposed, which allows finding the optimal resolution maximizing the signal in the map. The approach is demonstrated on gauge data in the Huai River Basin, China. Stochastic interpolation methods were applied to create grid maps of long-term mean values, as well as for estimating variances of the three water balance components in a range of scales from 5 × 5 km to 200 × 200 km2 grid cells. Interpolation algorithms using covariances of long-term means of data with different spatial support were developed. The identified optimal resolutions by the signal to noise ratio appeared to be very different - 10 × 10, 50 × 50, and 30 × 30 km2 for precipitation, actual evapotranspiration, and runoff, respectively. These values are directly linked to the observation network densities. The magnitude of the signal to noise ratio shows similar strong differences with values 34, 3.7, and 5.4, respectively. It gives a direct indication of the reliability of the map, which can be considered as satisfactory only for precipitation for the data available for the present study. The critical factors for this magnitude are parameters characterising the spatial covariance in data and the network density.

  1. Adjustment of the components of energy balance in response to temperature change in Ostrea edulis

    Energy Technology Data Exchange (ETDEWEB)

    Newell, R.C.; Johson, L.G.; Kofoed, L.H.

    1977-01-01

    Routine oxygen consumption (V/sub 02/ ..mu..l 285 mg/sup -1/ h/sup -1/) by specimens of Ostrea acclimated to temperatures between 5/sup 0/ and 25/sup 0/C increases with exposure temperature throughout much of the range 5 to 30/sup 0/C. There is little evidence of a relative suppression of the acutely-measured rate: temperature curves for routine oxygen consumption following warm acclimation. Energetic costs in Ostrea thus rise sharply with increase of environmental temperature. The clearance rate (V/sub w/, ml 285 mg/sup -1/ h/sup -1/) of Phaeodactylum measured synchronously shows a marked thermal optimum within the range 15 to 28/sup 0/C, followed by a decline towards high exposure temperatures. Maximal clearance rates of 600 to 750 ml water h/sup -1/ occur approximately 5/sup 0/C above the temperature to which the animals have been acclimated and are adjusted according to environmental temperature. The changes in filtration efficiency)V/sub w//V/sub 02/, ml/..mu..l) in Ostrea following thermal acclimation are controlled by compensatory responses of the irrigation rate rather than by a relative reduction of energy losses from metabolism. Because the clearance rate declines in animals acclimated to 25/sup 0/C, whereas the metabolic losses increase throughout the temperature range 5 to 30/sup 0/C, maximum filtration efficiency is achieved at 20/sup 0/C. Calculation of the energetic cost of filtration suggests that the improvement of filtration following warm acclimation offsets metabolic energy losses even at low food concentrations in Ostrea. Even if energy losses not accounted for in the study were substantial, a positive index of energy balance could be maintained during the summer months at ration levels which commonly occur in inshore waters.

  2. Dinitrogen emissions as an overlooked key component of the N balance of montane grasslands

    Science.gov (United States)

    Zistl-Schlingmann, Marcus; Feng, Jinchao; Kiese, Ralf; Stephan, Ruth; Dannenmann, Michael

    2017-04-01

    . Ammonia losses amounted to only 13-18%, N2O losses to 1-3 % and NO losses to 1% of applied manure-N. In the context of the ecosystem total N budget, our results show that N2 losses are a so far overlooked key component of the N balance in montane grasslands. Understanding controls of N2 loss is therefore an indispensable prerequisite for the development of grassland management strategies targeted to improve N use efficiency.

  3. Geostrophic balance preserving interpolation in mesh adaptive shallow-water ocean modelling

    CERN Document Server

    Maddison, James R; Farrell, Patrick E

    2010-01-01

    The accurate representation of geostrophic balance is an essential requirement for numerical modelling of geophysical flows. Significant effort is often put into the selection of accurate or optimal balance representation by the discretisation of the fundamental equations. The issue of accurate balance representation is particularly challenging when applying dynamic mesh adaptivity, where there is potential for additional imbalance injection when interpolating to new, optimised meshes. In the context of shallow-water modelling, we present a new method for preservation of geostrophic balance when applying dynamic mesh adaptivity. This approach is based upon interpolation of the Helmholtz decomposition of the Coriolis acceleration. We apply this in combination with a discretisation for which states in geostrophic balance are exactly steady solutions of the linearised equations on an f-plane; this method guarantees that a balanced and steady flow on a donor mesh remains balanced and steady after interpolation on...

  4. Impact of climate change on water balance, and nutrient leaching of (pre-) alpine grassland soils

    Science.gov (United States)

    Fu, Jin; Lu, Haiyan; Butterbach-bahl, Klaus; Kiese, Ralf

    2013-04-01

    On a global perspective terrestrial biosphere hosts significant pools of carbon and nitrogen. Due to cool and moist climatic conditions alpine grassland soils of moderate elevation (app. 1000m) in particular, are rich in soil organic carbon and associated nitrogen. In the framework of an in-situ climate change experiment we test the hypothesis that soil organic carbon and nitrogen are either volatilized (GHG emissions) or leached with seepage water due to increase in air temperature as induced by climate change. The infrastructure of the in-situ climate change experiment was funded by Helmholtz society and BMBF and allowed IMK-IFU to install a lysimeter network with undisturbed intact grassland soil cores (diameter approx. 1 m, depth 1.4 m, 2-3 t of soil) at three sites (Graswang 860m, Rottenbuch 750m, Fendt 600m) differing in altitude and climate. The lysimeter network consisting of a total of 36 lysimeters is operated since September 2011 and is run for climate change research with a long term perspective (>10years). Lysimeters were partly moved along the altitudinal gradient, with some soil cores still staying at sites as controls and some others translocated from higher elevation to sites at lower elevation with higher temperatures and slightly lower mean annual rainfall. The different components of the water balance i.e. precipitation, evapotranspiration and groundwater recharge of each lysimeter are measured by precision weighing of the lysimeters and a separate container for collection of seepage water at the lower boundary condition (1.4m). In addition, soil moisture (volumetric water content as well as water tension) and temperature are measured with sensors installed in 10, 30, 50, 140cm soil depth. Soil water in 10, 30, 50 and 140cm soil depth is drawn into glass bottles by under-pressurized suction cups. Water samples are collected regularly any 2 weeks and more often (e.g. 3 times a week) during fertilization events, and analyzed for nutrient

  5. Basin-scale partitioning of Greenland ice sheet mass balance components (2007-2011)

    DEFF Research Database (Denmark)

    Andersen, M.L.; Stenseng, Lars; Skourup, Henriette;

    2015-01-01

    The current deficit in Greenland ice sheet mass balance is due to both a decrease in surface mass balance (SMB) input and an increase in ice discharge (D) output. While SMB processes are beginning to be well captured by observationally-constrained climate modeling, insight into D is relatively li...

  6. The evolution and enlightenment of water resources accounting from accounts to balance sheet

    Institute of Scientific and Technical Information of China (English)

    FuHui Jian; XiaoYu Song; LiLi Li; WenQi Gao

    2016-01-01

    The Third Plenary Session of the 18th Central Committee of the Communist Party of China has proposed an important national strategic decision: to explore and establish the balance sheet of natural resources, to implement leaders' of-office auditing system about natural resources assets. Water is one of the most essential nature resources of human beings; water resources accounting, as an important water resources management tool, is an essential part of compiling the natural re-sources balance sheet. In this paper, we provide a summary of the historic evolution of water resources accounting and analyze its application in some typical countries. Although water resources accounting and water resources balance sheet reflect different implications and focus, both require water resources accounts as the basis in system establishment.

  7. Energy and water cycle over the Tibetan plateau : surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Zhongbo; Zhang, Ting; Ma, Yaoming; Jia, Li; Wen, Jun

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  8. Energy and water cycle over the Tibetan Plateau: surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Z.; Zhang, T.; Ma, Y.; Jia, L.; Wen, J.

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  9. Water Balance in a Moist Semi-Deciduous Forest of Ghana

    African Journals Online (AJOL)

    deciduous forest of Ghana was selected for this study because most food and export crops are grown there. ... balance model can be used in place of complicated models in the determination of soil water balance in the tropics. ... complex micro-meteorological and soil ..... better soil structure due to high carbon content.

  10. Investigating the terrestrial-atmospheric water balance for the Tana River basin, East Africa

    Science.gov (United States)

    Kerandi, Noah; Laux, Patrick; Arnault, Joel; Kunstmann, Harald

    2016-04-01

    The fully coupled atmospheric-hydrological WRF-Hydro modeling system is applied to the Tana River basin (TRB) in East Africa for the period 2011-2014 in order to analyze the terrestrial-atmospheric water balance components and their feedback mechanisms. The outputs from the fully coupled modeling system are compared to those of the WRF stand-alone model. The study area encompasses the Mathioya-Sagana subcatchment (3279 km²) in the upper TRB. Our model set up consists of two domains at 25 km and 5 km horizontal resolution covering East Africa and the study area, respectively. The WRF-Hydro inner domain is enhanced with hydrological routing at a 500 m horizontal grid resolution. The simulated monthly precipitation over the subcatchment compared with the Tropical Rainfall Measuring Mission (TRMM) satellite data gives an overall correlation coefficient of 0.8/0.7 for fully coupled/stand-alone model and a mean absolute error (MAE) of 1.5 mm/day for both models for the entire simulation period. Overall the models yield more annual total precipitation compared to TRMM. The two models are drier during the March, April, May (MAM) season and wetter during the October, November, December (OND) season. Compared to observation stations, both modeling systems provide a correlation coefficient of 0.6 for precipitation. The simulated and observed discharges at the Tana Rukanga gauge, located in the subcatchment, exhibit a correlation coefficient of 0.5 at daily resolution. The WRF-Hydro also overestimates the cumulated discharge (2011-2014) by about 50 %. The analysis of the atmospheric water balance in both WRF and WRF-Hydro simulation reveals a positive moisture divergence during the MAM and OND rainy seasons. Precipitation recycling and efficiency measures derived from the atmospheric water budget are also investigated.

  11. INVESTIGATION OF QUANTIFICATION OF FLOOD CONTROL AND WATER UTILIZATION EFFECT OF RAINFALL INFILTRATION FACILITY BY USING WATER BALANCE ANALYSIS MODEL

    OpenAIRE

    文, 勇起; BUN, Yuki

    2013-01-01

    In recent years, many flood damage and drought attributed to urbanization has occurred. At present infiltration facility is suggested for the solution of these problems. Based on this background, the purpose of this study is investigation of quantification of flood control and water utilization effect of rainfall infiltration facility by using water balance analysis model. Key Words : flood control, water utilization , rainfall infiltration facility

  12. The water balance of a seasonal stream in the semi-arid Western ...

    African Journals Online (AJOL)

    2011-02-16

    Feb 16, 2011 ... A detailed water balance and conceptual flow model was calculated and developed for the Sandspruit catchment for ..... reports naturalised mean annual runoff for the Sandspruit ...... Lewis Publishers, Boca Raton, New York.

  13. Century‐scale variability in global annual runoff examined using a water balance model

    National Research Council Canada - National Science Library

    McCabe, Gregory J; Wolock, David M

    2011-01-01

    A monthly water balance model (WB model) is used with CRUTS2.1 monthly temperature and precipitation data to generate time series of monthly runoff for all land areas of the globe for the period 1905 through 2002...

  14. Water balance in the complex mountainous terrain of Bhutan and linkages to land use

    DEFF Research Database (Denmark)

    Dorji, Ugyen; Olesen, Jørgen Eivind; Seidenkrantz, Marit-Solveig

    2016-01-01

    Bhutan is located in the Himalayas with extreme variation in elevation, climatic conditions and land use. The high dependency of the economy on agriculture and natural resources emphasizes the importance of understanding inter- and intra-seasonal variation in water balance linked to monsoonal pre...... types dominate, whereas an either small or negative water balance in the east-west belt of central Bhutan cause dry conditions in this region, which is dominated by coniferous forests....

  15. Water balance of global aquifers revealed by groundwater footprint

    NARCIS (Netherlands)

    Gleeson, T.; Wada, Y.; Bierkens, M.F.P.; Beek, L.P.H. van

    2012-01-01

    Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems1,2. Most assessments of global water resources have focused on surface water3–6, but unsustainable depletion of groundwater

  16. Water balance of global aquifers revealed by groundwater footprint

    NARCIS (Netherlands)

    Gleeson, T.; Wada, Y.; Bierkens, M.F.P.; Beek, L.P.H. van

    2012-01-01

    Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems1,2. Most assessments of global water resources have focused on surface water3–6, but unsustainable depletion of

  17. Design of a six-component side-wall balance using optical fibre sensors

    CSIR Research Space (South Africa)

    Pieterse, FF

    2017-01-01

    Full Text Available The requirements that a wind tunnel balance need to satisfy have become increasingly stringent. These requirements, as set out by the wind tunnel testing community, include: improved static force accuracy and resolution, increased stiffness...

  18. A fine balance : water treatment enabling CBM production

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, L.

    2008-11-15

    Wyoming is the third largest producer of coalbed methane (CBM) in the United States, following New Mexico and Colorado. Large quantities of salty water seep naturally from the coal seams when CBM is produced. Surface discharge has long been the primary method for dealing with CBM-produced water in the Powder River Basin (PRB). Today, operators use managed irrigation, impoundments, injection and subsurface irrigation and water treatment. Although treating the water is the most expensive option, several companies are conducting pilot projects to test at least 10 different water treatment methods. This article highlighted 5 of the methods currently used in the PRB, including Drake Water Technologies' continuous ion exchange system that produces clean water and no waste; EMIT Water Discharge Technology's countercurrent ion exchange technology which is used to treat about 10 per cent of all water produced in the PRB and 18 per cent of the water produced in the Upper Powder River watershed; Ontario-based Eco-Tec's portable RecoPur ion exchange system in which water is first filtered, followed by calcium, magnesium and sodium removal and replacement with hydrogen using acid generation, and then followed by carbon dioxide removal via a gasifier to leave a slightly acid solution that is neutralized with lime; Big Cat Energy's new Aquifer Recharge Injection Device (ARID) which eliminates the need for a separate injection well since produced water is redirected into nearby shallower, depleted aquifers; and, Bene Terra's subsurface drip irrigation technique which provides year-round water dispersal of CBM-produced water and puts it to use growing forage crops. 5 refs., 3 figs.

  19. GENERALIZED p-VALUES AND GENERALIZED CONFIDENCE INTERVALS FOR VARIANCE COMPONENTS IN GENERAL RANDOM EFFECT MODEL WITH BALANCED DATA

    Institute of Scientific and Technical Information of China (English)

    Rendao YE; Songgui WANG

    2007-01-01

    Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In this paper, we mainly consider these problems in general random effect model with balanced data. Exact tests and confidence intervals for a single variance component corresponding to random effect are developed by using generalized p-values and generalized confidence intervals.The resulting procedures are easy to compute and are applicable to small samples. Exact tests and confidence intervals are also established for comparing the random-effects variance components and the sum of random-effects variance components in two independent general random effect models with balanced data. Furthermore, we investigate the statistical properties of the resulting tests. Finally,some simulation results on the type Ⅰ error probability and power of the proposed test are reported.The simulation results indicate that exact test is extremely satisfactory for controlling type Ⅰ error probability.

  20. Modelling membrane hydration and water balance of a pem fuel cell

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh

    2015-01-01

    propose a novel mathematical zero-dimensional model for water mass balance of a polymer electrolyte membrane. Physical and electrochemical processes occurring in the membrane electrolyte are included; water adsorption/desorption phenomena are also considered. The effect of diffusivity, surface roughness...... and water content driving force is considered. We validate the model against experimental data. The water balance calculated by this model shows better fit with experimental data-points compared to other models such as the one by Springer et al.. We conclude that this discrepancy is due a different rate...

  1. Water balance-based actual evapotranspiration reconstruction from ground and satellite observations over the conterminous United States

    Science.gov (United States)

    Wan, Zhanming; Zhang, Ke; Xue, Xianwu; Hong, Zhen; Hong, Yang; Gourley, Jonathan J.

    2015-08-01

    The objective of this study is to produce an observationally based monthly evapotranspiration (ET) product using the simple water balance equation across the conterminous United States (CONUS). We adopted the best quality ground and satellite-based observations of the water budget components, i.e., precipitation, runoff, and water storage change, while ET is computed as the residual. Precipitation data are provided by the bias-corrected PRISM observation-based precipitation data set, while runoff comes from observed monthly streamflow values at 592 USGS stream gauging stations that have been screened by strict quality controls. We developed a land surface model-based downscaling approach to disaggregate the monthly GRACE equivalent water thickness data to daily, 0.125° values. The derived ET computed as the residual from the water balance equation is evaluated against three sets of existing ET products. The similar spatial patterns and small differences between the reconstructed ET in this study and the other three products show the reliability of the observationally based approach. The new ET product and the disaggregated GRACE data provide a unique, important hydro-meteorological data set that can be used to evaluate the other ET products as a benchmark data set, assess recent hydrological and climatological changes, and terrestrial water and energy cycle dynamics across the CONUS. These products will also be valuable for studies and applications in drought assessment, water resources management, and climate change evaluation.

  2. Impact of spatial data resolution on simulated catchment water balances and model performance of the multi-scale TOPLATS model

    Science.gov (United States)

    Bormann, H.

    2006-03-01

    This paper analyses the effect of spatial input data resolution on the simulated water balances and flow components using the multi-scale hydrological model TOPLATS. A data set of 25m resolution of the central German Dill catchment (693 km2) is used for investigation. After an aggregation of digital elevation model, soil map and land use classification to 50 m, 75 m, 100 m, 150 m, 200 m, 300 m, 500 m, 1000 m and 2000 m, water balances and water flow components are calculated for the entire Dill catchment as well as for 3 subcatchments without any recalibration. The study shows that model performance measures and simulated water balances almost remain constant for most of the aggregation steps for all investigated catchments. Slight differences in the simulated water balances and statistical quality measures occur for single catchments at the resolution of 50 m to 500 m (e.g. 0-3% for annual stream flow), significant differences at the resolution of 1000 m and 2000 m (e.g. 2-12% for annual stream flow). These differences can be explained by the fact that the statistics of certain input data (land use data in particular as well as soil physical characteristics) changes significantly at these spatial resolutions. The impact of smoothing the relief by aggregation occurs continuously but is barely reflected by the simulation results. To study the effect of aggregation of land use data in detail, in addition to current land use the effect of aggregation on the water balance calculations based on three different land use scenarios is investigated. Land use scenarios were available aiming on economic optimisation of agricultural and forestry practices at different field sizes (0.5 ha, 1.5 ha and 5.0 ha). The changes in water balance terms, induced by aggregation of the land use scenarios, are comparable with respect to catchment water balances compared to the current land use. A correlation analysis between statistics of input data and simulated annual water fluxes only in

  3. Sensitivity of a data-driven soil water balance model to estimate summer evapotranspiration along a forest chronosequence

    Directory of Open Access Journals (Sweden)

    J. A. Breña Naranjo

    2011-11-01

    Full Text Available The hydrology of ecosystem succession gives rise to new challenges for the analysis and modelling of water balance components. Recent large-scale alterations of forest cover across the globe suggest that a significant portion of new biophysical environments will influence the long-term dynamics and limits of water fluxes compared to pre-succession conditions. This study assesses the estimation of summer evapotranspiration along three FLUXNET sites at Campbell River, British Columbia, Canada using a data-driven soil water balance model validated by Eddy Covariance measurements. It explores the sensitivity of the model to different forest succession states, a wide range of computational time steps, rooting depths, and canopy interception capacity values. Uncertainty in the measured EC fluxes resulting in an energy imbalance was consistent with previous studies and does not affect the validation of the model. The agreement between observations and model estimates proves that the usefulness of the method to predict summer AET over mid- and long-term periods is independent of stand age. However, an optimal combination of the parameters rooting depth, time step and interception capacity threshold is needed to avoid an underestimation of AET as seen in past studies. The study suggests that summer AET could be estimated and monitored in many more places than those equipped with Eddy Covariance or sap-flow measurements to advance the understanding of water balance changes in different successional ecosystems.

  4. Water balance and its intra-annual variability in a permafrost catchment: hydrological interactions between catchment, lake and talik

    Directory of Open Access Journals (Sweden)

    E. Bosson

    2013-07-01

    Full Text Available Few hydrological studies have been made in Greenland with focus on permafrost hydrology rather than on the glacial hydrology associated with the Greenland ice sheet. Understanding permafrost hydrology, and its reflection and propagation of hydroclimatic change and variability, however, can be a key to understand important climate change effects and feedbacks in arctic landscapes. This paper presents a new extensive and detailed hydrological dataset, with high temporal resolution of main hydrological parameters, for a permafrost catchment with a lake underlain by a talik close to the Greenland ice sheet in the Kangerlussuaq region, western Greenland. The paper describes the hydrological site investigations and data collection, and their synthesis and interpretation to develop a conceptual hydrological model. The catchment and lake water balances and their intra-annual variability, and uncertainty intervals for key water balance components, are quantified. The study incorporates all relevant hydrological processes within the catchment and, specifically, links the surface water system to both supra-permafrost and sub-permafrost groundwater. The dataset enabled water balance quantification with high degree of confidence. The measured hydraulic gradient between the lake and the groundwater in the talik shows this to be a groundwater recharging talik. Surface processes, dominated by evapotranspiration during the active flow period, and by snow dynamics during the frozen winter period, influence the temporal variation of groundwater pressure in the talik. This shows the hydrology in the catchment as being rather independent from external large-scale landscape features, including those of the close-by ice sheet.

  5. Effect of cooling water on stability of NLC linac components

    Energy Technology Data Exchange (ETDEWEB)

    F. Le Pimpec et al.

    2003-02-11

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  6. A water balance model to estimate flow through the Old and Middle River corridor

    Science.gov (United States)

    Andrews, Stephen W.; Gross, Edward S.; Hutton, Paul H.

    2016-01-01

    We applied a water balance model to predict tidally averaged (subtidal) flows through the Old River and Middle River corridor in the Sacramento–San Joaquin Delta. We reviewed the dynamics that govern subtidal flows and water levels and adopted a simplified representation. In this water balance approach, we estimated ungaged flows as linear functions of known (or specified) flows. We assumed that subtidal storage within the control volume varies because of fortnightly variation in subtidal water level, Delta inflow, and barometric pressure. The water balance model effectively predicts subtidal flows and approaches the accuracy of a 1–D Delta hydrodynamic model. We explore the potential to improve the approach by representing more complex dynamics and identify possible future improvements.

  7. The Stochastic Component of the Postural Sway Variability is Higher in Children with Balance Impairments.

    Science.gov (United States)

    Kurz, Max J; Arpin, David J; Davies, Brenda L; Harbourne, Regina

    2013-08-01

    Children with balance impairments have an increased amount of variability in the sway of the center of pressure (COP) during standing. Limited efforts have been made to quantify the nature of the variability. This exploratory investigation examined the deterministic and stochastic features that comprise the time-dependent postural sway variability during standing. We measured the COP in standing of a heterogeneous group of children with balance impairments and an age-matched cohort of typically developing children, both with and without vision. The standard deviation of the COP was used to quantify the amount of variability present in the postural sway. A Langevin equation methodology was additionally employed to reconstruct the deterministic and stochastic features that comprised the postural sway variability. Our experiment resulted in three key findings: (1) removal of visual information increased the stochastic features of the postural sway variability, (2) the stochastic features were greater for the children with balance impairments, (3) the change in the amount of variability was strongly correlated with change the stochastic features. These results imply that the inability to suppress the stochastic features present in the nervous system may play a prominent role in the balance problems of children. Moreover, our results imply that alterations in the stochastic features drive the postural system away from successful balance strategies.

  8. Ozone exposure affects leaf wettability and tree water balance

    NARCIS (Netherlands)

    Schreuder, M.D.J.; Hove, van L.W.A.; Brewer, C.A.

    2001-01-01

    Relatively little is known about the influences of growing-season background ozone (O3) concentrations on leaf cuticles and foliar water loss. Using fumigation chambers, leaf wettability and foliar water loss were studied in two poplar species, Populus nigra and P. euramericana, and a conifer, Pseud

  9. Balancing food security and water demand for freshwater ecosystems

    Science.gov (United States)

    Pastor, Amandine; Palazzo, Amanda; Havlik, Petr; Obersteiner, Michael; Biemans, Hester; Wada, Yoshihide; Kabat, Pavel; Ludwig, Fulco

    2017-04-01

    Water is not an infinite resource and demand from irrigation, household and industry is constantly increasing. This study focused on including global water availability including environmental flow requirements with water withdrawal from irrigation and other sectors at a monthly time-step in the GLOBIOM model. This model allows re-adjustment of land-use allocation, crop management, consumption and international trade. The GLOBIOM model induces an endogenous change in water price depending on water supply and demand. In this study, the focus was on how the inclusion of water resources affects land-use and, in particular, how global change will influence repartition of irrigated and rainfed lands at global scale. We used the climate change scenario including a radiative forcing of 8.5 W/m2 (RCP8.5), the socio-economic scenario (SSP2: middle-of-road), and the environmental flow method based on monthly flow allocation (the Variable Monthly Flow method) with high and low restrictions. Irrigation withdrawals were adjusted to a monthly time-step to account for biophysical water limitations at finer time resolution. Our results show that irrigated land might decrease up to 40% on average depending on the choice of EFR restrictions. Several areas were identified as future hot-spots of water stress such as the Mediterranean and Middle-East regions. Other countries were identified to be in safe position in terms of water stress such as North-European countries. Re-allocation of rainfed and irrigated land might be useful information for land-use planners and water managers at an international level to decide on appropriate legislations on climate change mitigation/adaptation when exposure and sensitivity to climate change is high and/or on adaptation measures to face increasing water demand. For example, some countries are likely to adopt measures to increase their water use efficiencies (irrigation system, soil and water conservation practices) to face water shortages, while

  10. Integration of vegetation indices into a water balance model to estimate evapotranspiration of wheat and corn

    Directory of Open Access Journals (Sweden)

    F. L. M. Padilla

    2010-10-01

    Full Text Available Vegetation indices (VIs have been traditionally used for quantitative monitoring of vegetation. Remotely sensed radiometric measurements of visible and infrared solar energy, which is reflected or emitted by plant canopies, can be used to obtain rapid, non-destructive estimates of certain canopy attributes and parameters. One parameter of special interest for water management applications, is the crop coefficient employed by the FAO-56 model to derive actual crop evapotranspiration (ET. The aim of this study was to evaluate a methodology that combines the basal crop coefficient derived from VIs with a daily soil water balance in the root zone to estimate daily evapotranspiration rates for corn and wheat crops at field scale. The ability of the model to trace water stress in these crops was also assessed. Vegetation indices were first retrieved from field hand-held radiometer measurements and then from Landsat 5 and 7 satellite images. The results of the model were validated using two independent measurement systems for ET and regular soil moisture monitoring, in order to evaluate the behavior of the soil and atmosphere components of the model. ET estimates were compared with latent heat flux measured by an eddy covariance system and with weighing lysimeter measurements. Average overestimates of daily ET of 8 and 11% were obtained for corn and wheat, respectively, with good agreement between the estimated and measured root-zone water deficit for both crops when field radiometry was employed. Satellite remote-sensing inputs overestimated ET by 4 to 9%, showing a non-significant lost of accuracy when the satellite sensor data replaced the field radiometry data. The model was also used to monitor the water stress during the 2009 growing season, detecting several periods of water stress in both crops. Some of these stresses occurred during stages like grain filling, when the water stress is know to have a negative effect on yield. This fact could

  11. The observed evapotranspiration combining the energy and water balance for different land use under semiarid Mediterranean catchment

    Science.gov (United States)

    Zitouna Chebbi, Rim; Mekki, Insaf; Jacob, Frédéric; Masmoudi, Moncef; Prévot, Laurent; Ben Mechlia, Netij; Voltz, Marc; Albergel, Jean

    2014-05-01

    The Mediterranean semiarid cultivated catchments are affected by global and climate change and are characterized by very complex hydrological systems. The improvement of their management requires a best understanding of the hydrological processes and developing reliable means for characterizing the temporal dynamics of soil water balance in a spatially distributed manner. The main objective of this study is: i) to analyze the observed evapotranspiration in relation to natural drivers (i.e. rainfall and soil properties) and anthropogenic forcing (i.e. land use and crop successions), and ) ii to assess the differences in both energy and water balances. We focus on a hilly semiarid Mediterranean catchment devoted to rainfed agriculture, so-called the Kamech catchment, which is located in the Cap Bon Peninsula, north-eastern Tunisia. The site belongs to the OMERE observatory for environmental research and it is monitored for the different hydrological cycle components under influence of anthropogenic forcing. The analysis is based on in-situ data measured under the common cereals/legumes/pasture cropping systems within the Kamech catchment. Energy and water balance components and vegetation parameters were collected in different fields and during various crop growth cycles. The results showed the highly variable response of energy and water balances depending on soil types, land use, and climatic conditions. The annual rainfall is mainly converted into evapotranspiration during the growing cycle for different land uses. The runoff amounts, for most of the sites, correspond to less than 10% of the rainfall amount. The evapotransipration ratios differed significantly across site and season in relation to soil properties and cumulated rainfall. We observe large differences in soil water dynamics among the legumes (fababean and chickpea) and cereals (wheat, oat, and triticale). Soil water is larger for legume crops, despite substantial plant growth during winter

  12. Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile

    Directory of Open Access Journals (Sweden)

    G. Strauch

    2009-10-01

    Full Text Available For sustainable water resource management in semi-arid regions, sound information is required about interactions between the different components of the water system: rain/snow precipitation, surface/subsurface run-off, groundwater recharge. Exemplarily, the Huasco and Limarí river basins as water stressed river catchments have been studied by isotope and hydrochemical methods for (i the origin of water, (ii water quality, (iii relations of surface and groundwater.

    Applying the complex multi-isotopic and hydrochemical methodology to the water components of the Huasco and Limarí basins, a differentiation of water components concerning subsurface flow and river water along the catchment area and by anthropogenic impacts are detected. Sulphate and nitrate concentrations indicate remarkable input from mining and agricultural activities along the river catchment.

    The 2H-18O relations of river water and groundwater of both catchments point to the behaviour of river waters originated in an arid to semi-arid environment.

    Consequently, the groundwater from several production wells in the lower parts of the catchments is related to the rivers where the wells located, however, it can be distinguished from the river water. Using the hydrological water balance and the isotope mixing model, the interaction between surface and subsurface flows and river flow is estimated.

  13. Impacts of climate and management on water balance and nitrogen leaching from montane grassland soils

    Science.gov (United States)

    Fu, Jin; Gasche, Rainer; Wang, Na; Lu, Haiyan; Butterbach-Bahl, Klaus; Kiese, Ralf

    2017-04-01

    The impacts of climate and management on the water balance and nutrient leaching of montane grasslands have rarely been investigated, though such ecosystems may represent a major source for ground and surface water nitrates. In this study nitrogen (nitrate, ammonium, dissolved organic nitrogen) and dissolved organic carbon leaching as well as water balance components (precipitation, evapotranspiration, and groundwater recharge) were quantified (2012-2014) by means of replicated (N=3 per site/ treatment) measurements of weighable grassland lysimeters (1 m2 area, 1.2 m soil depth) at three sites (E860: 860 m a.s.l., E770: 770 m a.s.l. and E600: 600 m a.s.l.) in the pre-alpine region of S-Germany. Two grassland management strategies were investigated: a) intensive management with 5 cuts per year and cattle slurry application rates of 280 kg N ha-1 yr-1, and b) extensive management with 3 cuts per year and cattle slurry application rates of 56 kg N ha-1 yr-1. Our results show that at E600, the site with highest air temperature (8.6 °C) and lowest precipitation (981.9 mm), evapotranspiration losses were 100.7 mm higher as at the E860 site, i.e. the site with lowest mean annual air temperature (6.5 °C) and highest precipitation (1359.3 mm). On the other hand groundwater recharge was substantial lower at E600 (-440.9 mm) as compared to E860. Compared to climate, impacts of grassland management on water balance components were negligible. However, intensive management significantly increased mean total nitrogen leaching rates across sites as compared to extensive management from 2.6 kg N ha-1 year-1 (range: 0.5-6.0 kg N ha-1 year-1) to 4.8 kg N ha-1 year-1 (range: 0.9-12.9 kg N ha-1 year-1). N leaching losses were dominated by nitrate (64.7 %) and equally less by ammonium (14.6 %) and DON (20.7 %). The rather low rates of N leaching (0.8 - 6.9 % of total applied N) suggest a highly efficient nitrogen uptake by plants as measured by plant total N content at harvest

  14. Life in the Treetops: Drought Tolerance and Water Balance of Canopy Epiphytes in a Tropical Montane Cloud Forest

    Science.gov (United States)

    Gotsch, S. G.; Nadkarni, N.; Darby, A.; Dix, M.; Glunk, A.; Davidson, K.; Dawson, T. E.

    2014-12-01

    Tropical montane cloud forests (TMCFs) inhabit regions rich in biodiversity that play an important role in the local and regional water cycle. Canopy plants such as epiphytes and hemiepiphytes are an important component of the biodiversity in the TMCF and therefore play a significant role in the carbon, nutrient and water cycles. With only partial or no access to resources on the ground, canopy plants may be vulnerable to changes in climate that increase canopy temperatures and decrease atmospheric humidity or precipitation inputs. Despite their importance in the TMCF, there is little information regarding drought tolerance and water balance in this community. In this study we quantified variation in functional traits and water relations in 12 species of epiphytes and hemiepiphytes in a Costa Rican TMCF. We also generated pressure-volume curves and xylem vulnerability curves that we used as indicators of drought tolerance. Lastly, we determined the capacity for foliar water uptake in the laboratory and measured whole-plant transpiration in the field. We found that all species had a high turgor loss point (ψTLP), high vulnerability to cavitation (P50), and low bulk elastic modulus (ɛmax, i.e. high cell wall elasticity). These results indicate that capacitance may be high in canopy plants and that stored water may help to maintain high leaf water potentials during dry periods. We also found that all species had the capacity for foliar uptake and that this process contributed substantially to their water status and water balance. On average, foliar uptake contributed to the reabsorption of 70% of the water transpired over a 34-day period at the beginning of the dry season. Our results indicate that canopy plants can mitigate water loss substantially, but they may be vulnerable to changes in the overall precipitation patterns or increases in cloud base heights.

  15. Aquastress D2.3.3 - Integrated water balance models for water stress adapted to test sites

    OpenAIRE

    Schmidt, S; P. Rosso; Loubier, S.; Preziosi, E.; Tarnacki, K.; Van den Wyngaert, I.

    2008-01-01

    This report is based on the report Milestone 2.3-1 of the Aquastress project (Schmidt et al, 2005), which presented an inventory of examples of water balance models and gave a list of criteria to characterise hydrological models, and on the report Deliverable 2.3-1 of the Aquastress project (Schmidt et al, 2006), which describes the concept of the water balance model and the structure of the water stress assessment in the domestic, industrial, agricultural and (semi)natural ecosystem sectors....

  16. Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance

    NARCIS (Netherlands)

    Kindler, R.; Siemens, J.; Kaiser, K.; Moors, E.J.

    2011-01-01

    Estimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH4), at forests, grasslands, and

  17. Cerebral water and ion balance remains stable when humans are exposed to acute hypoxic exercise

    DEFF Research Database (Denmark)

    Avnstorp, Magnus B; Rasmussen, Peter; Brassard, Patrice

    2015-01-01

    Avnstorp, Magnus B., Peter Rasmussen, Patrice Brassard, Thomas Seifert, Morten Overgaard, Peter Krustrup, Niels H. Secher, and Nikolai B. Nordsborg. Cerebral water and ion balance remains stable when humans are exposed to acute hypoxic exercise. High Alt Med Biol 16:000-000, 2015.-Background...... metabolism and increased an index of cerebral blood flow, but cerebral net water and ion homeostasis remained stable. Thus, although AMS develops within hours and may be related to exercise-induced disturbance of cerebral ion and water balance, such changes are not detectable when subjects are exposed...

  18. Modelling membrane hydration and water balance of a pem fuel cell

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh

    2015-01-01

    and water content driving force is considered. We validate the model against experimental data. The water balance calculated by this model shows better fit with experimental data-points compared to other models such as the one by Springer et al.. We conclude that this discrepancy is due a different rate...

  19. Water Balance Simulations of a PEM Fuel Cell Using a Two-Fluid Model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, Madeleine; Kær, Søren Knudsen

    2010-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various humidificat......A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various...... humidification conditions. It was found that the specific surface area of the electrolyte in the catalyst layers close to the membrane is of critical importance for the overall water balance. Applying a high specific electrolyte surface area close to the membrane (a water-uptake layer) always leads to a lower...

  20. Finding Balance Between Biological Groundwater Treatment and Treated Injection Water

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Mark A.; Nielsen, Kellin R.; Byrnes, Mark E.; Simmons, Sally A.; Morse, John J.; Geiger, James B.; Watkins, Louis E.; McFee, Phillip M.; Martins, K.

    2015-01-14

    At the U.S. Department of Energy’s Hanford Site, CH2M HILL Plateau Remediation Company operates the 200 West Pump and Treat which was engineered to treat radiological and chemical contaminants in groundwater as a result of the site’s former plutonium production years. Fluidized bed bioreactors (FBRs) are used to remove nitrate, metals, and volatile organic compounds. Increasing nitrate concentrations in the treatment plant effluent and the presence of a slimy biomass (a typical microorganism response to stress) in the FBRs triggered an investigation of nutrient levels in the system. Little, if any, micronutrient feed was coming into the bioreactors. Additionally, carbon substrate (used to promote biological growth) was passing through to the injection wells, causing biological fouling of the wells and reduced specific injectivity. Adjustments to the micronutrient feed improved microorganism health, but the micronutrients were being overfed (particularly manganese) plugging the injection wells further. Injection well rehabilitation to restore specific injectivity required repeated treatments to remove the biological fouling and precipitated metal oxides. A combination of sulfamic and citric acids worked well to dissolve metal oxides and sodium hypochlorite effectively removed the biological growth. Intensive surging and development techniques successfully removed clogging material from the injection wells. Ultimately, the investigation and nutrient adjustments took months to restore proper balance to the microbial system and over a year to stabilize injection well capacities. Carefully tracking and managing the FBRs and well performance monitoring are critical to balancing the needs of the treatment system while reducing fouling mechanisms in the injection wells.

  1. Rethinking the terrestrial water balance: Steps toward a comprehensive indicator framework

    Science.gov (United States)

    Weiskel, P. K.; Wolock, D.; Zarriello, P. J.; Vogel, R. M.; Brandt, S. L.

    2009-12-01

    Freshwater scarcity for humans and ecosystems is one of the most serious global challenges of the 21st century. Caused in part by human disturbance of the hydrologic cycle, patterns of water scarcity also reflect large, underlying variations in terrestrial water availability that precede human influence. In recent years, growing concerns about water scarcity have prompted the development and application of distributed, continental-to-global scale water balance models for water-resource assessment, fostering the important new sub-discipline of global hydrology. However, fundamental concepts of water availability have not kept pace with developments in modeling tools. To facilitate fundamental thinking and communication in this growing field, we introduce a new indicator framework based on a spatially distributed, time-dependent approach to the terrestrial water balance. The framework takes advantage of gridded climate, hydrology, and landscape data, is equally pertinent to dryland and humid regions of the world, and integrates traditional (runoff-based) and emerging perspectives on terrestrial water availability—including the blue/green water paradigm now gaining currency in the global water planning and management community. We derive the indicator framework from a general statement of the landscape water balance equation, and then illustrate the relevance of the framework to the extremely diverse hydroclimates of the conterminous United States.

  2. Modelling the water balance of an inclined mature beech stand

    Science.gov (United States)

    Janott, Michael; Bittner, Sebastian; Gayler, Sebastian; Priesack, Eckart; Holst, Jutta

    2010-05-01

    We developed a xylem water transport model for European beech (Fagus sylvatica L.) to scale up organ based processes to the tree level and to quantify their influence on the whole tree transpiration and the water uptake from the soil. To better consider the root-soil interaction a finite element tree crown hydro-dynamics model was extended and further developed based on the 1D porous media equation by including in addition to the explicit 3D architectural representation of the tree crown a corresponding 3D characterisation of the root system. Subsequently this 1D xylem water flow model was coupled to a soil water flow model also derived from the 1D porous media equation. The model was tested using data of a 80 - 90 years old beech stand on a steep NE-slope on Rendzic Leptosol derived from limestone (Weißjura) located close to Tuttlingen, SW-Germany. The above-ground tree architecture of a representative mature beech tree was recorded by a laser scanner and digitized. The root architecture was estimated by applying a virtual root generator since detailed information on root distribution was not available due to the restricted accessibility of roots in soil. Input of measured meteorological and soil data in combination with plant specific parameters from literature enable the appropriate simulation of transpiration and soil water contents. In conclusion, the 1D porous media approach provided a computationally efficient method to simulate water flow in a soil-plant system as represented by mature beech trees. The model is able to reproduce main mechanisms of plant hydro-dynamics including sap flow and root water uptake from soil.

  3. Global, continental and regional water balance estimates from HYPE catchment modelling

    Science.gov (United States)

    Arheimer, Berit; Andersson, Jafet; Crochemore, Louise; Donnelly, Chantal; Gustafsson, David; Hasan, Abdoulghani; Isberg, Kristina; Pechlivanidis, Ilias; Pimentel, Rafael; Pineda, Luis

    2017-04-01

    In the past, catchment modelling mainly focused on simulating the lumped hydrological cycle at local to regional domains with high precision in a specific point of a river. Today, the level of maturity in hydrological process descriptions, input data and methods for parameter constraints makes it possible to apply these models also for multi-basins over large domains, still using the catchment modellers approach with high demands on agreement with observed data. HYPE is a process-oriented, semi-distributed and open-source model concept that is developed and used operationally in Sweden since a decade. Its finest calculation unit is hydrological response units (HRUs) in a catchment and these are assumed to give the same rainfall-runoff response. HRUs are normally made up of similar land cover and management, combined with soil type or elevation. Water divides are retrieved from topography and calculations are integrated for catchments, which can be of different spatial resolution and are coupled along the river network. In each catchment, HYPE calculates the water balance of a given time-step separately for various hydrological storages, such glaciers, active soil, groundwater, river channels, wetlands, floodplains, and lakes. The model is calibrated in a step-wise manner (following the water path-ways) against various sources additional data sources, including in-situ observations, Earth Observation products, soft information and expert judgements (Arheimer et al., 2012; Donnelly et al, 2016; Pechlivanidis and Arheimer 2015). Both the HYPE code and the model set-ups (i.e. input data and parameter values) are frequently released in new versions as they are continuously improved and updated. This presentation will show the results of aggregated water-balance components over large domains, such as the Arctic basin, the European continent, the Indian subcontinent and the Niger River basin. These can easily be compared to results from other kind of large-scale modelling

  4. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    Science.gov (United States)

    Lukáčová-Medvid'ová, M.; Noelle, S.; Kraft, M.

    2007-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensional hyperbolic systems, such that all of the infinitely many directions of wave propagation are taken into account explicitly. We derive a well-balanced approximation of the integral equations and prove that the FVEG scheme is well-balanced for the stationary steady states as well as for the steady jets in the rotational frame. Several numerical experiments for stationary and quasi-stationary states as well as for steady jets confirm the reliability of the well-balanced FVEG scheme.

  5. Leaching of heavy metals from water bottle components into the drinking water of rodents.

    Science.gov (United States)

    Nunamaker, Elizabeth A; Otto, Kevin J; Artwohl, James E; Fortman, Jeffrey D

    2013-01-01

    Providing high-quality, uncontaminated drinking water is an essential component of rodent husbandry. Acidification of drinking water is a common technique to control microbial growth but is not a benign treatment. In addition to its potential biologic effects, acidified water might interact with the water-delivery system, leading to the leaching of heavy metals into the drinking water. The goal of the current study was to evaluate the effects of water acidification and autoclaving on water-bottle assemblies. The individual components of the system (stainless-steel sipper tubes, rubber stoppers, neoprene stoppers, and polysulfone water bottles) were acid-digested and analyzed for cadmium, chromium, copper, iron, lead, magnesium, manganese, selenium, and zinc to quantify the metal composition of each material. In addition the amounts of these metals that leached into tap and acidified water with and without autoclaving were quantified after 1 wk of contact time. On a weight basis, sipper tubes contained the largest quantities of all metals except magnesium and zinc, which were greatest in the neoprene stoppers. Except for cadmium and selenium, all metals had leached into the water after 1 wk, especially under the acidified condition. The quantities of copper, lead, and zinc that leached into the drinking water were the most noteworthy, because the resulting concentrations had the potential to confound animal experiments. On the basis of these findings, we suggest that water-quality monitoring programs include heavy metal analysis at the level of water delivery to animals.

  6. Chemical and Physical Indicators in Drinking Water and Water Sources of Boroujerd Using Principal Components Analysis

    Directory of Open Access Journals (Sweden)

    Darabi , M. (MSC

    2014-05-01

    Full Text Available Background and Objective: Quality control of drinking water is important for maintaining health and safety of consumers, and the first step is to study the water quality variables. This study aimed to evaluate the chemical and physical indicators, water quality variables and qualitative classification of drinking water stations and water sources in Boroujerd. Material and Methods: This descriptive-cross sectional study was conducted on 70 samples of drinking water and 10 samples from sources in 2011-2012. Nine Water quality variables were measured and coded using STATISTICA10 Software. Principal component analysis (PCA was performed for qualitative classification of water samples and determination of water quality variables. Results: Based on PCA, chemical variables such as fluoride, nitrate, total hardness and iron, and physical variables such as pH and TDS were paramount importance to water quality. According to T-test, the average concentration of fluoride and iron, and the turbidity in all samples were significantly less than the standard. But other variables were up to standard. Conclusion: For the large water quality data, the use of PCA to identify the main qualitative variables and to classify physical and chemical variables can be used as an effective way in water quality management. Keywords: Physical and Chemical Indicators, Drinking Water and Sources, Boroujerd, Principal Component Analysis

  7. Implementation and evaluation of a monthly water balance model over the US on an 800 m grid

    Science.gov (United States)

    Hostetler, S. W.; Alder, J. R.

    2016-12-01

    We simulate the 1950-2010 water balance for the conterminous U.S. (CONUS) with a monthly water balance model (MWBM) using the 800 m Parameter-elevation Regression on Independent Slopes Model (PRISM) data set as model input. We employed observed snow and streamflow data sets to guide modification of the snow and potential evapotranspiration components in the default model and to evaluate model performance. Based on various metrics and sensitivity tests, the modified model yields reasonably good simulations of seasonal snowpack in the West (range of bias of ±50 mm at 68% of 713 SNOTEL sites), the gradients and magnitudes of actual evapotranspiration, and runoff (median correlation of 0.83 and median Nash-Sutcliff efficiency of 0.6 between simulated and observed annual time series at 1427 USGS gage sites). The model generally performs well along the Pacific Coast, the high elevations of the Basin and Range and over the Midwest and East, but not as well over the dry areas of the Southwest and upper Plains regions due, in part, to the apportioning of direct versus delayed runoff. Sensitivity testing and application of the MWBM to simulate the future water balance at four National Parks when driven by 30 climate models from the Climate Model Intercomparison Program Phase 5 (CMIP5) demonstrate that the model is useful for evaluating first-order, climate driven hydrologic change on monthly and annual time scales.

  8. Water balance in the complex mountainous terrain of Bhutan and linkages to land use

    Directory of Open Access Journals (Sweden)

    Ugyen Dorji

    2016-09-01

    Study Focus: Located in the Himalayas with elevation ranging 100–7550 m and with an area equivalent to Switzerland, Bhutan has great biodiversity despite its small area. A monsoon-dominated climate causes generally wet summer and dry winter. Bhutan is highly dependent of climatic conditions for its developmental activities. Using multiple regression analysis we have established models to predict the evapotranspiration (ETo and water balance and test the linkage to vegetation and land cover using meteorological data from 70 weather stations across Bhutan. Temperature-based ETo equations were evaluated in reference to the Penman-Monteith (PM method and a calibrated Hargreaves (H equation was used for computing the ETo. New Hydrological Insights for the Region. The calibrated Hargreaves equation gave good estimates of average daily ETo comparable to the PM ETo. The spatial variation in PM ETo is linked to variation in sunshine hours in summer and temperature in other seasons. Seasonal and annual ETo was mainly affected by elevation and latitude, which is linked to temperature and sunshine duration. Precipitation and water balance correlated positively with the Southern Oscillation Index (SOI while ETo correlated negatively. Our models for predicting ETo and water balances performed clearly better than the global CRU gridded data for Bhutan. A positive water balance is found in broadleaf forest areas and small or negative water balance for coniferous forests.

  9. Balancing the Interactions of Ions, Water, and DNA in the Drude Polarizable Force Field

    OpenAIRE

    Savelyev, Alexey; MacKerell, Alexander D.

    2014-01-01

    Recently we presented a first-generation all-atom Drude polarizable force field for DNA based on the classical Drude oscillator model, focusing on optimization of key dihedral angles followed by extensive validation of the force field parameters. Presently, we describe the procedure for balancing the electrostatic interactions between ions, water, and DNA as required for development of the Drude force field for DNA. The proper balance of these interactions is shown to impact DNA stability and...

  10. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    OpenAIRE

    Medvidová, Maria Lukáčová -; Noelle, Sebastian; Kraft, Marcus

    2015-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensio...

  11. Well-balanced finite volume evolution Galerkin methods for the shallow water equations

    OpenAIRE

    Lukácová-Medvid'ová, Maria; Kraft, Marcus

    2005-01-01

    We present a new well-balanced finite volume method within the framework of the finite volume evolution Galerkin (FVEG) schemes. The methodology will be illustrated for the shallow water equations with source terms modelling the bottom topography and Coriolis forces. Results can be generalized to more complex systems of balance laws. The FVEG methods couple a finite volume formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of the multidime...

  12. Water and solute balances as a basis for sustainable irrigation agriculture

    Science.gov (United States)

    Pla-Sentís, Ildefonso

    2015-04-01

    The growing development of irrigated agriculture is necessary for the sustainable production of the food required by the increasing World's population. Such development is limited by the increasing scarcity and low quality of the available water resources and by the competitive use of the water for other purposes. There are also increasing problems of contamination of surface and ground waters to be used for other purposes by the drainage effluents of irrigated lands. Irrigation and drainage may cause drastic changes in the regime and balance of water and solutes (salts, sodium, contaminants) in the soil profile, resulting in problems of water supply to crops and problems of salinization, sodification and contamination of soils and ground waters. This is affected by climate, crops, soils, ground water depth, irrigation and groundwater composition, and by irrigation and drainage management. In order to predict and prevent such problems for a sustainable irrigated agriculture and increased efficiency in water use, under each particular set of conditions, there have to be considered both the hydrological, physical and chemical processes determining such water and solute balances in the soil profile. In this contribution there are proposed the new versions of two modeling approaches (SOMORE and SALSODIMAR) to predict those balances and to guide irrigation water use and management, integrating the different factors involved in such processes. Examples of their application under Mediterranean and tropical climate conditions are also presented.

  13. Hydrogeophysics and Water Balance of Cerro Prieto Dam, NE Mexico

    Science.gov (United States)

    Yutsis, V.; de León Gómez, H.; Masuch Oesterreich, D.; Izaguirre, F.

    2007-05-01

    The geographical location of the State of Nuevo Leon, due to its physiographic features, has temperate and arid climate; undeveloped drainage, low precipitations, and high evapotranspiration rates, as well as rapid demographic growth. The hydrological data of the Pablillo basin, registered in the hydrometric station Cerro Prieto, showed an annual precipitation from 415 up to 1130 mm/a , the mean evaporation of 705 mm/a (up to 2460 mm/a in 1996). The maximum water storage of the Cerro Prieto reservoir is 395 millions m3 which corresponds to a water level of 295 meters. However, this level was reached only three times after the dam's construction. By the end of June 2006 the water level was at 276.2 m which corresponds to a water volume of about 127,806,300 m3 which is less than a third of maximum storage. Analysis of hydrological data showed sufficient misbalance between water recharge (by rain, river flow) and loss due to evaporation, filtration, extraction, discharge, etc. 160 gravity reading points, 400 onshore magnetic field readings as well as about 250 offshore magnetic points were carried out. The standard corrections as instrumental drift, latitude, elevation, IGRF, etc. were applied to obtained data. Data procession includes Fourier transformation, wavelength filters, upward continuation, vertical and horizontal derivates, etc. As a result a 2D geological-geophysical models and 3D maps were elaborated. The general trend of the magnetic field reduced to a pole is NW - SE on which background anomalies of northeast trend are obviously traced. The general trend of the gravity field received as a result of our works is the same. However, local magnetic and residual gravity anomalies have mosaic character and, being morphologically extended in a NE direction, grouped in chains of northwest trend. Potential data interpretation allows assuming a series of the superficial fractures focused in a NE direction, perpendicular (NW-SE) to the general deep fault. The

  14. The evolution and enlightenment of water resourcesaccounting from accounts to balance sheet

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    The Third Plenary Session of the 18th Central Committee of the Communist Party of China has proposed an importantnational strategic decision: to explore and establish the balance sheet of natural resources, to implement leaders' of-officeauditing system about natural resources assets. Water is one of the most essential nature resources of human beings; waterresources accounting, as an important water resources management tool, is an essential part of compiling the natural resourcesbalance sheet. In this paper, we provide a summary of the historic evolution of water resources accounting andanalyze its application in some typical countries. Although water resources accounting and water resources balance sheetreflect different implications and focus, both require water resources accounts as the basis in system establishment.

  15. Water balance complexities in ephemeral catchments with different land uses: Insights from monitoring and distributed hydrologic modeling

    Science.gov (United States)

    Dean, J. F.; Camporese, M.; Webb, J. A.; Grover, S. P.; Dresel, P. E.; Daly, E.

    2016-06-01

    Although ephemeral catchments are widespread in arid and semiarid climates, the relationship of their water balance with climate, geology, topography, and land cover is poorly known. Here we use 4 years (2011-2014) of rainfall, streamflow, and groundwater level measurements to estimate the water balance components in two adjacent ephemeral catchments in south-eastern Australia, with one catchment planted with young eucalypts and the other dedicated to grazing pasture. To corroborate the interpretation of the observations, the physically based hydrological model CATHY was calibrated and validated against the data in the two catchments. The estimated water balances showed that despite a significant decline in groundwater level and greater evapotranspiration in the eucalypt catchment (104-119% of rainfall) compared with the pasture catchment (95-104% of rainfall), streamflow consistently accounted for 1-4% of rainfall in both catchments for the entire study period. Streamflow in the two catchments was mostly driven by the rainfall regime, particularly rainfall frequency (i.e., the number of rain days per year), while the downslope orientation of the plantation furrows also promoted runoff. With minimum calibration, the model was able to adequately reproduce the periods of flow in both catchments in all years. Although streamflow and groundwater levels were better reproduced in the pasture than in the plantation, model-computed water balance terms confirmed the estimates from the observations in both catchments. Overall, the interplay of climate, topography, and geology seems to overshadow the effect of land use in the study catchments, indicating that the management of ephemeral catchments remains highly challenging.

  16. Water balance of global aquifers revealed by groundwater footprint.

    Science.gov (United States)

    Gleeson, Tom; Wada, Yoshihide; Bierkens, Marc F P; van Beek, Ludovicus P H

    2012-08-09

    Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems. Most assessments of global water resources have focused on surface water, but unsustainable depletion of groundwater has recently been documented on both regional and global scales. It remains unclear how the rate of global groundwater depletion compares to the rate of natural renewal and the supply needed to support ecosystems. Here we define the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services) and show that humans are overexploiting groundwater in many large aquifers that are critical to agriculture, especially in Asia and North America. We estimate that the size of the global groundwater footprint is currently about 3.5 times the actual area of aquifers and that about 1.7 billion people live in areas where groundwater resources and/or groundwater-dependent ecosystems are under threat. That said, 80 per cent of aquifers have a groundwater footprint that is less than their area, meaning that the net global value is driven by a few heavily overexploited aquifers. The groundwater footprint is the first tool suitable for consistently evaluating the use, renewal and ecosystem requirements of groundwater at an aquifer scale. It can be combined with the water footprint and virtual water calculations, and be used to assess the potential for increasing agricultural yields with renewable groundwaterref. The method could be modified to evaluate other resources with renewal rates that are slow and spatially heterogeneous, such as fisheries, forestry or soil.

  17. Shodagor Family Strategies : Balancing Work and Family on the Water.

    Science.gov (United States)

    Starkweather, Kathrine E

    2017-03-11

    The Shodagor of Matlab, Bangladesh, are a seminomadic community of people who live and work on small wooden boats, within the extensive system of rivers and canals that traverse the country. This unique ecology places particular constraints on family and economic life and leads to Shodagor parents employing one of four distinct strategies to balance childcare and provisioning needs. The purpose of this paper is to understand the conditions that lead a family to choose one strategy over another by testing predictions about socioecological factors that impact the sexual division of labor, including a family's stage in the domestic cycle, aspects of the local ecology, and the availability of alloparents. Results show that although each factor has an impact on the division of labor individually, a confluence of these factors best explains within-group, between-family differences in how mothers and fathers divide subsistence and childcare labor. These factors also interact in particular ways for Shodagor families, and it appears that families choose their economic strategies based on the constellation of constraints that they face. The results of these analyses have implications for theory regarding the sexual division of labor across cultures and inform how Shodagor family economic and parenting strategies should be contextualized in future studies.

  18. Studies on leaching of photoresist components by water

    Science.gov (United States)

    Oh, Seung Keun; Kim, Jong Yong; Jung, Young Ho; Lee, Jae Woo; Kim, Deog Bae; Kim, Jaehyun; Lee, Geun Su; Lee, Sung Koo; Ban, Keun Do; Jung, Jae Chang; Bok, Cheol Kyu; Moon, Seung Chan

    2005-05-01

    Immersion lithography has drawn tons of interests as a potential solution for sub-65nm patterning. High refractive index liquid, which is filled in the gap between exposure lens and a photoresist, can improve a resolution through increased effective numerical aperture (NA) of the exposure system. Most attractive liquid for this purpose is water. Our works were conducted as a part of the basic study for immersion lithography and aimed for the verification of leached resist components by water. It was observed that leaching relies largely on the free volume of a polymer and anion size of photoacid generator (PAG). The larger free volume and the smaller anion, the larger T-top resist profile was generated. Additionally, effects of solvents, quenchers and polarity of the polymer were investigated. Detailed results will be reported in this paper.

  19. Aestivation and diapause syndromes reduce the water balance requirements for pupae of the Hessian fly, Mayetiola destructor.

    Science.gov (United States)

    We report the water balance of aestivating (summer), diapausing (winter), and non-diapausing pupae of Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae). Maintaining water requirements during pupal dormancy is particularly important because water cannot be replenished actively by drink...

  20. Modelling the water balance of a precise weighable lysimeter for short time scales

    Science.gov (United States)

    Fank, Johann; Klammler, Gernot; Rock, Gerhard

    2015-04-01

    lysimeter has been calculated by adding lysimeter mass and the leachate tank mass for every minute. Based on the resolution of the scales and an evaluation of noise in periods without precipitation and evaporation a dmin-value of 0.002 to filter the leachate tank measurements and a dmin-value of 0.012 was used to filter the lysimeter weight data and the upper boundary data. A mandatory requirement for the quantification of P or ET from lysimeter measurements is that in a reasonably small time interval, either P or ET is negligible. With this assumption, every increase in upper boundary data is interpreted as P. Every increase of seepage mass is interpreted as L, every decrease as C. ΔS is evaluated from filtered lysimeter mass. ET is calculated using the water balance equation. The evaluation results are given as water balance components time series on a minute scale. P measured with the lysimeter for the two years 2010 and 2011 is 105 % of precipitation measured with a standard tipping bucket gauge 100 m beside the lysimeter. While P during the summer season (April to September) is very close to standard precipitation measurement, P during the winter season is more than 120 % of tipping bucket precipitation. Meissner et al. (2007) showed that P includes precipitation of dewfall and rime. A detailed evaluation of the HYDRO-Lysimeter in Wagna showed, that precipitation in the night and not recognized with the standard tipping bucket (interpreted as dew or rime) is about 1 % of P, the highest monthly sums (> 1 mm) are recognized from August to November. Klammler, G. and Fank, J.: Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria). Science of the Total Environment 499 (2014) 448-462. Meissner, R., Seeger, J., Rupp, H., Seyfarth, M., and Borg, H.: Measurement of dew, fog, and rime with a high-precision gravitation lysimeter, J. Plant Nutr. Soil Sci. 2007, 170, 335-344. Peters, A., Nehls, T., Schonsky, H

  1. Snow cover data derived from MODIS for water balance applications

    Directory of Open Access Journals (Sweden)

    A. Gafurov

    2009-02-01

    Full Text Available Snow cover information is of central importance for the estimation of water storage in cold mountainous regions. It is difficult to assess distributed snow cover information in a catchment in order to estimate possible water resources. It is especially a challenge to obtain snow cover information for high mountainous areas. Usually, snow depth is measured at meteorological stations, and it is relatively difficult to extrapolate this spatially or temporally since it highly depends on available energy and topography. The snow coverage of a catchment gives detailed information about the catchment's potential source for water. Many regions lack meteorological stations that measure snow, and usually no stations are available at high elevations.

    Satellite information is a very valuable source for obtaining several environmental parameters. One of the advantages is that the data is mostly provided in a spatially distributed format. This study uses satellite data to estimate snow coverage on high mountainous areas. Moderate-resolution Imaging Spectroradiometer (MODIS snow cover data is used in the Kokcha Catchment located in the north-eastern part of Afghanistan. The main disadvantage of MODIS data that restricts its direct use in environmental applications is cloud coverage. This is why this study is focused on eliminating cloud covered cells and estimating cell information under cloud covered cells using six logical, spatial and temporal approaches. The results give total cloud removal and mapping of snow cover for the study areas.

  2. Snow cover data derived from MODIS for water balance applications

    Science.gov (United States)

    Gafurov, A.; Bárdossy, A.

    2009-02-01

    Snow cover information is of central importance for the estimation of water storage in cold mountainous regions. It is difficult to assess distributed snow cover information in a catchment in order to estimate possible water resources. It is especially a challenge to obtain snow cover information for high mountainous areas. Usually, snow depth is measured at meteorological stations, and it is relatively difficult to extrapolate this spatially or temporally since it highly depends on available energy and topography. The snow coverage of a catchment gives detailed information about the catchment's potential source for water. Many regions lack meteorological stations that measure snow, and usually no stations are available at high elevations. Satellite information is a very valuable source for obtaining several environmental parameters. One of the advantages is that the data is mostly provided in a spatially distributed format. This study uses satellite data to estimate snow coverage on high mountainous areas. Moderate-resolution Imaging Spectroradiometer (MODIS) snow cover data is used in the Kokcha Catchment located in the north-eastern part of Afghanistan. The main disadvantage of MODIS data that restricts its direct use in environmental applications is cloud coverage. This is why this study is focused on eliminating cloud covered cells and estimating cell information under cloud covered cells using six logical, spatial and temporal approaches. The results give total cloud removal and mapping of snow cover for the study areas.

  3. Application of a water balance model for estimating deep infiltration in a karstic watershed

    Directory of Open Access Journals (Sweden)

    Maria Lúcia Calijuri

    2011-12-01

    Full Text Available The current scenario of water scarcity evidences the need for an adequate management of water resources. In karstic regions, the water flow through fractures significantly increases the water infiltration rate, which explains the small number of rivers and the importance of groundwater for urban supply. Therefore, the water balance is necessary since it may aid decision making processes and guide water management projects. The objective of this paper was to perform the water balance of a watershed situated in a karstic region quantifying infiltration, runoff and evapotranspiration. The study area is located near the Tancredo Neves International Airport in Confins, in the state of Minas Gerais, Brazil. Most of the area consists of forest formations (40.9%, and pastures (34.5%. In order to estimate deep infiltration, the BALSEQ model was used. BALSEQ is a numeric model of sequential water balance in which deep infiltration at the end of the day is given by the difference between daily precipitation and the sum of surface runoff, evapotranspiration and the variation of the amount of water stored in the soil. The results show that approximately 60% of total annual precipitation result in deep infiltration, considering the recharge period from September to March. After the dry period, the areas with no vegetal cover present higher deep infiltration. However, over the months, the contribution of the vegetated areas becomes greater, showing the importance of these areas to aquifer recharge.

  4. Increased fat catabolism sustains water balance during fasting in zebra finches.

    Science.gov (United States)

    Rutkowska, Joanna; Sadowska, Edyta T; Cichoń, Mariusz; Bauchinger, Ulf

    2016-09-01

    Patterns of physiological flexibility in response to fasting are well established, but much less is known about the contribution of water deprivation to the observed effects. We investigated body composition and energy and water budget in three groups of zebra finches: birds with access to food and water, food-deprived birds having access to drinking water and food-and-water-deprived birds. Animals were not stimulated by elevated energy expenditure and they were in thermoneutral conditions; thus, based on previous studies, water balance of fasting birds was expected to be maintained by increased catabolism of proteins. In contrast to this expectation, we found that access to water did not prevent reduction of proteinaceous tissue, but it saved fat reserves of the fasting birds. Thus, water balance of birds fasting without access to water seemed to be maintained by elevated fat catabolism, which generated 6 times more metabolic water compared with that in birds that had access to water. Therefore, we revise currently established views and propose fat to serve as the primary source for metabolic water production. Previously assumed increased protein breakdown for maintenance of water budget would occur if fat stores were depleted or if fat catabolism reached its upper limits due to high energy demands. © 2016. Published by The Company of Biologists Ltd.

  5. Dynamics of spectral components of heart rate variability during changes in autonomic balance

    DEFF Research Database (Denmark)

    Højgaard, M V; Holstein-Rathlou, N H; Agner, E;

    1998-01-01

    Frequency domain analysis of heart rate variability (HRV) has been proposed as a semiquantitative method for assessing activities in the autonomic nervous system. We examined whether absolute powers, normalized powers, and the low frequency-to-high frequency ratio (LF/HF) derived from the HRV power...... spectrum could detect shifts in autonomic balance in a setting with low sympathetic nervous tone. Healthy subjects were examined for 3 h in the supine position during 1) control conditions (n = 12), 2) acute beta-blockade (n = 11), and 3) chronic beta-blockade (n = 10). Heart rate fell during the first 40...

  6. Study of Six-Component Internal Strain Gage Balances for Use in the HIRT Facility

    Science.gov (United States)

    1975-07-01

    bridges, also provides a backlog of s t ress information on which to base this study. The two-shell balance has been an important instrument in the...Reference 1) Ftu (ksi) 300 Fty (ksi) 280 Fsu (ksi) 170 Elongation (%) 5 E (106 psi) 27,0 G (106psi) 10.2 Charpy V-notch (ft-lb) 17 KIC (ksi ~-n...varying BMC location can be used to attain higher normal force for given runs, thus allowing for more test points. Figure 7 is a graphic

  7. On the Links Between Photosynthesis and Soil Water Balance

    Science.gov (United States)

    Daly, E.; Porporato, A.; Rodriguez-Iturbe, I.

    2002-12-01

    The equations of soil moisture dynamics and a model of leaf gas exchange and water transport through the Soil-Plant-Atmosphere Continuum (SPAC) are coupled to explore the dependence of plant CO2 assimilation on soil moisture. The model is also coupled with a daily growing boundary layer model, that gives the values of air specific humidity and potential temperature during the day. Two different approaches for modeling stomatal conductance gs are implemented and compared. One is the mixed-empirical formulation of stomatal conductance used by Jarvis (1976), who assumed a multiplicative relationship among the main environmental factors affecting stomatal movement; the other one is the empirical relationship between stomatal conductance and assimilation introduced by Ball et al. (1987) and modified by Leuning (1990, 1995), that assume a direct dependence of stomatal movement on the assimilation rate. This second approach is extended to include drought conditions and the common bases underlying the two approaches are elucidated. The model also gives the soil moisture value below which plants are under stress and the moisture content at the wilting point. These are used to evaluate the probability distribution of soil moisture, carbon assimilation by photosynthesis and plant water stress, thus providing a more physical basis to a previous stochastic model of soil moisture by the authors.

  8. Adjusting soil water balance calculations for light rainfall, dew, and fog.

    Science.gov (United States)

    Snyder, R. L.; Spano, D.; Moratiel, R.

    2012-04-01

    The main sources of water for an irrigated crop include irrigation applications, precipitation, water tables, fog interception, and dew formation. For a well-drained soil in a climate where there are a few events of fog, dew, or light rainfall, computing a water balance is relatively easy, but it is complicated in regions characterized by considerable events of fog, dew and light rainfall. In these regions, growers are hesitant to use ET-Based scheduling because the cumulative crop evapotranspiration is often considerably higher than the soil water depletion. We will present a simple and practical procedure to estimate the contribution of fog interception, dew, and light rainfall to daily crop evapotranspiration in California and to show how to use the information to improve water balance calculations for efficient water use in irrigation. It is assumed that the relationship between normalized hourly ETo and time of the day is similar to the relationship between normalized hourly ETc and time of the day. We can describe the change in soil water depletion (ΔDSW) on that day as: ΔDsw =ETc x F where F is the fraction of ETc coming from the soil, and F is determined using the expression: F = --1--- 1+ e(t-11.265.5) Where t is the approximate local standard time in hours when the crop dries. This simple method improves water balance scheduling and the adoption of the ET-based scheduling method in microclimates where fog, dew, and light rainfall are common.

  9. Evaluating the Effects of Mulch and Irrigation Amount on Soil Water Distribution and Root Zone Water Balance Using HYDRUS-2D

    Directory of Open Access Journals (Sweden)

    Ming Han

    2015-05-01

    Full Text Available Water scarcity is the most critical constraint for sustainable cotton production in Xinjiang Province, northwest China. Drip irrigation under mulch is a major water-saving irrigation method that has been widely practiced for cotton production in Xinjiang. The performance of such an irrigation system should be evaluated for proper design and management. Therefore, a field experiment and a simulation study were conducted to (1 determine a modeling approach that can be applied to manage drip irrigation under mulch for cotton production in this region; and (2 examine the effects of irrigation amount and mulch on soil water distribution and root zone water balance components. In the experiment, four irrigation treatments were used: T1, 166.5 m3; T2, 140.4 m3; T3, 115.4 m3; and T4: 102.3 m3. The HYDRUS-2D model was calibrated, validated, and applied with the data obtained in this experiment. Soil water balance in the 0–70 cm soil profile was simulated. Results indicate that the observed soil water content and the simulated results obtained with HYDRUS-2D are in good agreement. The radius of the wetting pattern, root water uptake, and evaporation decreased as the amount of irrigation was reduced from T1 to T4, while a lot of stored soil water in the root zone was utilized and a huge amount of water was recharged from the layer below 70 cm to compensate for the decrease in irrigation amount. Mulch significantly reduced evaporation by 11.7 mm and increased root water uptake by 11.2 mm. Our simulation study suggests that this model can be applied to provide assistance in designing drip irrigation systems and developing irrigation strategies.

  10. Balancing water, religion and tourism on Redang Island, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Joshua B [Environmental Change Institute, School of Geography and the Environment, Oxford University, South Parks Road, Oxford OX1 0EZ (United Kingdom); Nawaz, Rizwan; Nawaz, Faiza [HydroRisk Ltd, Leeds University Union, Lifton Place, University of Leeds, Leeds LS2 9JT (United Kingdom); Fauzi, Rosmadi [Department of Geography, Universiti Malaya, 50603 Kuala Lumpur (Malaysia); Sadek, Eran Sadek Said Md; Latif, Zulkiflee Abd [Department of Surveying Science and Geomatics, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Blackett, Matthew [Department of Geography, King' s College London, Strand, London WC2R 2LS (United Kingdom)], E-mail: joshbfisher@gmail.com

    2008-04-15

    Redang Island (Pulau Redang) is an island off of Peninsular Malaysia that is part of a Marine Park archipelago of corals and thousands of fish and invertebrates. The relatively isolated local community is generally centered on fishing, and Islam guides daily life. Recently, the tourism industry has expanded on the island. New hotels and resorts provide jobs, but also expose the locals to western culture and touristic behavior, which may clash with deeply traditional community values. Further, the tourism industry may be putting a strain on the natural resources, especially the quantity and quality of freshwater. The island village may become divided between those who support the tourism industry and those who do not. Here we present an exploratory investigation into the development-environment-culture dynamics of tourism, water and religion on Redang Island while building collaborations between universities of this Muslim state and the West.

  11. Balancing water, religion and tourism on Redang Island, Malaysia

    Science.gov (United States)

    Fisher, Joshua B.; Nawaz, Rizwan; Fauzi, Rosmadi; Nawaz, Faiza; Sadek, Eran Sadek Said Md; Abd Latif, Zulkiflee; Blackett, Matthew

    2008-04-01

    Redang Island (Pulau Redang) is an island off of Peninsular Malaysia that is part of a Marine Park archipelago of corals and thousands of fish and invertebrates. The relatively isolated local community is generally centered on fishing, and Islam guides daily life. Recently, the tourism industry has expanded on the island. New hotels and resorts provide jobs, but also expose the locals to western culture and touristic behavior, which may clash with deeply traditional community values. Further, the tourism industry may be putting a strain on the natural resources, especially the quantity and quality of freshwater. The island village may become divided between those who support the tourism industry and those who do not. Here we present an exploratory investigation into the development environment culture dynamics of tourism, water and religion on Redang Island while building collaborations between universities of this Muslim state and the West.

  12. Norway's historical and projected water balance in TWh

    Science.gov (United States)

    Haddeland, Ingjerd; Holmqvist, Erik

    2015-04-01

    Hydroelectric power production is closely linked to the water cycle, and variations in power production numbers reflect variations in weather. The expected climate changes will influence electricity supply through changes in annual and seasonal inflow of water to hydropower reservoirs. In Norway, more than 95 percent of the electricity production is from hydroelectric plants, and industry linked to hydropower has been an important part of the society for more than a century. Reliable information on historical and future available water resources is hence of crucial importance both for short and long-term planning and adaptation purposes in the hydropower sector. Traditionally, the Multi-area Power-market Simulator (EMPS) is used for modelling hydropower production in Norway. However, due to the models' high level of details and computational demand, this model is only used for historical analyses and a limited number of climate projections. A method has been developed that transfers water fluxes (mm day-1) and states (mm) into energy units (GWh mm-1), based on hydrological modelling of a limited number of catchments representing reservoir inflow to more than 700 hydropower plants in Norway. The advantages of using the conversion factor method, compared to EMPS, are its simplicity and low computational requirements. The main disadvantages are that it does not take into account flood losses and the time lag between inflow and power production. The method is used operationally for weekly and seasonal energy forecasts, and has proven successful at the range of results obtained for reproducing historical hydropower production numbers. In hydropower energy units, mean annual precipitation for the period 1981-2010 is estimated at 154 TWh year-1. On average, 24 TWh year-1 is lost through evapotranspiration, meaning runoff equals 130 TWh year-1. There are large interannual variations, and runoff available for power production ranges from 91 to 165 TWh year-1. The snow pack

  13. Designing of Hydraulically Balanced Water Distribution Network Based on GIS and EPANET

    Directory of Open Access Journals (Sweden)

    RASOOLI Ahmadullah

    2016-02-01

    Full Text Available The main objectives of this paper are, designing and balancing of Water Distribution Network (WDN based on loops hydraulically balanced method as well as using Geographical Information System (GIS methodology with the contribution of EPANET. GIS methodology is used to ensure WDN’s integrity and skeletonized a proper and functional WDN by using Network Analyst utilizing the geometric network and topology network by hierarchical geo-databases. The problem is to make WDN hydraulically balanced by applying WDN balancing method. For that reason, we have analyzed water flows in each pipe and performed the iterations process on loops in order to make the algebraic summation of head loss“h_f” around any closed loop zero. In case, the summation of pipe flows must be equal to the flow amount entering or leaving the system through each node. At each iteration, reasonable changes occurred at pipes flow until the head loss has become very small or fixed zero as (optimizes correction by using excel sheet solver. Since this method is confirmed to be effective, simulations were done by using GIS and EPANET water distribution platform. As a result, we accomplished hydraulically balanced WDN. Finally, we have analyzed and simulated hydraulics parameters for the targeted area in Kabul city. Thus, determined successfully the hydraulics state of parameters around the network as a positive result. It is worth mentioning that, Hardy-cross method is being used for approaching more precise optimized correction and consequences concerning hydraulically-balanced and optimal WDN. This method can be done for complex loops WDN as well; the advantage of the method is simple math and self-correction. Managers and engineers who work in the field of water supply this methodology has been recommended as the more advantageous workflow in planning water distribution pattern.

  14. Semi-arid vegetation response to antecedent climate and water balance windows

    Science.gov (United States)

    Thoma, David P.; Munson, Seth M.; Irvine, Kathryn M.; Witwicki, Dana L.; Bunting, Erin

    2016-01-01

    Questions Can we improve understanding of vegetation response to water availability on monthly time scales in semi-arid environments using remote sensing methods? What climatic or water balance variables and antecedent windows of time associated with these variables best relate to the condition of vegetation? Can we develop credible near-term forecasts from climate data that can be used to prepare for future climate change effects on vegetation? Location Semi-arid grasslands in Capitol Reef National Park, Utah, USA. Methods We built vegetation response models by relating the normalized difference vegetation index (NDVI) from MODIS imagery in Mar–Nov 2000–2013 to antecedent climate and water balance variables preceding the monthly NDVI observations. We compared how climate and water balance variables explained vegetation greenness and then used a multi-model ensemble of climate and water balance models to forecast monthly NDVI for three holdout years. Results Water balance variables explained vegetation greenness to a greater degree than climate variables for most growing season months. Seasonally important variables included measures of antecedent water input and storage in spring, switching to indicators of drought, input or use in summer, followed by antecedent moisture availability in autumn. In spite of similar climates, there was evidence the grazed grassland showed a response to drying conditions 1 mo sooner than the ungrazed grassland. Lead times were generally short early in the growing season and antecedent window durations increased from 3 mo early in the growing season to 1 yr or more as the growing season progressed. Forecast accuracy for three holdout years using a multi-model ensemble of climate and water balance variables outperformed forecasts made with a naïve NDVI climatology. Conclusions We determined the influence of climate and water balance on vegetation at a fine temporal scale, which presents an opportunity to forecast vegetation

  15. Characteristics of the Surface Turbulent Flux and the Components of Radiation Balance over the Grasslands in the Southeastern Tibetan Plateau

    Science.gov (United States)

    Li, H.; Xiao, Z.; Wei, J.

    2016-12-01

    Characteristics of the Surface Turbulent Flux and the Components of Radiation Balance over the Grasslands in the Southeastern Tibetan PlateauHongyi Li 1, Ziniu Xiao 2 and Junhong Wei31 China Meteorological Administration Training Centre, Beijing, China2 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China 3Theory of Atmospheric Dynamics and Climate, Institute for Atmospheric and Environmental Sciences, Goethe University of Frankfurt, Campus Riedberg, GermanyAbstract:Based on the field observation data over the grasslands in the southeastern Tibetan Plateau and the observational datasets in Nyingchi weather station for the period from May 20 to July 9, 2013, the variation characteristics of the basic meteorological elements in Nyingchi weather station, the surface turbulent fluxes and the components of radiation balance over the grasslands, as well as their relationships, are analyzed in this paper. The results show that in Nyingchi weather station, the daily variations of relative humidity and average total cloud cover are consistent with that of precipitation, but that those of daily average air temperature, daily average ground temperature, daily average wind speed and daily sunshine duration have an opposite change to that of precipitation. During the observation period, latent heat exchange is greater than sensible heat exchange, and latent heat flux is significantly higher when there is rainfall, but sensible heat flux and soil heat flux are lower. The daily variation of the total solar radiation (DR) is synchronous with that of sensible heat flux, and the daily variations of reflective solar radiation (UR), long wave radiation by earth (ULR), net radiation (Rn) and surface albedo are consistent with DR, but that of the long wave radiation by atmosphere (DLR) has an opposite change. The diurnal variations of sensible heat flux, latent

  16. The Climate change impact on the water balance and use efficiency of two contrasting water limited Mediterranean ecosystems in Sardinia

    Science.gov (United States)

    Montaldo, Nicola; Corona, Roberto; Albertson, John

    2016-04-01

    . Sardinia island is a very interesting and representative region of Mediterranean ecosystems. It is low urbanized, and is not irrigated, except some plan areas close to the main cities where main agricultural activities are concentrated. The two case study sites are within the Flumendosa river basin, with similar height a.s.l., and close (distance of 4 km). But the first site is a typically grass site located on an alluvial plan valley with a soil depth more than 2m, while the second site is a patchy mixture of Mediterranean vegetation types with wild olive trees and C3 herbaceous (grass) species and the soil thickness varies from 15-40 cm. In both sites land-surface fluxes and CO2 fluxes are estimated by eddy correlation technique based micrometeorological towers. Soil moisture profiles were also continuously estimated using water content reflectometers and gravimetric method, and periodically leaf area index (LAI) PFTs are estimated from 2003. An ecohydrologic model is successfully tested to the case studies. It couples a vegetation dynamic model (VDM), which computes the change in biomass over time for the PFTs, and a 3-component (bare soil, grass and woody vegetation) land surface model (LSM). Model is first used for simulating historically land surface fluxes from 1922 at the two sites. Climate change scenarios are then generated using a stochastic weather generator. It simulates hydrometeorological variables from historical time series altered by IPCC meteorological change predictions. The VDM-LSM predicts soil water balance and vegetation dynamics for the generated hydrometeorological scenarios at the two sites. Results demonstrate that contrasting climate change effects (decrease of winter precipitation vs increase of spring-summer air temperature) are significantly impacting land surface interactions (evapotranspiration and runoff dynamics) but with different effects on the two contrasting sites, due to the key role of the soil depth. Water resources predictions

  17. Performance of materials in the component cooling water systems of pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.S.

    1993-06-01

    The component cooling water (CCW) system provides cooling water to several important loads throughout the plant under all operating conditions. An aging assessment CCW systems in pressurized water reactors (PWRs) was conducted as part of Nuclear Plant Aging Research Program (NPAR) instituted by the US Nuclear Regulatory Commission. This paper presents some of the results on the performances of materials in respect of their application in CCW Systems. All the CCW system failures reported to the Nuclear Plant Reliability Data System (NPRDS) from January 1988 to June 1990 were reviewed; it is concluded that three of the main contributors to CCW system failures are valves, pumps, and heat exchangers. This study identified the modes and causes of failure for these components; most of the causes for the aging-related failures could be related to the performance of materials. Also, in this paper the materials used for these components are reviewed, and there aging mechanisms under CCW system conditions are discussed.

  18. Isotopic Estimation of Water Balance and Groundwater-Surface Water Interactions of Tropical Wetland Lakes in the Pantanal, Brazil

    Science.gov (United States)

    Schwerdtfeger, J.; Johnson, M. S.; Weiler, M.; Couto, E. G.

    2009-12-01

    The Pantanal is the largest and most pristine wetland of the world, yet hydrological research there is still in its infancy. In particular the water balance of the millions of lakes and ponds and their interaction with the groundwater and the rivers are not known. The aim of this study was to assess the hydrological behaviour between different water bodies in the dry season of the northern Pantanal wetland, Brazil, to provide a more general understanding of the hydrological functioning of tropical floodplain lakes and surface water-groundwater interactions of wetlands. In the field 6-9 water sample of seven different lakes were taken during 3 months and were analyzed for stable water isotopes and chloride. In addition meteorological data from a nearby station was used to estimate daily evaporation from the water surface. This information was then used to predict the hydrological dynamics to determine whether the lakes are evaporation-controlled or throughflow-dominated systems. A chloride mass balance served to evaluate whether Cl- enrichment took place due to evaporation only, or whether the system has significant inflow and/or outflow rates. The results of those methods showed that for all lakes the water budget in the dry season, output was controlled by strong evaporation while significant inflow rates were also apparent. Inflow rates and their specific concentrations in stable isotopes and chloride were successfully estimated using the simple mass balance model MINA TrêS. This approach enabled us to calculate the water balance for the lakes as well as providing an information on source water flowing into the lakes.

  19. Performance of Water Recirculation Loop Maintentance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  20. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  1. A stochastic approach for the description of the water balance dynamics in a river basin

    Directory of Open Access Journals (Sweden)

    S. Manfreda

    2008-09-01

    Full Text Available The present paper introduces an analytical approach for the description of the soil water balance dynamics over a schematic river basin. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance. This equation can be solved assuming known the spatial distribution of the soil moisture over the basin transforming the two-dimensional problem in space in a one dimensional one. This assumption is particularly true in the case of humid and semihumid environments, where spatial redistribution becomes dominant producing a well defined soil moisture pattern. The model allowed to derive the probability density function of the saturated portion of a basin and of its relative saturation. This theory is based on the assumption that the soil water storage capacity varies across the basin following a parabolic distribution and the basin has homogeneous soil texture and vegetation cover. The methodology outlined the role played by the soil water storage capacity distribution of the basin on soil water balance. In particular, the resulting probability density functions of the relative basin saturation were found to be strongly controlled by the maximum water storage capacity of the basin, while the probability density functions of the relative saturated portion of the basin are strongly influenced by the spatial heterogeneity of the soil water storage capacity. Moreover, the saturated areas reach their maximum variability when the mean rainfall rate is almost equal to the soil water loss coefficient given by the sum of the maximum rate of evapotranspiration and leakage loss in the soil water balance. The model was tested using the results of a continuous numerical simulation performed with a semi-distributed model in order to validate the proposed theoretical distributions.

  2. Evaporation and energy balance of partially covered water reservoirs using self-assembling floating elements

    Science.gov (United States)

    Aminzadeh, Milad; Lehmann, Peter; Or, Dani

    2017-04-01

    The projected increase in fresh water storage to meet growing municipal and irrigation needs and mitigate effects of rainfall variability and prolonged droughts will require new measures for suppressing evaporation from reservoirs and conserve water resources. A low risk and cost effective means for evaporation suppression uses self-assembling floating elements. We seek to develop a systematic framework for quantifying impacts of various cover designs and properties on heat and mass fluxes and energy balance of water reservoirs of different characteristics and climatic regions. The vertical energy balance equation including diurnal and seasonal variations in atmospheric forcing and energy transport to the water column was employed to resolve temperature and flux dynamics from water bodies. We then consider energy coupling of a unit floating cover element with water body (including lateral heat exchanges) to evaluate effect of different cover designs, climate conditions, and reservoir characteristics on evaporation suppression and energy balance of water body. The mechanistic framework offers a means for evaluating ecological impacts of covers, enables consideration of different cover designs (shape, size, thermal and radiative properties), and advances this largely empirical resource conservation strategy into a predictive framework for design and management purposes.

  3. Water balance of different forests types in Kiskunság Sandridge

    Science.gov (United States)

    Bolla, Bence; Kalicz, Péter

    2017-04-01

    Kiskunság Sandridge in central Hungary shows the signs of significant drying caused by anthropogenic (e.g. river regulation and water consumption) and climatic reasons. These factors generated dramatically decreasing of groundwater levels which was an important water supply for forest ecosystems. These worsening in site conditions bring up several questions in forest management and natural protection as well because significant part of forests are in protected areas in Kiskunság. This study aims to give a picture of the characteristic features of Sandridge forests concerning their water balance. Hydrology of forest sites were evaluated throughout measurement of hydrological elements and water balance modelling with the Coup 1D water-balance model. Three forest stands and five control stations in the grasslands were settled and monitored to compare the water consumption of different forests with native grasslands. This case study helps the work of forest managers with the quantification of water consumption of forests in Kiskunság. This research has been partly supported by the Agroclimate.2 VKSZ_12-1-2013-0034 project, and the second author's work was also supported by the János Bolyai Scholarship of the Hungarian Academy of Sciences.

  4. Vascular functioning and the water balance of ripening kiwifruit (Actinidia chinensis) berries

    Science.gov (United States)

    Clearwater, Michael J.; Luo, Zhiwei; Ong, Sam Eng Chye; Blattmann, Peter; Thorp, T. Grant

    2012-01-01

    Indirect evidence suggests that water supply to fleshy fruits during the final stages of development occurs through the phloem, with the xylem providing little water, or acting as a pathway for water loss back to the plant. This inference was tested by examining the water balance and vascular functioning of ripening kiwifruit berries (Actinidia chinensis var. chinensis ‘Hort16A’) exhibiting a pre-harvest ‘shrivel’ disorder in California, and normal development in New Zealand. Dye labelling and mass balance experiments indicated that the xylem and phloem were both functional and contributed approximately equally to the fruit water supply during this stage of development. The modelled fruit water balance was dominated by transpiration, with net water loss under high vapour pressure deficit (Da) conditions in California, but a net gain under cooler New Zealand conditions. Direct measurement of pedicel sap flow under controlled conditions confirmed inward flows in both the phloem and xylem under conditions of both low and high Da. Phloem flows were required for growth, with gradual recovery after a step increase in Da. Xylem flows alone were unable to support growth, but did supply transpiration and were responsive to Da-induced pressure fluctuations. The results suggest that the shrivel disorder was a consequence of a high fruit transpiration rate, and that the perception of complete loss or reversal of inward xylem flows in ripening fruits should be re-examined. PMID:22155631

  5. Strengthening of the hydrological cycle in future scenarios: atmospheric energy and water balance perspective

    Directory of Open Access Journals (Sweden)

    A. Alessandri

    2012-07-01

    Full Text Available Future climate scenarios experiencing global warming are expected to strengthen hydrological cycle during 21st century by comparison with the last decades of 20th century. We analyze strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. Furthermore, by combining energy and water equations for the whole atmosphere we profitably obtain constraints for the changes in surface fluxes and for the partitioning at the surface between sensible and latent components.

    Above approach is applied to investigate difference in strengthening of hydrological cycle in two scenario centennial simulations performed with an Earth System model forced with specified atmospheric concentration pathways. Alongside the medium-high non-mitigation scenario SRES A1B, we considered a new aggressive-mitigation scenario (E1 with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K. Quite unexpectedly, mitigation scenario is shown to strengthen hydrological cycle more than SRES A1B till around 2070. Our analysis shows that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to the abated aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B.

    In contrast, last decades of 21st century (21C show marked increase of global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost same overall increase of radiative imbalance with respect to 20th century. Our results show that radiative cooling is weakly effective in A1B throughout all 21C, so that two distinct mechanisms characterize the diverse strengthening of hydrological cycle in mid and end 21C. It is only through a very large perturbation of surface fluxes that A1B achieves larger increase

  6. Evaluating the hydrological consistency of satellite based water cycle components

    KAUST Repository

    Lopez Valencia, Oliver M.

    2016-06-15

    Advances in multi-satellite based observations of the earth system have provided the capacity to retrieve information across a wide-range of land surface hydrological components and provided an opportunity to characterize terrestrial processes from a completely new perspective. Given the spatial advantage that space-based observations offer, several regional-to-global scale products have been developed, offering insights into the multi-scale behaviour and variability of hydrological states and fluxes. However, one of the key challenges in the use of satellite-based products is characterizing the degree to which they provide realistic and representative estimates of the underlying retrieval: that is, how accurate are the hydrological components derived from satellite observations? The challenge is intrinsically linked to issues of scale, since the availability of high-quality in-situ data is limited, and even where it does exist, is generally not commensurate to the resolution of the satellite observation. Basin-scale studies have shown considerable variability in achieving water budget closure with any degree of accuracy using satellite estimates of the water cycle. In order to assess the suitability of this type of approach for evaluating hydrological observations, it makes sense to first test it over environments with restricted hydrological inputs, before applying it to more hydrological complex basins. Here we explore the concept of hydrological consistency, i.e. the physical considerations that the water budget impose on the hydrologic fluxes and states to be temporally and spatially linked, to evaluate the reproduction of a set of large-scale evaporation (E) products by using a combination of satellite rainfall (P) and Gravity Recovery and Climate Experiment (GRACE) observations of storage change, focusing on arid and semi-arid environments, where the hydrological flows can be more realistically described. Our results indicate no persistent hydrological

  7. Vegetation water stress monitoring with remote sensing-based energy balance modelling

    Science.gov (United States)

    González-Dugo, Maria P.; Andreu, Ana; Carpintero, Elisabet; Gómez-Giráldez, Pedro; José Polo, María

    2014-05-01

    Drought is one of the major hazards faced by agroforestry systems in southern Europe, and an increase in frequency is predicted under the conditions of climate change for the region. Timely and accurate monitoring of vegetation water stress using remote sensing time series may assist early-warning services, helping to assess drought impacts and the design of management actions leading to reduce the economic and environmental vulnerability of these systems. A holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs, and it is considered an example of sustainable land use, with great importance in the rural economy. Soil water dynamics is known to have a central role in current tree decline and the reduction of the forested area that is threatening its conservation. A two-source thermal-based evapotranspiration model (TSEB) has been applied to monitor the effect on vegetation water use of soil moisture stress in a dehesa located in southern Spain. The TSEB model separates the soil and canopy contributions to the radiative temperature and to the exchange of surface energy fluxes, so it is especially suited for partially vegetated landscapes. The integration of remotely sensed data in this model may support an evaluation of the whole ecosystem state at a large scale. During two consecutive summers, in 2012 and 2013, time series of optical and thermal MODIS images, with 250m and 1 km of spatial resolution respectively, have been combined with meteorological data provided by a ground station to monitor the evapotranspiration (ET) of the system. An eddy covariance tower (38°12' N; 4°17' W, 736 m a.s.l), equipped with instruments to measure all the components of the energy balance and 1 km of homogeneous fetch in the predominant wind

  8. Treatment of alternated water-electrolyte balance and endocrine status after removal of craniopharyngioma in adults

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; ZHAO Shang-feng; ZHANG Wei; ZHANG Mao-zhi

    2006-01-01

    Background Water-electrolyte disturbance and endocrine alterations are common complications of adult patients with craniopharygioma in the postoperative period and may affect their recovery and prognosis. Some of these complications even lead to death. Appropriate remedy based upon the status of water-electrolyte balance and the endocrine system is essential to good therapeutic results of adult patients with craniopharyngioma.Methods The alterations in water-electrolyte balance (117 patients) and endocrine status (42) of adult patients with craniopharyngioma after surgery were analyzed retrospectively.Results Most patients with craniopharyngioma experienced postoperative water-electrolyte disturbances and hypotonic dehydration. Moreover, the incidences of hypothyroidism and hypoadrenocorticism were relatively high.Conclusion It is critical to deal with dehydration and endocrine disorders for a sound outcome of craniopharyngioma surgery.

  9. Climatological evaluation of some fluxes of the surface energy and soil water balances over France

    Directory of Open Access Journals (Sweden)

    E. M. Choisnel

    Full Text Available This paper presents some statistical evaluations of the surface energy and soil water balance fluxes, for a prairie-type canopy, using the Earth model with a double-reservoir system for the management of the soil water reserve and the regulation of actual evapotranspiration. The mean values of these fluxes are estimated from energy and water balance simulations done on a 30-year climatic reference period (1951–1980. From values of these fluxes calculated for each meteorological synoptic station, mappings of net radiation, actual evapotranspiration, drainage and conduction fluxes have been made over French territory. Lastly, a few conclusions pertaining to the spatial variability of fluxes and to the partition of rainfall between run-off and drainage on the one hand and replenishment of the soil water reserve on the other hand are drawn from these preliminary results.

  10. Soil moisture assimilation using a modified ensemble transform Kalman filter with water balance constraint

    Science.gov (United States)

    Wu, Guocan; Zheng, Xiaogu; Dan, Bo

    2016-04-01

    The shallow soil moisture observations are assimilated into Common Land Model (CoLM) to estimate the soil moisture in different layers. The forecast error is inflated to improve the analysis state accuracy and the water balance constraint is adopted to reduce the water budget residual in the assimilation procedure. The experiment results illustrate that the adaptive forecast error inflation can reduce the analysis error, while the proper inflation layer can be selected based on the -2log-likelihood function of the innovation statistic. The water balance constraint can result in reducing water budget residual substantially, at a low cost of assimilation accuracy loss. The assimilation scheme can be potentially applied to assimilate the remote sensing data.

  11. A balanced water layer concept for subglacial hydrology in large-scale ice sheet models

    Directory of Open Access Journals (Sweden)

    S. Goeller

    2013-07-01

    Full Text Available There is currently no doubt about the existence of a widespread hydrological network under the Antarctic Ice Sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux–basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  12. A balanced water layer concept for subglacial hydrology in large scale ice sheet models

    Science.gov (United States)

    Goeller, S.; Thoma, M.; Grosfeld, K.; Miller, H.

    2012-12-01

    There is currently no doubt about the existence of a wide-spread hydrological network under the Antarctic ice sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain inspired by the Gamburtsev Mountains, Antarctica. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux-basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out, that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  13. Water Balance Simulations of a PEM Fuel Cell Using a Two-Fluid Model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, Madeleine; Kær, Søren Knudsen

    2010-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various humidificat...

  14. Model studies on salt and water balances at Konanki pilot area, Andhra Pradesh, India

    NARCIS (Netherlands)

    Srinivasulu, A.; Sujani Rao, C.; Lakshmi, G.V.; Satyanarayana, T.V.; Boonstra, J.

    2004-01-01

    The salt and water balances at Konanki pilot area in Nagarjunasagar project right canal command in Andhra Pradesh State of India were analysed using SALTMOD. The model was calibrated by using two-year data collected in the pilot area. From the calibration, the leaching efficiencies of the root and t

  15. Assessing climate change impacts on water balance in the Mount Makiling forest, Philippines

    Indian Academy of Sciences (India)

    E A Combalicer; R V O Cruz; S Lee; S Im

    2010-06-01

    A statistical downscaling known for producing station-scale climate information from GCM output was preferred to evaluate the impacts of climate change within the Mount Makiling forest watershed, Philippines. The lumped hydrologic BROOK90 model was utilized for the water balance assessment of climate change impacts based on two scenarios (A1B and A2) from CGCM3 experiment. The annual precipitation change was estimated to be 0.1–9.3% increase for A1B scenario, and −3.3 to 3.3% decrease/increase for the A2 scenario. Difference in the mean temperature between the present and the 2080s were predicted to be 0.6–2.2°C and 0.6–3.0°C under A1B and A2 scenarios, respectively. The water balance showed that 42% of precipitation is converted into evaporation, 48% into streamflow, and 10% into deep seepage loss. The impacts of climate change on water balance reflected dramatic fluctuations in hydrologic events leading to high evaporation losses, and decrease in streamflow, while groundwater flow appeared unaffected. A study on the changes in monthly water balance provided insights into the hydrologic changes within the forest watershed system which can be used in mitigating the effects of climate change.

  16. Surface energy balance of fresh and saline waters : AquaSEBS

    NARCIS (Netherlands)

    Abdelrady, A.R.; Timmermans, J.; Vekerdy, Z.; Salama, M.S.

    2016-01-01

    Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System) model

  17. Evaluation of a spatially-distributed Thornthwaite water-balance model

    Energy Technology Data Exchange (ETDEWEB)

    Lough, J.A. (Univ. of New Hampshire, Durham, NH (United States). Complex Systems Research Center)

    1993-03-01

    A small watershed of low relief in coastal New Hampshire was divided into hydrologic sub-areas in a geographic information system on the basis of soils, sub-basins and remotely-sensed landcover. Three variables were spatially modeled for input to 49 individual water-balances: available water content of the root zone, water input and potential evapotranspiration (PET). The individual balances were weight-summed to generate the aggregate watershed-balance, which saw 9% (48--50 mm) less annual actual-evapotranspiration (AET) compared to a lumped approach. Analysis of streamflow coefficients suggests that the spatially-distributed approach is more representative of the basin dynamics. Variation of PET by landcover accounted for the majority of the 9% AET reduction. Variation of soils played a near-negligible role. As a consequence of the above points, estimates of landcover proportions and annual PET by landcover are sufficient to correct a lumped water-balance in the Northeast. If remote sensing is used to estimate the landcover area, a sensor with a high spatial resolution is required. Finally, while the lower Thornthwaite model has conceptual limitations for distributed application, the upper Thornthwaite model is highly adaptable to distributed problems and may prove useful in many earth-system models.

  18. The long-term benefits of a multi-component exercise intervention to balance and mobility in healthy older adults.

    Science.gov (United States)

    Bird, M; Hill, K D; Ball, M; Hetherington, S; Williams, A D

    2011-01-01

    We examined the long-term effects of a multi-component exercise program on balance, mobility and exercise behavior. The benefits of a community-based resistance and flexibility exercise intervention in a group of healthy older (60-75 years) individuals were recorded 12 months after completion of the randomized control intervention. Differences between those participants who continued to exercise and those who discontinued were investigated. Significant improvements from baseline in sit to stand (pexercise intervention group, with a control group unchanged. Participants who continued exercising had significantly greater improvements in strength immediately after the intervention, compared to those who discontinued (p=0.004). Those who continued regular resistance training performed better in the step test at 12-month follow up (p=0.009) and believed that the program was of more benefit to their physical activity (pexercising. Benefits to balance and mobility persist 1 year after participation in a multi-component exercise program, due in part to some continuing participation in resistance training. Motivation to continue resistance training may be related real and perceived benefits attained from the intervention as well as the environmental context of the intervention.

  19. Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance

    DEFF Research Database (Denmark)

    Kindler, Reimo; Siemens, Jan; Kaiser, Klaus;

    2011-01-01

    Estimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH4), at forests, grasslands......, and croplands across Europe. Biogenic contributions to DIC were estimated by means of its d13C signature. Leaching of biogenic DIC was 8.34.9 gm2 yr1 for forests, 24.17.2 gm2 yr1 for grasslands, and 14.64.8 gm2 yr1 for croplands. DOC leaching equalled 3.51.3 gm2 yr1 for forests, 5.32.0 gm2 yr1 for grasslands...... (hydr)oxides. Partial pressures of CO2 in soil air and soil pH determined DIC concentrations and fluxes, but soil solutions were often supersaturated with DIC relative to soil air CO2. Leaching losses of biogenic carbon (DOC plus biogenic DIC) from grasslands equalled 5–98% (median: 22%) of net...

  20. The Influence of Pinus brutia on the Water Balance of Fractured Mediterranean Mountain Environments

    Science.gov (United States)

    Eliades, Marinos; Bruggeman, Adriana; Lubczynski, Maciek; Christou, Andreas

    2016-04-01

    In dry Mediterranean environments, both rainfall and temperature vary throughout the year and frequent droughts occur. The mountainous topography is characterized by steep slopes, often leading to shallow soil layers with limited water storage capacity. While for most of the tree species, these conditions can be characterized as unfavourable, Pinus brutia trees manage to survive and thrive. The main objective of this study is to define and quantify the water balance components of a Pinus brutia forest at tree level. Our study was conducted from 30/12/2014 until 31/09/2015 in an 8966-m2 fenced area of Pinus brutia forest. The site is located on the northern foothills of Troodos mountain at 620 m elevation, in Cyprus. The slope of the site ranged between 0 and 82%. The average daily minimum temperature is 5 0C in January and the average daily maximum temperature is 35 oC in August. The mean annual rainfall is 425 mm. We measured the diameter at breast height (DBH) from a total of 122 trees. Based on the average DBH, four trees were selected for monitoring (two were above the average DBH and two were below). We measured soil depth in a 1-m grid around each of the four selected trees. We processed soil depths in ArcGIS software (ESRI) to create a soil depth map. We used a Total Station and a differential GPS for the creation of a high resolution DEM of the area covering the four selected trees. We installed soil moisture sensors at 15-cm depth at distances of 1 and 2 m from the selected trees and a second sensor at 30-cm depth when the soil was deeper than 20 cm.. We randomly installed four metric manual rain gauges under each trees' canopy to measure throughfall and for stemflow we installed a plastic tube around each tree trunk and connected it to a manual rain gauge. We used six sap flow heat ratio method instruments to determine sap flow rates of the Pinus brutia trees. Two trees had one sensor installed at 1.3 m height facing north. The remaining trees had two sap

  1. Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data

    Directory of Open Access Journals (Sweden)

    M. Shaltout

    2011-06-01

    Full Text Available This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of −0.4 °C and −0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m−2 was balanced by net heat in flow through the Sicily Channel.

  2. Calculating the water and heat balances of the Eastern Mediterranean basin using ocean modelling and available meteorological, hydrological, and ocean data

    Science.gov (United States)

    Shaltout, M.; Omstedt, A.

    2011-06-01

    This paper analyses the Eastern Mediterranean water and heat balances over a 52-yr period. The modelling uses a process-oriented approach resolving the one-dimensional equations of momentum, heat, and salt conservation, with turbulence modelled using a two-equation model. The exchange through the Sicily Channel connecting the Eastern and Western basins is calculated from satellite altimeter data. The results illustrates that calculated surface temperature and salinity follow the reanalysed data well and with biases of -0.4 °C and -0.004, respectively. Monthly and yearly temperature and salinity cycles are also satisfactory simulated. Reanalysed data and calculated water mass structure and heat balance components are in good agreement, indicating that the air-sea interaction and the turbulent mixing are realistically simulated. The study illustrates that the water balance in the Eastern Mediterranean basin is controlled by the difference between inflows/outflows through the Sicily Channel and by the net precipitation rates. The heat balance is controlled by the heat loss from the water surface, sun radiation into the sea, and heat flow through the Sicily Channel, the first two displaying both climate trends. An annual net heat loss of approximately 9 W m-2 was balanced by net heat in flow through the Sicily Channel.

  3. Spatially-Explicit Water Balance Implications of Carbon Capture and Sequestration

    Science.gov (United States)

    Sathre, R. C.; Breunig, H.; Greenblatt, J.; Larsen, P.; McKone, T.; Quinn, N. W.; Scown, C.

    2012-12-01

    Carbon dioxide capture and sequestration (CCS) is increasingly discussed as a means to reduce greenhouse gas emissions and limit climate destabilization. CCS implementation is likely to have varied effects on local water balances. On one hand, power plants equipped with CO2 capture may require substantially more cooling water than plants without CO2 capture. On the other hand, injection of captured CO2 into saline aquifers may require brine extraction for pressure management, and the extracted brine may be desalinated and used as a fresh water resource. We conduct a geospatial analysis detailing how CCS implementation affects the county-level balance of water supply and demand across the contiguous United States. We calculate baseline water stress indices for each county for the year 2005, and explore CCS deployment scenarios for the year 2030 and their impacts on local water supply and demand. We use GIS mapping to identify locations where water supply will likely not constrain CCS deployment, locations where fresh water supply may constrain CCS deployment but brine extraction can overcome these constraints, and locations where limited fresh water and brine availability are likely to constrain CCS deployment. We conduct sensitivity analyses to determine bounds of uncertainty and to identify the most influential parameters. We find that CCS can strongly affect freshwater supply and demand in specific regions, but overall it has a moderate effect on water balances.; Locations of 217 coal-fired (red) and natural gas-fired (green) power plants that meet criteria for CO2 capture. Size of circle corresponds to amount of CO2 emission in 2005.

  4. Analyzing Atmosphere, Cryosphere and Hydrosphere Interactions to Understand Water Balance Changes of Data-scarce Lake Basins, Tibet

    Science.gov (United States)

    Biskop, S.; Maussion, F.; Krause, P.; Fink, M.

    2013-12-01

    Our knowledge on atmo-, cryo- and hydrosphere couplings in the unique environment of the Tibetan Plateau is still limited. Lake level fluctuations of endorheic lakes on the Tibetan Plateau serve as a sensible indicator for the climate induced impacts on the local water balance. Recent studies addressing the causes of lake level fluctuations are mostly qualitative and remain controversial. Detailed water balance studies in this remote environment are highly uncertain due to the scarcity of reliable data for model input and validation. To address this problem we developed an approach integrating remote sensing, GIS techniques as well as atmospheric and hydrological modeling. It is applied in the closed basin of Nam Co (30°N/90°E, 4718 m a.s.l.) where most appropriate data for validation are available, and transferred to selected ungauged benchmark basins on the central Tibetan Plateau. The new High Asia Reanalysis (HAR) atmospheric data set for the period 2001-2011 (10 km and daily resolution) is used as meteorological driver for the process-oriented conceptual hydrological model built within the Jena Adapatable Modelling system. The multiple-response validation includes lake level measurements of Nam Co, lake level data derived from Radar-Altimetry, MODIS snow cover data, independent modeled data of the Zhadang Glacier, etc. The impact of variations in input data as well as model parameters on the model results is analyzed by using Monte-Carlo simulations. The uncertainty of simulated lake level changes as well as several water balance components (evapotranspiration, snow melt, glacier melt water release, etc.) is quantified by applying the Generalized Likelihood Uncertainty Estimation (GLUE). Model results show that despite glacier shrinkage the contribution of ice melt to total runoff plays a minor role compared to precipitation and snow melt runoff components. However, wind-induced sublimation (blowing snowdrift) that is still not represented in the model and

  5. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY...- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water... management of stainless steel structures and components exposed to treated borated water. In response to...

  6. Consequences of declining snow accumulation for water balance of mid-latitude dry regions

    Science.gov (United States)

    Schlaepfer, Daniel R.; Lauenroth, William K.; Bradford, John B.

    2012-01-01

    Widespread documentation of positive winter temperature anomalies, declining snowpack and earlier snow melt in the Northern Hemisphere have raised concerns about the consequences for regional water resources as well as wildfire. A topic that has not been addressed with respect to declining snowpack is effects on ecosystem water balance. Changes in water balance dynamics will be particularly pronounced at low elevations of mid-latitude dry regions because these areas will be the first to be affected by declining snow as a result of rising temperatures. As a model system, we used simulation experiments to investigate big sagebrush ecosystems that dominate a large fraction of the semiarid western United States. Our results suggest that effects on future ecosystem water balance will increase along a climatic gradient from dry, warm and snow-poor to wet, cold and snow-rich. Beyond a threshold within this climatic gradient, predicted consequences for vegetation switched from no change to increasing transpiration. Responses were sensitive to uncertainties in climatic prediction; particularly, a shift of precipitation to the colder season could reduce impacts of a warmer and snow-poorer future, depending on the degree to which ecosystem phenology tracks precipitation changes. Our results suggest that big sagebrush and other similar semiarid ecosystems could decrease in viability or disappear in dry to medium areas and likely increase only in the snow-richest areas, i.e. higher elevations and higher latitudes. Unlike cold locations at high elevations or in the arctic, ecosystems at low elevations respond in a different and complex way to future conditions because of opposing effects of increasing water-limitation and a longer snow-free season. Outcomes of such nonlinear interactions for future ecosystems will likely include changes in plant composition and productivity, dynamics of water balance, and availability of water resources.

  7. Management approach of Keibul Lamjao National Park in Loktak Lake, Manipur using water balance analysis

    Science.gov (United States)

    Eliza, Khwairakpam; Khosa, Rakesh; Gosain, Ashvani; Nema, Arvind

    2017-04-01

    Keibul Lamjao National Park (KLNP) is situated in Loktak Lake which is a Ramsar designated and Montreaux record listed wetland. KLNP, the only floating national park in the world, is the only natural home of Manipur's brow-antlered deer popularly known as Sangai. Naturally, this natural park has ecological phenomenon of sinking during dry season and staying afloat during rainy season. The primary objective of this study is to formulate management approach for the conservation of KLNP by developing water balance models and correlating to the ecological processes of KLNP. Lake water balance models for two scenarios, Pre and Post Ithai barrage construction have been developed considering various parameters such as direct precipitation, runoff from the sub-basins, evaporation from the open water surface, evapotranspiration from Phumdis and domestic consumption. Hydropower generation, irrigation purposes and releases through the Ithai Barrage are also considered in Post Ithai barrage scenario. Run-off from each sub-basins have been simulated from hydrological-hydraulic models developed using Coupled MIKE SHE, MIKE 11 and SWAT. SWAT is used to model hilly terrain region of each hydrological-hydraulic models and runoff obtain from SWAT have been integrated as input data in MIKE SHE-MIKE11 models. Models have been calibrated and validated using observed runoff for hydrological-hydraulic models and observed lake water level for water balance models. The performance of each hydrological-hydrodynamic and water balance models have been assessed using Nash-Sutcliffe coefficient (E) and Coefficient of determination (R2) and the overall efficiency is found to be greater than 0.80. The obtained results have been investigated for causal correlation with the deteriorating ecological condition of the national park to formulate management approach. Results demonstrate the requirement to consider ecology of KLNP while developing wetland water-level management plans.

  8. Urban water metabolism indicators derived from a water mass balance - Bridging the gap between visions and performance assessment of urban water resource management.

    Science.gov (United States)

    Renouf, M A; Serrao-Neumann, S; Kenway, S J; Morgan, E A; Low Choy, D

    2017-10-01

    Improving resource management in urban areas has been enshrined in visions for achieving sustainable urban areas, but to date it has been difficult to quantify performance indicators to help identify more sustainable outcomes, especially for water resources. In this work, we advance quantitative indicators for what we refer to as the 'metabolic' features of urban water management: those related to resource efficiency (for water and also water-related energy and nutrients), supply internalisation, urban hydrological performance, sustainable extraction, and recognition of the diverse functions of water. We derived indicators in consultation with stakeholders to bridge this gap between visions and performance indicators. This was done by first reviewing and categorising water-related resource management objectives for city-regions, and then deriving indicators that can gauge performance against them. The ability for these indicators to be quantified using data from an urban water mass balance was also examined. Indicators of water efficiency, supply internalisation, and hydrological performance (relative to a reference case) can be generated using existing urban water mass balance methods. In the future, indicators for water-related energy and nutrient efficiencies could be generated by overlaying the urban water balance with energy and nutrient data. Indicators of sustainable extraction and recognising diverse functions of water will require methods for defining sustainable extraction rates and a water functionality index. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Comparative analysis of the actual evapotranspiration of Flemish forest and cropland, using the soil water balance model WAVE

    Directory of Open Access Journals (Sweden)

    W. W. Verstraeten

    2005-01-01

    Full Text Available This paper focuses on the quantification of the green – vegetation related – water flux of forest stands in the temperate lowland of Flanders. The underlying reason of the research was to develop a methodology for assessing the impact of forests on the hydrologic cycle in comparison to agriculture. The tested approach for calculating the water use by forests was based on the application of the soil water balance model WAVE. The study involved the collection of data from 14 forest stands, the calibration and validation of the WAVE model, and the comparison of the water use (WU components – transpiration, soil and interception evaporation – between forest and cropland. For model calibration purposes simulated and measured time series of soil water content at different soil depths, period March 2000–August 2001, were compared. A multiple-site validation was conducted as well. Actual tree transpiration calculated with sap flow measurements in three forest stands gave similar results for two of the three stands of pine (Pinus sylvestris L., but WAVE overestimated the actual measured transpiration for a stand of poplar (Populus sp.. A useful approach to compare the WU components of forest versus cropland is scenario analysis based on the validated WAVE model. The statistical Profile Analysis method was implemented to explore and analyse the simulated WU time series. With an average annual rainfall of 819 mm, the results reveal that forests in Flanders consume more water than agricultural crops. A 30 years average of 491 mm for 10 forests stands versus 398 mm for 10 cropped agricultural fields was derived. The WU components, on yearly basis, also differ between the two land use types (transpiration: 315 mm for forest and 261 mm for agricultural land use; soil evaporation: 47 mm and 131 mm, for forest and cropland, respectively. Forest canopy interception evaporation was estimated at 126 mm, while it was negligible for cropland.

  10. Education in Medicine as a component of Modern Science; restoring the balance

    Directory of Open Access Journals (Sweden)

    SN Arseculeratne

    2014-10-01

    Full Text Available Since 1871 when the Colombo Medical College was instituted, the education of undergraduates and postgraduates in medicine, over the succeeding decades, had the prime aim of producing doctors who could deliver health care. This was the continuation of British colonial policy. The establishment of the University of Ceylon in 1942 continued this orientation, while in later decades and in contemporary times, the place of medicine as a component of modern science has been ignored. If the major function of a modern university in the sciences is to establish a scientific culture, an overhaul of the system of medical education is essential. In instruction and evaluation, the inordinately heavy emphasis on factual content needs supplementation with the sponsoring of creative, integrated thinking and with discussions on the historical and philosophical aspects of medicine as a component of modern science, instead of considering it merely as a utilitarian task, that would produce only medical technicians, and not medical scientists, whom our country needs.

  11. Annual safe groundwater yield in a semiarid basin using combination of water balance equation and water table fluctuation

    Science.gov (United States)

    Rezaei, Abolfazl; Mohammadi, Zargham

    2017-10-01

    The safe groundwater yield plays a major role in the appropriate management of groundwater systems, particularly in (semi-)arid areas like Iran. This study incorporates both the water balance equation and the water table fluctuation to estimate the annual safe yield of the unconfined aquifer in the eastern part of the Kaftar Lake, an Iranian semiarid region. Firstly, the water balance year 2002-03, owing same water table elevation at the beginning and year-end, was chosen from the monthly representative groundwater hydrograph of the aquifer to be taken into account as a basic water year for determining the safe yield. Then the ratio of the total groundwater pumping to the annual groundwater recharge in the selected water balance year together with the quantity of total recharge occurred in the wet period (October to May) of the year of interest were applied to evaluate the annual safe yield at the initiation of the dry period (June to September) of the year of interest. Knowing the annual safe groundwater withdrawal rate at the initiation of each dry period could be helpful to decision makers in managing groundwater resources conservation. Analysis results indicate that to develop a safe management strategy in the aquifer; the ratio of the annual groundwater withdrawal to the annually recharged volume should not exceed 0.69. In the water year 2003-04 where the ratio is equal to 0.52, the water table raised up (about 0.48 m) while the groundwater level significantly declined (about 1.54 m) over the water year 2007-08 where the ratio of the annual groundwater withdrawal to the annually recharged volume (i.e., 2.76) is larger than 0.69.

  12. A geo-informatics approach for estimating water resources management components and their interrelationships

    KAUST Repository

    Liaqat, Umar Waqas

    2016-09-21

    A remote sensing based geo-informatics approach was developed to estimate water resources management (WRM) components across a large irrigation scheme in the Indus Basin of Pakistan. The approach provides a generalized framework for estimating a range of key water management variables and provides a management tool for the sustainable operation of similar schemes globally. A focus on the use of satellite data allowed for the quantification of relationships across a range of spatial and temporal scales. Variables including actual and crop evapotranspiration, net and gross irrigation, net and gross groundwater use, groundwater recharge, net groundwater recharge, were estimated and then their interrelationships explored across the Hakra Canal command area. Spatially distributed remotely sensed estimates of actual evapotranspiration (ETa) rates were determined using the Surface Energy Balance System (SEBS) model and evaluated against ground-based evaporation calculated from the advection-aridity method. Analysis of ETa simulations across two cropping season, referred to as Kharif and Rabi, yielded Pearson correlation (R) values of 0.69 and 0.84, Nash-Sutcliffe criterion (NSE) of 0.28 and 0.63, percentage bias of −3.85% and 10.6% and root mean squared error (RMSE) of 10.6 mm and 12.21 mm for each season, respectively. For the period of study between 2008 and 2014, it was estimated that an average of 0.63 mm day−1 water was supplied through canal irrigation against a crop water demand of 3.81 mm day−1. Approximately 1.86 mm day−1 groundwater abstraction was estimated in the region, which contributed to fulfil the gap between crop water demand and canal water supply. Importantly, the combined canal, groundwater and rainfall sources of water only met 70% of the crop water requirements. As such, the difference between recharge and discharge showed that groundwater depletion was around −115 mm year−1 during the six year study period. Analysis indicated that

  13. A conceptual water balance model to explore the impact of different soil management on water availability for vineyards under contrasting environments

    Science.gov (United States)

    Gomez, Jose Alfonso; Guzman, Gema; Lorite, Ignacio

    2016-04-01

    Vines are one of the most extended tree crops in Europe covering a wide range of environmental and management conditions. Soil management is a key element in maintaining vines in adequate agronomic conditions, as well as in determining not only yield but also grape quality. The soil management practices adopted in vineyards could favor accelerated erosion. Particularly, cultivation with rows running up-and-down the slope on sloping vineyards, maintenance of bare soil, compaction due to high traffic of machinery are some of the vineyard's management practices that expose soil to degradation, favoring runoff and soil erosion processes. In fact high erosion rates in vines have been recently reported by Gomez et al., (2011). The adoption of grass cover in vineyards as a soil management technique has a fundamental role in soil protection against erosion, but it can have a major impact on water balance and then in grape yield and quality. This effect, the possibility of competition for soil water with the vine, is in fact mentioned by vine growers as a limiting factor for use of cover crops in vineyards under semiarid conditions or during dry periods even in sub-humid climates. To evaluate the interaction between the use of cover crops and soil management adjustments (eg. spatial extension in the vineyard and time for seeding and mowing) In order to achieve an optimum equilibrium between soil protection and grape production we developed a conceptual water balance model that reproduces the major processes in vineyards, WABYN. This model simulates the effect of different soil management alternatives, as for instance conventional tillage or cover crop, on soil water balance components. It has been implemented in a user friendly interface in order to allow its use by technicians and other stakeholders in the vine sector. It follows the methodology of a previous model specific for olive orchards (Abazi et al., 2012) using a model called WABOL. In spite of this simplified

  14. An attempt to perform water balance in a Brazilian municipal solid waste landfill.

    Science.gov (United States)

    São Mateus, Maria do Socorro Costa; Machado, Sandro Lemos; Barbosa, Maria Cláudia

    2012-03-01

    This paper presents an attempt to model the water balance in the metropolitan center landfill (MCL) in Salvador, Brazil. Aspects such as the municipal solid waste (MSW) initial water content, mass loss due to decomposition, MSW liquid expelling due to compression and those related to weather conditions, such as the amount of rainfall and evaporation are considered. Superficial flow and infiltration were modeled considering the waste and the hydraulic characteristics (permeability and soil-water retention curves) of the cover layer and simplified uni-dimensional empirical models. In order to validate the modeling procedure, data from one cell at the landfill were used. Monthly waste entry, volume of collected leachate and leachate level inside the cell were monitored. Water balance equations and the compressibility of the MSW were used to calculate the amount of leachate stored in the cell and the corresponding leachate level. Measured and calculated values of the leachate level inside the cell were similar and the model was able to capture the main trends of the water balance behavior during the cell operational period.

  15. Water balance in two species of desert fleas, Xenopsylla ramesis and X. conformis (Siphonaptera: Pulicidae).

    Science.gov (United States)

    Fielden, Laura J; Krasnov, Boris R; Still, Kelly M; Khokhlova, Irina S

    2002-11-01

    The role of water balance capabilities of fleas was examined in desert habitats. The fleas studied were Xenopsylla ramesis Rothschild and Xenopsylla conformis Wagner. Both fleas occur on Sundevall's jird, Meriones crassus, in the Negev Highlands of Israel but in different macro- and microhabitats. Because M. crassus occurs in several habitats of the highlands, it was used as a model for investigating the effect of habitat parameters on species composition of fleas within a host species. Water balance parameters investigated were the range of humidities over which active water uptake occurs in the larvae and prepupae of X. ramesis and X. conformis. Critical equilibrium humidity estimates were close to 65% RH for larvae and prepupae of both species. Water loss rates were determined for each life stage, except eggs, and represented water loss from cuticular, respiratory, and other body openings) under conditions of little or no bulk air movement. When converted to a proportional rate (1.44 -2.37% mass loss h(-1)) water loss rates did not differ significantly between stages or species. Thus, geographic separation of X. ramesis and X. conformis could not be explained by any difference in water uptake capabilities or water loss rates. Other factors that may be important include interspecific competition for resource availability among larval fleas and effect of soil texture on cocoon construction.

  16. Instrumentation and analytical methods in carbon balance studies - inorganic components in a marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Skjelvan, I.; Johannessen, T.; Miller, L.; Stoll, M.

    1996-03-01

    This paper was read at the workshop ``The Norwegian Climate and Ozone Research Programme`` held on 11-12 March 1996. Substantial amounts of anthropogenic CO{sub 2} enters the atmosphere. The land biota acts as a sink for CO{sub 2}, with uncertain consequences. About 30% of the anthropogenic CO{sub 2} added to the atmosphere is absorbed by the ocean and how the ocean acts as a sink is central in understanding the carbon cycle. In their project the authors investigate the inorganic carbon in the ocean, especially total dissolved inorganic carbon, alkalinity, and partial pressure of CO{sub 2} (pCO{sub 2}) in surface ocean and atmosphere. To determine total dissolved inorganic carbon, coulometric analysis is used in which an exact amount of sea water is acidified and the amount of carbon extracted is determined by a coulometer. Alkalinity is determined by potentiometric titration. In the pCO{sub 2} measurement, a small amount of air is circulated in a large amount of sea water and when after some time the amount of CO{sub 2} in the air reflects the CO{sub 2} concentration in the water, the pCO{sub 2} in the gas phase is determined by infra-red detection. The atmospheric pCO{sub 2} is also determined, and the difference between the two partial pressures gives information about source or sink activities. Total carbon and alkalinity measurements are done on discrete samples taken from all depths in the ocean, but for partial pressure detection an underway system is used, which determines the pCO{sub 2} in the surface ocean continuously

  17. Shift of annual water balance in the Budyko space for catchments with groundwater-dependent evapotranspiration

    Science.gov (United States)

    Wang, Xu-Sheng; Zhou, Yangxiao

    2016-09-01

    The Budyko framework represents the general relationship between the evapotranspiration ratio (F) and the aridity index (φ) for the mean annual steady-state water balance at the catchment scale. It is interesting to investigate whether this standard F - φ space can also be applied to capture the shift of annual water balance in catchments with varying dryness. Previous studies have made significant progress in incorporating the storage effect into the Budyko framework for the non-steady conditions, whereas the role of groundwater-dependent evapotranspiration was not investigated. This study investigates how groundwater-dependent evapotranspiration causes the shift of the annual water balance in the standard Budyko space. A widely used monthly hydrological model, the ABCD model, is modified to incorporate groundwater-dependent evapotranspiration into the zone with a shallow water table and delayed groundwater recharge into the zone with a deep water table. This model is applied in six catchments in the Erdos Plateau, China, to estimate the actual annual evapotranspiration. Results show that the variations in the annual F value with the aridity index do not satisfy the standard Budyko formulas. The shift of the annual water balance in the standard Budyko space is a combination of the Budyko-type response in the deep groundwater zone and the quasi-energy limited condition in the shallow groundwater zone. Excess evapotranspiration (F > 1) could occur in dry years, which is contributed by the significant supply of groundwater for evapotranspiration. Use of groundwater for irrigation can increase the frequency of the F > 1 cases.

  18. Water Isotope framework for lake water balance monitoring and modelling in the Nam Co Basin, Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Shichang Kang

    2017-08-01

    New hydrological insights: A water isotope framework for the Nam Co basin, including the Local Meteoric Water Line, limiting isotopic composition of evaporation and two hypothetical evaporation trajectories, is established. We further applied the isotope mass balance model to estimate the overall isotopic composition of input water to the Nam Co, the evaporation over inputs ratios (E/I for three consecutive years, and the water yields (Wy, depth equivalent runoff at a basin scale. Our results clearly suggest a positive water budget (i.e., E/I < 1, providing another line of evidence that the subsurface leakage from Nam Co is likely. The discrepancy between isotope-based water yields estimations and field-based runoff observations suggest that, compared to the well-studied Nyainqentanglha Mountains and southwestern mountains, the ridge-and-valley landscape in the western highlands and northwestern hogbacks are possibly low yields area, which should draw more research attentions in future hydrological investigations.

  19. The Influence of the Soil Water Balance Within Catchment Hillslopes on Runoff Variability and Fluvial Incision

    Science.gov (United States)

    Rossi, M. W.; Whipple, K. X.; Vivoni, E. R.; DiBiase, R.; Heimsath, A. M.

    2014-12-01

    The variability of daily runoff has direct consequences on water availability, flood hazard, ecosystem function, and erosional processes. One component to predicting runoff variability is solid understanding of soil moisture dynamics and the runoff response to rainfall events. By using a point-scale soil water balance model that accounts for vegetation and soil properties, we test how daily rainfall statistics and vegetation response to water availability affect mean hydrologic partitioning and the runoff response during rare storms. Simulations span a transect in mean annual precipitation (MAP) from 200 to 1200 mm/year and are motivated by analysis of a long-term observational network of rainfall in the contiguous U.S. Whether driven by higher storm depths or increased frequency of storm arrivals, increases in MAP always lead to more fractional runoff generation due to the synchronous increase in mean antecedent soil moisture and probability of large rainfall events. Simulations also show that at any given MAP, there are important tradeoffs between increasing the probability of large rainfall events and associated decreases in the mean soil moisture state. Results from this ecohydrologic analysis are then used to drive 1-D simulations of the longitudinal river profile that account for runoff variability and thresholds to incision. We show that in natural settings where long-term hydrologic observations are available and where millennial-scale erosion rates were measured, much of the observed variation between local relief and long-term erosion rates can be explained by combining these two relatively simple models. However, we also show that large differences in MAP often lead to comparatively small differences in the geomorphically effective climate. This partially explains why prior studies have struggled to isolate a climatic control on long-term erosion rates. Expectations for how vegetation influences landscape evolution are often based on the seminal work by

  20. Long-term energy balance and vegetation water stress monitoring of Mediterranean oak savanna using satellite thermal data

    Science.gov (United States)

    González-Dugo, Maria P.; Chen, Xuelong; Andreu, Ana; Carpintero, Elisabet; Gómez-Giraldez, Pedro; Su, Z.(Bob)

    2017-04-01

    Drought is one of the major hazards faced by natural and cropped vegetation in the Mediterranean Sea Basin. Water scarcity is likely to be worsened under the predicted conditions of climate change, which is expected to make this region both warmer and drier. A Holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs. This ecosystem is considered an example of sustainable land use, supporting a large number of species and diversity of habitats and for its importance in rural economy. A similar ecosystem is worldwide distributed in areas with Mediterranean climate (as California or South Africa) and shares structural and functional properties with tropical savannas in Africa, Australia and South America. Remote sensing time series can assist the monitoring of the energy balance components, with special attention to the evapotranspiration and vegetation water stress over these areas. Long-term data analysis may improve our understanding of the functioning of the system, helping to assess drought impacts and leading to reduce the economic and environmental vulnerability of this ecosystem. This work analyzes the evolution the surface energy balance components, mapping the evapotranspiration and moisture stress of holm oak woodlands of Spain and Portugal during the last 15 years (2001-2015). The surface energy balance model (SEBS) has been applied over the Iberian Peninsula on a monthly time scale and 0.05° spatial resolution, using multi-satellite and meteorological forcing data. Modelled energy and water fluxes have been validated using ground measurements of two eddy covariance towers located in oak savanna sites during 3 years, resulting in moderate deviations from observations (10-25 W/m2). The departure of actual ET from the

  1. Respiratory exposure to components of water-miscible metalworking fluids.

    Science.gov (United States)

    Suuronen, Katri; Henriks-Eckerman, Maj-Len; Riala, Riitta; Tuomi, Timo

    2008-10-01

    Water-miscible metalworking fluids (MWFs) are capable of causing respiratory symptoms and diseases. Recently, much emphasis has been put on developing new methods for assessing respiratory exposure to MWF emulsions. The air concentrations of ingredients and contaminants of MWF and inhalable dust were measured in 10 metal workshops in southern Finland. Oil mist was determined by infra red spectroscopy analysis after tetrachloroethylene extraction from the filter. Aldehydes were collected on Sep-Pak chemosorbents and analysed by liquid chromatography. Volatile organic compounds (VOCs) were collected on Tenax adsorbents and analysed by gas chromatography with mass spectrometric detection after thermal desorption. Endotoxins were collected on glass fibre filter and analysed by enzyme-based spectrophotometry, and viable microbes were collected on polycarbonate filter and cultured. Inhalable dust was collected on cellulose acetate filter and quantified gravimetrically. Associations between the different exposures were calculated with Spearman's correlations. The mean concentration of oil mist was 0.14 (range aliphatic hydrocarbons. Several potential sensitizing chemicals such as terpenes were found in small quantities. The concentration of microbial contaminants was low. All the measured air concentrations were below the Finnish occupational exposure limits. The exposure in machine shops was quantitatively dominated by volatile compounds. Additional measurements of MWF components such as aldehydes, alkanolamines and VOCs are needed to get more information on the chemical composition of workshops' air. New air cleaning methods should be introduced, as oil mist separators are insufficient to clean the air of small molecular impurities.

  2. Interfacial properties of dissolved crude oil components in produced water

    OpenAIRE

    Eftekhardadkhah, Mona

    2013-01-01

    Produced water is a mixture of water trapped in underground formations and injection water that is brought to the surface along with oil or gas. In general, produced water is a mixture of dispersed oil in water (o/w), dissolved organic compounds (including hydrocarbons), residual concentration of chemical additives from the production line, heavy metals, dissolved minerals and suspended solids.In the year 2011, 131 million m3 of produced water were discharged on the Norwegian Continental Shel...

  3. Exercise, energy expenditure and energy balance, as measured with doubly labelled water.

    Science.gov (United States)

    Westerterp, Klaas R

    2017-07-20

    The doubly labelled water method for the measurement of total daily energy expenditure (TDEE) over 1-3 weeks under daily living conditions is the indicated method to study effects of exercise and extreme environments on energy balance. Subjects consume a measured amount of doubly labelled water (2H2 18O) to increase background enrichment of body water for 18O and 2H, and the subsequent difference in elimination rate between 18O and 2H, as measured in urine, saliva or blood samples, is a measure for carbon dioxide production and thus allows calculation of TDEE. The present review describes research showing that physical activity level (PAL), calculated as TDEE (assessed with doubly labelled water) divided by resting energy expenditure (REE, PAL = TDEE/REE), reaches a maximum value of 2·00-2·40 in subjects with a vigorously active lifestyle. Higher PAL values, while maintaining energy balance, are observed in professional athletes consuming additional energy dense foods to compete at top level. Exercise training can increase TDEE/REE in young adults to a value of 2·00-2·40, when energy intake is unrestricted. Furthermore, the review shows an exercise induced increase in activity energy expenditure can be compensated by a reduction in REE and by a reduction in non-exercise physical activity, especially at a negative energy balance. Additionally, in untrained subjects, an exercise-induced increase in activity energy expenditure is compensated by a training-induced increase in exercise efficiency.

  4. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2011-10-01

    Full Text Available Estimates of surface actual evapotranspiration (ET can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  5. Links Between Flood Frequency and Annual Water Balance Behaviors: A Basis for Similarity and Regionalization

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiali; Li, Hongyi; Leung, Lai-Yung R.; Guo, Shenglian; Liu, Pan; Sivapalan, Murugesu

    2014-03-28

    This paper presents the results of a data based comparative study of several hundred catchments across continental United States belonging to the MOPEX dataset, which systematically explored the connection between the flood frequency curve and measures of mean annual water balance. Two different measures of mean annual water balance are used: (i) a climatic aridity index, AI, which is a measure of the competition between water and energy availability at the annual scale; and, (ii) baseflow index, BFI, the ratio of slow runoff to total runoff also at the annual time scale, reflecting the role of geology, soils, topography and vegetation. The data analyses showed that the aridity index, AI, has a first order control on both the mean and Cv of annual maximum floods. While mean annual flood decreases with increasing aridity, Cv increases with increasing aridity. BFI appeared to be a second order control on the magnitude and shape of the flood frequency curve. Higher BFI, meaning more subsurface flow and less surface flow leads to a decrease of mean annual flood whereas lower BFI leads to accumulation of soil moisture and increased flood magnitudes that arise from many events acting together. The results presented in this paper provide innovative means to delineate homogeneous regions within which the flood frequency curves can be assumed to be functionally similar. At another level, understanding the connection between annual water balance and flood frequency will be another building block towards developing comprehensive understanding of catchment runoff behavior in a holistic way.

  6. The influence of frozen soil change on water balance in the upper Yellow River Basin, China

    Science.gov (United States)

    Cuo, L.; Zhao, L.; Zhou, B.

    2013-12-01

    Yellow River supports 30% of China's population and 13% of China's total cultivated area. About 35% of the Yellow River discharge comes from the upper Yellow River Basin. Seasonally frozen, continuous and isolated permafrost soils coexist and cover the entire upper Yellow River Basin. The spatial distribution of various frozen soisl is primarily determined by the elevation in the basin. Since the past five decades, air temperature has increased by a rate of 0.03 C/year in the upper Yellow River Basin. Many studies reported the conversions of continuous to isolated permafrost soil, permafrost soil to seasonally frozen soil and the thickening of the active layer due to rising temperature in the basin. However, very few studies reported the impact of the change of frozen soil on the water balance in the basin. In this study, the Variable Infiltration Capacity (VIC) model is applied in the upper Yellow River Basin to study the change of frozen soil and its impact on the water balance. Soil temperature and soil liquid content measured up to 3 m below ground surface at a number of sites in the upper Yellow River Basin and the surroundings are used to evaluate the model simulation. Streamflow is also calibrated and validated using historical streamflow records. The validated VIC model is then used to investigate the frozen soil change and the impact of the change on water balance terms including surface runoff, baseflow, evapotranspiration, soil water content, and streamflow in the basin.

  7. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Science.gov (United States)

    Sánchez, J. M.; López-Urrea, R.; Rubio, E.; Caselles, V.

    2011-10-01

    Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h-1 and ±1.0 mm d-1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  8. A Water Balance Model for Hill reservoir - Aquifer Exchange Water Flux Quantification and Uncertainty Analysis - Application to the Kamech catchment, Tunisia

    Science.gov (United States)

    Bouteffeha, Maroua; Dagès, Cécile; Bouhlila, Rachida; Raclot, Damien; Molénat, Jérôme

    2013-04-01

    In Mediterranean regions, food and water demand increase with population growth leading to considerable changes of the land use and agricultural practices. In North Africa, particularly in the Mediterranean zones, hill reservoirs are water harvesting infrastructures that have been increasingly adopted to mobilize runoff and create alternative water resource that can be used to develop agriculture. Hill reservoirs are also used to prevent from silting of downstream dams. Management of water resources collected in these infrastructures requires a good knowledge of their hydrological functioning. In particular, the rate of water exchanges between the reservoir and the underlying aquifer, called surface-subsurface exchange hereafter, is still an open question. The main purpose of the study is to better know the hydrological functioning of hill reservoirs in quantifying at the annual and intra-annual time scales the flux of surface-subsurface exchange and the uncertainty associated to the flux. The approach is based on the hydrological water balance of the hill reservoir. It was applied to the hill reservoir of the 2.6 km² Kamech catchment (Tunisia), which belongs to the long term Mediterranean hydrological observatory OMERE (Voltz and Albergel, 2002). The dense monitoring of the observation catchment allowed quantifying the fluxes of all hydrological processes governing the reservoir hydrology, and their associated uncertainties. The water balance was established by considering water inputs (direct rainfall, waddy and hillslope runoff, surface-subsurface exchange), water outputs (evaporation, spillway discharge) and hill reservoir water volume changes. The surface-subsurface exchange component was deduced as the default closure term in the water balance. The results first demonstrate the ability of the proposed approach to estimate the net surface-subsurface exchange flux and its uncertainty at various time scales. Its application on the Kamech catchment for two

  9. Mapping land water and energy balance relations through conditional sampling of remote sensing estimates of atmospheric forcing and surface states

    Science.gov (United States)

    Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido

    2016-04-01

    In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links atmospheric forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on conditional averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.

  10. Water Balance Analysis at Karangmumus River Basin Area (RBA Samarinda City

    Directory of Open Access Journals (Sweden)

    Ismail

    2009-11-01

    Full Text Available Karangmumus RBA to getting degradation pressure being concrete drying and flooding so much to frighten. Climate data from BMG Temindung and SPAS Lempake has to water balance analysis based on Hewlett and Nutter methode. This region have the Area Class III (1500–2000 mm/year. With the bimodel or double wave rainfall models with C patern. The hight rainfall depth periode at December and April, therefore the low rainfall depth at September and November. Have level Q = ± 9.9%, or rainfall tipe A (very wet area with tropical wet vegetation and E1 agroclimte zone. Water balance monthly indicated that this area have to water surplus 8 month, i.e. January (27.0 mm, February (57.3 mm, March (119.7 mm, April (72.8 mm, May (48.4 mm, Juni (19.6 mm, November (58.7 mm and December (75.3 mm, or total amounts water surplus 478.8 mm/year. The water deficits at Juni (0.4 mm, July (0.3 mm, Augus (3.9 mm, September (13.6 mm and October (26.7 mm or total amount water deficits (44.5 mm/year.

  11. Relation between Water Balance and Climatic Variables Associated with the Geographical Distribution of Anurans.

    Directory of Open Access Journals (Sweden)

    Braz Titon

    Full Text Available Amphibian species richness increases toward the equator, particularly in humid tropical forests. This relation between amphibian species richness and environmental water availability has been proposed to be a consequence of their high rates of evaporative water loss. In this way, traits that estimate water balance are expected to covary with climate and constrain a species' geographic distribution. Furthermore, we predicted that coexisting species of anurans would have traits that are adapted to local hydric conditions. We compared the traits that describe water balance in 17 species of anurans that occur in the mesic Atlantic Forest and xeric Cerrado (savannah habitats of Brazil. We predicted that species found in the warmer and dryer areas would show a lower sensitivity of locomotor performance to dehydration (SLPD, increased resistance to evaporative water loss (REWL and higher rates of water uptake (RWU than species restricted to the more mesic areas. We estimated the allometric relations between the hydric traits and body mass using phylogenetic generalized least squares. These regressions showed that REWL scaled negatively with body mass, whereas RWU scaled positively with body mass. Additionally, species inhabiting areas characterized by higher and more seasonally uniform temperatures, and lower and more seasonally concentrated precipitation, such as the Cerrado, had higher RWU and SLPD than species with geographical distributions more restricted to mesic environments, such as the Atlantic Forest. These results support the hypothesis that the interspecific variation of physiological traits shows an adaptation pattern to abiotic environmental traits.

  12. Preliminary estimation of Lake El'gygytgyn water balance and sediment income

    Directory of Open Access Journals (Sweden)

    G. Fedorov

    2013-07-01

    Full Text Available Modern process studies of the hydrologic balance of Lake El'gygytgyn, central Chukotka, and the sediment income from the catchment were carried out during a field campaign in spring and summer 2003. Despite high uncertainties due to the limited data, the results provide important first estimates for better understanding the modern and past sedimentation processes in this basin. Formed ca. 3.6 million years ago as a result of a meteorite impact, the basin contains one of the longest paleoclimate records in the terrestrial Arctic. Fluvial activity is concentrated over the short snowmelt period (about 20 days in second part of June. Underground outflow plays a very important role in the water balance and predominates over surface outflow. The residence time of the lake water is estimated to be about 100 yr.

  13. Potential foraging decisions by a desert ungulate to balance water and nutrient intake in a water-stressed environment

    Science.gov (United States)

    Gedir, Jay V.; Cain, James W.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.; Morgart, John R.

    2016-01-01

    Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8–55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during

  14. Carbon dioxide and the stomatal control of water balance and photosynthesis in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Taiz, L.; Zeiger, E.; Mawson, B. T.; Cornish, K.; Radin, J. W.; Turcotte, E. L.; Hercovitz, S.; Tallman, G.; Karlsson, P. E.; Bogomolni, R. A.; Talbott, L. D.; Srivastava, A.

    1992-01-01

    Research continued into the investigation of the effects of carbon dioxide on stomatal control of water balance and photosynthesis in higher plants. Topics discussed this period include a method of isolating a sufficient number of guard cell chloroplasts for biochemical studies by mechanical isolation of epidermal peels; the measurement of stomatal apertures with a digital image analysis system; development of a high performance liquid chromatography method for quantification of metabolites in guard cells; and genetic control of stomatal movements in Pima cotton. (CBS)

  15. Soil Water Balance and Recharge Monitoring at the Hanford Site - FY09 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L.; Saunders, Danielle L.; Strickland, Christopher E.; Waichler, Scott R.; Clayton, Ray E.

    2009-09-28

    Recharge provides the primary driving force for transporting contaminants from the vadose zone to underlying aquifer systems. Quantification of recharge rates is important for assessing contaminant transport and fate and for evaluating remediation alternatives. This report describes the status of soil water balance and recharge monitoring performed by Pacific Northwest National Laboratory at the Hanford Site for Fiscal Year 2009. Previously reported data for Fiscal Years 2004 - 2008 are updated with data collected in Fiscal Year 2009 and summarized.

  16. U.S. Biofuel Policies and Domestic Shifts in Agricultural Land Use and Water Balances

    Science.gov (United States)

    Teter, J.; Yeh, S.; Mishra, G. S.

    2014-12-01

    Policies promoting domestic biofuels production could lead to significant changes in cropping patterns. Types of direct and indirect land use change include: switching among crops (displacement), expanding cropped area (extensification), and altering water/soil management practices (e.g. irrigation, tillage) (intensification). Most studies of biofuels water use impacts calculate the water intensity of biofuels in liters of irrigated/total evapotranspired water per unit energy of biofuels. But estimates based on this approach are sensitive to assumptions (e.g. co-product allocation, system boundaries), and do not convey policy-relevant information, as highlighted by the issue of land use change. We address these shortcomings by adopting a scenario-based approach that combines economic modeling with crop-water modeling of major crops and biofuel feedstocks. This allows us to holistically compare differences in water balances across policy scenarios in an integrated economic/agricultural system. We compare high spatial resolution water balance estimates under three hypothetical policy scenarios: 1) a counterfactual no-policy scenario, 2) modified Renewable Fuels Standard mandates (M-RFS2), & 3) a national Low Carbon Fuel Standard plus a modified RFS2 scenario (LCFS+RFS2). Differences between scenarios in crop water balances (i.e. transpiration, evaporation, runoff, groundwater infiltration, & irrigation) are regional and are a function of changes in land use patterns (i.e. displacement, intensification, & extensification), plus variation in crop water-use characteristics. Cropped land area increases 6.2% and 1.6% under M-RFS2 and LCFS+RFS2 scenarios, respectively, by 2030. Both policy scenarios lead to reductions in net irrigation volumes nationally compared to the no-policy scenario, though more irrigation occurs in regions of the Midwest and West. The LCFS+RFS2 reduces net irrigation water use by 3.5 times more than M-RFS2. However, both policies drive

  17. Conjoint Analysis of the Surface and Atmospheric Water Balances of the Andes-Amazon System

    Science.gov (United States)

    Builes-Jaramillo, Alejandro; Poveda, Germán

    2017-04-01

    Acknowledging the interrelation between the two branches of the hydrological cycle, we perform a comprehensive analysis of the long-term mean surface and atmospheric water balances in the Amazon-Andes River basins system. We estimate the closure of the water budgets based on the long-term approximation of the water balance equations, and estimate the imbalance between both atmospheric and surface budgets. The analysis was performed with observational and reanalysis datasets for the entire basin, for several sub-catchments inside the entire Amazon River basin and for two physical and geographical distinctive subsystems of the basin, namely upper Andean the low-lying Amazon River basin. Our results evidence that for the entire Amazon River basin the surface water balance can be considered to be in balance (P = 2225 mm.yr-1, ET= 1062 mm.yr-1, R= 965 mm.yr-1), whereas for the separated subsystems it not so clear, showing high discrepancies between observations and reanalysis datasets. In turn, the atmospheric budget does not close regardless of datasets or geographical disaggregation. Our results indicate that the amount of imbalance of the atmospheric branch of the water balance depends on the evaporation data source used. The imbalance calculated as I=(C/R)-1, where C is net moisture convergence (C= -∇Q where ∇Q is the net vertically integrated moisture divergence) and R the runoff,represents the difference between the two branches of the hydrological cycle. For the entire Amazon River basin we found a consistent negative imbalance driven by higher values of runoff, and when calculated for monthly time scales the imbalance is characterized by a high dependence on the Amazon dry season. The separated analysis performed to the Andes and Low-lying Amazonia subsystems unveils two shortcomings of the available data, namely a poor quality of the representation of surface processes in the reanalysis models (including precipitation and evapotranspiration), and the

  18. Assessment of the water balance over France using regionalized Turc-Pike formula

    Science.gov (United States)

    Le Lay, Matthieu; Garçon, Rémy; Gailhard, Joël; Garavaglia, Federico

    2016-04-01

    With extensive use of hydrological models over a wide range of hydro-climatic contexts, bias in hydro-climatic data may lead to unreliable models and thus hydrological forecasts and projections. This issue is particularly pregnant when considering mountainous areas with great uncertainties on precipitations, or when considering complex unconservative catchments (e.g. karstic systems). The Turc-Pike water balance formula, analogous to the classical Budyko formula, is a simple and efficient mathematical formulation relating long-term average streamflow to long-term average precipitation and potential evaporation. In this study, we propose to apply this framework to assess and eventually adjust the water-balance before calibrating an operational hydrologic model (MORDOR model). Considering a large set of 350 french catchments, the Turc-Pike formula is regionalized based on ecohydrologic criterions to handle various hydro-climatic contexts. This interannual regional model is then applied to assess the water-balance over numerous catchments and various conditions, such as karstic, snow-driven or glaciarized and even anthropized catchments. Results show that it is possible to obtain pretty realistic corrections of meteorological inputs (precipitations, temperature or potential evaporation) or hydrologic surface (or runoff). These corrections can often be confirmed a posteriori by exogenous information. Positive impacts on hydrologic model's calibration are also demonstrated. This methodology is now operational for hydrologic applications at EDF (Electricité de France, French electric utility company), and therefore applied on hundreds of catchments.

  19. A well-balanced scheme for the shallow-water equations with topography or Manning friction

    Science.gov (United States)

    Michel-Dansac, Victor; Berthon, Christophe; Clain, Stéphane; Foucher, Françoise

    2017-04-01

    We consider the shallow-water equations with Manning friction or topography, as well as a combination of both these source terms. The main purpose of this work concerns the derivation of a non-negativity preserving and well-balanced scheme that approximates solutions of the system and preserves the associated steady states, including the moving ones. In addition, the scheme has to deal with vanishing water heights and transitions between wet and dry areas. To address such issues, a particular attention is paid to the study of the steady states related to the friction source term. Then, a Godunov-type scheme is obtained by using a relevant average of the source terms in order to enforce the required well-balance property. An implicit treatment of both topography and friction source terms is also exhibited to improve the scheme while dealing with vanishing water heights. A second-order well-balanced MUSCL extension is designed, as well as an extension for the two-dimensional case. Numerical experiments are performed in order to highlight the properties of the scheme.

  20. Assessment of the Water Balance Over France Using Regionalized Turc-Pike Formula for Operational Hydrology

    Science.gov (United States)

    LE Lay, M.; Garcon, R.; Gailhard, J.; Garavaglia, F.

    2015-12-01

    With extensive use of hydrological models over a wide range of hydro-climatic contexts, bias in hydro-climatic data may lead to unreliable models and thus hydrological forecasts and projections. This issue is particularly pregnant when considering mountainous areas with great uncertainties on precipitations, or when considering complex unconservative catchments (e.g. karstic systems). The Turc-Pike water balance formula, analogous to the classical Budyko formula, is a simple and efficient mathematical formulation relating long-term average streamflow to long-term average precipitation and potential evaporation. In this study, we propose to apply this framework to assess and eventually adjust the water-balance before calibrating an operational hydrologic model (MORDOR model). Considering a large set of 350 french catchments, the Turc-Pike formula is regionalized based on ecohydrologic criterions to handle various hydro-climatic contexts. This interannual regional model is then applied to assess the water-balance over numerous catchments and various conditions, such as karstic, snow-driven or glaciarized and even anthropized catchments. Results show that it is possible to obtain pretty realistic corrections of meteorological inputs (precipitations, temperature or potential evaporation) or hydrologic surface (or runoff). These corrections can often be confirmed a posteriori by exogenous information. Positive impacts on hydrologic model's calibration are also demonstrated. This methodology is now operational for hydrologic applications at EDF (Electricité de France, French electric utility company), and therefore applied on hundreds of catchments.

  1. Derivation of a climatic dataset for water balance modelling of Pacific atolls

    Energy Technology Data Exchange (ETDEWEB)

    Helbig, Manuel [Univ. of Hamburg (Germany). Inst. of Soil Science; De Freitas, Chris R. [Univ. of Auckland (New Zealand). School of Environment; Matzarakis, Andreas [Freiburg Univ. (Germany). Meteorological Inst.

    2011-10-15

    There are a large number of low islands in the tropical Pacific region where fresh water resources are seriously limited by climate. The resource is coming under increasing pressure as populations grow and rates of development increase. This and the realisation of the possible impact of climate change have highlighted the sensitivity of island communities to the availability of water. However, to assess this sensitivity requires not only standard climatic data such as air temperature and rainfall, but also more specialised data on solar and longwave radiation. Therein lies a major problem as very little island-specific climatic data are available. The aim here is to identify data required for water balance assessments, then assemble and validate that database. It is argued that this is a crucial first step to successful modelling of the water balance of atolls. The study focuses on the vast area of the tropical Pacific bounded by latitudes 30 S to 30 N and longitudes 150 E to 120 W. ERA40 reanalysis data are identified as meeting the requirements both in terms of the number of climatic variables and length of time series. These data are compared with surface climate records of selected low islands. The results show that, although the reanalysis data do provide a reliable database for modelling the water balance of atolls, problems arise from overestimated precipitation and underestimated energy available for evapotranspiration. The significance of this is the aim of the second part of this work that aims to assess the sensitivity of water resources of atolls to climate change and variability at the regional scale. (orig.)

  2. Employing Hot Wire Anemometry to Directly Measure the Water Balance in a Proton Exchange membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Hussain, Nabeel; Berning, Torsten

    2015-01-01

    Water management in proton exchange membrane fuel cells (PEMFC’s) remains a critical problem for their durability, cost, and performance. Because the anode side of this fuel cell has the tendency to become dehydrated, measuring the water balance can be an important diagnosis tool during fuel cell...... can be directly converted into the fuel cell water balance. In this work, experimental ex-situ results are presented and the elegance and usefulness of this method is demonstrated....

  3. Estimation of effective hydrologic properties of soils from observations of vegetation density. M.S. Thesis; [water balance of watersheds in Clinton, Maine and Santa Paula, California

    Science.gov (United States)

    Tellers, T. E.

    1980-01-01

    An existing one-dimensional model of the annual water balance is reviewed. Slight improvements are made in the method of calculating the bare soil component of evaporation, and in the way surface retention is handled. A natural selection hypothesis, which specifies the equilibrium vegetation density for a given, water limited, climate-soil system, is verified through comparisons with observed data and is employed in the annual water balance of watersheds in Clinton, Ma., and Santa Paula, Ca., to estimate effective areal average soil properties. Comparison of CDF's of annual basin yield derived using these soil properties with observed CDF's provides excellent verification of the soil-selection procedure. This method of parameterization of the land surface should be useful with present global circulation models, enabling them to account for both the non-linearity in the relationship between soil moisture flux and soil moisture concentration, and the variability of soil properties from place to place over the Earth's surface.

  4. Analysis of confidence in continental-scale groundwater recharge estimates for Africa using a distributed water balance model

    Science.gov (United States)

    Mackay, Jonathan; Mansour, Majdi; Bonsor, Helen; Pachocka, Magdalena; Wang, Lei; MacDonald, Alan; Macdonald, David; Bloomfield, John

    2014-05-01

    There is a growing need for improved access to reliable water in Africa as population and food production increases. Currently approximately 300 million people do not have access to a secure source of safe drinking water. To meet these current and future demands, groundwater will need to be increasingly abstracted; groundwater is more reliable than surface water sources due to its relatively long response time to meteorological stresses and therefore is likely to be a more secure water resource in a more variable climate. Recent studies also quantified the volumes of groundwater potentially available which suggest that, if exploited, groundwater could help to meet the demand for fresh water. However, there is still considerable uncertainty as to how these resources may respond in the future due to changes in groundwater recharge and abstraction. Understanding and quantifying groundwater recharge is vital as it forms a primary indicator of the sustainability of underlying groundwater resources. Computational hydrological models provide a means to do this, but the complexity of recharge processes in Africa mean that these simulations are often highly uncertain. This study aims to evaluate our confidence in simulating groundwater recharge over Africa based on a sensitivity analysis using a distributed hydrological model developed by the British Geological Survey, ZOODRM. The model includes land surface, canopy, river, soil and groundwater components. Each component is able to exchange water and as such, forms a distributed water balance of Africa. The components have been parameterised using available spatial datasets of African vegetation, land-use, soil and hydrogeology while the remaining parameters have been estimated by calibrating the model to available river flow data. Continental-scale gridded precipitation and potential evapotranspiration datasets, based on remotely sensed and ground observations, have been used to force the model. Following calibration, the

  5. Components of near-surface energy balance derived from satellite soundings – Part 1: Net available energy

    Directory of Open Access Journals (Sweden)

    K. Mallick

    2014-08-01

    Full Text Available This paper introduces a relatively simple method for recovering global fields of near-surface net available energy (the sum of the sensible and latent heat flux or the difference between the net radiation and surface heat accumulation using satellite visible and infra-red products derived from the AIRS (Atmospheric Infrared Sounder and MODIS (MOderate Resolution Imaging Spectroradiometer platforms. The method focuses on first specifying net surface radiation by considering its various shortwave and longwave components. This was then used in a surface energy balance equation in conjunction with satellite day–night surface temperature difference to derive 12 h discrete time estimates of surface, system heat capacity and heat accumulation, leading directly to retrieval for surface net available energy. Both net radiation and net available energy estimates were evaluated against ground truth data taken from 30 terrestrial tower sites affiliated to the FLUXNET network covering 7 different biome classes. This revealed a relatively good agreement between the satellite and tower data, with a pooled root mean square deviation of 98 and 72 W m−2 for net radiation and net available energy, respectively, although both quantities were underestimated by approximately 25 and 10%, respectively relative to the tower observations. Analysis of the individual shortwave and longwave components of the net radiation revealed the downwelling shortwave radiation to be the main source of this systematic underestimation.

  6. Soil Water Balance and Water Use Efficiency of Dryland Wheat in Different Precipitation Years in Response to Green Manure Approach

    Science.gov (United States)

    Zhang, Dabin; Yao, Pengwei; Na, Zhao; Cao, Weidong; Zhang, Suiqi; Li, Yangyang; Gao, Yajun

    2016-05-01

    Winter wheat (Triticum aestivum L.) monoculture is conventionally cultivated followed by two to three months of summer fallow in the Loess Plateau. To develop a sustainable cropping system, we conducted a six-year field experiment to investigate the effect of leguminous green manure (LGM) instead of bare fallow on the yield and water use efficiency (WUE) of winter wheat and the soil water balance (SWB) in different precipitation years in a semi-arid region of northwest China. Results confirmed that planting LGM crop consumes soil water in the fallow season can bring varied effects to the subsequent wheat. The effect is positive or neutral when the annual precipitation is adequate, so that there is no significant reduction in the soil water supplied to wheat. If this is not the case, the effect is negative. On average, the LGM crop increased wheat yield and WUE by 13% and 28%, respectively, and had considerable potential for maintaining the SWB (0-200 cm) compared with fallow management. In conclusion, cultivation of the LGM crop is a better option than fallow to improve the productivity and WUE of the next crop and maintain the soil water balance in the normal and wet years in the Loess Plateau.

  7. Strengthening of the hydrological cycle in future scenarios: atmospheric energy and water balance perspective

    Directory of Open Access Journals (Sweden)

    A. Alessandri

    2012-11-01

    Full Text Available Future climate scenarios experiencing global warming are expected to strengthen the hydrological cycle during the 21st century (21C. We analyze the strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. By combining energy and water equations for the whole atmosphere, we obtain constraints for the changes in surface fluxes and partitioning at the surface between sensible and latent components. We investigate the differences in the strengthening of the hydrological cycle in two centennial simulations performed with an Earth system model forced with specified atmospheric concentration pathways. Alongside the Special Report on Emissions Scenario (SRES A1B, which is a medium-high non-mitigation scenario, we consider a new aggressive-mitigation scenario (E1 with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K.

    Our results show that the mitigation scenario effectively constrains the global warming with a stabilization below 2 K with respect to the 1950–2000 historical period. On the other hand, the E1 precipitation does not follow the temperature field toward a stabilization path but continues to increase over the mitigation period. Quite unexpectedly, the mitigation scenario is shown to strengthen the hydrological cycle even more than SRES A1B till around 2070. We show that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to decreased sulfate aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B.

    The last decades of the 21C show a marked increase in global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost the same overall increase of radiative imbalance with respect to the 20th century. Our

  8. An estimation of the water balance in a reformer/fuel-cells system

    Energy Technology Data Exchange (ETDEWEB)

    Jovan, Vladimir [Jo-ef Stefan Institute and Centre of Excellence Low-Carbon Technologies (Slovenia); Cufar, Alja [University of Ljubljana, Faculty of Mathematics and Physics (Slovenia)], e-mail: vladimir.jovan@ijs.si

    2011-07-01

    PEM fuel cells use hydrogen as fuel. Since it is a very light element, its energy density is small despite its high caloric value. Thus hydrogen storage requires a lot of space. One possible solution is simultaneous production of hydrogen from higher-density materials, such as methanol. The object of this paper is to determine what is the total water balance in a system consisting of a methanol reformer and a fuel-cells-based generator set, and to determine if water should be supplied to, or removed from, the system. Based on relatively little information obtained from technical sources and on some simple assumptions, this paper presents a model which helps to determine the actual water balance in the system. In conclusion, commercially available fuel-cell systems with realistic water production can be used for fuel reforming purposes in the methanol reformer. It is also shown that under normal operating conditions, and using commercially available devices, there is always an excess of water produced.

  9. Portrayal of fuzzy recharge areas for water balance modelling - a case study in northern Oman

    Science.gov (United States)

    Gerner, A.; Schütze, N.; Schmitz, G. H.

    2012-06-01

    The research project IWAS Oman aims at implementing integrated water resources management (IWRM) to a pilot area in Al Batinah, Oman. This requires - amongst others - a realistic assessment of groundwater recharge to the alluvial aquifer which obviously has to be based upon the extension of recharge areas. In this context, the subsequent investigation focuses on the role of vagueness as regards the portrayal of the areas that provide water for particular aquifers. For that purpose, concepts of fuzziness in spatial analysis are applied to describe possible extents of recharge areas. In general, any water assessment is based on clearly delineated boundaries. However, in many cases, aquifer recharge areas are not clearly defined due to the nature of the study area. Hence, surfaces indicating a gradual membership to the recharge area of a particular aquifer are used in this investigation. These surfaces, which are based on available qualitative information, visualise a potential range of spatial extension. With regard to water balance calculations, functional relationships in tabular form are derived as well. Based on a regionalisation approach providing spatially distributed recharge rates, the corresponding recharge volume is calculated. Hence, this methodology provides fuzzy input data for water balance calculations. Beyond the portrayal of one singular aquifer recharge area, this approach also supports the complementary consideration of adjacent areas.

  10. Balance of Water Supply-demand in Paddy Fields in Hilly Regions in Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    Hong ZHANG; Xinlu JIANG; Hongzhu FAN; Jiaguo ZHENG

    2012-01-01

    Abstract [Objective] The aim was to study the effects of water supply and con- sumption on water saving and drought resistance. [Method] Controlling field experi- ment was conducted to explore water balance between supply and demand in paddy fields in hilly regions in Sichuan Province. [Result] Rainfall in hilly areas was 3 611.10 m3/hm2; water for irrigation was 6 299.25 m3/hm~, evapotranspiration of rice was 6 424.95 m3/hm2; deep leakage was 2 459.55 m3/hm2; overflowing amount was 1 026.00 m3/hm2. In addition, water consumption totaled 8 884.50 m3/hm2 during rice production; water use was 0.99 kg/m3 and use efficiency of irrigated water was 1.40 kg/m3, [Conclu- sion] Water supply and consumption should be further organized to save water and fight against drought in hilly areas in Sichuan Province.

  11. Impacts of Cropland Changes on Water Balance, Sediment and Nutrient Transport in Eden River, UK

    Science.gov (United States)

    Huang, Yumei; Quinn, Paul; Liang, Qiuhua; Adams, Russell

    2017-04-01

    Water is the key to food and human life. Farming is the main part of economic and society in Eden, with approximately 2000 farms which covers 95% of under crops. However, with the growth of farming practice and global climate changes, Eden has presented great challenges and bringing uncertainty in the water quality caused by the agricultural diffuse pollution. This expected to reduce negative impacts of the water diffuse pollution from agriculture in Eden. Therefore, there is a high need to ensure effective water resource management to enhance water quality, to address the flow pathways and sediment transport in different farming practice and cropland changes. Hence we need to understand nutrient and the hydrological flow pathways from soil to Hillslope to channel. The aim of this research is to evaluate the impacts of different cropland changes on water balance, sediment and nutrient transport. By using the hydrological models Soil and Water Assessment Tool (SWAT) and the Catchment Runoff Attenuation Flux Tool (CRAFT), it can show the sediment and nutrient export from the load for each flow pathways (overland flow, soil water flow and ground water flow). We will show results from a small research catchment (10km2) area to the whole of Eden (800km2) at a daily time step.

  12. Performance Measurement of Water Desalination Supply Chain Using Balanced Scorecard Model

    Directory of Open Access Journals (Sweden)

    Hasan Balfaqih

    2016-02-01

    Full Text Available The purpose of this study is to propose a theoretical framework based on a balanced scorecard (BSC for performance measurement in the water desalination supply chain (WDSC. The reason for choosing this context is that the supply chain (SC of water desalination has received a great amount of attention, due to issues related to the increased need of fresh water for agricultural, industrial and human consumptions. The research methodology is based on literature analysis concerning performance measurement and metrics, the water desalination industry and the BSC model. Different SC performance measures which related to WDSC have been reviewed and distributed into four BSC perspectives: financial, customer, internal business, and learning & growth. The article provides a structured theoretical framework specific for WDSC. This is the first developed framework in WDSC which could serve as a reference to develop applicable performance indicators, and it is expected that both researchers and practitioners would benefit from the proposed framework.

  13. Energy and water balance response of a vegetated wetland to herbicide treatment of invasive Phragmites australis

    Science.gov (United States)

    Mykleby, Phillip M.; Lenters, John D.; Cutrell, Gregory J.; Herrman, Kyle S.; Istanbulluoglu, Erkan; Scott, Durelle T.; Twine, Tracy E.; Kucharik, Christopher J.; Awada, Tala; Soylu, Mehmet E.; Dong, Bo

    2016-08-01

    The energy and water balance of a Phragmites australis dominated wetland in south central Nebraska was analyzed to assess consumptive water use and the potential for "water savings" as a result of vegetation eradication via herbicide treatment. Energy balance measurements were made at the field site for two growing seasons (treated and untreated), including observations of net radiation, heat storage, and sensible heat flux, which was measured using a large-aperture scintillometer. Latent heat flux was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons and with model simulations to examine the relative impacts of vegetation removal and climate variability. Observed ET rates dropped by roughly 32% between the two growing seasons, from a mean of 4.4 ± 0.7 mm day-1 in 2009 (with live vegetation) to 3.0 ± 0.8 mm day-1 in 2010 (with dead P. australis). These results are corroborated by the Agro-IBIS model simulations, and the reduction in ET implies a total "water savings" of 245 mm over the course of the growing season. The significant decreases in ET were accompanied by a more-than-doubling of sensible heat flux, as well as a ∼60% increase in heat storage due to decreased LAI. Removal of P. australis was also found to cause measurable changes in the local micrometeorology at the wetland. Consistent with the observed increase in sensible heat flux during 2010, warmer, drier, windier conditions were observed in the dead, P. australis section of the wetland, compared to an undisturbed section of live, native vegetation. Modeling results suggest that the elimination of transpiration in 2010 was partially offset by an increase in surface evaporation, thereby reducing the subsequent water savings by roughly 60%. Thus, the impact of vegetation removal depends on the local climate, depth to groundwater, and management decisions related to regrowth of vegetation.

  14. Role of water balance in the enhanced potassium excretion and hypokalaemia of rats with diabetes insipidus.

    Science.gov (United States)

    Fernández-Repollet, E; Martínez-Maldonado, M; Opava-Stitzer, S

    1980-08-01

    1. The role of water balance in the hypokalaemia of rats with diabetes insipidus (DI rats) was studied. 2. After a 3-day balance study DI rats had a lower muscle potassium content, and plasma [K+], and the urinary excretion of potassium in response to oral KCl loading was reduced when compared to normal rats. The hypokalaemia was found to be associated with elevated concentrations of potassium in renal medulla and papilla when compared to values in normal Long-Evans rats. 3. During a 9-day balance study urinary potassium excretion was higher than that of normal rats on days 1-3, but not different on days 4-9; this transient elevation was observed in DI rats on normal, high and low potassium diets. On a low potassium diet the urinary potassium excretion of DI rats fell to minimal levels, making unlikely the existence of a renal defect in potassium handling. 4. Muscle potassium content and plasma [K+] were normal after 9 days in metabolism cages. This spontaneous reversal of the hypokalaemia of DI rats was associated with increased water content of renal medulla and papilla, and decreased potassium concentration in these zones. 5. The effect of acute mild dehydration on potassium handling of DI rats was evaluated. Water deprivation for 1-8 hr was sufficient to raise the urinary potassium excretion of DI rats above that of DI rats drinking ad lib. Renal tissue [K+] was significantly increased after 8 hr of dehydration. Water deprivation also enhanced the response of DI rats to an oral KCl load. Two days of chronic dehydration in the form of water rationing also significantly enhanced the urinary potassium excretion of DI rats. 6. These data suggest that chronic mild dehydration may be responsible for the modest potassium deficiency observed in DI rats via alterations in renal tissue [K+] and consequently in urinary potassium excretion. Correction of dehydration during prolonged periods in metabolism cages may account for the spontaneous reversal of the hypokelaemic

  15. Closing the Water Balance for Arid Soils - First Results from a Large Lysimeter Study

    Science.gov (United States)

    Twarakavi, N.; Chief, K.; Berli, M.; Caldwell, T. G.; Daniels, J.; Young, M.

    2011-12-01

    Many ecological and hydrological processes cannot be fully assessed without full closure of the water balance. The weighing lysimeter facility in Boulder City, NV provides an excellent opportunity to study water infiltration, redistribution, storage and evaporation of bare soils at the intermediate (meter) scale under well-defined boundary conditions. Each of three lysimeters is weighed on separate balances, with a resolution of roughly 100 g or 0.025 mm of water. Each lysimeter contains 12 m3 of repacked homogenized and layered desert soil (dimensions: 2.26 m diameter and 3 m deep) and is instrumented with 13 different sensor technologies to measure state variables including water content, matric potential, and thermal properties at 15 depth planes. An angled rhizotron tube visually monitors movement the infiltration front. Between July 2008 and 2011, 15 storm events were recorded, with the largest storm total from 19-22 December 2010 yielding 62 mm of precipitation (originally in the form of snow). By July 2011, nearly 350 mm of cumulative precipitation was recorded, and the wetting front had reached 150 cm depth. This presentation analyzes storm events over the past three years with respect to changes in total soil mass to determine the amount of infiltration, storage, and evaporation; alterations in soil moisture and matric potential profiles determined by in situ sensors; and wetting front movement observed by the rhizotron. This lysimeter facility fills a critical gap in the vadose zone hydrology of arid environments by closing the total water balance and providing discrete data on soil moisture redistribution in a 3 meter deep soil profile to evaluate and improve infiltration models.

  16. Water balance-based estimation of groundwater recharge in the Lake Chad Basin

    Science.gov (United States)

    Babamaaji, R. A.; Lee, J.

    2012-12-01

    Lake Chad Basin (LCB) has experienced drastic changes of land cover and poor water management practices during the last 50 years. The successive droughts in the 1970s and 1980s resulted in the shortage of surface water and groundwater resources. This problem of drought and shortage of water has a devastating implication on the natural resources of the Basin with great consequence on food security, poverty reduction and quality of life of the inhabitants in the LCB. Therefore, understanding the change of land use and its characteristics must be a first step to find how such changes disturb the water cycle especially the groundwater in the LCB. The abundance of groundwater is affected by the climate change through the interaction with surface water, such as lakes and rivers, and vertical recharge through an infiltration process. Quantifying the impact of climate change on the groundwater resource requires not only reliable forecasting of changes in the major climatic variables, but also accurate estimation of groundwater recharge. Spatial variations in the land use/land cover, soil texture, topographic slope, and meteorological conditions should be accounted for in the recharge estimation. In this study, we employed a spatially distributed water balance model WetSpass to simulate a long-term average change of groundwater recharge in the LCB of Africa. WetSpass is a water balance-based model to estimate seasonal average spatial distribution of surface runoff, evapotranspiration, and groundwater recharge. The model is especially suitable for studying the effect of land use/land cover change on the water regime in the LCB. The present study describes the concept of the model and its application to the development of recharge map of the LCB.

  17. The Effect of Nitrogen Cross-over on Proton Exchange Membrane Fuel Cell Water Balance Measurements Using Constant Temperature Anemometry

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    A novel method to obtain an ad-hoc and real time electrical signal of the PEMFC water balance by employing a constant temperature hot wire anemometry has been developed by our fuel cell research group. In this work, the effect of nitrogen-cross over on this method is experimentally demonstrated....... This is due to the effect of 1% nitrogen on power law constant’s “m” which can be used in determining the water balance as explained in previous work was extremely low. Thus, the hot wire technique for measuring the PEMFC water balance is still accurate with the nitrogen cross-over...

  18. Integrated Modeling System for Analysis of Watershed Water Balance: A Case Study in the Tims Branch Watershed, South Carolina

    Science.gov (United States)

    Setegn, S. G.; Mahmoudi, M.; Lawrence, A.; Duque, N.

    2015-12-01

    The Applied Research Center at Florida International University (ARC-FIU) is supporting the soil and groundwater remediation efforts of the U.S. Department of Energy (DOE) Savannah River Site (SRS) by developing a surface water model to simulate the hydrology and the fate and transport of contaminants and sediment in the Tims Branch watershed. Hydrological models are useful tool in water and land resource development and decision-making for watershed management. Moreover, simulation of hydrological processes improves understanding of the environmental dynamics and helps to manage and protect water resources and the environment. MIKE SHE, an advanced integrated modeling system is used to simulate the hydrological processes of the Tim Branch watershed with the objective of developing an integrated modeling system to improve understanding of the physical, chemical and biological processes within the Tims Branch watershed. MIKE SHE simulates water flow in the entire land based phase of the hydrological cycle from rainfall to river flow, via various flow processes such as, overland flow, infiltration, evapotranspiration, and groundwater flow. In this study a MIKE SHE model is developed and applied to the Tim branch watershed to study the watershed response to storm events and understand the water balance of the watershed under different climatic and catchment characteristics. The preliminary result of the integrated model indicated that variation in the depth of overland flow highly depend on the amount and distribution of rainfall in the watershed. The ultimate goal of this project is to couple the MIKE SHE and MIKE 11 models to integrate the hydrological component in the land phase of hydrological cycle and stream flow process. The coupled MIKE SHE/MIKE 11 model will further be integrated with an Ecolab module to represent a range of water quality, contaminant transport, and ecological processes with respect to the stream, surface water and groundwater in the Tims

  19. WATER TEMPERATURE, VOLUNTARY DRINKING AND FLUID BALANCE IN DEHYDRATED TAEKWONDO ATHLETES

    Directory of Open Access Journals (Sweden)

    Saeed Khamnei

    2011-12-01

    Full Text Available Voluntary drinking is one of the major determiners of rehydration, especially as regards exercise or workout in the heat. The present study undertakes to search for the effect of voluntary intake of water with different temperatures on fluid balance in Taekwondo athletes. Six young healthy male Taekwondo athletes were dehydrated by moderate exercise in a chamber with ambient temperature at 38-40°C and relative humidity between 20-30%. On four separate days they were allowed to drink ad libitum plane water with the four temperatures of 5, 16, 26, and 58°C, after dehydration. The volume of voluntary drinking and weight change was measured; then the primary percentage of dehydration, sweat loss, fluid deficit and involuntary dehydration were calculated. Voluntary drinking of water proved to be statistically different in the presented temperatures. Water at 16°C involved the greatest intake, while fluid deficit and involuntary dehydration were the lowest. Intake of water in the 5°C trial significantly correlated with the subject's plasma osmolality change after dehydration, yet it showed no significant correlation with weight loss. In conclusion, by way of achieving more voluntary intake of water and better fluid state, recommending cool water (~16°C for athletes is in order. Unlike the publicly held view, drinking cold water (~5°C does not improve voluntary drinking and hydration status.

  20. Mapping crop evapotranspiration by integrating vegetation indices into a soil water balance model

    Science.gov (United States)

    Consoli, Simona; Vanella, Daniela

    2015-04-01

    The approach combines the basal crop coefficient (Kcb) derived from vegetation indices (VIs) with the daily soil water balance, as proposed in the FAO-56 paper, to estimate daily crop evapotranspiration (ETc) rates of orange trees. The reliability of the approach to detect water stress was also assessed. VIs were simultaneously retrieved from WorldView-2 imagery and hyper-spectral data collected in the field for comparison. ETc estimated were analysed at the light of independent measurements of the same fluxes by an eddy covariance (EC) system located in the study area. The soil water depletion in the root zone of the crop simulated by the model was also validated by using an in situ soil water monitoring. Average overestimate of daily ETc of 6% was obtained from the proposed approach with respect to EC measurements, evidencing a quite satisfactory agreement between data. The model also detected several periods of light stress for the crop under study, corresponding to an increase of the root zone water deficit matching quite well the in situ soil water monitoring. The overall outcomes of this study showed that the FAO-56 approach with remote sensing-derived basal crop coefficient can have the potential to be applied for estimating crop water requirements and enhancing water management strategies in agricultural contexts.

  1. Phloem transport in Ricinus: Its dependence on the water balance of the tissues.

    Science.gov (United States)

    Hall, S M; Milburn, J A

    1973-03-01

    Phloem exudation from Ricinus has been examined in plants subjected to changes in water balance induced by a number of means. The results have provided a clear demonstration that the phloem system can operate osmotically. When the availability of water in the xylem is reduced by withholding water, the rate of exudation decreases sharply and this is accompanied by a rise in the sap concentration. On removing the water stress, the rate increases rapidly with a corresponding fall in sap concentration.Small variations in water availability do not give significant results and may be buffered by responses from the plant itself. This could also explain the insignificant changes in sap composition during exudation previously reported, where exudation rate, which should bear some relation to sieve tube turgor pressure, seems independent of sap concentration. Fluctuations in exudation rate are large in comparison with the changes in sap concentration when severe water stresses are applied. This result, coupled with the observation that exudation will occur from plants under considerable water stress suggests the operation of a "sugar pump" capable of maintaining a high turgor pressure at the source against a considerable water potential gradient. The main "pump" is probably located in the leaves.Thus interpreted, the results seem to accord with the Münch pressure flow hypothesis in all significant aspects.

  2. Acid-base balance and hydration status following consumption of mineral-based alkaline bottled water

    Directory of Open Access Journals (Sweden)

    Heil Daniel P

    2010-09-01

    Full Text Available Abstract Background The present study sought to determine whether the consumption of a mineral-rich alkalizing (AK bottled water could improve both acid-base balance and hydration status in young healthy adults under free-living conditions. The AK water contains a naturally high mineral content along with Alka-PlexLiquid™, a dissolved supplement that increases the mineral content and gives the water an alkalizing pH of 10.0. Methods Thirty-eight subjects were matched by gender and self-reported physical activity (SRPA, hrs/week and then split into Control (12 women, 7 men; Mean +/- SD: 23 +/- 2 yrs; 7.2 +/- 3.6 hrs/week SRPA and Experimental (13 women, 6 men; 22 +/- 2 yrs; 6.4 +/- 4.0 hrs/week SRPA groups. The Control group consumed non-mineralized placebo bottled water over a 4-week period while the Experimental group consumed the placebo water during the 1st and 4th weeks and the AK water during the middle 2-week treatment period. Fingertip blood and 24-hour urine samples were collected three times each week for subsequent measures of blood and urine osmolality and pH, as well as total urine volume. Dependent variables were analyzed using multivariate repeated measures ANOVA with post-hoc focused on evaluating changes over time within Control and Experimental groups (alpha = 0.05. Results There were no significant changes in any of the dependent variables for the Control group. The Experimental group, however, showed significant increases in both the blood and urine pH (6.23 to 7.07 and 7.52 to 7.69, respectively, a decreased blood and increased urine osmolality, and a decreased urine output (2.51 to 2.05 L/day, all during the second week of the treatment period (P Conclusions Consumption of AK water was associated with improved acid-base balance (i.e., an alkalization of the blood and urine and hydration status when consumed under free-living conditions. In contrast, subjects who consumed the placebo bottled water showed no changes over the

  3. A Multifunctional Surface That Simultaneously Balances Hydrophilic Enzyme Catalysis and Hydrophobic Water Repellency.

    Science.gov (United States)

    Lawton, Timothy J; Uzarski, Joshua R; Filocamo, Shaun F

    2016-08-16

    The compatibility of multiple functions at a single interface is difficult to achieve, but is even more challenging when the functions directly counteract one another. This study provides insight into the creation of a simultaneously multifunctional surface formed by balancing two orthogonal functions; water repellency and enzyme catalysis. A partially fluorinated thiol is used to impart bulk hydrophobicity on the surface, and an N-hydroxysuccinimide ester-terminated thiol provides a specific anchoring sites for the covalent enzyme attachment. Different ratios of the two thiols are mixed together to form amphiphilic self-assembled monolayers, which are characterized with polarization-modulation infrared reflection-absorption spectroscopy and contact angle goniometry. The enzyme activity is measured by a fluorescence assay. With the results collected here, specific surface compositions are identified at which the orthogonal functions of water repellency and enzyme catalysis are balanced and exist simultaneously. An understanding of how to effectively balance orthogonal functions at surfaces can be extended to a number of higher-scale applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Assessment of green roof systems in terms of water and energy balance

    Directory of Open Access Journals (Sweden)

    Mert Ekşi

    2016-01-01

    Full Text Available Green roofs concept term is used for extensive green roofs which are planted with herbaceous plants that can be adapted into changeable environmental conditions on a shallow substrate layer, require minimal maintenance, installed for their benefits to building and urban scale. Main objective of this study is to determine the characteristics of a green roof such as thermal insulation, water holding capacity, runoff characteristics, plant growth and its interaction with environmental factors in Istanbul climate conditions by performing comparative measurements. In this study, a research site (IU Green Roof Research Station was founded to assess water and energy balance of green roofs. Thus, a typical green roof was evaluated in terms of water and energy balance and its interaction with the building and city was determined. energy efficiency of green roof system was 77% higher than reference roof. Temperature fluctuations on green roof section of the roof were 79% lower. In addition, green roof retained 12,8% - 100% of precipitation and delayed runoff up to 23 hours depending on water content of substrate.

  5. Balanced Fertilization and the Effect of Fertiliztion on Water Use Efficiency of Upland Winter Wheat in Western Henan,China

    Institute of Scientific and Technical Information of China (English)

    LIGUIBAO; LEIQUANKUI; 等

    1998-01-01

    A study on balanced fertilization was conducted by means of long-term field experiments,and a conve-nient table for balanced fertilization was compiled.The experimental results about the effect of fertilization on water use efficiency of upland wheat showed that the input of inorganic fertilizer should be reduced in dry years.

  6. Estimating Evapotranspiration of an Apple Orchard Using a Remote Sensing-Based Soil Water Balance

    Directory of Open Access Journals (Sweden)

    Magali Odi-Lara

    2016-03-01

    Full Text Available The main goal of this research was to estimate the actual evapotranspiration (ETc of a drip-irrigated apple orchard located in the semi-arid region of Talca Valley (Chile using a remote sensing-based soil water balance model. The methodology to estimate ETc is a modified version of the Food and Agriculture Organization of the United Nations (FAO dual crop coefficient approach, in which the basal crop coefficient (Kcb was derived from the soil adjusted vegetation index (SAVI calculated from satellite images and incorporated into a daily soil water balance in the root zone. A linear relationship between the Kcb and SAVI was developed for the apple orchard Kcb = 1.82·SAVI − 0.07 (R2 = 0.95. The methodology was applied during two growing seasons (2010–2011 and 2012–2013, and ETc was evaluated using latent heat fluxes (LE from an eddy covariance system. The results indicate that the remote sensing-based soil water balance estimated ETc reasonably well over two growing seasons. The root mean square error (RMSE between the measured and simulated ETc values during 2010–2011 and 2012–2013 were, respectively, 0.78 and 0.74 mm·day−1, which mean a relative error of 25%. The index of agreement (d values were, respectively, 0.73 and 0.90. In addition, the weekly ETc showed better agreement. The proposed methodology could be considered as a useful tool for scheduling irrigation and driving the estimation of water requirements over large areas for apple orchards.

  7. Insights into the effects of patchy ice layers on water balance heterogeneity in peatlands

    Science.gov (United States)

    Dixon, Simon; Kettridge, Nicholas; Devito, Kevin; Petrone, Rich; Mendoza, Carl; Waddington, Mike

    2017-04-01

    Peatlands in boreal and sub-arctic settings are characterised by a high degree of seasonality. During winter soils are frozen and snow covers the surface preventing peat moss growth. Conversely, in summer, soils unfreeze and rain and evapotranspiration drive moss productivity. Although advances have been made in understanding growing season water balance and moss dynamics in northern peatlands, there remains a gap in knowledge of inter-seasonal water balance as layers of ice break up during the spring thaw. Understanding the effects of ice layers on spring water balance is important as this coincides with periods of high wildfire risk, such as the devastating Fort McMurrary wildfire of May, 2016. We hypothesise that shallow layers of ice disconnect the growing surface of moss from a falling water table, and prevent water from being supplied from depth. A disconnect between the evaporating surface and deeper water storage will lead to the drying out of the surface layer of moss and a greater risk of severe spring wildfires. We utilise the unsaturated flow model Hydrus 2D to explore water balance in peat layers with an impermeable layer representing ice. Additionally we create models to represent the heterogeneous break up of ice layers observed in Canadian boreal peatlands; these models explore the ability of breaks in an ice layer to connect the evaporating surface to a deeper water table. Results show that peatlands with slower rates of moss growth respond to dry periods by limiting evapotranspiration and thus maintain moist conditions in the sub-surface and a water table above the ice layer. Peatlands which are more productive continue to grow moss and evaporate during dry periods; this results in the near surface mosses drying out and the water table dropping below the level of the ice. Where there are breaks in the ice layer the evaporating surface is able to maintain contact with a falling water table, but connectivity is limited to above the breaks, with

  8. Calculating the water and heat balances of the Eastern Mediterranean Basin using ocean modelling and available meteorological, hydrological and ocean data

    Directory of Open Access Journals (Sweden)

    Anders Omstedt

    2012-04-01

    Full Text Available Eastern Mediterranean water and heat balances wereanalysed over 52 years. The modelling uses a process-orientedapproach resolving the one-dimensional equations of momentum,heat and salt conservation; turbulence is modelled using a two-equation model. The results indicate that calculated temperature and salinity follow the reanalysed data well. The water balance in the Eastern Mediterranean basin was controlled by the difference between inflows and outflows through the Sicily Channel and by net precipitation. The freshwater component displayed a negative trend over the study period, indicating increasing salinity in the basin.The heat balance was controlled by heat loss from the water surface, solar radiation into the sea and heat flow through the Sicily Channel. Both solar radiation and net heat loss displayed increasing trends, probably due to decreased total cloud cover. In addition, the heat balance indicated a net import of approximately 9 W m-2 of heat to the Eastern Mediterranean Basin from the Western Basin.

  9. Evaluating the impact of SWOT observations§ on the water balance of lakes and wetlands

    Science.gov (United States)

    Andreadis, K.; Moller, D.; Rodriguez, E.; Alsdorf, D.

    2012-04-01

    Lakes and wetlands can exert controls on the water and energy fluxes, playing an important role in the local and regional climate. The spatial extent and storage volume of water bodies globally is poorly known, due to lack of measurements over large areas. The planned Surface Water Ocean Topography (SWOT) satellite mission will provide observations of water surface elevation and inundated area globally at an unprecedented spatial resolution. Apart from being used directly, these observations can be used to constrain the water balance simulated hydrologic model over large-scale basins. In this study, the Variable Infiltration Capacity (VIC) macroscale hydrologic model is implemented over the Great Lakes region within an identical twin synthetic experiment. VIC solves an energy and water balance over a gridded domain, and represents lakes and wetlands dynamically as fractional areas of each model grid cell. A baseline simulation of the water and energy balance is designated as "truth", and errors in precipitation, temperature and model parameters are added to simulate a "first-guess" of hydrologic variables of interest. Synthetic SWOT observations are generated from the instrument simulator (developed at JPL) with the anticipated orbital and error characteristics. These "virtual" observations are then assimilated into the "first-guess" model to estimate runoff, evapotranspiration and sensible/latent heat fluxes. The assimilation technique used is the Ensemble Kalman Filter (EnKF), which solves the optimal estimation problem by approximating model and observation errors through a Monte Carlo ensemble approach. The "first-guess" simulation consists of an ensemble of model states that is propagated temporally until a SWOT observation becomes available. The impact of merging the SWOT observations is examined in terms of water and energy fluxes, and the sensitivity of the results to the different observation errors is assessed. The latter can include errors in lake

  10. Holding Water in the Landscape; striking a balance between food production and healthy catchment function

    Science.gov (United States)

    Quinn, Paul; Wilkinson, Mark; Stutter, Marc; Adams, Russell

    2015-04-01

    Here it is proposed that ~5 % of the rural landscape could be modified to hold water during storm events. Hence ~95% of land remains for food production, commercial forestry and amenity. This is a catchment scale commitment to sustainably reducing flood and drought risk, improving water quality, biodiversity and thereby climate proofing our catchments. The farmed landscape has intensified and as a result, runoff rates are no longer in balance with the catchment needs, which in turn contributes to floods, droughts and water pollution problems. The loss of infiltration rates, soil water holding capacity and the increase in ditches and drains through intense farming has resulted in a reduction of the overall water holding capacity of the landscape, therefore deeper soil and aquifer recharge rates are lower. However, adequate raw water supply and food production is also vital. Here we consider how ~5% of productive land could be used to physically hold water during and after storms. This is a simple philosophy for water stewardship that could be delivered by farmers and land managers themselves. In this poster we consider a 'treatment train' of mitigation in headwaters by the construction of:- Rural SuDs - by creating swales, bunds and grassy filters; Buffer Strips - (designed to hold water); The Ditch of The Future - by creating the prime location for holding water and recovering lost top soil and finally the better use of Small Headwater Floodplains - by storing flood water, creating wetlands, planting new forest, installing woody debris and new habitats. We present examples of where and how these measures have been installed and show the cost-effectiveness of temporarily holding storm runoff in several case study catchments taken from the UK.

  11. A Distributed Monthly Water Balance Model for Analyzing Impacts of Land Cover Change on Flow Regimes

    Institute of Scientific and Technical Information of China (English)

    XIA Jun; WANG Gang-Sheng; YE Ai-Zhong; NIU Cun-Wen

    2005-01-01

    The Miyun Reservoir is the most important water source for Beijing Municipality, the capital of China with a population of more than 12 million. In recent decades, the inflow to the reservoir has shown a decreasing trend, which has seriously threatened water use in Beijing. In order to analyze the influents of land use and cover change (LUCC)upon inflow to Miyun Reservoir, terrain and land use information from remote sensing were utilized with a revised evapotranspiration estimation formula; a water loss model under conditions of human impacts was introduced; and a distributed monthly water balance model was established and applied to the Chaobai River Basin controlled by the Miyun Reservoir. The model simulation suggested that not only the impact of land cover change on evapotranspiration, but also the extra water loss caused by human activities, such as the water and soil conservation development projects should be considered. Although these development projects were of great benefit to human and ecological protection, they could reallocate water resources in time and space, and in a sense thereby influence the stream flow.

  12. Water Reserves Program. An adaptation strategy to balance water in nature

    Science.gov (United States)

    Lopez Perez, M.; Barrios, E.; Salinas-Rodriguez, S.; Wickel, B.; Villon, R. A.

    2013-05-01

    Freshwater ecosystems occupy approximately 1% of the earth's surface yet possess about 12% of all known animal species. By virtue of their position in the landscape they connect terrestrial and coastal marine biomes and provide and sustain ecosystem services vital to the health and persistence of human communities. These services include the supply of water for food production, urban and ind ustrial consumption, among others. Over the past century many freshwater ecosystems around the world have been heavily modified or lost due to the alteration of flow regimes (e.g. due to damming, canalization, diversion, over-abstraction). The synergistic impacts of land use change, changes in flows, chemical deterioration, and climate change have left many systems and their species very little room to adjust to change, while future projections indicate a steady increase in water demand for food and energy production and water supply to suit the needs of a growing world population. In Mexico, the focus has been to secure water for human development and maximize economic growth, which has resulted in allocation of water beyond available amounts. As a consequence episodic water scarcity severely constrains freshwater ecosystems and the services they provide. Climatic change and variability are presenting serious challenges to a country that already is experiencing serious strain on its water resources. However, freshwater ecosystems are recognized by law as legitimate user of water, and mandate a flow allocation for the environment ("water reserve" or "environmental flows"). Based on this legal provision the Mexican government through the National Water Commission (Conagua), with support of the Alliance WWF - Fundación Gonzalo Río Arronte, and the Interamerican Development Bank, has launched a national program to identify and implement "water reserves": basins where environmental flows will be secured and allocated and where the flow regime is then protected before over

  13. Analysis of Soil and Water Balance on the Land Arrangement Function

    Institute of Scientific and Technical Information of China (English)

    Cao Yue'e; Tashpolat Tiyip; He Lijun; Zhang Jing

    2007-01-01

    The natural supply of land resources is limited, but the economic supply may change along with social and economic development, and its size is decided bye nature and social and economic body conditions. When the supplying ability of land resources threatens the development of society and the conflict between people and land becomes tense, it forced people to improve land utilization and to increase the effective supply of land resources. The paper made an overall consideration on the characteristics of the irrigated fanning and the frail ecological environment in Fuhai County, Altay Area, Xinjiang Uigur Autonomous Region and explored land arrangement planning as well as water resource planning and environmental protection. The paper evaluated natural resources, land utilization and water resource of the case study areas and focused on the spatio-temporal balance between the utilization of water and land resources. In the end the paper a feasible plan was made out for the land arrangement project.

  14. Monthly urban (municipal and industrial use) pumpage for the Central Valley Hydrologic Model (CVHM) by Water Balance Subregion (WBS)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly urban (municipal and industrial use) pumpage for the Central Valley Hydrologic Model (CVHM) by Water Balance Subregion...

  15. Hybrid calibration method for six-component force/torque transducers of wind tunnel balance based on support vector machines

    Institute of Scientific and Technical Information of China (English)

    Ma Yingkun; Xie Shilin; Zhang Xinong; Luo Yajun

    2013-01-01

    A hybrid calibration approach based on support vector machines (SVM) is proposed to characterize nonlinear cross coupling of multi-dimensional transducer.It is difficult to identify these unknown nonlinearities and crosstalk just with a single conventional calibration approach.In this paper,a hybrid model comprising calibration matrix and SVM model for calibrating linearity and nonlinearity respectively is built up.The calibration matrix is determined by linear artificial neural network (ANN),and the SVM is used to compensate for the nonlinear cross coupling among each dimension.A simulation of the calibration of a multi-dimensional sensor is conducted by the SVM hybrid calibration method,which is then utilized to calibrate a six-component force/torque transducer of wind tunnel balance.From the calibrating results,it can be indicated that the SVM hybrid calibration method has improved the calibration accuracy significantly without increasing data samples,compared with calibration matrix.Moreover,with the calibration matrix,the hybrid model can provide a basis for the design of transducers.

  16. New data on the bottom topography, recent sedimentation and water balance of Cerro Prieto dam, Mexico

    Science.gov (United States)

    Yutsis, Vsevolod; Levchenko, Oleg; Lowag, Jens; Krivosheya, Konstantin; de León Gómez, Héctor; Kotsarenko, Anatolyi

    2010-05-01

    Cerro Prieto Dam, a small water reservoir in the NE Mexico, is characterized by very high velocity of recent sedimentation, high sub-bottom seepage and erosion, and as a result, nonlinear water balance. These phenomenons never were studied since construction of the dam in the beginning of 1980th. So the goal of our work was to investigate the bottom topography and also sub-bottom near surface structure using the parametric acoustical effect. High-resolution sub-bottom profiling, using the Innomar SES-2000 compact echosounder, was carried out in Cerro Prieto Dam during February-April of 2008. The survey was conducted onboard of a small motor boat. The SES transducer was mounted on the front side of the boat using light metal pipe, and all electronic equipment was installed on the deck. Accurate positioning of the boat was reached by GPS. Average speed was 8-10 km/h. Innomar's software tool ISE was provides near real-time post-processing of the collected SES data and operation procedure could be corrected on-line. Acoustic signal ensured vertical resolution of 10-15 cm at acceptable penetration up to 15 m. Bathymetry map was compiled assuming average sound velocity of 1450 m/s. The irregular bottom topography of Cerro Prieto dam was discovered. The present elevation of the water surface is about 181 m above see level, and the lake depth varies from 1-2 to 28 m. The SES records show a distinct bottom layer of recent sediments by 0.5 - 4 m thickness which follows reservoir floor topography. Very specific acoustic anomalies, which seem to be related with gas sediments, are observed. The integrated SES, gravity, magnetic and geoelectrical data interpretation allows assuming a series of the superficial fractures focused in a NW direction, perpendicular (NE-SW) to the general deep fault zone. Hydrological balance for the Cerro Prieto water reservoir has been analyzed for last two decades. There are three types of water level fluctuations on the Cerro Prieto dam: long

  17. EU Water Governance: Striking the Right Balance between Regulatory Flexibility and Enforcement?

    Directory of Open Access Journals (Sweden)

    Olivia O. Green

    2013-06-01

    Full Text Available Considering the challenges and threats currently facing water management and the exacerbation of uncertainty by climate change, the need for flexible yet robust and legitimate environmental regulation is evident. The European Union took a novel approach toward sustainable water resource management with the passage of the EU Water Framework Directive in 2000. The Directive promotes sustainable water use through long-term protection of available water resources, progressively reduces discharges of hazardous substances in ground and surface waters, and mitigates the effects of floods and droughts. The lofty goal of achieving good status of all waters requires strong adaptive capacity, given the large amounts of uncertainty in water management. Striking the right balance between flexibility in local implementation and robust and enforceable standards is essential to promoting adaptive capacity in water governance, yet achieving these goals simultaneously poses unique difficulty. Applied resilience science reveals a conceptual framework for analyzing the adaptive capacity of governance structures that includes multiple overlapping levels of control or coordination, information flow horizontally and vertically, meaningful public participation, local capacity building, authority to respond to changed circumstances, and robust monitoring, system feedback, and enforcement. Analyzing the Directive through the lens of resilience science, we highlight key elements of modern European water management and their contribution to the resilience of the system and conclude that the potential lack of enforcement and adequate feedback of monitoring results does not promote managing for resilience. However, the scale-appropriate governance aspects of the EU approach promotes adaptive capacity by enabling vertical and horizontal information flow, building local capacity, and delegating control at multiple relevant scales.

  18. Armenia - Water to Market Farmer Training Credit Component

    Data.gov (United States)

    Millennium Challenge Corporation — The Farming Practices Survey (FPS) was commissioned by MCC to evaluate the impact of Water-to-Market (WtM) activities, particularly farmer training, on rural farmers...

  19. Water balance and soil moisture dynamics of field plots with barley and grass ley

    Science.gov (United States)

    Johnsson, Holger; Jansson, Per-Erik

    1991-12-01

    A physically based soilwater and heat model was used to estimate the water balance of an arable field in central Sweden for each of three different crop covers (barley with and without N fertilization and grass ley). Annual water balances were calculated for each year from 1981 to 1985. On-site measurements of soil physical properties, meteorological variables and plant development were used as input to the model. Simulated soil forst, snow cover, soilwater contents, soilwater tensions and relative differences in simulated drainage between treatments were in agreement with the corresponding measured values. In the simulation, surface runoff (70 mm year -1 in all treatments) mainly occurred during snowmelt periods and accounted for much of the variation in the total runoff estimate. Annual mean precipitation amounted to 610 mm year -1, whereas average evapotranspiration was calculated to be 320, 360 and 435 mm year -1 in barley without N fertilization, barley with N fertilization and grass ley, respectively. Soil evaporation accounted for 60, 43 and 23% whereas evaporation of intercepted water accounted for 5, 12 and 19% of the total evapotranspiration, respectively. Drainage estimates amounted to 205, 170 and 110 mm year -1.

  20. Climate change impacts on the water balance of coastal and montane rainforests in northern Queensland, Australia

    Science.gov (United States)

    Wallace, Jim; McJannet, Dave

    2012-12-01

    SummaryHow the water balance of coastal and montane rainforests in northern Queensland could change in response to climate change was examined using physically based models of interception and transpiration along with long term weather records. Future rainfall and temperature changes were based on the most recent climate modelling for the region and were assumed to fall within the range ±20% for rainfall with a temperature increase of 1-3 K. Climate change will affect the water balance of Australian rainforests primarily via rainfall changes rather than temperature. Any given change in rainfall produces a greater change in downstream runoff, the amplification ranging from 1.1 to 1.5 in the wet season to a factor of 12 in the dry season. Changes in wet season rainfall (80% of the annual total) dominate the total annual amount of water released for downstream flow, but dry season rainfall (20% of the annual total) changes are also very important as they affect onset and the duration of the period when there is no runoff. This period is currently ˜110 days and this would change by ±30 days under the above climate scenarios. There are also potential in situ impacts of climate change that affect how long the rainforest canopy is wet, which may have important implications for the epiphytes and mosses that depend on these wet canopy conditions. Similarly there may be significant impacts on downstream freshwater species whose life cycles are adapted to the current dry season flow regime.

  1. Comparison of root water uptake modules using either the surface energy balance or potential transpiration

    Science.gov (United States)

    Braud, Isabelle; Varado, Noémie; Olioso, Albert

    2005-01-01

    Numerical models simulating changes in soil water content with time rely on accurate estimation of root water uptake. This paper considers two root water uptake modules that have a compensation mechanism allowing for increased root uptake under conditions of water stress. These modules, proposed by Lai and Katul and Li et al. [Adv. Water Resour. 23 (2000) 427 and J. Hydrol. 252 (2001) 189] use potential transpiration weighted, for each soil layer, by a water stress and a compensation function in order to estimate actual transpiration. The first objective of the paper was to assess the accuracy of the proposed root extraction modules against two existing data sets, acquired under dry conditions for a winter wheat and a soybean crop. In order to perform a fair comparison, both modules were included as possible root water extraction modules within the Simple Soil Plant Atmosphere Transfer (SiSPAT) model. In this first set of simulations, actual transpiration was calculated using the solution of the surface energy budget as implemented in the SiSPAT model. Under such conditions, both root extraction modules were able to reproduce accurately the time evolution of soil moisture at various depths, soil water storage and daily evaporation. Results were generally improved when we activated the compensation mechanisms. However, we showed that Lai and Katul [Adv. Water Resour. 23 (2000) 427] module was sensitive to soil hydraulic properties through its water stress function, whereas the Li et al. [J. Hydrol. 252 (2001) 189] module was not very sensitive to the specification of its parameter. The latter module is therefore recommended for inclusion into a larger scale hydrological model, due to its robustness. When water balance models are run at larger scales or on areas with scarce data, actual transpiration is often calculated using models based on potential transpiration without solving the surface energy balance. The second objective of the paper was to assess the loss of

  2. Analysis of plant available water in the context of climate change using Thornthwaite type monthly water balance model

    Science.gov (United States)

    Herceg, Andras; Gribovszki, Zoltan; Kalicz, Peter

    2016-04-01

    The hydrological impact of climate change can be dramatic. The primary objective of this paper was to analyze plant available water in the context of climate change using Thornthwaite type monthly water balance calibrated by remote sensing based ET maps. The calibrated model was used for projection on the basis of 4 climate model datasets. The 3 periods of projection were: 2010-2040, 2040-2070, and 2070-2100. The benefit of this method is its robust build up, which can be applied if temperature and precipitation time series are accessible. The key parameter is the water storage capacity of the soil (SOILMAX), which can be calibrated using the actual available evapotranspiration data. If the soil's physical properties are available, the maximal rooting depth is also projectable. Plant available water was evaluated for future scenarios focusing water stress periods. For testing the model, a dataset of an agricultural parcel next to Mosonmagyaróvár and a dataset of a small forest covered catchment next to Sopron were successfully used. Each of the models projected slightly ascending evapotranspiration values (+7 percent), but strongly decreasing soil moisture values (-15 percent) for the 21st century. The soil moisture minimum values (generally appeared at the end of the summer) reduced more than 50 percent which indicate almost critical water stress for vegetation. This research has been supported by Agroclimate.2 VKSZ_12-1-2013-0034 project.

  3. Component

    Directory of Open Access Journals (Sweden)

    Tibor Tot

    2011-01-01

    Full Text Available A unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal stromal component is described. The tumor grew rapidly and measured 9 cm at the time of diagnosis. No lymph node metastases were present. The disease progressed rapidly and the patient died two years after the diagnosis from a hemorrhage caused by brain metastases. The morphology and phenotype of the tumor are described in detail and the differential diagnostic options are discussed.

  4. Water balance modeling of Upper Blue Nile catchments using a top-down approach

    Directory of Open Access Journals (Sweden)

    S. Tekleab

    2011-07-01

    Full Text Available The water balances of twenty catchments in the Upper Blue Nile basin have been analyzed using a top-down modeling approach based on Budyko's hypotheses. The objective of this study is to obtain better understanding of water balance dynamics of upper Blue Nile catchments on annual and monthly time scales and on a spatial scale of meso scale to large scale. The water balance analysis using a Budyko-type curve at annual scale reveals that the aridity index does not exert a first order control in most of the catchments. This implies the need to increase model complexity to monthly time scale to include the effects of seasonal soil moisture dynamics. The dynamic water balance model used in this study predicts the direct runoff and other processes based on the limit concept; i.e. for dry environments since rainfall amount is small, the aridity index approaches to infinity or equivalently evaporation approaches rainfall and for wet environments where the rainfall amount is large, the aridity index approaches to zero and actual evaporation approaches the potential evaporation. The uncertainty of model parameters has been assessed using the GLUE (Generalized Likelihood Uncertainty Estimation methodology. The results show that the majority of the parameters are reasonably well identifiable. However, the baseflow recession constant was poorly identifiable. Parameter uncertainty and model structural errors could be the reason for the poorly identifiable parameter. Moreover, a multi-objective model calibration strategy has been employed to emphasize the different aspects of the hydrographs on low and high flows.

    The model has been calibrated and validated against observed streamflow time series and it shows good performance for the twenty study catchments in the upper Blue Nile. During the calibration period (1995–2000 the Nash and Sutcliffe efficiency (E NS for monthly flow prediction varied between 0.52 to 0.93 (dominated by

  5. On the treatment of evapotranspiration, soil moisture accounting, and aquifer recharge in monthly water balance models.

    Science.gov (United States)

    Alley, W.M.

    1984-01-01

    Several two- to six-parameter regional water balance models are examined by using 50-year records of monthly streamflow at 10 sites in New Jersey. These models include variants of the Thornthwaite-Mather model, the Palmer model, and the more recent Thomas abcd model. Prediction errors are relatively similar among the models. However, simulated values of state variables such as soil moisture storage differ substantially among the models, and fitted parameter values for different models sometimes indicated an entirely different type of basin response to precipitation.-from Author

  6. The potential of the spectral 'water balance index' (WABI) for crop irrigation scheduling.

    Science.gov (United States)

    Rapaport, Tal; Hochberg, Uri; Cochavi, Amnon; Karnieli, Arnon; Rachmilevitch, Shimon

    2017-08-10

    Hyperspectral sensing can detect slight changes in plant physiology, and may offer a faster and nondestructive alternative for water status monitoring. This premise was tested in the current study using a narrow-band 'water balance index' (WABI), which is based on independent changes in leaf water content (1500 nm) and the efficiency of the nonphotochemical quenching (NPQ) photo-protective mechanism (531 nm). The hydraulic, photo-protective and spectral behaviors of five important crops - grapevine, corn, tomato, pea and sunflower - were evaluated under water deficit conditions in order to associate the differences in stress physiology with WABI suitability. Rapid alterations in both leaf water content and NPQ were observed in grapevine, pea and sunflower, and were effectively captured by WABI. Apart from water status monitoring, the index was also successful in scheduling the irrigation of a vineyard, despite phenological and environmental variability. Conversely, corn and tomato displayed a relatively strict stomatal regime and/or mild NPQ responses and were, thus, unsuitable for WABI-based monitoring. WABI shows great potential for irrigation scheduling of various crops, and has a clear advantage over spectral models that focus on either of the abovementioned physiological mechanisms. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  7. Surface Energy Balance of Fresh and Saline Waters: AquaSEBS

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelrady

    2016-07-01

    Full Text Available Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System model for large water bodies and add the effect of water salinity to the evaporation rate. Firstly, SEBS is modified for fresh-water whereby new parameterizations of the water heat flux and sensible heat flux are suggested. This is achieved by adapting the roughness heights for momentum and heat transfer. Secondly, a salinity correction factor is integrated into the adapted model. Eddy covariance measurements over Lake IJsselmeer (The Netherlands are carried out and used to estimate the roughness heights for momentum (~0.0002 m and heat transfer (~0.0001 m. Application of these values over the Victoria and Tana lakes (freshwater in Africa showed that the calculated latent heat fluxes agree well with the measurements. The root mean-square of relative-errors (rRMSE is about 4.1% for Lake Victoria and 4.7%, for Lake Tana. Verification with ECMWF data showed that the salinity reduced the evaporation at varying levels by up to 27% in the Great Salt Lake and by 1% for open ocean. Our results show the importance of salinity to the evaporation rate and the suitability of the adapted-SEBS model (AquaSEBS for fresh and saline waters.

  8. Regional estimation of base recharge to ground water using water balance and a base-flow index.

    Science.gov (United States)

    Szilagyi, Jozsef; Harvey, F Edwin; Ayers, Jerry F

    2003-01-01

    Naturally occurring long-term mean annual base recharge to ground water in Nebraska was estimated with the help of a water-balance approach and an objective automated technique for base-flow separation involving minimal parameter-optimization requirements. Base recharge is equal to total recharge minus the amount of evapotranspiration coming directly from ground water. The estimation of evapotranspiration in the water-balance equation avoids the need to specify a contributing drainage area for ground water, which in certain cases may be considerably different from the drainage area for surface runoff. Evapotranspiration was calculated by the WREVAP model at the Solar and Meteorological Surface Observation Network (SAMSON) sites. Long-term mean annual base recharge was derived by determining the product of estimated long-term mean annual runoff (the difference between precipitation and evapotranspiration) and the base-flow index (BFI). The BFI was calculated from discharge data obtained from the U.S. Geological Survey's gauging stations in Nebraska. Mapping was achieved by using geographic information systems (GIS) and geostatistics. This approach is best suited for regional-scale applications. It does not require complex hydrogeologic modeling nor detailed knowledge of soil characteristics, vegetation cover, or land-use practices. Long-term mean annual base recharge rates in excess of 110 mm/year resulted in the extreme eastern part of Nebraska. The western portion of the state expressed rates of only 15 to 20 mm annually, while the Sandhills region of north-central Nebraska was estimated to receive twice as much base recharge (40 to 50 mm/year) as areas south of it.

  9. 76 FR 69292 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-11-08

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY... Staff Guidance (LR-ISG), LR- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG revises the guidance in the Standard Review Plan...

  10. 77 FR 27815 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2012-05-11

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY..., ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG... Power Plants (SRP-LR) and Generic Aging Lessons Learned (GALL) Report for the aging management...

  11. Cumulative human threats on fish biodiversity components in Tunisian waters

    Directory of Open Access Journals (Sweden)

    F. BEN RAIS LASRAM

    2015-02-01

    Full Text Available Human activities are increasingly impacting biodiversity. To improve conservation planning measures in an ecosystem-based management context, we need to explore how the effects of these activities interact with different biodiversity components. In this study, we used a semi-quantitative method to assess the cumulative impacts of human activities on three biodiversity components (species richness, phylogenetic diversity, and functional diversity in Tunisia’s exclusive economic zone. For each of the nine activities considered, we developed an understanding of their effects from local studies and the expert opinion of stakeholders with country-specific experience. We mapped the cumulative effects and the three biodiversity components and then assessed the degree to which these elements overlapped using an overlap index. This is the first time such an assessment has been made for Tunisia’s marine ecosystems and our assessment highlight the inappropriateness of current conservation measures. The results of this study have specific application for the prioritization of future management actions.

  12. Cumulative human threats on fish biodiversity components in Tunisian waters

    Directory of Open Access Journals (Sweden)

    F. BEN RAIS LASRAM

    2014-06-01

    Full Text Available Human activities are increasingly impacting biodiversity. To improve conservation planning measures in an ecosystem-based management context, we need to explore how the effects of these activities interact with different biodiversity components. In this study, we used a semi-quantitative method to assess the cumulative impacts of human activities on three biodiversity components (species richness, phylogenetic diversity, and functional diversity in Tunisia’s exclusive economic zone. For each of the nine activities considered, we developed an understanding of their effects from local studies and the expert opinion of stakeholders with country-specific experience. We mapped the cumulative effects and the three biodiversity components and then assessed the degree to which these elements overlapped using an overlap index. This is the first time such an assessment has been made for Tunisia’s marine ecosystems and our assessment highlight the inappropriateness of current conservation measures. The results of this study have specific application for the prioritization of future management actions.

  13. ASSESSMENT OF EARLY SEASON AGRICULTURAL DROUGHT THROUGH LAND SURFACE WATER INDEX (LSWI AND SOIL WATER BALANCE MODEL

    Directory of Open Access Journals (Sweden)

    K. Chandrasekar

    2012-08-01

    Full Text Available An attempt was made to address the early season agriculture drought, by monitoring the surface soil wetness during 2010 cropping seasons in the states of Andhra Pradesh and Tamil Nadu. Short Wave Infrared (SWIR based Land Surface Water Index (LSWI and Soil Water Balance (SWB model using inputs from remote sensing and ancillary data were used to monitor early season agriculture drought. During the crop season, investigation was made on LSWI characteristics and its response to the rainfall. It was observed that the Rate of Increase (RoI of LSWI was the highest during the fortnights when the onset of monsoon occurred. The study showed that LSWI is sensitive to the onset of monsoon and initiation of cropping season. The second part of this study attempted to develop a simple book keeping – bucket type – water tight soil water balance model to derive the top 30cm profile soil moisture using climatic, soil and crop parameters as the basic inputs. Soil moisture derived from the model was used to compute the Area Conducive for Sowing (ACS during the sowing window of the cropping season. The soil moisture was validated spatially and temporally with the ground observed soil moisture values. The ACS was compared with the RoI of LSWI. The results showed that the RoI was high during the sowing window whenever the ACS was greater than 50% of the district area. The observation was consistent in all the districts of the two states. Thus the analysis revealed the potential of LSWI for early season agricultural drought management.

  14. Aedes aegypti Global Suitability Maps Using a Water Container Energy Balance Model for Dengue Risk Applications

    Science.gov (United States)

    Steinhoff, D.

    2015-12-01

    Dengue infections are estimated to total nearly 400 million per year worldwide, with both the geographic range and the magnitude of infections having increased in the past 50 years. The primary dengue vector mosquito Aedes aegypti is closely associated with humans. It lives exclusively in urban and semi-urban areas, preferentially bites humans, and spends its developmental stages in artificial water containers. Climate regulates the development of Ae. aegypti immature mosquitoes in artificial containers. Potential containers for Ae. aegypti immature development include, but are not limited to, small sundry items (e.g., bottles, cans, plastic containers), buckets, tires, barrels, tanks, and cisterns. Successful development of immature mosquitoes from eggs to larvae, pupae, and eventually adults is largely dependent on the availability of water and the thermal properties of the water in the containers. Recent work has shown that physics-based approaches toward modeling container water properties are promising for resolving the complexities of container water dynamics and the effects on immature mosquito development. An energy balance container model developed by the author, termed the Water Height And Temperature in Container Habitats Energy Model (WHATCH'EM), solves for water temperature and height for user-specified containers with readily available weather data. Here we use WHATCH'EM with NASA Earth Science products used as input to construct global suitability maps based on established water temperature ranges for immature Ae. aegypti mosquitoes. A proxy for dengue risk is provided from habitat suitability, but also population estimates, as Ae. aegypti is closely associated with human activity. NASA gridded Global Population of the World data is used to mask out rural areas with low dengue risk. Suitability maps are illustrated for a variety of containers (size, material, color) and shading scenarios.

  15. Human impacts on land cover and water balances in a coastal Mediterranean county.

    Science.gov (United States)

    Bellot, Juan; Bonet, Andreu; Peña, Juan; Sánchez, Juan Rafael

    2007-03-01

    We analyzed the effects of changes in land cover on the water balance in Spain's Marina Baixa County, on the Mediterranean coast. To reveal how different land management strategies have affected the area's environment, four municipalities within the same catchment were studied: Benidorm, Callosa d'en Sarrià, Beniardà, and Guadalest. In the municipalities of Callosa and Benidorm, the proportion of the area covered by woodland declined by 4.2% and 30.2%, respectively, and woodland was replaced by agriculture and urban development. The abandonment of farmland produced a 17% increase in the proportion of the area covered by vegetation in Guadalest and Beniardá, where frequent forest fires have exacerbated a decrease in the area of pine woodland. Tourism development in Benidorm has been accompanied by an increase in the transportation infrastructure and by an expansion of areas with an impermeable surface, with the lowest level of infiltration into the aquifer system. These changes have generated a net water deficit in Callosa and Benidorm of more than 6 Mm(3)/year, creating a high demand for water imported from other municipalities (Guadalest and Beniardá) or from outside of the county to maintain the sustainability of the current water management strategies. The Marina Baixa case study is representative of many of the world's coastal areas that are undergoing rapid urban development based on an inappropriate understanding of human progress based mainly on economic development and thus provides insights into water management in other areas.

  16. Water Balance Map of Norway Based On A Distributed Hydrological Model

    Science.gov (United States)

    Beldring, S.; Engeland, K.; Roald, L. A.; Sælthun, N. R.

    Water balance maps of Norway for the period 1961-1990 have been produced with a distributed hydrological model. The model applies regional parameters conditioned on catchment characteristics. As this models must consider the relationship between climate and land surface hydrological processes everywhere it must account for the water balance of ungauged areas. Since data are generally not available to calibrate a model for this task in the same way as catchment models, its parameters must be estimated using available hydrological data and information about land surface properties. The structure of this model must be geographically transferable, and its parameters must be derived from knowledge of physical characteristics of the landscape. A distributed HBV-model using 1 km2 grid cells and daily time step was calibrated against monthly runoff data from 141 catchments located in different parts of Norway. Model parameters were conditioned on land use data and digital elevation data. These parameter sets were applied in 43 independent catchments in order to evaluate model performance. The model was run for the entire land surface of Norway in order to determine average yearly runoff for the period 1961-1990. Finally, a river routing procedure based on the kinematic wave approximation was inserted in the model. Daily runoff at the outlet of different subcatchments of river Glomma upstreams Hummelvoll (2411 km2) were calculated and compared to observed data.

  17. Long Term Sea Level Change and Water Mass Balance in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    RONG Zengrui; LIU Yuguang; ZONG Haibo; XIU Peng

    2009-01-01

    Sea level anomalies observed by altimeter during the 1993-2006 period, thermosterie sea level anomalies estimated by using subsurface temperature data produced by Ishii and SODA reanalysis data, tide gauge records and HOAPS freshwater flux data were analyzed to investigate the long term sea level change and the water mass balance in the South China Sea. The altimeter-observed sea level showed a rising rate of (3.5±0.9)mm yr-1 during the period 1993-2006, but this figure was considered to have been highly distorted by the relatively short time interval and the large inter-decadal variability, which apparently exists in both the thermosteric sea level and the observed sea level. Long term thermosteric sea level from 1945 to 2004 gave a rising rate of 0.15±0.06 mmyr-1. Tide gauge data revealed this discrepancy and the regional distributions of the sea-level trends. Both the 'real' and the thermosteric sea level showed a good correspondence to ENSO: decreasing during E1 Nifio years and increasing during La Nina years. Amplitude and phase differences between the 'real' sea level and the thermosteic sea level were substantially revealed on both seasonal and interannual time scales. As one of the possible factors, the freshwater flux might play an important role in balancing the water mass.

  18. Identifying streamgage networks for maximizing the effectiveness of regional water balance modeling

    Science.gov (United States)

    Fry, L. M.; Hunter, T. S.; Phanikumar, M. S.; Fortin, V.; Gronewold, A. D.

    2013-05-01

    One approach to regional water balance modeling is to constrain rainfall-runoff models with a synthetic regionalized hydrologic response. For example, the Large Basin Runoff Model (LBRM), a cornerstone of hydrologic forecasting in the Laurentian Great Lakes basin, was calibrated to a synthetic discharge record resulting from a drainage area ratio method (ARM) for extrapolating beyond gaged areas. A challenge of such approaches is the declining availability of observations for development of synthetic records. To advance efficient use of the declining gage network in the context of regional water balance modeling, we present results from an assessment of ARM. All possible combinations of "most-downstream" gages were used to simulate runoff at the gaged outlet of Michigan's Clinton River watershed in order to determine the influence of gages' drainage area and other physical characteristics on model skill. For nearly all gage combinations, ARM simulations resulted in good model skill. However, the gages' catchment area relative to that of the outlet's catchment is not an unquestionable predictor of model performance. Results indicate that combinations representing less than 30% of the total catchment area (less than 10% in some cases) can provide very good discharge simulations, but that similarity of the gaged catchments' developed and cultivated area, stream density, and permeability relative to the outlet's catchment is also important for successful simulations. Recognition of thresholds on the relationship between the number of gages and their relative value in simulating flow over large area provides an opportunity for improving historical records for regional hydrologic modeling.

  19. Water balance creates a threshold in soil pH at the global scale

    Science.gov (United States)

    Slessarev, E. W.; Lin, Y.; Bingham, N. L.; Johnson, J. E.; Dai, Y.; Schimel, J. P.; Chadwick, O. A.

    2016-12-01

    Soil pH regulates the capacity of soils to store and supply nutrients, and thus contributes substantially to controlling productivity in terrestrial ecosystems. However, soil pH is not an independent regulator of soil fertility—rather, it is ultimately controlled by environmental forcing. In particular, small changes in water balance cause a steep transition from alkaline to acid soils across natural climate gradients. Although the processes governing this threshold in soil pH are well understood, the threshold has not been quantified at the global scale, where the influence of climate may be confounded by the effects of topography and mineralogy. Here we evaluate the global relationship between water balance and soil pH by extracting a spatially random sample (n = 20,000) from an extensive compilation of 60,291 soil pH measurements. We show that there is an abrupt transition from alkaline to acid soil pH that occurs at the point where mean annual precipitation begins to exceed mean annual potential evapotranspiration. We evaluate deviations from this global pattern, showing that they may result from seasonality, climate history, erosion and mineralogy. These results demonstrate that climate creates a nonlinear pattern in soil solution chemistry at the global scale; they also reveal conditions under which soils maintain pH out of equilibrium with modern climate.

  20. Chlorination or monochloramination: Balancing the regulated trihalomethane formation and microbial inactivation in marine aquaculture waters

    KAUST Repository

    Sanawar, Huma

    2017-08-15

    Disinfection methods like chlorination are increasingly used to sanitize the water, equipment, tools and surfaces in aquaculture facilities. This is to improve water quality, and to maintain a hygienic environment for the well-being of aquatic organisms. However, chlorination can result in formation of regulated disinfection byproducts (DBPs) that can be carcinogenic and toxic. This study aims to evaluate if an optimal balance can be achieved between minimal regulated DBP formation and effective microbial inactivation with either chlorination or monochloramination for application in the Red Sea aquaculture waters. Upon chlorination, the concentration of total trihalomethanes (THMs), primarily bromoform, exceeded the regulatory limit of 80μg/L even at the lowest tested concentration of chlorine (1mg/L) and contact time (1h). Comparatively, regulated THMs concentration was only detectable at 30μg/L level in one of the three sets of monochloraminated marine aquaculture waters. The average log reduction of antibiotic-resistant bacteria (ARB) by chlorine ranged from 2.3-log to 3.2-log with different contact time. The average log reduction of ARB by monochloramine was comparatively lower at 1.9 to 2.9-log. Although viable Staphylococcus aureus was recovered from monochloraminated samples as opposed to chlorinated samples, the abundance of S. aureus was not high enough to result in any significant microbial risks. Both chlorination and monochloramination did not provide any significant improvement in the reduction of antibiotic resistance genes (ARGs). This study demonstrates that a systematic evaluation is needed to determine the optimal disinfectant required to balance both microbial and chemical risks. Compared to chlorine, monochloramine may be a more appropriate disinfection strategy for the treatment of aquaculture effluents prior to discharge or for recirculatory use in the aquaculture facility.

  1. The Role of Vegetation Dynamics on the Soil Water Balance in Water-Limited Ecosystems

    Science.gov (United States)

    Montaldo, N.; Rondena, R.; Albertson, J. D.; Mancini, M.

    2003-12-01

    The structure and function of the vegetation regulates the exchange of mass, energy and momentum across the biosphere-atmosphere interface. Vegetation dynamics are usually neglected, other than seasonal phenology, in land surface models (LSMs). However, changes in vegetation densities, influencing the partitioning of incoming solar energy into sensible and latent heat fluxes, can result in long-term changes in both local and global climates (e.g., precipitation and temperature), which in turn will feedback to affect the vegetation growth. In semi-arid regions, this may result in persistent drought and desertification, with substantial impacts on the human populations of these regions through reduction in agricultural productivity and reduction in quantity and quality of water supply. With an objective of finding a simple vegetation model able to accurately simulate the leaf area index (LAI) dynamics, vegetation models of different level of complexity (e.g., including or not the modeling of the root biomass or the modeling of the dead biomass) are developed and compared. The vegetation dynamics models are coupled to a LSM, with the vegetation models providing the green biomass and the LAI evolution through time, and the LSM using this information in the computation of the land surface fluxes and updating the soil water content in the root-zone. We explore the models on a case study of a water limited grass field in California. Results show that a simple vegetation model that simulates the living aboveground green biomass (i.e., with low parameterization and computational efforts) is able to accurately simulate the LAI. Results also highlight the importance of including the plant growth model in the LSM when studying the climate-soil-vegetation interactions and the impact of watershed management practices on the scarce water resources over moderate to long time scales. The inclusion of the vegetation model in the LSM is demonstrated to be essential for assessing the

  2. Water management as a key component of integrated weed management

    Directory of Open Access Journals (Sweden)

    Giuseppe Zanin

    2011-02-01

    Full Text Available Water management within the cropping system is a key factor for an integrated weed management. Soil moisture affects seed persistence and seed dormancy, thus influencing their germination, the establishment of seedlings as well as the competition at adult stage and the number, vitality and dormancy of the new seeds produced by the weeds. The interactions among water availability and competition are very complex and still not fully understood. A research effort in this sector should the be very relevant for the development of new approaches of weed management, such as “Ecological weed management”, aiming to reduce weed density and competitiveness and, in the medium term, to prevent undesired modifications of the weed flora.

  3. Component failures at pressurized water reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reisinger, M.F.

    1980-10-01

    Objectives of this study were to identify those systems having major impact on safety and availability (i.e. to identify those systems and components whose failures have historically caused the greatest number of challenges to the reactor protective systems and which have resulted in greatest loss of electric generation time). These problems were identified for engineering solutions and recommendations made for areas and programs where research and development should be concentrated. The program was conducted in three major phases: Data Analysis, Engineering Evaluation, Cost Benefit Analysis.

  4. Examination of water phase transitions in Loblolly pine and cell wall components by differential scanning calorimetry

    Science.gov (United States)

    Samuel L. Zelinka; Michael J. Lambrecht; Samuel V. Glass; Alex C. Wiedenhoeft; Daniel J. Yelle

    2012-01-01

    This paper examines phase transformations of water in wood and isolated wood cell wall components using differential scanning calorimetry with the purpose of better understanding "Type II water" or "freezable bound water" that has been reported for cellulose and other hydrophilic polymers. Solid loblolly pine (Pinus taeda...

  5. Actual Evapotranspiration in the Al-Khazir Gomal Basin (Northern Iraq Using the Surface Energy Balance Algorithm for Land (SEBAL and Water Balance

    Directory of Open Access Journals (Sweden)

    Hussein Jassas

    2015-04-01

    Full Text Available Increasing dependence on groundwater requires a detailed determination of the different outputs and inputs of a basin for better water management. Determination of spatial and temporal actual evapotranspiration (ETa, in this regard, is of vital importance as there is significant water loss from drainage basins. This research paper uses the Surface Energy Balance Algorithm for Land (SEBAL, as well as the water balance, to estimate the spatial and temporal ETa in the Al-Khazir Gomal Basin, Northern Iraq. To compensate for the shortage in rainfall, and to irrigate summer crops, farmers in this basin have been depending, to a large extent, on groundwater extracted from the underlying unconfined aquifer, which is considered the major source for both domestic and agricultural uses in this basin. Rainfed farming of wheat and barley is one of the most important activities in the basin in the winter season, while in the summer season, agricultural activity is limited to small rice fields and narrow strips of vegetable cultivation along the Al-Khazir River. The Landsat Thematic Mapper images (TM5 acquired on 21 November 2006, 9 March 2007, 5 May 2007, 21 July 2007, and 23 September 2007 were used, along with a digital elevation model (DEM and ground-based meteorological data, measured within the area of interest. Estimation of seasonal ETa from periods between satellite overpasses was computed using the evaporative fraction (Ʌ. The water balance approach was utilized, using meteorological data and river hydrograph analysis, to estimate the ETa as the only missing input in the predefined water balance equation. The results of the two applied methods were comparable. SEBAL results were compared with the land use land cover (LULC map. The river showed the highest ETa, as evaporation from the free-water surface. Rice fields, irrigated in the summer season, have a high ETa in the images, as these fields are immersed in water during June, July and August

  6. Structural Integrity of Water Reactor Pressure Boundary Components.

    Science.gov (United States)

    1981-02-20

    RES-79-103 UNCLASSIFIED NRL--- 400 NURE-CR-17B3 NL mnmmnuunin -’El-.--. IIIIIIINI ., *q. - - ,aM T? * NUREG /CI 73 NIL Iteof AW, SOIituA 1 nert of Water...Progress Report for July-September 1979," NUREG /CR-1197, Oak Ridge National Labora- tory, Oak Ridge, Tn., Oct. 1978. 2. F. J. Loss, Ed., "Structural...Progress Report for April-June 1976," ORNL/ NUREG /TM-49, Oak Ridge National Labora- tory, Oak Ridge, Tn., Oct. 1976, pp. 27-38. 5. R. G. Berggren

  7. Structural Integrity of Water Reactor Pressure Boundary Components.

    Science.gov (United States)

    1980-08-01

    tests of reference steels of the NRC light water reactor, pressure vessel irradiation dosimetry program. SECURITY CLAS5IICATION 0PHiS PA6GMbn" Dfat ...multiple specimen R- curve approach; NRL emphasis was on the SSC procedure as it is being developed for hot- cell testing of irradiated materials. MULTIPLE...a second autoclave, capable of testing 50 or 100 mm (2T or 4T) thick CT or WOL specimens, was installed in a hot cell and a test was started on 2T-CT

  8. Hydrological functioning and water balance in a heavily modified hydrographic system

    Science.gov (United States)

    Carbonnel, Vincent; Brion, Natacha; Elskens, Marc; Claeys, Philippe; Verbanck, Michel A.

    2017-04-01

    Rivers and canals are often the location for the historical settlement of cities and the backbone for their expansion, as they permit the transport of goods and people, the access to water for industrial activities and energy production, and the evacuation of the domestic and industrial wastewaters. In turn, human activities can result in modifications of the natural river systems to allow for instance ship transport or protection against flooding. The complex interconnected hydrographic network composed of the Zenne and the parallel Charleroi-Brussels-Scheldt Canal, which supports the development of the economy and urbanization of Brussels Metropolitan Area (Belgium), is a good example of such an altered system. The natural water course has been profoundly modified by the deviation of rivers to feed the canal, the control of the water flow in the canal by locks and pumps and the overflow exchange of water between the river and the canal for flood protection purposes. Also, the functioning of this system is strongly impacted by urban hydrology in Brussels, which results in amounts of wastewater discharged in the Zenne River that are nearly equivalent to the natural riverine flow. Water and water quality management in such complex and altered systems correspond to difficult tasks. They require, as a first step, a deep understanding of their hydrological functioning. Building an accurate water budget is also a necessary step in the investigation of the pollution sources, sinks, dynamics and mass-balance. In order to assess the water quality and provide insights for water management in the Zenne-Canal hydrographic network (cf. other contributions in this session), we established a detailed box-model representation of the water budget for the whole system, with a particular interest on the importance and the effects of the exchanges of water between the river and the canal. A particularity of this study is that, in contrast to the widespread use of hydrological

  9. Daily Runoff Simulation at River Network by the WWASS (Watershed Water balance And Stream flow Simulation) Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Young; Hwang, Cheol Sang; Kang, Seok Man; Lee, Kwang Ya [Rural Development Corp., Seoul (Korea)

    1998-08-31

    When various elements of water balance are displayed at several points of a river network, the runoff amounts at an estuary especially tidal influenced are affected from the elements. This problem can be solved by a model that can generalize and formulate the elements and simulate daily runoff and water requirement. The WWASS model was built using DIROM for the simulation of daily runoff and water requirement, and the water balance elements were modeled to be balanced at the each control point of river network. The model was calibrated, verified and applied to the watershed for the Saemankeum tidal land reclamation development project. It showed that the results from the stream flow simulation at the Mankyung and Dongjin estuary were acceptable for the design of the Saemankeum estuary reservoir. (author). 7 refs., 3 tabs., 8 figs.

  10. Resilience Through Disturbance: Effects of Wildfire on Vegetation and Water Balance in the Sierra Nevadas

    Science.gov (United States)

    Boisrame, G. F. S.; Thompson, S. E.; Stephens, S.; Collins, B.; Tague, N.

    2015-12-01

    A century of fire suppression in the Western United States has drastically altered the historically fire-adapated ecology in California's Sierra Nevada Mountains. Fire suppression is understood to have increased the forest cover, as well as the stem density, canopy cover and water demand of montane forests, reducing resilience of the forests to drought, and increasing the risk of catastrophic fire by drying the landscape and increasing fuel loads. The potential to reverse these trends by re-introducing fire into the Sierra Nevada is highly promising, but the likely effects on vegetation structure and water balance are poorly quantified. The Illilouette Creek Basin in Yosemite National Park represents a unique experiment in the Sierra Nevada, in which managers have moved from fire suppression to allowing a near-natural fire regime to prevail since 1972. Changes in vegetation structure in the Illilouette since the restoration of natural burning provides a unique opportunity to examine how frequent, mixed severity fires can reshape the Sierra Nevada landscape. We characterize these changes from 1969 to the present using a combination of Landsat products and high-resolution aerial imagery. We describe how the landscape structure has changed in terms of vegetation composition and its spatial organization, and explore the drivers of different post-fire vegetation type transitions (e.g. forest to shrubland vs. forest to meadow). By upscaling field data using vegetation maps and Landsat wetness indices, we explore how these vegetation transitions have impacted the water balance of the Illilouette Creek Basin, potentially increasing its resilience in the face of drought, climate change, and catastrophic fire. In a region that is adapted to frequent disturbance from fire, this work helps us understand how allowing such natural disturbances to take place can increase the sustainability of diverse landscapes in the long term.

  11. Water-Cooled Components Testing Program. Water-cooled nozzle testing

    Energy Technology Data Exchange (ETDEWEB)

    1985-05-01

    This experimental program involving full-sized gas turbine components was directed towards investigating the nature, composition, and formation rates of the ash deposited on these components by the combustion of hot, minimally cleaned coal gas (MCCG) under actual operating environments. Fired combustion testing was performed using the hot coal gas generated by the fixed-bed coal gasifier in the GE/CRD Process Evaluation Facility (PEF). The hot gas was routed from the gasifier at approx.1000/sup 0/F to a hot cyclone for particulate removal, following which the gas was burned in the turbine simulator, a pressurized test rig. The cyclone was found to have an average particulate removal efficiency of approximately 98%. The concentration of total alkali in the fuel gas entering the turbine simulator was 0.3 to 0.6 ppM, half of which was water-soluble; this corresponds to 1 to 2 ppM in a liquid petroleum-based fuel. The ash content of the fuel gas was 9 to 16 ppM, which would correspond to 51 to 91 ppM of ash in a residual fuel oil, i.e., much lower than that usually found in the latter fuel. Very little ash was found to deposit on the water-cooled nozzle airfoils. Ash deposits on the airfoils were primarily PbSO/sub 4/ and Fe/sub 2/O/sub 3/, which proved to be readily removed by water washing. While the MCCG combustion process was satisfactory, testing indicated that a potential area of concern in burning hot MCCG fuel is the formation of carbonaceous deposits in the fuel nozzle and piping. Variations in operating parameters and procedures may be effective in avoiding such deposits. Test data and analysis thus provided clearer insight into the additional work needed to enable a gas turbine to utilize hot (>1000/sup 0/F), minimally cleaned coal gas fuel. Five problems are described. 5 refs., 82 figs., 26 tabs.

  12. Characterizing the Water Balance of the Sooke Reservoir, British Columbia over the Last Century

    Directory of Open Access Journals (Sweden)

    Arelia T. Werner

    2015-03-01

    Full Text Available Infrastructure such as dams and reservoirs are critical water-supply features in several regions of the world. However, ongoing population growth, increased demand and climate variability/change necessitate the better understanding of these systems, particularly in terms of their long-term trends. The Sooke Reservoir (SR of British Columbia, Canada is one such reservoir that currently supplies water to ~300,000 people, and is subject to considerable inter and intra-annual climatic variations. The main objectives of this study are to better understand the characteristics of the SR through an in-depth assessment of the contemporary water balance when the basin was intensively monitored (1996–2005, to use standardized runoff to select the best timescale to compute the Standard Precipitation (SPI and Standard Precipitation Evaporation Indices (SPEI to estimate trends in water availability over 1919 to 2005. Estimates of runoff and evaporation were validated by comparing simulated change in storage, computed by adding inputs and subtracting outputs from the known water levels by month, to observed change in storage. Water balance closure was within ±11% of the monthly change in storage on average when excluding months with spill pre-2002. The highest evaporation, dry season (1998 and lowest precipitation, wet season (2000/2001 from the intensively monitored period were used to construct a worst-case scenario to determine the resilience of the SR to drought. Under such conditions, the SR could support Greater Victoria until the start of the third wet season. The SPEI and SPI computed on a three-month timescale had the highest correlation with the standardized runoff, R2 equaled 0.93 and 0.90, respectively. A trend toward drier conditions was shown by SPEI over 1919 to 2005, while moistening over the same period was shown by SPI, although trends were small in magnitude. This study contributes a validated application of SPI and SPEI, giving more

  13. Using isotope, hydrochemical methods and energy-balance modelling to estimate contribution of different components to flow forming process in a high-altitude catchment (Dzhancuat river basin case study)

    Science.gov (United States)

    Rets, Ekaterina; Loshakova, Nadezhda; Chizhova, Julia; Kireeva, Maria; Frolova, Natalia; Tokarev, Igor; Budantseva, Nadine; Vasilchuk, Yurij

    2016-04-01

    A multicomponent structure of sources of river runoff formation is characteristic of high-altitude territories: ice and firn melting; seasonal snow melting on glacier covered and non-glacier area of a watershed; liquid precipitation; underground waters. In addition, each of these components can run off the watershed surface in different ways. Use of isotopic, hydrochemical methods and energy balance modelling provides possibility to estimate contribution of different components to river runoff that is an essential to understand the mechanism of flow formation in mountainious areas. A study was carried out for Dzhancuat river basin that was chosen as representative for North Caucasus in course of the International Hydrological Decade. Complex glaciological, hydrological and meteorological observation have been carried in the basin since 1965. In years 2013-2015 the program also included daily collecting of water samples on natural stable isotopes on the Dzhancuat river gauging station, and sampling water nourishment sources (ice, snow, firn, liquid precipitation) within the study area. More then 800 water samples were collected. Application of an energy balance model of snow and ice melt with distributed parameters provided an opportunity to identify Dzhancuat river runoff respond to glaciers melt regime and seasonal redistribution of melt water. The diurnal amplitude of oscillation of the Dzhakuat river runoff in the days without precipitation is formed by melting at almost snow-free areas of the Dzhancuat glacier tongues. Snowmelt water from the non-glacierized part contributes to the formation of the next day runoff. A wave of snow and firn melt in upper zones of glacier flattens considerably during filtration through snow and run-off over the surface and in the body of the glacier. This determines a general significant inertia of the Dzhacuat river runoff. Some part of melt water is stored into natural regulating reservoirs of the watershed that supply the

  14. Productive Application of Automatic Water Balance System (WBS) in Water Treatment Plant%水厂自动水平衡系统的生产性应用

    Institute of Scientific and Technical Information of China (English)

    徐鸿凯; 顾振国; 高炜; 孙青

    2011-01-01

    A case study on water balance system(WBS) was presented with discussions. The application of water quantity balance in water treatment plants was primarily generalized. Such investigation is likely to be implemented in many other water treatment plants for automatic water balance system.%通过分析某自来水厂自动水平衡系统的实例,初步总结了自来水厂自动水平衡系统的生产性应用,探讨自来水厂实现生产水量自动平衡的方法和手段,可为其它自来水厂实施自动水平衡系统提供参考.

  15. Receptive vocabulary knowledge tests: Their potential importance for planning a well-balanced vocabulary component of a language program

    OpenAIRE

    Wakeling, Elliott

    2015-01-01

    iii Abstract Nation and Webb (2011) state ‘Testing is one of the major jobs of the vocabulary teacher, because without good information about our learners’ vocabulary knowledge, we cannot do the most important job of planning a well-balanced program’ (p. 219). This paper evaluated different receptive vocabulary knowledge tests and assessed their potential to help a teacher plan a well-balanced vocabulary program. The Vocabulary Levels Test (VLT) was selected to assess the vocabulary kno...

  16. Forms and Balance of Nitrogen and Phosphorus in Cage Culture Waters in Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to approach the characteristics of nitrogen and phosphorus pollution caused by cage culture and the balance of nitrogen and phosphorus during the process of cage culture, a monitoring was conducted in Daya Bay of Guangdong Province, China from April 2002 to Jane 2003. The results show that the concentrations of total nitrogen (TN) in the waters at the sites with five and ten years of cage culture history are 1.8 and 2.3 times of that at control site respectively. Ammonium (NH3-N) is the main form of nitrogen in spring while nitrate (NO3-) in winter. The concentrations of TN, total dissolved nitrogen (TDN) and dissolved organic nitrogen (DON) are highest in autumn. The concentration of phosphorus increases with the increasing of the culturing time, among which phosphate (PO34-) increases most obviously.The concentrations of total phosphorus (TP) and total dissolved phosphorus (TDP) are highest in autumn. The nitrogen and phosphorus are accumulated significantly in the sediment of cage culture area. The model of N balance in the cage culture area: bait (70.62%) + fry (0.28%) + input by tide (14.8%) + release from sediment (14.3%) = harvest of adult fish (12.07%) + deposition into sediment (28.75%) + output by tide (56.18%) + others (3.00%). The model of P balance: bait (83.11%) + fry (0.17%) + input by tide (12.23%) + release from sediment (4.49%) = harvest of adult fish (8.43%) + deposition into sediment (48.59%) + output by tide (41.94%) + others (1.04%). In one fish growth year, the contents of nitrogen and phosphorus in harvest of adult fish are only 17.0% and 10.1% of the contents of nitrogen and phosphorus in fish bait and fry, wherein 83% of nitrogen and more than 89% of phosphorus in fish bait became marine pollutants.

  17. The role of event water, a rapid shallow flow component, and catchment size in summer stormflow

    Science.gov (United States)

    Brown, V.A.; McDonnell, Jeffery J.; Burns, Douglas A.; Kendall, C.

    1999-01-01

    Seven nested headwater catchments (8 to 161 ha) were monitored during five summer rain events to evaluate storm runoff components and the effect of catchment size on water sources. Two-component isotopic hydrograph separation showed that event-water contributions near the time of peakflow ranged from 49% to 62% in the 7 catchments during the highest intensity event. The proportion of event water in stormflow was greater than could be accounted for by direct precipitation onto saturated areas. DOC concentrations in stormflow were strongly correlated with stream 18O composition. Bivariate mixing diagrams indicated that the large event water contributions were likely derived from flow through the soil O-horizon. Results from two-tracer, three-component hydrograph separations showed that the throughfall and O-horizon soil-water components together could account for the estimated contributions of event water to stormflow. End-member mixing analysis confirmed these results. Estimated event-water contributions were inversely related to catchment size, but the relation was significant for only the event with greatest rainfall intensity. Our results suggest that perched, shallow subsurface flow provides a substantial contribution to summer stormflow in these small catchments, but the relative contribution of this component decreases with catchment size.Seven nested headwater catchments (8 to 161 ha) were monitored during five summer rain events to evaluate storm runoff components and the effect of catchment size on water sources. Two-component isotopic hydrograph separation showed that event-water contributions near the time of peakflow ranged from 49% to 62% in the 7 catchments during the highest intensity event. The proportion of event water in stormflow was greater than could be accounted for by direct precipitation onto saturated areas. DOC concentrations in stormflow were strongly correlated with stream 18O composition. Bivariate mixing diagrams indicated that the

  18. The Water, Energy and Food Nexus: Finding the Balance in Infrastructure Investment

    Science.gov (United States)

    Huber-lee, A. T.; Wickel, B.; Kemp-Benedict, E.; Purkey, D. R.; Hoff, H.; Heaps, C.

    2013-12-01

    There is increasing evidence that single-sector infrastructure planning is leading to severely stressed human and ecological systems. There are a number of cross-sectoral impacts in these highly inter-linked systems. Examples include: - Promotion of biofuels that leads to conversion from food crops, reducing both food and water security. - Promotion of dams solely built for hydropower rather than multi-purpose uses, that deplete fisheries and affect saltwater intrusion dynamics in downstream deltas - Historical use of water for cooling thermal power plants, with increasing pressure from other water uses, as well as problems of increased water temperatures that affect the ability to cool plants efficiently. This list can easily be expanded, as these inter-linkages are increasing over time. As developing countries see a need to invest in new infrastructure to improve the livelihoods of the poor, developed countries face conditions of deteriorating infrastructure with an opportunity for new investment. It is crucial, especially in the face of uncertainty of climate change and socio-political realities, that infrastructure planning factors in the influence of multiple sectors and the potential impacts from the perspectives of different stakeholders. There is a need for stronger linkages between science and policy as well. The Stockholm Environment Institute is developing and implementing practical and innovative nexus planning approaches in Latin America, Africa and Asia that brings together stakeholders and ways of integrating uncertainty in a cross-sectoral quantitative framework using the tools WEAP (Water Evaluation and Planning) and LEAP (Long-range Energy Alternatives Planning). The steps used include: 1. Identify key actors and stakeholders via social network analysis 2. Work with these actors to scope out priority issues and decision criteria in both the short and long term 3. Develop quantitative models to clarify options and balances between the needs and

  19. Water balance monitoring for two bioretention gardens in Omaha, Nebraska, 2011–14

    Science.gov (United States)

    Strauch, Kellan R.; Rus, David L.; Holm, Kent E.

    2016-01-29

    Bioretention gardens are used to help mitigate stormwater runoff in urban settings in an attempt to restore the hydrologic response of the developed land to a natural predevelopment response in which more water is infiltrated rather than routed directly to urban drainage networks. To better understand the performance of bioretention gardens in facilitating infiltration of stormwater in eastern Nebraska, the U.S. Geological Survey, in cooperation with the Douglas County Environmental Services and the Nebraska Environmental Trust, assessed the water balance of two bioretention gardens located in Omaha, Nebraska by monitoring the amount of stormwater entering and leaving the gardens. One garden is on the Douglas County Health Center campus, and the other garden is on the property of the Eastern Nebraska Office on Aging.For the Douglas County Health Center, bioretention garden performance was evaluated on the basis of volume reduction by comparing total inflow volume to total outflow volume. The bioretention garden reduced inflow volumes from a minimum of 33 percent to 100 percent (a complete reduction in inflow volume) depending on the size of the event. Although variable, the percent reduction of the inflow volume tended to decrease with increasing total event rainfall. To assess how well the garden reduces stormwater peak inflow rates, peak inflows were plotted against peak outflows measured at the bioretention garden. Only 39 of the 255 events had any overflow, indicating 100 percent peak reduction in the other events. Of those 39 events having overflow, the mean peak reduction was 63 percent.No overflow events were recorded at the bioretention garden at the Eastern Nebraska Office on Aging; therefore, data were not available for an event-based overflow analysis.Monitoring period summary of the water balance at both bio-retention gardens indicates that most of the stormwater in the bioretention gardens is stored in the subsurface.Evapotranspiration was attributed

  20. A worldwide evaluation of basin-scale evapotranspiration estimates against the water balance method

    Science.gov (United States)

    Liu, Wenbin; Wang, Lei; Zhou, Jing; Li, Yanzhong; Sun, Fubao; Fu, Guobin; Li, Xiuping; Sang, Yan-Fang

    2016-07-01

    Evapotranspiration (ET) plays a critical role in linking the water and energy cycles but is difficult to estimate at regional and basin scales. In this study, we present a worldwide evaluation of nine ET products (three diagnostic products, three land surface model (LSM) simulations and three reanalysis-based products) against reference ET (ETwb) calculated using the water balance method corrected for the water storage change at an annual time scale over the period 1983-2006 for 35 global river basins. The results indicated that there was no significant intra-category discrepancy in the annual ET estimates for the 35 basins calculated using the different products in 35 basins, but some products performed better than others, such as the Global Land surface Evaporation estimated using the Amsterdam Methodology (GLEAM_E) in the diagnostic products, ET obtained from the Global Land Data Assimilation System version 1 (GLDAS 1) with the Community Land Model scheme (GCLM_E) in LSM simulations, and ET from the National Aeronautics and Space Administration (NASA) Modern Era Retrospective-analysis for Research and Applications reanalysis dataset (MERRA_E) in the reanalysis-based products. Almost all ET products (except MERRA_E) reasonably estimated the annual means (especially in the dry basins) but systematically underestimated the inter-annual variability (except for MERRA_E, GCLM_E and ET simulation from the GLDAS 1 with the MOSAIC scheme - GMOS_E) and could not adequately estimate the trends (e.g. GCLM_E and MERRA_E) of ETwb (especially in the energy-limited wet basins). The uncertainties in nine ET products may be primarily attributed to the discrepancies in the forcing datasets and model structural limitations. The enhancements of global forcing data (meteorological data, solar radiation, soil moisture stress and water storage changes) and model physics (reasonable consideration of the water and energy balance and vegetation processes such as canopy interception loss

  1. Nitrate leaching through climatologic water balance in a fertigated coffee plantation

    Directory of Open Access Journals (Sweden)

    Rafael Pivotto Bortolotto

    2013-12-01

    Full Text Available Nitrate losses from soil profiles by leaching should preferentially be monitored during high rainfall events and during irrigation when fertilizer nitrogen applications are elevated. Using a climatologic water balance, based on the models of Thornthwaite and Penman Monteith for potential evapotranspiration, drainage soil water fluxes below the root zone were estimated in a fertigated coffee crop. Soil solution extraction at the depth of 1 m allowed the calculation of nitrate leaching. The average nitrate concentration in soil solution for plots that received nitrogen by fertigation at a rate of 400 kg ha-1, was 5.42 mg L-1, surpassing the limit of the Brazilian legislation of 10.0 mg L-1, only during one month. For plots receiving 800 kg ha-1 of nitrogen, the average was 25.01 mg L-1, 2.5 times higher than the above-mentioned limit. This information indicates that nitrogen rates higher than 400 kg ha-1 are potentially polluting the ground water. Yearly nitrate amounts of leaching were 24.2 and 153.0 kg ha-1 for the nitrogen rates of 400 and 800 kg ha-1, respectively. The six times higher loss indicates a cost/benefit problem for coffee fertigations above 400 kg ha-1.

  2. Mechanical balance laws for fully nonlinear and weakly dispersive water waves

    CERN Document Server

    Kalisch, Henrik; Mitsotakis, Dimitrios

    2015-01-01

    The Serre-Green-Naghdi system is a coupled, fully nonlinear system of dispersive evolution equations which approximates the full water wave problem. The system is an extension of the well known shallow-water system to the situation where the waves are long, but not so long that dispersive effects can be neglected. In the current work, the focus is on deriving mass, momentum and energy densities and fluxes associated with the Serre-Green-Naghdi system. These quantities arise from imposing balance equations of the same asymptotic order as the evolution equations. In the case of an even bed, the conservation equations are satisfied exactly by the solutions of the Serre-Green-Naghdi system. The case of variable bathymetry is more complicated, with mass and momentum conservation satisfied exactly, and energy conservation satisfied only in a global sense. In all cases, the quantities found here reduce correctly to the corresponding counterparts in both the Boussinesq and the shallow-water scaling. One consequence o...

  3. Evaporation estimates from the Dead Sea and their implications on its water balance

    Science.gov (United States)

    Oroud, Ibrahim M.

    2011-12-01

    The Dead Sea (DS) is a terminal hypersaline water body situated in the deepest part of the Jordan Valley. There is a growing interest in linking the DS to the open seas due to severe water shortages in the area and the serious geological and environmental hazards to its vicinity caused by the rapid level drop of the DS. A key issue in linking the DS with the open seas would be an accurate determination of evaporation rates. There exist large uncertainties of evaporation estimates from the DS due to the complex feedback mechanisms between meteorological forcings and thermophysical properties of hypersaline solutions. Numerous methods have been used to estimate current and historical (pre-1960) evaporation rates, with estimates differing by ˜100%. Evaporation from the DS is usually deduced indirectly using energy, water balance, or pan methods with uncertainty in many parameters. Accumulated errors resulting from these uncertainties are usually pooled into the estimates of evaporation rates. In this paper, a physically based method with minimum empirical parameters is used to evaluate historical and current evaporation estimates from the DS. The more likely figures for historical and current evaporation rates from the DS were 1,500-1,600 and 1,200-1,250 mm per annum, respectively. Results obtained are congruent with field observations and with more elaborate procedures.

  4. Cold-water immersion alters muscle recruitment and balance of basketball players during vertical jump landing.

    Science.gov (United States)

    Macedo, Christiane de Souza Guerino; Vicente, Rafael Chagas; Cesário, Mauricio Donini; Guirro, Rinaldo Roberto de Jesus

    2016-01-01

    The purpose of this study was to evaluate the effects of cold-water immersion on the electromyographic (EMG) response of the lower limb and balance during unipodal jump landing. The evaluation comprised 40 individuals (20 basketball players and 20 non-athletes). The EMG response in the lateral gastrocnemius, tibialis anterior, fibular longus, rectus femoris, hamstring and gluteus medius; amplitude and mean speed of the centre of pressure, flight time and ground reaction force (GRF) were analysed. All volunteers remained for 20 min with their ankle immersed in cold-water, and were re-evaluated immediately post and after 10, 20 and 30 min of reheating. The Shapiro-Wilk test, Friedman test and Dunn's post test (P < 0.05) were used. The EMG response values decreased for the lateral gastrocnemius, tibialis anterior, fibular longus and rectus femoris of both athletes and non-athletes (P < 0.05). The comparison between the groups showed that the EMG response was lower for the athletes. Lower jump flight time and GRF, greater amplitude and mean speed of centre of pressure were predominant in the athletes. Cold-water immersion decreased the EMG activity of the lower limb, flight time and GRF and increased the amplitude and mean speed of centre of pressure.

  5. Balancing Water Uptake and Loss through the Coordinated Regulation of Stomatal and Root Development.

    Directory of Open Access Journals (Sweden)

    Christopher Hepworth

    Full Text Available Root development is influenced by nutrient and water availabilities. Plants are able to adjust many attributes of their root in response to environmental signals including the size and shape of the primary root, lateral roots and root hairs. Here we investigated the response of roots to changes in the levels of leaf transpiration associated with altered stomatal frequency. We found that plants with high stomatal density and conductance produce a larger rooting area and as a result have enhanced phosphate uptake capacity whereas plants with low stomatal conductance produce a smaller root. Manipulating the growth environment of plants indicated that enhanced root growth is most likely a result of an increased demand for water rather than phosphate. Plants manipulated to have an increase or reduction in root hair growth show a reduction or increase respectively, in stomatal conductance and density. Our results demonstrate that plants can balance their water uptake and loss through coordinated regulation of both stomatal and root development.

  6. Water balance of two earthen landfill caps in a semi-arid climate

    Energy Technology Data Exchange (ETDEWEB)

    Khire, M.V. [GeoSyntec Consultants, Boca Raton, FL (United States); Benson, C.H.; Bosscher, P.J. [Univ. of Wisconsin, Madison, WI (United States)

    1997-12-31

    Water balance data are presented that were obtained from two earthen cap test sections located in a semi-arid region. The test sections were constructed on a municipal solid waste landfill in East Wenatchee, Washington, USA. One test section represents a traditional resistive barrier, and is constructed with a compacted silty clay barrier 60 cm thick and a vegetated silty clay surface layer 15 cm thick. The other test section represents a capillary barrier and has a sand layer 75 cm thick overlain by a 15-cm-thick vegetated surface layer of silt. Extensive hydrological and meteorological data have been collected since November 1992. Unsaturated hydraulic properties of soils, hydrologic parameters, and vegetation have been extensively characterized. Results of the study show that capillary barriers can be effective caps in semi-arid and arid regions. They are also cheaper to construct and can perform better than traditional resistive barriers.

  7. Sulfur balance of sulfur dioxide-ethanol-water fractionation of sugarcane straw.

    Science.gov (United States)

    You, Xiang; van Heiningen, Adriaan; Sixta, Herbert; Iakovlev, Mikhail

    2017-10-01

    The sulfur balance of SO2-ethanol-water (AVAP®) fractionation of sugarcane (SC) straw was investigated. Hydrogen sulfite and sulfite anions are nearly absent in the liquors, despite cations present in straw, whose effect is thus limited to neutralization of lignosulfonic acids decreasing the acidity. Higher degree of sulfonation was observed for dissolved straw lignin compared to wood lignin (0.8-0.9 vs. 0.25 S/C9). Sulfur dioxide amounts of 0.9-1.2, 4.1-4.3 and 44-49g per o.d.kg straw were bound to pulp, precipitated lignin and lignosulfonic acid, respectively, while the rest of SO2 was recovered by distillation from the spent fractionation suspensions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Assessing variability of evapotranspiration over the Ganga river basin using water balance computations

    Science.gov (United States)

    Syed, Tajdarul H.; Webster, Peter J.; Famiglietti, James S.

    2014-03-01

    A thorough assessment of evapotranspiration (ET) pervades several important issues of the 21st century including climate change, food-security, land-management, flood and drought prediction, and water resources assessment and management. Such a proper assessment is of particular importance in the Ganga river basin (GRB) with its backdrop of a rapidly increasing population pressure and unregulated use of water resources. Spatially averaged ET over the GRB is computed as the residual of atmospheric and terrestrial water budget computations using a combination of model simulations and satellite and ground-based observations. The best estimate of monthly ET is obtained as the monthly mean of atmospheric and terrestrial water balance computations for the period 1980-2007. The mean monthly average of ET from these various estimates is 72.3 ± 18.8 mm month-1. Monthly variations of ET peak between July and August and reach a minimum in February. For the entire study period, the rate of change of ET across the GRB is -11 mm yr-2 (i.e., mm/yr/yr). Alongside a notable influence of the 1997-1998 El Niño, results allude to the existence of interim periods during which ET trends varied significantly. More specifically, during the period of 1998-2002, the rate of decline increased to -55.8 mm yr-2, which is almost 5 times the overall trend. Based on the correlation between ET and independent estimates of near-surface temperature and soil moisture, we can infer that the ET over the GRB is primarily limited by moisture availability. The analysis has important potential for use in large-scale water budget assessments and intercomparison studies. The analysis also emphasizes the importance of synergistic use of mutliplatform hydrologic information.

  9. A land surface scheme for atmospheric and hydrologic models: SEWAB (Surface Energy and Water Balance)

    Energy Technology Data Exchange (ETDEWEB)

    Mengelkamp, H.T.; Warrach, K.; Raschke, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    A soil-vegetation-atmosphere-transfer scheme is presented here which solves the coupled system of the Surface Energy and Water Balance (SEWAB) equations considering partly vegetated surfaces. It is based on the one-layer concept for vegetation. In the soil the diffusion equations for heat and moisture are solved on a multi-layer grid. SEWAB has been developed to serve as a land-surface scheme for atmospheric circulation models. Being forced with atmospheric data from either simulations or measurements it calculates surface and subsurface runoff that can serve as input to hydrologic models. The model has been validated with field data from the FIFE experiment and has participated in the PILPS project for intercomparison of land-surface parameterization schemes. From these experiments we feel that SEWAB reasonably well partitions the radiation and precipitation into sensible and latent heat fluxes as well as into runoff and soil moisture Storage. (orig.) [Deutsch] Ein Landoberflaechenschema wird vorgestellt, das den Transport von Waerme und Wasser zwischen dem Erdboden, der Vegetation und der Atmosphaere unter Beruecksichtigung von teilweise bewachsenem Boden beschreibt. Im Erdboden werden die Diffusionsgleichungen fuer Waerme und Feuchte auf einem Gitter mit mehreren Schichten geloest. Das Schema SEWAB (Surface Energy and Water Balance) beschreibt die Landoberflaechenprozesse in atmosphaerischen Modellen und berechnet den Oberflaechenabfluss und den Basisabfluss, die als Eingabedaten fuer hydrologische Modelle genutzt werden koennen. Das Modell wurde mit Daten des FIFE-Experiments kalibriert und hat an Vergleichsexperimenten fuer Landoberflaechen-Schemata im Rahmen des PILPS-Projektes teilgenommen. Dabei hat sich gezeigt, dass die Aufteilung der einfallenden Strahlung und des Niederschlages in den sensiblen und latenten Waermefluss und auch in Abfluss und Speicherung der Bodenfeuchte in SEWAB den beobachteten Daten recht gut entspricht. (orig.)

  10. Water balance modeling of Upper Blue Nile catchments using a top-down approach

    Directory of Open Access Journals (Sweden)

    S. Tekleab

    2010-09-01

    Full Text Available The hydrological behavior and functioning of twenty catchments in the Upper Blue Nile basin have been analyzed using a top-down modeling approach that is based on Budyko's hypotheses. The objective is to obtain better understanding of catchment response for prediction in ungauged catchments. The water balance analysis using Budyko-type curve at annual scale reveals that the aridity index does not exert a first order control in most of the catchments. This implies the need to increase model complexity to a monthly time scale to include the effects of seasonal soil moisture dynamics. The dynamic water balance model used in this study predicts the direct runoff and other processes based on limit concept. The uncertainty of model parameters has been assessed using the GLUE (Generalized Likelihood Uncertainty Estimation. The results show that the majority of the parameters are reasonably well identifiable. Moreover, a multi-objective model calibration strategy has been employed within the GLUE framework to emphasize the different aspects of the hydrographs on low and high flows. The model has been calibrated and validated against observed streamflow time series and it shows good performance for the twenty catchments of the upper Blue Nile. During the calibration period (1995–2000 the Nash and Sutcliffe coefficient of efficiency for monthly flow prediction varied between 0.52 to 0.93 during high flows, while it varied between 0.32 to 0.90 during low flows (logarithms of flow series. The model is parsimonious and it is suggested that the resulting parameters can be used to predict monthly stream flows in the ungauged catchments of the Upper Blue Nile basin, which accounts about 60% of total Nile basin flow.

  11. Metabolic acidosis and changes in water and electrolyte balance after maximal exercise.

    Science.gov (United States)

    Sejersted, O M; Medbø, J I; Hermansen, L

    1982-01-01

    The purpose of this investigation was to study lactate production and the consequent changes in acid-base status, and in water and electrolyte balance, in response to 1 min of maximal exercise in sprint- and endurance-trained subjects. So far, the results from only two subjects (one sprinter and one marathon runner) have been analysed. The rate of lactate production was higher in the sprinter than in the marathon runner, as shown by peak blood lactate concentrations of 20.8 and 13.3 mM for the two subjects, respectively. Arterial blood pH fell from 7.43 to 7.14 in the sprinter and from 7.44 to 7.23 for the marathon runner. The metabolic acidosis was partly compensated for by a lowering of arterial CO2 tension by 0.0775 kPa per 1 mM drop in base excess. In each subject large changes in water and electrolyte balance occurred. Haematocrit increased dramatically in both subjects, and the calculated decrease in plasma volume was 20% for the marathon runner and 30% for the sprinter. In each subject sodium was removed from the circulation in amounts sufficient to keep the plasma sodium concentration constant. Plasma potassium concentration was unrelated to the state of acidosis, being 2.5 mM above the resting concentration immediately after maximal exercise, and dropping by 3 mM in the subsequent 2-3 min of recovery during prevailing acidosis. The degree of lactic acidosis was large in both subjects, although more severe in the sprinter than in the endurance runner. However, buffer capacity and compensatory mechanisms were largely similar in both subjects.

  12. Micro-components survey of residential indoor water consumption in Chiang Mai

    Directory of Open Access Journals (Sweden)

    T. Aramaki

    2008-08-01

    Full Text Available The direct measurement of the micro-components of water consumption (i.e., consumption by each residential activity, such as toilet-, laundry-, bath-, and kitchen-use, both in the dry season and in the rainy season, was conducted in Chiang Mai, Thailand. It was expected that rainfall differences between the dry and rainy season would influence awareness for water resources so that water consumption in the dry season would be smaller than that in the rainy season. In addition, it was examined whether the differences in water resources such as public waterworks or non-public waterworks (i.e., community waterworks, mountainous water and groundwater, affected the amount of water use. A small-sized accumulative water meter was developed for measurement. This survey provides important information for water demand estimations and water supply planning in middle-developed countries where water consumption is expected to increase in future.

  13. Micro-components survey of residential indoor water consumption in Chiang Mai

    Directory of Open Access Journals (Sweden)

    T. Aramaki

    2008-02-01

    Full Text Available The direct measurement of the micro-components of water consumption (i.e., consumption by each residential activity, such as toilet, laundry, bath, and kitchen both in the dry season and in the rainy season was conducted in Chiang Mai, Thailand. It was expected that rainfall differences between the dry and rainy season could influence awareness for water resources so that water consumption in the dry season may be smaller than that in the rainy season. It was also examined that whether the differences in water resources such as public waterworks or non-public waterworks like community waterworks, mountainous water and groundwater, affect the water use amount. A small-sized accumulative water meter was developed for measurement. This survey can provide the important information for water demand estimation and water supply planning in middle-developed countries where their water consumption should be expected to increase from here on.

  14. Meeting the challenges of on-host and off-host water balance in blood-feeding arthropods

    Science.gov (United States)

    Benoit, Joshua B.; Denlinger, David L.

    2010-01-01

    In this review, we describe water balance requirements of blood-feeding arthropods, particularly contrasting dehydration tolerance during the unfed, off-host state and the challenges of excess water that accompany receipt of the bloodmeal. Most basic water balance characteristics during the off-host stage are applicable to other terrestrial arthropods, as well. A well-coordinated suite of responses enable arthropods to conserve water resources, enhance their desiccation tolerance, and increase their water supplies by employing a diverse array of molecular, structural and behavioral responses. Water loss rates during the off-host phase are particularly useful for generating a scheme to classify vectors according to their habitat requirements for water, thus providing a convenient tool with potential predictive power for defining suitable current and future vector habitats. Blood feeding elicits an entirely different set of challenges as the vector responds to overhydration by quickly increasing its rate of cuticular water loss and elevating the rate of diuresis to void excess water and condense the bloodmeal. Immature stages that feed on blood normally have a net increase in water content at the end of a blood-feeding cycle, but in adults the water content reverts to the prefeeding level when the cycle is completed. Common themes are evident in diverse arthropods that feed on blood, particularly the physiological mechanisms used to respond to the sudden influx of water as well as the mechanisms used to counter water shortfalls that are encountered during the nonfeeding, off-host state. PMID:20206630

  15. Mean annual water-budget components for the Island of Maui, Hawaii, 1978-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The shapefile associated with this metadata file represents the spatial distribution of mean annual water-budget components, in inches, for the Island of Maui,...

  16. Cyber-physical system for a water reclamation plant: Balancing aeration, energy, and water quality to maintain process resilience

    Science.gov (United States)

    Zhu, Junjie

    Aeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at older WRPs can satisfy effluent permit requirements, they typically operate with excess aeration. More effective process controls at older WRPs can be challenging as operators work to balance higher energy costs and more stringent effluent limitations while managing fluctuating loads. Therefore, understandings of process resilience or ability to quickly return to original operation conditions at a WRP are important. A state-of-art WRP should maintain process resilience to deal with different kinds of perturbations even after optimization of energy demands. This work was to evaluate the applicability and feasibility of cyber-physical system (CPS) for improving operation at Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) Calumet WRP. In this work, a process model was developed and used to better understand the conditions of current Calumet WRP, with additional valuable information from two dissolved oxygen field measurements. Meanwhile, a classification system was developed to reveal the pattern of historical influent scenario based on cluster analysis and cross-tabulation analysis. Based on the results from the classification, typical process control options were investigated. To ensure the feasibility of information acquisition, the reliability and flexibility of soft sensors were assessed to typical influent conditions. Finally, the process resilience was investigated to better balance influent perturbations, energy demands, and effluent quality for long-term operations. These investigations and evaluations show that although the energy demands change as the influent conditions and process controls. In general, aeration savings could be up to 50% from the level of current consumption; with a more complex process controls, the saving could be up to 70% in relatively steady-state conditions and at least 40

  17. THE COMPARISON OF STANDARDIZED PRECIPITATION INDEX (SPI, STANDARDIZED REFERENCE EVAPOTRANSPIRATION INDEX (SEI AND STANDARDIZED CLIMATIC WATER BALANCE (SCWB

    Directory of Open Access Journals (Sweden)

    Marian Rojek

    2014-10-01

    Full Text Available The standardized precipitation index (SPI, standardized reference evapotranspiration index (SEI and standardized climatic water balance (SCWB were used to analyze the humidity conditions in the vegetation period of years 1964–2006 in Wrocław-Swojec Observatory. SPI and SEI were calculated on the assumption that empirical monthly precipitation sums and monthly sums of reference evapotraspiration, obtained from Wrocław-Swojec data, are gamma distributed. Since monthly sums of climatic water balance for analogous data are normally distributed, CWB required standardization to SCWB. The aim of study was to compare those three indexes: standardized precipitation index (SPI, standardized reference evapotranspiration index (SEI and standardized climatic water balance (SCWB.

  18. Examination of groundwater flow scales and results of water balance observation in the regional hydrogeological study project field.

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Tomoya; Inaba, Kaoru; Saegusa, Hiromitsu; Takeuchi, Shinji [Japan Nuclear Cycle Development Inst., Tono Geoscience Center, Toki, Gifu (Japan)

    2002-09-01

    The Tono Geoscience center has been continuing water balance observation since fiscal 1998, and examining groundwater recharge into the basement rock. This report analyzes water balance at seven catchments in the regional hydrogeological study project field, and the applicability of area precipitation, an important item of water balance analysis, is examined. The result of the examination is shown below. Values of groundwater recharge in the small-scale catchments, such as upstream and downstream of the Shobagawa, are influence by the local groundwater flow system. But, those in the Shobagawa catchment are influenced by the larger groundwater flow system. The plane distribution of groundwater recharge matches the result of the distribution of groundwater flow analysis. (author)

  19. Thermal behaviour analysis on ITER component cooling water system loop 2B

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Bin, E-mail: guobin@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Fu, Peng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Dell’Orco, Giovanni; Liliana, Teodoros; Tao, Jun [ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Yang, Lei [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-11-15

    Highlights: • Thermal hydraulic analysis model has been developed to perform thermal analysis on the component cooling water system loop 2B. • The cooling water temperature profile at client inlet and outlet during one cycle of the most demanding plasma operation scenario was obtained. • Operation behaviour of the main heat exchanger for CCWS-2B has been depicted. - Abstract: ITER cooling water system is composed by several cooling loops, the primary heat transfer loops that form the Tokamak Cooling Water System (TCWS), the secondary heat transfer loops that form the Component Cooling Water System (CCWS) and the Chilled Water System (CHWS) and a tertiary heat transfer loop which is the Heat Rejection System (HRS). The CCWS is further divided into CCWS-1, CCWS-2A, CCWS-2B, CCWS-2C, CCWS-2D depending on the water chemistry needs of clients and wetted area material. The component cooling water system loop 2B (CCWS-2B) has the function to remove heat load from coil power supply component, Neutral Beam Injectors (NBIs) system component and diagnostic system which are located in different buildings. As the total number of the client connections for the loop is a few hundreds, simplified thermal hydraulic analysis model has been developed to perform thermal analysis on the component cooling water system loop 2B. The curve of the cooling water temperature at client inlet and outlet during one cycle of the most demanding plasma operation scenario was obtained and the cooling water flow rate can meet the thermal removal requirement of client was also confirmed from this analysis. In addition, operation behaviour of the main heat exchanger for CCWS-2B in this thermal analysis was depicted for main heat exchanger selection purposes. This study has been carried out with the AFT Fathom code.

  20. THE USE OF DRINKING WATER IN THE CONDITIONS OF MAINTAINING ECOLOGICAL BALANCE

    Directory of Open Access Journals (Sweden)

    Avtandil SILAGADZE

    2016-02-01

    pipelines. Thus, there is proposed a model of bacteriological pure underground artesian water supply from Georgia to Europe in the conditions of maintaining ecological balance. This model takes into account the analysis of water pipeline alternatives, “Georgia-Europe” pipeline construction, as Europe's population is in need of high-quality drinking water, and Georgia is interested in its export.

  1. The effect of using a geotextile in a monolithic (evapotranspiration) alternative landfill cover on the resulting water balance.

    Science.gov (United States)

    Sun, Jianlei; Yuen, Samuel T S; Fourie, Andy B

    2010-11-01

    This paper examines the potential effects of a geotextile layer used in a lysimeter pan experiment conducted in a monolithic (evapotranspiration) soil cover trial on its resulting water balance performance. The geotextile was added to the base of the lysimeter to serve as a plant root barrier in order to delineate the root zone depth. Both laboratory data and numerical modelling results indicated that the geotextile creates a capillary barrier under certain conditions and retains more water in the soil above the soil/geotextile interface than occurs without a geotextile. The numerical modelling results also suggested that the water balance of the soil cover could be affected by an increase in plant transpiration taking up this extra water retained above the soil/geotextile interface. This finding has a practical implication on the full-scale monolithic cover design, as the absence of the geotextile in the full-scale cover may affect the associated water balance and hence cover performance. Proper consideration is therefore required to assess the final monolithic cover water balance performance if its design is based on the lysimeter results.

  2. Water and energy balance in a Mediterranean snowpack: the importance of evaposublimation

    Science.gov (United States)

    Herrero, Javier; Pimentel, Rafael; María José, Pérez-Palazón; María José, Polo

    2016-04-01

    In low-latitude snowpacks or those located in semiarid regions, snow dynamics becomes an essential driver of the hydrological cycle, as well as an important support for a number of ecosystem services with an influence over the economy and the ecology of the whole region. Therefore, it is crucial to understand the processes that are taking place in the snowpack and the relative importance and timing of the different mass and energy fluxes. Sierra Nevada is a linear mountain range parallel to the Mediterranean coastline of southern Spain at 37°N. It reaches up to 3479 m.a.s.l. in approximately 40 km from the sea. Despite the semiarid climatic conditions that surround the high mountain area, it presents a regular snow cover above 2500 m.a.s.l. during the winter season. Previous studies have shown at this site that this snowpack is very exposed to high insolation rates and strong winds, and, like in other low-latitude areas, the radiative and evaposublimation (combination of the sublimation of ice and the evaporation of the water drops melted on the surface of the snow) fluxes may have a significant and prominent value in the coupled balance. In this work, we study the evaposublimation fraction in the annual water and energy balance over the snowpack in Sierra Nevada. For this, we apply a one-layer mass and energy balance snow model developed in previous works, which has proven to adequately simulate the shallow snowpacks of Sierra Nevada during the year. High evaposublimation rates were simulated and subsequently measured during several field campaigns. Evaposublimation fractions were found to range from 24 to 33% of the total annual ablation at this site. This ratio is very changeable between years, like the local meteorology itself, even though there was not a direct relationship between this rate and the dry or humid nature of each particular year. In fact, it is the particular distribution of the rainfall throughout the year what defines the dynamics of the

  3. 77 FR 23513 - Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water...

    Science.gov (United States)

    2012-04-19

    ... COMMISSION Updated Aging Management Criteria for Reactor Vessel Internal Components of Pressurized Water... Management Criteria for PWR Reactor Vessel Internal Components.'' The original notice provided the ADAMS... published a notice requesting public comments on draft LR-ISG-2011-04, ``Updated Aging Management...

  4. Sensitivity of water balance and water use efficiency to climate and crop type at an agricultural site

    Science.gov (United States)

    Brümmer, C.; Kutsch, W. L.

    2012-04-01

    The effects of climatic factors and crop type on evapotranspiration (E) and water use efficiency (WUE) were analyzed using tower-based eddy-covariance data for an agricultural site in Thuringia, Germany. During ten years of observation, winter wheat (five times) and winter barley (once) were alternately planted with potato (twice), rapeseed (once) and sugar beet (once). The seasonal pattern of E was closely linked to growing-season length and rainfall distribution. Although annual precipitation (P) was highly variable (380-700 mm), minimum annual E was not less than 250 mm and was limited to 380 mm. However, a positive correlation between annual P and annual E with E plateauing at high P as was usually found at forest, grassland and peatland sites could not be observed. Winter wheat tended to limit annual E and was found to be relatively insensitive with changing annual P and solar irradiance. A hysteretic relationship between monthly mean values of E and net radiation (Rn) indicated that E lagged behind the typical seasonal progression of Rn. Annual means of daytime dry-foliage Priestley-Taylor α much less than the theoretical maximum of 1.26 for extensive well-watered vegetation showed that E on an annual basis was either water limited and/or stomatal control of transpiration must have been prevalent. In all years, a strong linear correlation between monthly mean values of gross primary production and E resulted in WUE being relatively constant between 2.5 and 3.5 g C kg-1 H2O. Our study shows that crop selection has a major impact on the water balance of an agricultural site with the influence of climatic factors being significantly different than usually found for natural ecosystems.

  5. An integrative water balance model framework for a changing glaciated catchment in the Andes of Peru

    Science.gov (United States)

    Drenkhan, Fabian; Huggel, Christian; García Hernández, Javier; Fluixá-Sanmartín, Javier; Seidel, Jochen; Muñoz Asmat, Randy

    2017-04-01

    In the Santa River catchment [SRC] (Cordillera Blanca, Andes of Peru), human livelihoods strongly depend on year-round streamflow from glaciers and reservoirs, particularly in the dry season and in adjacent arid lowlands. Perennial glacial streamflow represents a buffer to water shortages, annual discharge variability and river contamination levels. However, climate change impacts, consecutive glacier shrinkage as well as new irrigated agriculture and hydropower schemes, population growth and thus water allocation might increase water scarcity in several areas of the SRC. This situation exerts further pressure and conflict potential over water resources and stresses the need to analyze both water supply and demand trends in a multidisciplinary and interlinked manner. In this context, an integrative glacio-hydrological framework was developed based on the Glacier and Snow Melt (GSM) and SOil CONTribution (SOCONT) models using the semi-distributed free software RS MINERVE. This water balance model incorporates hydroclimatic, socioeconomic and hydraulic objects and data at daily scale (with several gaps) for the last 50 years (1965-2015). A particular challenge in this context represents the poor data availability both in quantity and quality. Therefore, the hydroclimatic dataset to be used had to be carefully selected and data gaps were filled applying a statistical copula-based approach. The socioeconomic dataset of water demand was elaborated using several assumptions based on further census information and experiences from other projects in the region. Reservoirs and hydropower models were linked with additional hydraulic data. In order to increase model performance within a complex topography of the 11660 km2 SRC, the area was divided into 22 glaciated (GSM) and 42 non-glaciated (SOCONT) subcatchment models. Additionally, 382 elevation bands at 300 m interval were created and grouped into 22 different calibration zones for the whole SRC. The model was calibrated

  6. Water balance simulations of a polymer-electrolyte membrane fuel cell using a two-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, M.; Kær, Søren Knudsen

    2011-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell cathode has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various...... humidification conditions. It was found that the specific surface area of the electrolyte in the catalyst layers close to the membrane is of critical importance for the overall water balance. Applying a high specific electrolyte surface area close to the membrane (a water-uptake layer) can prevent drying out...... of the anode and flooding at the cathode while the average membrane water content is only weakly affected. The results also indicate that in contrast to common presumption membrane dehydration may occur at either anode or cathode side, entirely depending on the direction of the net water transport because...

  7. Mechanical balance laws for fully nonlinear and weakly dispersive water waves

    Science.gov (United States)

    Kalisch, Henrik; Khorsand, Zahra; Mitsotakis, Dimitrios

    2016-10-01

    The Serre-Green-Naghdi system is a coupled, fully nonlinear system of dispersive evolution equations which approximates the full water wave problem. The system is known to describe accurately the wave motion at the surface of an incompressible inviscid fluid in the case when the fluid flow is irrotational and two-dimensional. The system is an extension of the well known shallow-water system to the situation where the waves are long, but not so long that dispersive effects can be neglected. In the current work, the focus is on deriving mass, momentum and energy densities and fluxes associated with the Serre-Green-Naghdi system. These quantities arise from imposing balance equations of the same asymptotic order as the evolution equations. In the case of an even bed, the conservation equations are satisfied exactly by the solutions of the Serre-Green-Naghdi system. The case of variable bathymetry is more complicated, with mass and momentum conservation satisfied exactly, and energy conservation satisfied only in a global sense. In all cases, the quantities found here reduce correctly to the corresponding counterparts in both the Boussinesq and the shallow-water scaling. One consequence of the present analysis is that the energy loss appearing in the shallow-water theory of undular bores is fully compensated by the emergence of oscillations behind the bore front. The situation is analyzed numerically by approximating solutions of the Serre-Green-Naghdi equations using a finite-element discretization coupled with an adaptive Runge-Kutta time integration scheme, and it is found that the energy is indeed conserved nearly to machine precision. As a second application, the shoaling of solitary waves on a plane beach is analyzed. It appears that the Serre-Green-Naghdi equations are capable of predicting both the shape of the free surface and the evolution of kinetic and potential energy with good accuracy in the early stages of shoaling.

  8. Evaluation of water-energy balance frameworks to predict the sensitivity of streamflow to climate change

    Directory of Open Access Journals (Sweden)

    M. Renner

    2012-05-01

    Full Text Available Long term average change in streamflow is a major concern in hydrology and water resources management. Some simple analytical methods exist for the assessment of the sensitivity of streamflow to climatic variations. These are based on the Budyko hypothesis, which assumes that long term average streamflow can be predicted by climate conditions, namely by annual average precipitation and evaporative demand. Recently, Tomer and Schilling (2009 presented an ecohydrological concept to distinguish between effects of climate change and basin characteristics change on streamflow. We relate the concept to a coupled consideration of the water and energy balance. We show that the concept is equivalent to the assumption that the sum of the ratio of annual actual evapotranspiration to precipitation and the ratio of actual to potential evapotranspiration is constant, even when climate conditions are changing.

    Here, we use this assumption to derive analytical solutions to the problem of streamflow sensitivity to climate. We show how, according to this assumption, climate sensitivity would be influenced by different climatic conditions and the actual hydrological response of a basin. Finally, the properties and implications of the method are compared with established Budyko sensitivity methods and illustrated by three case studies. It appears that the largest differences between both approaches occur under limiting conditions. Specifically, the sensitivity framework based on the ecohydrological concept does not adhere to the water and energy limits, while the Budyko approach accounts for limiting conditions by increasing the sensitivity of streamflow to a catchment parameter encoding basin characteristics. Our findings do not support any application of the ecohydrological concept under conditions close to the water or energy limits, instead we suggest a correction based on the Budyko framework.

  9. THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER-SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Hexi Corridor is an important base of agriculture development in Northwest China. According to re-cent statistics, there are 65.94 × 108m3 of water resources available in the Hexi Corridor. At present, net consumption indevelopment and utilization is 43.33 x 108m3. Water supply and demand reach a balance on the recent level of produc-tion, but loss of evaporation and evapotranspiration is as much as 25.69 × 108m3. So net use efficiency of water resourcesis 59%. Based on analyzing balance between water and land considering ecological environment at present, there existsthe serious water shortage in the Shiyang River system where irrigation lands have overloaded. There is a comparative bal-ance between supply and demand of water resource in the Heihe River system; and the Sule River system has some sur-plus water to extend irrigation land. Use of agriculture water accounts for 83.3% and ecological forest and grass for6. 9%. The Hexi Corridor still has a great potential for water saving in agriculture production. Water-saving efficiency ofirrigation is about 10% by using such traditional technologies as furrow and border-dike irrigation and small check irriga-tion, and water-saving with plastic film cover and techniques of advanced sprinkler and drip/micro irrigation etc. cansave more than 60% of irrigated water. Incremental irrigation area for water-saving potential in the Hexi Corridor hasbeen estimated as 56% - 197% to original irrigation area. So the second water sources can be developed from water sav-ing agriculture in the Hexi Corridor under Development of the Western Part of China in large scale. This potential can berealized step by step through developing the water-saving measures, improving the ecological condition of oasis agricul-ture, and optimizing allocation of water resources in three river systems.

  10. Water, ice, and meteorological measurements at South Cascade Glacier, Washington, 1996 balance year

    Science.gov (United States)

    Krimmel, Robert M.

    1997-01-01

    Winter snow accumulation and summer snow, firn, and ice melt were measured at South Cascade Glacier, Washington to determine the winter and net balances for the 1996 balance year. The 1996 winter balance, averaged over the glacier, was 2.94 meters, and the net balance was 0.10meter. The winter balance was approximately 0.6 meter greater than the 1977-95 average winter balance (2.30 meters). The net balance, which was positive for the first time since 1984, was more than a meter greater than the 1977-95 average net balance (-0.96 meter). The glacier retreated about 15 meters from its 1995 position. Runoff was measured from the glacier and an adjacent non-glacierized basin. Air temperature, precipitation, and barometric pressure were measured nearby. This report makes these data available to the glaciological and climatological community

  11. Water, ice, meteorological, and speed measurements at South Cascade Glacier, Washington, 1999 balance year

    Science.gov (United States)

    Krimmel, Robert M.

    2001-01-01

    Winter snow accumulation and summer snow, firn, and ice melt were measured at South Cascade Glacier, Washington, to determine the winter and net balances for the 1999 balance year. The 1999 winter snow balance, averaged over the glacier, was 3.59 meters, and the net balance was 1.02 meters. Since the winter balance record began in 1959, only three winters have had a higher winter balance. Since the net balance record began in 1953, only 2 years have had a greater positive net balance than 1999. Runoff was measured from the glacier and an adjacent non-glacierized basin. Air temperature, precipitation, and humidity were measured nearby, and ice speed was measured. This report makes these data available to the glaciological and climatological community.

  12. Water, ice, and meteorological measurements at South Cascade Glacier, Washington, 1994 balance year

    Science.gov (United States)

    Krimmel, R.M.

    1995-01-01

    Winter snow accumulation and summer snow, firn, and ice melt were measured at South Cascade Glacier, Washington to determine the winter and net balances for the 1994 balance year. The 1994 winter balance, averaged over the glacier, was 2.39 meters, and the net balance was -1.60 meters. The winter balance was approximately that of the 1977-94 average winter balance. The net balance was more negative than the 1977-94 average net balance of -1.02 meters. Runoff was measured from the glacier and an adjacent non- glacierized basin. Air temperature, precipitation, barometric pressure, solar radiation, and wind speed were measured nearby. This report makes these data available to the glaciological and climatological community.

  13. Water, ice, and meteorological measurements at South Cascade Glacier, Washington, 1995 balance year

    Science.gov (United States)

    Krimmel, R.M.

    1996-01-01

    Winter snow accumulation and summer snow, firn, and ice melt were measured at South Cascade Glacier, Washington to determine the winter and net balances for the 1995 balance year. The 1995 winter balance, averaged over the glacier, was 2.86 meters, and the net balance was -0.69 meter. The winter balance was approximately 0.5 meter greater than the 1977-94 average winter balance. The net balance was approximately 0.3 meter less negative than the 1977-94 average net balance. Runoff was measured from the glacier and an adjacent non-glacierized basin. Air temperature, precipitation, barometric pressure, solar radiation, and wind speed were measured adjacent to the glacier. This report makes these data available to the glaciological and climatological community.

  14. Use of System Thinking Software for Determining Climate Change Impacts in Water Balance for the Rio Yaqui Basin, Sonora, Mexico

    Science.gov (United States)

    Tapia, E. M.; Minjarez, J. I.; Espinoza, I. G.; Sosa, C. M.

    2013-05-01

    the most important basins in Sonora. It is located in northwestern Mexico, and covers an approximate area of 74,054 km2, providing water for one of the most prominent agricultural zones in the state. We used the System Thinking Software "Stella 9.0.2" to dynamically visualize the effects of climate change on the Rio Yaqui Basin. In this software, the main components of the water balance are simulated over the designated period of time with tools that include stocks and flow diagrams, causal loops, model equations and built in functions. Climate change projections for the Rio Yaqui Basin showed highly variable runoff behaviors, indicating the possibility of frequent droughts alternating with years of extraordinary runoff. Simulations generated through the System Thinking Software provides a reasonable basis for establishing policies for optimizing storage of water during extraordinary runoff periods that can serve as water supplies during frequent droughts.

  15. Using an integrated approach between hydrological and crop models to assess surface water balance in ungauged basin

    Science.gov (United States)

    Negm, Amro; D'Agostino, Daniela; Lamaddalena, Nicola; Bacchi, Baldassare; Iacobellis, Vito

    2013-04-01

    In the last decades hydrological models have been extensively used in research fields in order to improve water balance assessment and to support integrated water resources management by quantifying the soil-plant-atmosphere interface. Due to complexity of the physical system, the mathematical models can generally represent and simulate only the basic components of the system. On the other hand, calibration and validation processes of the hydrological models in ungauged basins are still complex tasks, due to the lack of reliable methods and the uncertainty in representing the hydrological processes and the physical features of a basin. Therefore, in order to practically apply model's results, there is a continuous needing to assess their accuracy through the calibration and validation processes at gauged sites. In this context, an integrated approach is presented that couples a semi-distributed hydrological model called Distributed model for Runoff, Evapotranspiration, and Antecedent soil Moisture simulation (DREAM) with the FAO's Crop Water Productivity Simulation Model (AQUACROP). DREAM uses rainfall, Leaf Area Index (LAI) and potential evapotranspiration as inputs and streamflow, infiltration, real evapotranspiration, subsurface flow and deep percolation as outputs. Soil moisture content is accounted for as an internal variable. The simulations were done for Lama San Giorgio, a basin located in a wadi area in the central part of Apulia region (Southern Italy) for the period 2001-2005 and the meadow is mainly covered by durum wheat. According to ACLA2 project survey (Caliandro et al., 2005), the depth of the soil upper layers is about 80 cm. Calibration and validation of the DREAM model were carried out by assessing an accurate estimation of soil water content using AQUACROP model which is a more detailed model in terms of soil water dynamics. Instead, one of the most significant features of DREAM model is the evaluation of lateral flow exchanges by means of a

  16. Otimizando o componente farmacológico da terapia integrada da vertigem Optimizing the pharmacological component of integrated balance therapy

    Directory of Open Access Journals (Sweden)

    Maurício Malavasi Ganança

    2007-02-01

    Full Text Available A farmacoterapia é opção importante no tratamento das vestibulopatias periféricas. OBJETIVO: Identificar a medicação que otimiza a terapia integrada da vertigem (TIV na doença de Ménière e em outras vestibulopatias periféricas. MATERIAL E MÉTODO: Estudo de casos em que pacientes com doença de Ménière ou outras vestibulopatias periféricas receberam TIV com betaistina, cinarizina, clonazepam, flunarizina, Ginkgo biloba ou sem medicação durante 120 dias. RESULTADOS: Na doença de Ménière, TIV com qualquer um dos medicamentos foi mais eficaz do que TIV sem medicação, após 60 dias; a betaistina foi mais efetiva que todas as outras drogas, após 60 e 120 dias. Nas outras vestibulopatias periféricas, diferenças significantes foram observadas entre TIV com betaistina, cinarizina, clonazepam ou flunarizina e TIV sem medicação após 60 dias e todas as drogas foram mais efetivas que TIV sem medicação após 120 dias; betaistina, cinarizina ou clonazepam foram igualmente efetivos e betaistina foi mais efetiva que flunarizina e Ginkgo biloba. Os tratamentos foram bem tolerados. CONCLUSÕES: TIV incluindo medicação é mais efetiva que sem medicação na doença de Ménière ou em outras vestibulopatias periféricas. Betaistina foi o medicamento mais efetivo na doença de Ménière e tão eficaz quanto cinarizina ou clonazepam em outras vestibulopatias periféricas.Drug treatment is an important option for the treatment of peripheral vestibular diseases. AIM: To identify the drug component associated with optimal integrated balance therapy (IBT for Ménière’s disease or other peripheral vestibular disorders. MATERIALS AND METHODS: Analysis of a series of patients with Ménière’s disease patients or patients with other peripheral vestibular disorders that received IBT involving either no medication or betahistine, cinnarizine, clonazepam, flunarizine or Ginkgo biloba during 120 days. RESULTS: In Ménière’s disease

  17. Dynamics of leaf water relations components in co-occurring iso- and anisohydric conifer species

    Science.gov (United States)

    Frederick Meinzer; David Woodruff; Danielle Marias; Katherine McCulloh; Sanna Sevanto

    2014-01-01

    Because iso- and anisohydric species differ in stomatal regulation of the rate and magnitude of fluctuations in shoot water potential, they may be expected to show differences in the plasticity of their shoot water relations components, but explicit comparisons of this nature have rarely been made. We subjected excised shoots of co-occurring anisohydric Juniperus...

  18. A microbial fuel cell-based biosensor for the detection of toxic components in water

    NARCIS (Netherlands)

    Stein, N.E.

    2011-01-01

    In a microbial fuel cell bacteria produce electricity. When water with a constant quality is lead passed the bacteria, a constant current will be measured. When toxic components enter the cell with the water, the bacteria are affected a

  19. Water Balance in the Amazon Basin from a Land Surface Model Ensemble

    Science.gov (United States)

    Getirana, Augusto C. V.; Dutra, Emanuel; Guimberteau, Matthieu; Kam, Jonghun; Li, Hong-Yi; Decharme, Bertrand; Zhang, Zhengqiu; Ducharne, Agnes; Boone, Aaron; Balsamo, Gianpaolo; Rodell, Matthew; Toure, Ally M.; Xue, Yongkang; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi; Drapeau, Guillaume; Leung, L. Ruby; Ronchail, Josyane; Sheffield, Justin

    2014-01-01

    Despite recent advances in land surfacemodeling and remote sensing, estimates of the global water budget are still fairly uncertain. This study aims to evaluate the water budget of the Amazon basin based on several state-ofthe- art land surface model (LSM) outputs. Water budget variables (terrestrial water storage TWS, evapotranspiration ET, surface runoff R, and base flow B) are evaluated at the basin scale using both remote sensing and in situ data. Meteorological forcings at a 3-hourly time step and 18 spatial resolution were used to run 14 LSMs. Precipitation datasets that have been rescaled to matchmonthly Global Precipitation Climatology Project (GPCP) andGlobal Precipitation Climatology Centre (GPCC) datasets and the daily Hydrologie du Bassin de l'Amazone (HYBAM) dataset were used to perform three experiments. The Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme was forced with R and B and simulated discharges are compared against observations at 165 gauges. Simulated ET and TWS are compared against FLUXNET and MOD16A2 evapotranspiration datasets andGravity Recovery and ClimateExperiment (GRACE)TWSestimates in two subcatchments of main tributaries (Madeira and Negro Rivers).At the basin scale, simulated ET ranges from 2.39 to 3.26 mm day(exp -1) and a low spatial correlation between ET and precipitation indicates that evapotranspiration does not depend on water availability over most of the basin. Results also show that other simulated water budget components vary significantly as a function of both the LSM and precipitation dataset, but simulated TWS generally agrees with GRACE estimates at the basin scale. The best water budget simulations resulted from experiments using HYBAM, mostly explained by a denser rainfall gauge network and the rescaling at a finer temporal scale.

  20. Hydrological behaviour and water balance analysis for Xitiaoxi catchment of Taihu Basin

    Institute of Scientific and Technical Information of China (English)

    Xue Lijuan; Li Lijiao; Zhang Qi

    2008-01-01

    With the rapid social and economic development of the Taihu region, Taihu Lake now faces an increasingly severe eutrophication problem. Pollution from surrounding catchments contributes greatly to the eutrophication of water bodies in the region. Investigation of surface flow and associated mass transport for the Xitiaoxi catchment is of a significant degree of importance as the Xitiaoxi catchment is one of the major catchments within the Taihu region. A SWAT-based distributed hydrological model was established for the Xitiaoxi catchment. The model was calibrated and verified using hydrometeorological data from 1988 to 2001. The results indicate that the modeled daily and annual stream flow match the observed data both in the calibration period and the verification period, with a linear regression coefficient R2 and a coefficient e for modeleddaily stream flow greater than 0.8 at Hengtangcun and Fanjiacun gauge stations. The results show that the runoffprocess in the Xitiaoxi catchment is affected both by rainfall and human activities (e.g., reservoirs and polder areas). Moreover, the human activities weaken flood peaks more noticeably during rainstorms. The water balance analysis reveals the percentages of precipitation made up by surface flow, evapotranspiration, groundwater recharge and the change of soil storage, all of which are considered useful to the further understanding of the hydrological processes in the Xitiaoxi catchment. This study provides a good base for further studies in mass transport modeling and comparison of modeling results from similar hydrological models.

  1. Hydrological behaviour and water balance analysis for Xitiaoxi catchment of Taihu Basin

    Directory of Open Access Journals (Sweden)

    Li-juan XUE

    2008-09-01

    Full Text Available With the rapid social and economic development of the Taihu region, Taihu Lake now faces an increasingly severe eutrophication problem. Pollution from surrounding catchments contributes greatly to the eutrophication of water bodies in the region. Investigation of surface flow and associated mass transport for the Xitiaoxi catchment is of a significant degree of importance as the Xitiaoxi catchment is one of the major catchments within the Taihu region. A SWAT-based distributed hydrological model was established for the Xitiaoxi catchment. The model was calibrated and verified using hydrometeorological data from 1988 to 2001. The results indicate that the modeled daily and annual stream flow match the observed data both in the calibration period and the verification period, with a linear regression coefficient R2 and a coefficient e for modeled daily stream flow greater than 0.8 at Hengtangcun and Fanjiacun gauge stations. The results show that the runoff process in the Xitiaoxi catchment is affected both by rainfall and human activities (e.g., reservoirs and polder areas. Moreover, the human activities weaken flood peaks more noticeably during rainstorms. The water balance analysis reveals the percentages of precipitation made up by surface flow, evapotranspiration, groundwater recharge and the change of soil storage, all of which are considered useful to the further understanding of the hydrological processes in the Xitiaoxi catchment. This study provides a good base for further studies in mass transport modeling and comparison of modeling results from similar hydrological models.

  2. A simple water-energy balance framework to predict the sensitivity of streamflow to climate change

    Directory of Open Access Journals (Sweden)

    M. Renner

    2011-09-01

    Full Text Available Long term average change in streamflow is a major concern in hydrology and water resources management. Some simple analytical methods exist for the assessment of the sensitivity of streamflow to climatic variations. These are based on the Budyko hypothesis, which assumes that long term average streamflow can be predicted by climate conditions, namely by annual average precipitation and evaporative demand. Recently, Tomer and Schilling (2009 presented an ecohydrological concept to distinguish between effects of climate change and basin characteristics change on streamflow. We provide a theoretical foundation of this concept by showing that it is based on a coupled consideration of the water and energy balance. The concept uses a special condition that the sum of the ratio of annual actual evapotranspiration to precipitation and the ratio of actual to potential evapotranspiration is constant, even when climate conditions are changing.

    Here we apply this assumption and derive analytical solutions to the problem of streamflow sensitivity on climate. We show how climate sensitivity is influenced by different climatic conditions and the actual hydrological response of a basin. Finally, the properties and implications of the new method are compared with established Budyko sensitivity methods.

  3. Parameter regionalization of a monthly water balance model for the conterminous United States

    Science.gov (United States)

    Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

    2016-07-01

    A parameter regionalization scheme to transfer parameter values from gaged to ungaged areas for a monthly water balance model (MWBM) was developed and tested for the conterminous United States (CONUS). The Fourier Amplitude Sensitivity Test, a global-sensitivity algorithm, was implemented on a MWBM to generate parameter sensitivities on a set of 109 951 hydrologic response units (HRUs) across the CONUS. The HRUs were grouped into 110 calibration regions based on similar parameter sensitivities. Subsequently, measured runoff from 1575 streamgages within the calibration regions were used to calibrate the MWBM parameters to produce parameter sets for each calibration region. Measured and simulated runoff at the 1575 streamgages showed good correspondence for the majority of the CONUS, with a median computed Nash-Sutcliffe efficiency coefficient of 0.76 over all streamgages. These methods maximize the use of available runoff information, resulting in a calibrated CONUS-wide application of the MWBM suitable for providing estimates of water availability at the HRU resolution for both gaged and ungaged areas of the CONUS.

  4. Safe drinking water: critical components of effective inter-agency relationships.

    Science.gov (United States)

    Jalba, Daniel I; Cromar, Nancy J; Pollard, Simon J T; Charrois, Jeffrey W; Bradshaw, Roland; Hrudey, Steve E

    2010-01-01

    The paper supports the development of evidence-based emergency management frameworks of cooperation between agencies in the area of drinking water and public health, as part of developing the overall risk management culture within water utilities. We employed a qualitative research design to understand critical gaps in inter-agency relations that aggravated past drinking water and health incidents and from these identified determinants of effective relationships. We identified six critical institutional relationship components that were deficient in past incidents, namely proactivity, communication, training, sharing expertise, trust and regulation. We then analysed how these components are addressed by reputable water utilities and public health departments to develop positive examples of inter-agency cooperation. Control of different risks (e.g. public health, business, and reputation) resulting from drinking water incidents should employ a preventive framework similar to the multiple barrier approach for management of drinking water quality.

  5. Study on variation of smoke component concentration with water mist applying

    Institute of Scientific and Technical Information of China (English)

    Fang Yudong

    2014-01-01

    Interaction between water mist and fire smoke is studied by experiments in an ISO 9705 room, The variation of 02, CO and CO2 concentration is disclosed, and the mathematical models of smoke component con- centration with water mist pressure and ventilation speed are established according to the experimental results. It is found in the experiment that the smoke component concentration will break when ventilation speed exceeds 1.5 kg/s. This paper provides necessary theory for water mist technology using in smoke restraining.

  6. Study on variation of smoke component concentration with water mist applying

    Institute of Scientific and Technical Information of China (English)

    Fang Yudong

    2014-01-01

    Interaction between water mist and fire smoke is studied by experiments in an ISO 9705 room. The variation of O2,CO and CO2 concentration is disclosed,and the mathematical models of smoke component con-centration with water mist pressure and ventilation speed are established according to the experimental results. It is found in the experiment that the smoke component concentration will break when ventilation speed exceeds 1.5 kg/s. This paper provides necessary theory for water mist technology using in smoke restraining.

  7. Influence of the Aral Sea negative water balance on its seasonal circulation patterns: use of a 3D hydrodynamic model

    Science.gov (United States)

    Sirjacobs, D.; Grégoire, M.; Delhez, E.; Nihoul, J. C. J.

    2004-06-01

    A 3D hydrodynamic model of the Aral Sea was successfully implemented to address the complex hydrodynamic changes induced by the combined effect of hydrologic and climatic change in the Aral region. The first barotropic numerical experiments allowed us to produce a comparative description of the mean general seasonal circulation patterns corresponding to the original situation (1956-1960) and of the average situation for the period from 1981 to 1985, a very low river flow period. The dominant anticyclonic circulation suggested by our seasonal simulation is in good agreement with previous investigations. In addition, this main anticyclonic gyre was shown to be stable and clearly established from February to September, while winter winds led to another circulation scenario. In winter, the main anticyclonic gyre was considerably limited, and cyclonic circulations appeared in the deep western basin and in the northeast of the shallow basin. In contrast, stronger anticyclonic circulation was observed in the Small Aral Sea during winter. As a consequence of the 10-m sea level drop observed between the two periods considered, the 1981-1985 simulation suggests an intensification of seasonal variability. Total water transport of the main gyre was reduced with sea level drop by a minimum of 30% in May and up to 54% in September. Before 1960, the study of the net flows through Berg and Kokaral Straits allowed us to evaluate the component of water exchange between the Small and the Large Seas linked with the general anticyclonic circulation around Kokaral Island. This exchange was lowest in summer (with a mean anticyclonic exchange of 222 m 3/s for July and August), highest in fall and winter (with a mean value of 1356 m 3/s from September to February) and briefly reversed in the spring (mean cyclonic circulation of 316 m 3/s for April and May). In summer, the water exchange due to local circulation at the scale of each strait was comparatively more important because net flows

  8. Ecohydrology of saltcedar (Tamarix spp.) in the western United States and implications of water balance following a biocontrol agent introduction

    Science.gov (United States)

    Nagler, P. L.; Glenn, E. P.

    2012-12-01

    With increased demand on water sources for human use and likely diminished supplies due to climate change, it is important to understand the variation in evapotranspiration (ET) and vegetation water use by transpiration (T) in arid and semi-arid zone riparian areas in the western U.S. Understanding riparian plant water use is critical for accuracy of climate models, predictions used in water resources management, and assessment of land use change impacts on the water balance of ecosystems. Moore and Heilman (2011) suggested the following three principles for predicting when vegetation changes will impact the local or regional water budget: (i) variation will result if energy balance partitioning has been altered, (ii) if deeper or shallower active rooting depth has changed the amount of soil moisture accessible to plants, or (iii) if temporary changes in water use add up over longer time scales. They note that large changes in vegetation types do not necessarily result in changes in water discharge. We will use these principles to consider the case of saltcedar (Tamarix spp.) on western U.S. rivers. Once considered a high-water-use plant that out-competed native trees, research over the past two decades has shown that saltcedar water use is low to moderate, and less than native trees. Consequently, the prospects of salvaging water for human use by replacing saltcedar with native trees, once thought to be bright, now appear questionable. Furthermore, saltcedar has come to occupy ecohydrological niches on altered river systems that are no longer available to native plants. However, with the widespread introduction and spread of saltcedar leaf beetles (Diorhabda carinulata) on western rivers, introduced in part to reduce riparian water use through reduction of saltcedar abundance, saltcedar ecology has now entered a new phase. The talk will present a synthesis of the recent literature on saltcedar water use and provide an overview of saltcedar ecohydrology in terms of

  9. Selected approaches to estimate water-budget components of the High Plains, 1940 through 1949 and 2000 through 2009

    Science.gov (United States)

    Stanton, Jennifer S.; Qi, Sharon L.; Ryter, Derek W.; Falk, Sarah E.; Houston, Natalie A.; Peterson, Steven M.; Westenbroek, Stephen M.; Christenson, Scott C.

    2011-01-01

    The High Plains aquifer, underlying almost 112 million acres in the central United States, is one of the largest aquifers in the Nation. It is the primary water supply for drinking water, irrigation, animal production, and industry in the region. Expansion of irrigated agriculture throughout the past 60 years has helped make the High Plains one of the most productive agricultural regions in the Nation. Extensive withdrawals of groundwater for irrigation have caused water-level declines in many parts of the aquifer and increased concerns about the long-term sustainability of the aquifer. Quantification of water-budget components is a prerequisite for effective water-resources management. Components analyzed as part of this study were precipitation, evapotranspiration, recharge, surface runoff, groundwater discharge to streams, groundwater fluxes to and from adjacent geologic units, irrigation, and groundwater in storage. These components were assessed for 1940 through 1949 (representing conditions prior to substantial groundwater development and referred to as "pregroundwater development" throughout this report) and 2000 through 2009. Because no single method can perfectly quantify the magnitude of any part of a water budget at a regional scale, results from several methods and previously published work were compiled and compared for this study when feasible. Results varied among the several methods applied, as indicated by the range of average annual volumes given for each component listed in the following paragraphs. Precipitation was derived from three sources: the Parameter-Elevation Regressions on Independent Slopes Model, data developed using Next Generation Weather Radar and measured precipitation from weather stations by the Office of Hydrologic Development at the National Weather Service for the Sacramento-Soil Moisture Accounting model, and precipitation measured at weather stations and spatially distributed using an inverse-distance-weighted interpolation

  10. Water and nutrient balances in a large tile-drained agricultural catchment: a distributed modeling study

    Directory of Open Access Journals (Sweden)

    H. Li

    2010-11-01

    Full Text Available This paper presents the development and implementation of a distributed model of coupled water nutrient processes, based on the representative elementary watershed (REW approach, to the Upper Sangamon River Basin, a large, tile-drained agricultural basin located in central Illinois, mid-west of USA. Comparison of model predictions with the observed hydrological and biogeochemical data, as well as regional estimates from literature studies, shows that the model is capable of capturing the dynamics of water, sediment and nutrient cycles reasonably well. The model is then used as a