Significant Water Loss Research Articles

Impairment of wound healing by reactive skin decontamination lotion (RSDL®) in a Göttingen minipig® model

Reactive Skin Decontamination Lotion (RSDL®) is an FDA-approved skin decontamination kit carried by service members for removal and neutralisation of vesicants and nerve agents. The RSDL kit, comprised of a lotion-impregnated sponge, was shown to be the superior medical decontamination device for chemical warfare agent (CWA) exposure on intact skin. In the event of a chemical exposure situation (i.e. terrorism, battlefield) physical injuries are probable, and preservation of life will outweigh the risk associated with application of RSDL to compromised skin. The purpose of this study was to quantify the rate and quality of wound healing in epidermal skin wounds treated with RSDL in a porcine model. Degree of wound healing was assessed using bioengineering methods to include ballistometry, colorimetry, evaporimetry, and high-frequency ultrasonography. Clinical observation, histopathology and immunohistochemistry were also utilised. All pigs received four bilateral superficial abdominal wounds via a pneumatic dermatome on their ventral abdomen, then were treated with the following dressings over a seven-day period: RSDL sponge, petroleum based Xeroform® gauze, 3 M™ Tegaderm™ Film, and 3 M™ Tegaderm™ Foam. Two additional non-wounded sites on the flank were used as controls. Two groups of pigs were then evaluated for a 21- or 56-day time period, representing short- and long-term wound-healing progression. Our findings indicated RSDL had a negative impact on wound-healing progression at both 21 and 56 days post-injury. Wounds receiving RSDL demonstrated a decreased skin elasticity, significant transepidermal water loss, and altered skin colouration and thickness. In addition, the rate of wound healing was delayed, and return to a functional skin barrier was altered when compared to non-RSDL-treated wounds. In conclusion, wound management care and clinical therapeutic intervention plans should be established to account for a prolonged duration of healing in patients with RSDL-contaminated wounds.

Profitability of erosion control with cover crops in European vineyards under consideration of environmental costs

Vine cultivation on slopes causes serious erosion with significant losses of nutrients, organic matter and water, followed by an overall loss of soil biodiversity and ecosystem services (ES). Cover crops (CC) in inter-rows can reduce these effects, but are often renounced by winegrowers due to economic causes. Soil erosion rates obtained from field data and simulations with ORUSCAL (Orchard RUSle CALibration) lay the basis for comparing three different scenarios of soil management; conventional tillage (CT), temporary cover crops (TCC) and permanent cover crops (PCC). We use the Policy Analysis Matrix (PAM) to include on- and off-site costs of erosion and to demonstrate their economic implications. The scenarios are calculated for two different European wine regions, Montilla-Moriles (Spain) and Carnuntum (Austria). Resultsfrom ORUSCAL show that erosion is decreased in most cases with increasing use of vegetation cover. Overall, the consideration of erosion costs in the budget of farmers has only minor effects on their competitiveness and additional costs for CC are not covered by private erosion cost savings. However, if social erosion costs are added, CC are cost-effective in both regions. This is even without the valuation of non-marketed ecosystem services such as cultural and aesthetic aspects which most likely will increase social costs of erosion.

Groundwater use of a small Eucalyptus patch during the dry monsoon phase

Given the critical role of water in rural development, it is essential to quantify water use by various sectors. Reportedly, a significant water loss during the dry monsoon phase is by Eucalyptus trees in the Ethiopian highlands but few quantitative studies have been carried out. In our study in the Fogera plain near Lake Tana, consumptive water use of a small Eucalyptus patch was calculated from the fluctuating diurnal water table observations for two dry monsoon phases. During the dry monsoon phase in 2014, the groundwater table declined linearly at a rate of 2.6 cm d−1 and in 2015 the decline was 2.5 cm d−1. Daily fluctuations in groundwater were around 20 cm. Translating changing groundwater levels in precise evapotranspiration rates was cumbersome because of uncertainty in the value of drainable porosity. We concluded that the evapotranspiration over the small Eucalyptus patch was at a minimum 3.4 mm d−1 but more likely around 10 mm d−1 at the end of the dry phase. The 10 mm d−1 is twice the reference evaporation rate. This is in accordance with advection aridity approach where the actual evaporation of isolated patches with access to groundwater in dry environments can evaporate at twice the reference rate. The current and future extent of Eucalyptus patches and forests need, therefore, be considered in the management of the groundwater resource.

Long-Term Monitoring for Leaks in Water Distribution Networks Using Association Rules Mining

Early detection of small and large leaks in water distribution pipes allows for proactive maintenance and corrective actions to take place in a timely manner, thus mitigating significant water loss and increasing the longevity of the network. Most of the acoustic leak detection methods today are geared toward inspections—focused on probing periodic short-term data acquired in the process of inspection—rather than dealing with large volumes of long-term data acquired from monitoring programs. The common challenge encountered in both the acoustic inspection methods and in long-term monitoring of acoustic signatures lies in delineating weak leak-induced signatures within the highly noisy and nonstationary acoustic environment typical of uncontrolled real-world operating water distribution systems. This paper focuses on addressing the problem of leak detection where long-term monitoring acoustic data is available to characterize the operating conditions, without relying on controlled experiments to acquire data or expert user knowledge. The key contribution of this paper is to present a new data-driven approach using association rules (ARs) to extract information from large volumes of monitored acoustic data which can enable identification of relatively small changes in the acoustic signatures due to leaks. ARs are employed to model and synthesize the information contained in long-term monitored acoustic data and associations between statistical features obtained from such measurements are identified and used to design a leak indicator that captures the deviation of leak-induced data from a reference leak-free model. It will be shown that the proposed indicator has a high detection rate, can detect relatively small leaks, and crucially, conducive to work in uncontrolled long-term monitoring situations.

The structural evolution of water and gluten in refined and whole grain breads: A study of soft and hard wheat breads from postmixing to final product

AbstractBackground and objectivesRecent work investigating gluten secondary structure in dough systems has provided tantalizing insights as to how small perturbations in gluten structure may impact bread quality. Specifically, shifts in gluten structure from β‐turns to β‐sheets in doughs with bran may be partially responsible for quality defects in whole grain bread. This study aimed to further that knowledge by monitoring gluten secondary structure in soft and hard wheat refined and whole grain bread at different stages during processing. Commercial hard red spring (HW) and soft red winter wheat (SW) flours were used to make breads with whole grain doughs created by substituting bran for 15% of the refined flour. ATR‐FTIR spectra were collected from samples and analyzed for gluten secondary structural content.FindingsFreshly mixed doughs demonstrated the greatest β‐sheet content (53%–57%) compared to any other dough stage. Refined HW doughs demonstrated continual relaxation of β‐sheets to β‐turns through dough processing (−13% to panning), whereas relaxed SW doughs (−6% to 10%) partially reverted to sheets during punching and panning (1%–3%). The data also confirmed earlier findings that the presence of bran triggers the formation of additional β‐sheets (+4% to 5%) in both HW and SW doughs. Doughs with bran exhibited less structural relaxation (−3% to 6% β‐sheets) during processing. Interestingly, HW doughs exhibited only 1%–2% more β‐turns and only 1%–4% fewer β‐sheets than SW doughs. Analysis of the bread during baking revealed that SW generates a larger sheets:turns ratio compared to HW in refined bread, 21.3 versus 3.6, respectively, that grows to 129 versus 5.3 on addition of bran.ConclusionsGluten structural relaxation takes place during proofing in optimally hydrated doughs and largely follows water relaxation trends. The ratio of sheets:turns increases rapidly as water is lost during baking. The extent of this build‐up in the ratio is dependent on the wheat source for the flour (hard vs. soft wheat), presence/absence of bran, and the water loss (i.e., denaturation).Significance and noveltyThese results show that the ability of gluten to resist significant loss of bulk water during baking is related to better bread making performance. Additionally, the ability of gluten to resist substantial secondary structural alteration during baking, specifically formation of excessive β‐sheets, may be a key factor in high‐quality bread.

FEM simulation of water lost through damaged household water connection

The problem of water supply pipe’s failures is one of the most onerous for water distribution network’s (WDN) operators. Multiple actions undertaken to detect, minimise and eliminate the phenomenon of water losses are mainly focused on financial aspect of lost water. However, at some point, the further minimisation of water losses is unprofitable due to reaching the economic level of water leakages. In WDNs failures analysis the biggest emphasis is put on damages of main pipes and distribution pipes, while failures of household water connections are often neglected. That is because the most typical water losses in household connections are hard-to-detect background leakages with relatively small water outflow. Still, in a long-time perspective, such leakages can cause significant water losses. The aim of this paper was to evaluate the parameters of water lost through damaged household water connection (volume, velocity, suffosion conditions). The basis for the analysis were laboratory investigations and a numerical simulation of a pipe failure using the FEFLOW v. 5.3 software. The results of the simulation, compared with laboratory tests results, enabled to state that, contrary to the widespread practice, leakages from household connections cannot be ignored.

QUANTITATIVE WATER MANAGEMENT IN RABAT, SALE AND TIMISOARA DRINKING WATER SYSTEM

For efficient management of the losses of drinking water distribution networks, it is essential to have a precise knowledge of the system and its infrastructures. In this context, our study focused on describing two drinking water distribution networks, from two different countries: Rabat and Sale, Morocco and Timisoara, Romania, for water losses over a period of four and five years, respectively. The work consists of calculating some performance indicators to establish thematic maps using Geographical Information System (GIS) in order to identify and prioritize the critical sectors by the method Analytical Hierarchy Process (AHP) based on technical criteria. Timisoara, Romania has a huge volume of water losses, inefficient use of resources, scarce data and poor control. Whereas, the Rabat and Sale, Morocco network also has significant water losses, but the great contribution provided by the sectorization network and flow measurements that the data are available for local managers. The technical performance indicators and the results obtained gave us an idea of the reliability of the leak management methods adopted by each manager.

Leakproofness of the reinforced concrete tank for water with a capacity of 45000 m3

The clean water tank discussed consists of four reinforced concrete tanks. The structure is symmetrical for each of the tank pairs, which consist of two storage tanks and two water transfer tanks for the water supply network. All chambers are technologically connected with each other. The tanks are partially recessed in the ground, monolithic, and completely roofed. The projection of chambers within external walls is 96 x 96 m = 9,216 m2. The total capacity of internal chambers and external chambers is about 45,000 m3. The clean water tank was made as a reinforced concrete structure, monolithic. The owner of the facility observed significant losses of stored water, which translated into large financial losses of the company. In order to determine the current technical condition of the reservoir and the causes of its leakage, a comprehensive, multi-level analysis was carried out in terms of strength, stability and durability of the structure. A few dozens of samples were taken at random, and the compressive strength of the concrete, modulus of longitudinal deformation and degree of carbonatization were evaluated. For the assessment of the technical condition of the expansion joints, boreholes were also drilled through them. On the basis of the results obtained from the tests, numerical analysis of the stress on the structure and its deformations was performed in order to select the most stressed areas as well as to assess expansion deformations as potential spots of the largest leaks. The results of the analysis were used to prepare the concept of sealing repairs of the tank chambers.

Influence of mouth breathing on outcome of scaling and root planing in chronic periodontitis

IntroductionDryness is known to be associated with inflammatory diseases such as dry eye disease and atopic dermatitis. There is significant water loss from the oral cavity during mouth breathing. This study is conducted to estimate the influence of mouth breathing on the outcome of scaling and root planing (SRP) in chronic periodontitis (CP).Materials and methodsCP patients comprising of 33 mouth breathers (MBs) and 33 nose breathers (NBs) were recruited. Thirty patients in each group completed the study. At baseline, plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were measured. SRP was done in both groups. At the 4th, 8th, and 12th week, PI, GI, and BOP were recorded. PD and CAL were also assessed at the 12th week.ResultsAt the 12th week, there was significantly less improvement in GI at palatal sites of maxillary anterior and maxillary posterior teeth in MB group. Sixty-nine percent of BOP positive sites with PD >4 mm were converted into BOP negative sites with PD ≤4 mm in maxillary posterior palatal sites in NB. This success was 38% in MB.ConclusionControl of periodontal inflammation by SRP in CP patients is affected at palatal sites of mouth breathers.

ОЦІНКА СТАНУ ВОДОПРОВІДНО-КАНАЛІЗАЦІЙНОГО ГОСПОДАРСТВА УКРАЇНИ

The article analyzes the condition of the water supply and sewerage system of Ukraine (WSS). The WSS is a water supply and sanitation system, including water treatment facilities and sewage systems, pumping stations, water supply sources, water body sites used for diluting and treating sewage, and other real estate. It is emphasized that at the current moment in the industry a considerable number of problems have accumulated. The critical condition of the fixed assets of WSS enterprises - the depreciation of funds exceeds 65%. High energy consumption of water production - energy intensity of production of 1 m3 of water in Ukraine is in the range 0.44 - 1.82 kWh; at the same time in Berlin - 0.27 kWh; Shanghai - 0.28 kWh). The growth of accidents at the water supply and sewerage systems. Loss of water during transportation - the indicator of water losses in urban networks remains too high and lies within the limits of 0.4-3.0 m3 / km / h, in comparison with those in Western Europe, which are 0.1-0.4 m3 / km / h.). Pollution of drinking water. Shortage of financial resources. Growth of people's debts for water supply and sewerage services: as of December 31, 2017, the population's arrears for water supply and sanitation are 1.8 billion UAH. And other problems. No less urgent problems of the water supply of Ukraine are: the imperfection of water policy in the development of water supply systems for cities and settlements; low provision of centralized water supply to the rural population; insufficient provision of water supply systems with water treatment facilities for drinking purposes; departmental fragmentation of the systems of household drinking water supply; imperfection of the methodology of planning and design of long-term development of water supply systems, populated areas; low coverage of the facilities of abstraction, supply, distribution of water and consumers; irrational use of water; lack of economic incentives for the rational use of water. The main causes that have caused such a critical situation are identified, namely: high-energy intensity and low efficiency of communal systems, significant water losses; obsolete water purification technologies; imperfection of the regulatory framework.

Analyzing the effect of the unreported leakages in service connections of water distribution networks on non-revenue water

In water distribution systems, depending on various factors, the failures and leakages occur in service connections, main pipes, and fittings. A significant part of these leakages are not visible at surface, occur underground, and are expressed as unreported leakages. The aim of this study was to investigate and analyze the effect of the unreported leakages occurring on service connections to water loss volume by applying a water loss model based on the minimum night flow and the active leakage control methods. For this aim, a total of 14 district metered areas in Malatya water distribution system were selected as study area. For the water loss model, the minimum night flows were monitored at the lowest consumption times, and the potential leakages points were detected by applying active leakage control method. As a result of this method, a high rate of 77.4% of the identified leakages was observed in service connections. After repairing the leakages detected in the district metered areas, it was determined that a total reduction of approximately 148.9 l/s was achieved at minimum night flow. In the study, it was determined that the water loss model developed on the basis of minimum night flow and active leakage control methods provided important contributions to the monitoring, detection and control of the unreported leakages. Furthermore, according to the developed water loss model, it has been determined that a significant portion of the unreported leakages are caused by leakages that occur in the service connections and cause significant water loss.

Effect of different sugars on the freezing characteristics of Kyoho grape.

The aim of this work was to analyze the effect of different osmotic dehydration (OD) processes (sucrose, trehalose, glucose, and lactose) as a pretreatment for grape before exposure to freezing. The osmotic treatment had less effect on blueberry moisture content among different sugars. Impregnation with sugars decreases the freezing time of grapes, compared to untreated grapes. Trehalose and lactose had a remarkable effect on shortening the time for grapes to pass the zone of maximum crystallization of ice. It was concluded that drip loss and electrolyte permeability of cell membranes decreased and the soluble solids content increased after OD treatment. In addition, the firmness and L* values of trehalose-treated grapes were significantly higher than those of other treatments (p < .05). In summary, osmosis with a carbohydrate solution not only increased the freezing rate but improved quality characteristics of grapes after freezing and thawing. PRACTICAL APPLICATIONS: Grapes are subject to freezing damage during storage, including significant water loss, berry softening, off flavor occurrence, which reduce the commodity and consumption of grapes. OD can improve the freezing rate by reducing the moisture content in the raw material and reducing the impact of freezing on the quality of fruits and vegetables, which may be beneficial to the process of freezing grapes.

Compaction history of Upper Cretaceous shale and related tectonic framework, Arabian Plate, Eastern Oman Mountains

Shale of the Upper Cretaceous Al-Khod Formation intruded younger conglomerates of the same formation. Intrusion followed a preexisting fault that had been widened by extension. The fissility of the shale mimics the contact contours of the conglomeratic host rocks. Sandstone and conglomerate clasts are “floating” in the shale. Vertical postintrusive calcite veins are ptygmatically folded by compaction. These ptygmatically folded compaction veins display horizontal to gently dipping axial planes. Shortening amounts to ~ 40%, indicating that shale intrusion ensued with high water content. It also shows that an estimated amount of 35 to 45% of water content was expelled by compaction after vein formation. Countless, randomly oriented calcite veins in the conglomerate at the shale contact point to fluid expulsion from the shale into the conglomerate. Shale intrusion postdates the late Cretaceous obduction of the Semail Ophiolite. Intrusion most likely occurred during the Oligocene for which extension of the nearby Frontal Range Fault was due to gravitational collapse, associated with isostatic/elastic rebound. Shale dike formation is related to a widened fault within a sinistral negative flower structure with a minimum width of 100 m. Intrusion ensued at an overburden of approximately 100 m of the upper part of the Al-Khod Formation and approximately 900 m of the Paleogene limestone. Folding of calcite veins and the significant water loss was caused by corresponding compaction. Nontronite is the red shale’s main clay mineral. It derived from a source area of exposed and weathered mafic to ultramafic rocks.

Evaluation of technical performance of pipes in water distribution systems by analytic hierarchy process

Pipes with in poor condition in water distribution systems cause significant operational problems and water losses. Therefore, it is important to evaluate the technical performance of these pipes. In this study, the evaluation of technical performance of the individual water pipes by Analytic Hierarchy Process (AHP) according to various main-factors such physical, environmental and operational and sub-factors is aimed. The weight coefficients for the physical, environmental and operational main factors were calculated as, 0.43, 0.14 and 0.43, respectively. Physical Factor Score (PFS), Environmental Factor Score (EFS) and Operational Factor Score (EFS) were calculated to define the technical evaluation score of the water pipes. Finally, the Performance Evaluation Score (PES) was calculated using the weights and scores of the PFS, EFS and OFS and applied for 17 individual water pipes selected for testing the technical performance. It was determined that the structural condition and performance of ACP and PVC pipes was bad and the risk of damage was high. It is considered that the AHP model developed may be an important tool in the technical evaluation of pipes for water supply utilities.

Deep Percolation under Irrigated Water-Intensive Crops

AbstractDeep percolation from an irrigated field has received little attention in research studies although it contributes to significant loss of fresh water in a given region. Deep percolation is ...

Effect of water deficiency on relationships between metabolism, physiology, biomass, and yield of upland cotton (Gossypium hirsutum L.)

Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield, physiologic and metabolomic attributes in upland cotton cultivars (Gossypium hirsutum L). Cotton cultivars, 'Ishonch' and 'Tashkent-6' were selected to study the relationships among their physiologic, metabolomic and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant height, the number of internodes, and sympodial branches in both cultivars. However, yield components such as the number of bolls, boll seed, lint mass, and individual plant yield were significantly reduced only in 'Tashkent-6'. The leaf area decreased and the specific leaf weight increased in 'Ishonch' under deficit irrigation conditions. However, 'Tashkent-6' demonstrated significant water loss compared to 'Ishonch', and both cultivars showed reduced transpiration rates. Untargeted metabolite profiles of leaves showed clear separation in 'Ishonch', but not in 'Tashkent-6' under deficit irrigation compared to full irrigation. The individual metabolites such as proline and galactinol showed strong association with yield under water deficit stress. Moreover, this study indicates that leaf area and transpiration intensity influence yield during water deficiency. In summary, the correlation among morpho-physiologic, metabolic, and yield components significantly varied between the two cultivars under water deficiency. The flowering stage was sensitive to water stress for both cultivars. The direct relationship between physiology, metabolism, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.

Effect of dehydration on performance and technique of three-point shooting in elite basketball.

Basketball play is classically accompanied with a significant loss of body water with a potential negative impact on both physical and cognitive performance 1. Very few studies have examined the impact of dehydration on biomechanical adjustments required to score in basketball, though joints angles, the position of the centre of mass and ball release parameters (i.e. height, release speed and angle) are among the best predictive factors of success in basketball shooting 2. Dehydration might alter the biomechanical requirements of successful shots and especially three-point shots (3PS) which generate 16% of points scored during a match. However, only 35% of 3PS are successful in game. Within this framework we analysed the effects of a controlled dehydration protocol on the success and technique of 3PS in elite basketball players. Changes in shooting technique were analysed through changes in body kinematics (i.e. 3D angles of the ankle, knee, hip, shoulder, elbow and wrist, and the height of the centre of mass) and ball release parameters (i.e. height, velocity and angle of the ball at release) of 3PS in a dynamic playing condition.

Local Structure of Zr(OH)4 and the Effect of Calcination Temperature from X-ray Pair Distribution Function Analysis.

Analysis of X-ray pair distribution function data has provided a detailed picture of the local structure of amorphous Zr(OH)4 and its thermal decomposition into ZrO2. In the untreated phase, the Zr atoms tend to be coordinated by six or seven oxygen atoms. The Zr centered polyhedra connect to each other primarily by sharing edges, but also with a significant amount of corner sharing, to form two-dimensional sheets in which the Zr are connected to an average of about five other Zr. This local structure is related to the structure of monoclinic ZrO2 and can be derived from it by removing certain Zr neighbors to form sheets and reduce the corner to edge sharing ratio. The maximum correlation length in Zr(OH)4 is about 12 Å. Heating up to 125 °C results in significant water loss but does not alter the network of Zr and bridging O atoms. Additional water loss caused by heating to 250 °C triggers a reorganization into a new type of amorphous phase with a three-dimensional network and a greater number of Zr-Zr neighbors. Further heating to 330 °C causes crystallization into a mixture of tetragonal and monoclinic ZrO2, with the minor tetragonal phase having a smaller average domain size. The tetragonal component vanishes by 900 °C.

Chemical weathering outputs from the flood plain of the Ganga

Transport of sediment across riverine flood plains contributes a significant but poorly constrained fraction of the total chemical weathering fluxes from rapidly eroding mountain belts which has important implications for chemical fluxes to the oceans and the impact of orogens on long term climate. We report water and bedload chemical analyses from the Ganges flood-plain, a major transit reservoir of sediment from the Himalayan orogen. Our data comprise six major southern tributaries to the Ganga, 31 additional analyses of major rivers from the Himalayan front in Nepal, 79 samples of the Ganga collected close to the mouth below the Farakka barrage every two weeks over three years and 67 water and 8 bedload samples from tributaries confined to the Ganga flood plain. The flood plain tributaries are characterised by a shallow δ18O - δD array, compared to the meteoric water line, with a low δDexcess from evaporative loss from the flood plain which is mirrored in the higher δDexcess of the mountain rivers in Nepal. The stable-isotope data confirms that the waters in the flood plain tributaries are dominantly derived from flood plain rainfall and not by redistribution of waters from the mountains. The flood plain tributaries are chemically distinct from the major Himalayan rivers. They can be divided into two groups. Tributaries from a small area around the Kosi river have 87Sr/86Sr ratios >0.75 and molar Na/Ca ratios as high as 6. Tributaries from the rest of the flood plain have 87Sr/86Sr ratios ≤0.74 and most have Na/Ca ratios <1. One sample of the Gomti river and seven small adjacent tributaries have elevated Na concentrations likely caused by dissolution of Na carbonate salts. The compositions of the carbonate and silicate components of the sediments were determined from sequential leaches of floodplain bedloads and these were used to partition the dissolved cation load between silicate and carbonate sources. The 87Sr/86Sr and Sr/Ca ratios of the carbonate inputs were derived from the acetic-acid leach compositions and silicate Na/Ca and 87Sr/86Sr ratios derived from silicate residues from leaching. Modelling based on the 87Sr/86Sr and Sr/Ca ratios of the carbonate inputs and 87Sr/86Sr ratios of the silicates indicates that the flood plain waters have lost up to 70% of their Ca (average ∼ 50%) to precipitation of secondary calcite which is abundant as a diagenetic cement in the flood plain sediments. 31% of the Sr, 8% of the Ca and 45% of the Mg are calculated to be derived from silicate minerals. Because of significant evaporative loss of water across the flood plain, and in the absence of hydrological data for flood plain tributaries, chemical weathering fluxes from the flood plain are best calculated by mass balance of the Na, K, Ca, Mg, Sr, SO4 and 87Sr/86Sr compositions of the inputs, comprising the flood plain tributaries, Himalayan rivers and southern rivers, with the chemical discharge in the Ganga at Farakka. The calculated fluxes from the flood plain for Na, K, Ca and Mg are within error of those estimated from changes in sediment chemistry across the flood plain (Lupker et al., 2012, Geochemica Cosmochimica Acta). Flood plain weathering supplies between 41 and 63% of the major cation and Sr fluxes and 58% of the alkalinity flux carried by the Ganga at Farakka which compares with 24% supplied by Himalayan rivers and 18% by the southern tributaries.

A graph partitioning algorithm for leak detection in water distribution networks

Urban water distribution networks (WDNs) are large scale complex systems with limited instrumentation. Due to aging and poor maintenance, significant loss of water can occur through leaks. We present a method for leak detection in WDNs using repeated water balance and minimal use of additional off-line flow measurements. A multi-stage graph partitioning approach is used to determine where the off-line flow measurements are to be made, with the objective of minimizing the measurement cost. The graph partitioning problem is formulated and solved as a multi-objective mixed integer linear program (MILP). We further derive an approximate method inspired by spectral graph bisection to solve the MILP, which is suitable for very large scale networks. The proposed methods are tested on large scale benchmark networks, and the results indicate that on average, flows in less than 3% of the pipes need to be measured to identify the leaky pipe or joint.