Minimize Water Loss Research Articles

Application of feedback control to stomatal optimisation in a global land surface model

Accurate representations of stomatal conductance are required to predict the effects of climate change on terrestrial ecosystems. Stomatal optimisation theory, the idea that plants have evolved to maximise carbon gain under certain constraints, such as minimising water loss or preventing hydraulic damage, is a powerful approach to representing stomatal behaviour that bypasses the need to represent complex physiological processes. However, while their ability to replicate observed stomatal responses is promising, optimisation models often present practical problems for those trying to simulate the land surface. In particular, when realistic models of photosynthesis and more complex cost functions are used, closed-form solutions for the optimal stomatal conductance are often very difficult to find. As a result, implementing stomatal optimisation in land surface models currently relies either on simplifying approximations, that allow closed-form solutions to be found, or on numerical iteration which can be computationally expensive. Here we propose an alternative approach, using a method motivated by control theory that is computationally efficient and does not require simplifying approximations to be made to the underlying optimisation. Stomatal conductance is treated as the control variable in a simple closed-loop system and we use the Newton-Raphson method to track the time-varying maximum of the objective function. We compare the method to both numerical iteration and a semi-analytical approach by applying the methods to the SOX stomatal optimisation model at multiple sites across the Amazon rainforest. The feedback approach is able to more accurately replicate the results found by numerical iteration than the semi-analytical approach while maintaining improved computational efficiency.

The potential of direct air capture using adsorbents in cold climates.

Global warming threatens the entire planet, and solutions such as direct air capture (DAC) can be used to meet net-zero goals and go beyond. This study investigates using DAC in a 5-step temperature vacuum swing adsorption (TVSA) cycle with adsorbents' Li-X and Na-X, readily available industrial zeolites, to capture and concentrate CO2 from air in cold climates. From this study, we report that Na-X in cold conditions has the highest known CO2 adsorption capacity in air of 2.54mmol/g. This combined with Na-X's low CO2 heat of adsorption, and fast uptake-rate in comparison to other benchmark materials, allowed for Na-X operating in cold conditions to have the lowest reported DAC operating energy of 1.1 MWh/tonCO2. These findings from this study show the promise of this process in cold climates of Canada, Alaska, Greenland, and Antarctica to be part of the solution to global warming.

How can structure and nectar composition explain the secretory process in super productive nuptial nectaries of Mabea fistulifera Mart. (Euphorbiaceae)?

Mabea fistulifera, a species pollinated mainly by diurnal and nocturnal vertebrates, presents pendulous inflorescences with approximately 70 pairs of nuptial nectaries (NNs). These NNs exude voluminous nectar drops that defy gravity, remaining exposed at the inflorescence for more than a day. We aimed to investigate the NN secretory process and the unique nectar presentation of M. fistulifera. NNs and their exudate were collected at different secretory stages and submitted to structural studies and chemical analysis. The epidermis is devoid of stomata and constitutes the main site of synthesis for non-sugar metabolites found on nectar and nectar-coating film. Nectary parenchyma presents few small starch grains, and vascular strands are distributed until the nectary parenchyma cells close to the epidermis. Vascular tissues at the nectary parenchyma seem to provide sugar and water for the nectar. A film composed of lipids, alkaloids, and proteins covers the nectar drops. The film guarantees the nectar offering for several hours, as it minimizes water loss and prevents falls by gravitational action. The release of large nectar drops is intrinsically linked to the NN anatomical traits and the exudate composition. Low sugar concentration and predominance of hexoses in M. fistulifera nectar are essential for maintaining nectar exudation for many hours, which results in the visitation of a broad spectrum of pollinators.

Incorporating an Environmental Management Plan in Water Utilities Management Systems to Reduce Water Loss; Case of Non-Revenue Water in Kisumu City, Kenya

One of the biggest issues facing water utilities is the water loss experienced during the distribution process. This study sought to examine water distribution process in Kisumu and formulate an Environmental Management Plan (EMP) to minimize water loss and mitigate their negative environmental impacts. A qualitative research approach and a case study research design were employed where 25 participants from Kisumu Water and Sanitation Company (KIWASCO) were interviewed in a Focus Group Discussion (FGD). Content analysis of the data collected indicated that water quality and quantity were greatly affected by water loss and the problems associated with them included water pollution due to introduction of contaminants when leakages or pipe bursts occur and water scarcity where the water utility was unable to make up for the amount of water lost. Water abstraction technique was also identified as a vital factor that determines how much water is lost even before it gets into the distribution system. Land/soil, socioeconomic and political environment were also some of the factors identified as they form the backbone of a functional EMP. The research concluded that as much as KIWASCO has a strategic plan to minimize these water losses, the goal entirely focuses on doing so for economic gains and not to address the associated negative environmental impacts hence the recommendation that there is need to incorporate an EMP in their management systems that will not only ensure high revenue generation but also guarantee the conservation of the said water resource to achieve environmental excellence.

Comparison of Infiltration Rates of Soils for Run-Off Management and Irrigation Planning in Makurdi Benue State, Nigeria

Understanding of initial infiltration rates and steady state infiltration rates of soil is very important for runoff management and irrigation scheduling. Therefore, a field experiment was conducted at the Teaching and Research Farm of Joseph Sarwuan Tarka University, Makurdi in 2018 to evaluate the initial and steady state infiltration rates of soils in Makurdi, Nigeria. Infiltration test was carried out using double ring infiltrometer at eighteen points. Initial and steady state infiltration rates and the cumulative infiltration were then calculated. Soil samples were collected from the adjacent area of the marked points at 0-15 cm and 15-30 cm depths for routine analysis. Undisturbed soil samples were also collected for the measurement of saturated hydraulic conductivity, bulk density, total porosity and moisture content determination. Simple descriptive statistic of mean, variance and standard deviation was used to analyze the data. The soils were predominantly sandy loan texture, with percentage sand, silt and clay as 710.7, 118.9, and 170.4 g kg-1 respectively. Soil bulk density and saturated hydraulic conductivity were 1.40 g cm-3 and 10.27 cm hr-1 at 0 – 15 cm depth, while soil organic carbon and CEC were 0.67 % and 6.62 cmol/kg respectively. The initial infiltration rate ranged from 7.40 - 87.46 mm hr-1 with a mean of 44.09 mm hr-1, meanwhile, the steady state infiltration rate ranged between 4.99 – 22 mm hr-1, with a mean value of 15.42 mm hr-1. High soil bulk density caused moderate to low infiltration capacity. The mean values for the steady state infiltration rate suggest that the soils of the study area have moderate infiltration capacity, therefore, water application for irrigation should be less or equal to the infiltration capacity of the soils to minimize water loss by surface runoff and erosion.

Assessing Water Losses in Drinking Water Distribution Systems Using the SCADA System: The Erzincan Case

Reasons such as rapid population growth, urbanization, unconscious water use, environmental pollution, and changes in climate conditions increase water consumption, and water is consumed before completing its cycle in nature. This situation has directed the water producers to search for new resources in the face of increasing water demand and decreasing resources, but due to the high cost of the resource search, the water producers have turned to the understanding of reducing the high amounts of lost water and using water resources in a more planned and efficient manner. Minimizing water losses in drinking water distribution networks is among these objectives.
 In this study, drinking water data between January 2014 and January 2020 in Erzincan was examined, and the SCADA (Supervising Control and Data Acquisition) system placed in the drinking water distribution network in March 2018 was evaluated by considering the pre and post-drinking water data in the system. First of all, the terms between January 2014 and March 2018 which means before the installation of the SCADA system were examined, the data of the amount of water produced and the data of water consumed by the subscribers was collected from the Municipal Waterworks Unit, these data were transferred to the Water Balance Table, the results was analyzed and the actual water loss rates in the system were estimated. As a result of this estimation, before the SCADA system was established, the total physical and administrative water loss rate was seen as 64%, while the physical water loss rate was 28%. After the establishment of the SCADA automation system after March 2018, the date of the amount of water produced received from the SCADA system and the amount of water consumed was transferred to the Water Balance Table and the total physical and administrative loss was seen as 37% while the physical water loss rate was 14%. According to these results, it was observed that the water loss rate approached the minimum level within a short period with the SCADA automation system.

Development of a real-time wireless sensor network-based information system for efficient irrigation of upland and lowland crop production systems

This study developed a real-time web-and WSN-based information system for efficient irrigation water management and automation of drip-irrigated upland crop and intermittently-irrigated lowland crop production systems. The web-based system uses Flutter and DART to accommodate multiple end user platforms, while the WSN-based system uses state-of-the-art hardware and sensors for real-time monitoring of soil moisture, water level and weather conditions. The sensors are wirelessly connected in a low-power mesh network that sends data to a central server. The sensor readings are uploaded to the web application via MQTT, which generates charts and graphs for data analysis. The sensor readings compared well with measurements from conventional instruments. The system in this study provides a sustainable solution for improving irrigation efficiencies under both upland and lowland crop production systems, in minimizing water losses and in improving the overall agricultural crop productivity.

Drip Irrigation (Financial analysis) System for Strawberry Plants (Fragaria sp): Case Study in Pandanrejo Village, Bumiaji Sub-district, Batu City

Drip irrigation is a method of providing water with a low flow rate. The drip irrigation system can savewater usage, because it can minimize water losses that may occur. The use of drip irrigation systems needsto be considered from a financial analysis point of view. Financial analysis is one of the aspects used inassessing the investment plan of a development. There are several investment criteria that can be used inproject evaluation, including Net Present Value (NPV), Net Benefit Cost Ratio (Net B/C), IRR, and BEP.Based on the description above, it will raise important issues that will become the details of the problem,namely to provide an assessment of the economic efficiency of operations and maintenance of the dripirrigation system. The results of the drip irrigation project research show that it is feasible to run based oninvestment criteria. The results of the NPV calculation are Rp. 74,293,523.47. The result of IRR calculation is36.53%. The result of the calculation of Net B/C is 1.75. The calculation result of BEP is 547.7 kg/year, whilethe rupiah BEP is Rp. 24,902.15/kg. The results of the feasibility and sensitivity test gives a conclusion thatthe application of drip irrigation is feasible for the owner farmers, especially the scavenger farmers inPandanrejo Village.

Effect of Leak Geometry on Water Characteristics Inside Pipes

Water leaks from pipelines have large economic and ecological impacts. Minimizing water loss from supply pipelines has favorable effects on the environment as well as on energy consumption. This paper aims to understand the effect of the geometry of a leaking crack in a pipe wall by examining fluid flow characteristics, namely pressure and velocity distributions, inside the pipe. Practical observations show that the cause of wall rupture influences the geometry of cracks formed in a pipe wall, impacting aspects such as excessive pressure, corrosion. Knowledge of fluid flow characteristics could help in detecting and identifying leak characteristics at an early stage and assist in improving the energy and resource efficiency of water supply services. An experimental setup is developed to detect water leakage in a pipe when the leak is at an early stage and is difficult to detect by visual inspection. A computational fluid dynamic (CFD) model is developed using the COMSOL software. A comprehensive analysis of the effect of leak geometry on pressure and velocity distributions along the pipe is carried out while considering factors such as different pipe sizes, leak geometries, and steady-state flow conditions. It is observed that both velocity and pressure magnitudes rapidly fluctuate in the vicinity of leaks. Leaking cracks with slot, circle, and square shapes are found to generate distinguishing pressure and velocity distributions along the pipe. Thus, the geometry of the leaking crack and potentially its root cause(s) could be predicted by measuring velocity and pressure distributions.

Do Various Conifers Respond Differently to Water Stress? A Comparative Study of White Pine, Concolor and Balsam Fir

Aim of study: Two-year-old containerized balsam and concolor fir and one-year-old Eastern white pine transplants were grown under variable watering regimes with the goal of identifying plant morphological and some physiological traits under water stress. Area of study: This experiment was conducted in a greenhouse at the Tree Research Center on the Michigan State University campus, East Lansing, Michigan. Material and methods: Relative root collar diameter (RRCD), height growth (RHG), and root length (RRL) were measured as growth parameters. Stem water potential (Ψ), stomatal conductance (gs), net photosynthetic rate (Anet), intrinsic water use efficiency (iWUE=Anet/gs), foliar potassium (K+), and calcium (Ca+2) concentration were measured as physiological traits. Main results: Well-watered transplants had significantly higher RRCD, RHG, and RRL in fir species. Balsam fir and white pine transplants had a higher Ψ than concolor fir under severe stress. Fir species had higher Anet, gs, and a lower iWUE than white pine. White pine had a lower foliar K+ concentration, while balsam fir had the highest foliar Ca+2 concentration. Balsam fir had higher growth and Anet, gs, and iWUE under water stress due to their ability to maintain higher water uptake despite a reduced soil water content. Highlights: It is concluded that white pine has better drought tolerance because of the ability to withstand water stress through the mechanism of reduced photosynthetic activities and growth, minimize water loss, and increase water uptake.

Development of Hybrid (Sb/Ca) Flooded Lead-Acid Battery for Minimizing Water Loss

Development of Hybrid (Sb/Ca) Flooded Lead-Acid Battery for Minimizing Water Loss

Discrete controller synthesis applied to smart greenhouse

The popularization of the Internet of Things allowed the emergence of different monitoring and control solutions in different economic sectors. For example, in agriculture, this type of technology has supported the monitoring of environmental variables essential in decision-making, defining when and how much water to use in a given crop. Besides, it made it possible to control various devices to meet each crop type's environmental requirements, increasing productivity. In this sense, there is a need for increasingly improved control strategies to meet crop requirements in real-time, ensuring sustainable production and reliable quality. This work presents Discrete Event System techniques to develop an agricultural greenhouse controller considering self-configuring mechanisms for adapting to dynamic environments and preventing conflicting rules from violating control objectives. The controller was validated through a simulator based on temperature balance equations, allowing the environment's temperature control. We used accurate climate data from actual Brazilian meteorological stations to evaluate different control scenarios in the year's four seasons, checking the controller's efficiency and the control strategy adopted, guaranteeing the crop's thermal comfort and minimizing water loss. Applying this control technique, we achieved the crop's thermal comfort under 87% of the time, influencing the absolute humidity and evapotranspiration rates over 31 days. Besides, we were also able to reach 66% more energy efficiency than other approaches.

Adaptative Leaf Morphology of Eurya japonica Thunb. (Ternstroemiaceae) in Serpentine Areas

Serpentine soils are known to affect plant growth and plants in these soils have morphological and anatomical modifications. Comparative leaf morphology and anatomy studies of Eurya japonica Thunb. was conducted between serpentine and inland (control) areas. Our morphological analyses revealed that the individuals in the serpentine areas had significantly smaller and thicker leaves than those in the inland areas. Our anatomical analyses showed that the smaller leaves of serpentines had decreased numbers of cells, and their thicker leaves contributed to the increased height of epidermal cells, palisade tissue, and spongy tissue. Furthermore, the stomatal size of serpentines was significantly smaller than those from the inland areas. We concluded that E. japonica adapted to the serpentine areas by decreasing leaf size due to low levels of nutrients, by thickening the leaves to store water and reducing the stomatal size to minimize water loss via gas exchange.

Rehabilitation in Intermittent Water Distribution Networks for Optimal Operation

Equitable distribution of water is a growing source of worry, and concerns water systems’ managers as water-stressed areas steadily increase and situations of water scarcity are becoming more frequent. The problem goes beyond just the water sector and globally affects many countries’ economies since water resources have multiple uses (i.e., power generation, irrigation, etc.). One of the various strategies to overcome periods of extreme events (e.g., water scarcity) is the adoption of intermittent operation. Intermittent operation can minimize water losses, and manages to supply the same water demand (in terms of volume) during a reduced period of time. However, despite minimizing water losses, the energy consumption necessary to cope with the increased flows and head loss, due to the reduced number of operating hours, increases. This paper explores a strategy based on rehabilitation of the system’s main pipes. It also considers optimal selection and scheduling of pumps aiming at improving the system’s hydraulic parameters (e.g., velocity and head losses) and at reducing the operating costs. Both selection and scheduling of pumps and resizing of main pipes are optimized using Particle Swarm Optimization. The obtained results show that this strategy can significantly reduce the energy consumed and can be economically feasible.

An intelligent irrigation system based on internet of things (IoT) to minimize water loss

This paper proposes a comparison of three machine learning algorithms for a better intelligent irrigation system based on internet of things (IoT) for differents products. This work's major contribution is to specify the most accurate algorithm among the three machine learning algorithms (k-nearest neighbors (KNN), support vector machine (SVM), artificial neural network (ANN)). This is achieved by collecting irrigation data of a specific products and split it into training data and test data then compare the accuracy of the three algorithms. To evaluate the performance of our algorithm we built a system of IoT devices. The temperature and humidity sensors are installed in the field interact with the Arduino microcontroller. The Arduino is connected to Raspberry Pi3, which holds the machine learning algorithm. It turned out to be ANN algorithm is the most accurate for such system of irrigation. The ANN algorithm is the best choice for an intelligent system to minimize water loss for some products.

Análisis de los niveles de automatización de los procesos industriales

El presente proyecto de investigación está enfocado en el análisis de los niveles de automatización de los procesos industriales de la empresa Unidad de Negocios Termopichincha Quevedo II CELEC EP con el fin de identificar los problemas y oportunidades de mejora que permitan el aumento de la eficiencia y el incremento de la productividad. Cada uno de los métodos utilizado en la investigación como el método inductivo, de observación y analítico han sido de vital importancia para llegar a los resultados y conclusiones finales; donde se ha determinado por medio de una entrevista realizada al jefe encargado de la empresa, Ing. Gabriel Robinson que la empresa mantiene un nivel 5 de automatización correspondiente a la pirámide del mismo, debido a que la mayoría de sus procesos son automatizados a excepción del proceso de recepción de combustible y agua cruda el cual requiere mejoras en automatización. Por ende, se ha propuesto la utilización de una boya industrial para minimizar pérdidas de agua y tiempos innecesarios de monitoreo al momento de llenado dentro del proceso de recepción de agua cruda. El resultado del estudio es la descripción y evaluación de las alternativas de acuerdo a los problemas, necesidades y posibilidades de implementación teniendo en cuenta la infraestructura con que cuenta la Empresa y a la proyección de la misma.

Appraising the Impact of Pressure Control on Leakage Flow in Water Distribution Networks

Water losses in Water Distribution Networks (WDNs) are inevitable. This is due to joints interconnections, ageing infrastructure and excessive pressure at lower demand. Pressure control has been showing promising results as a means of minimising water loss. Furthermore, it has been shown that pressure information at critical nodes is often adequate to ensure effective control in the system. In this work, a greedy algorithm for the identification of critical nodes is presented. An emulator for the WDN solution is put forward and used to simulate the dynamics of the WDN. A model-free control scheme based on reinforcement learning is used to interact with the proposed emulator to determine optimal pressure reducing valve settings based on the pressure information from the critical node. Results show that flows through the pipes and nodal pressure heads can be reduced using this scheme. The reduction in flows and nodal pressure leads to reduced leakage flows from the system. Moreover, the control scheme used in this work relies on the current operation of the system, unlike traditional machine learning methods that require prior knowledge about the system.

Variation in salinity tolerance and water use strategies in an introduced woody halophyte (Tamarix spp.)

Abstract The form and function of terrestrial plants is largely governed by the availability of water, with plants in water‐limited environments expressing traits minimizing water loss and tissue damage during drought. Areas with high salinity are analogous to those with low water availability, even where water is abundant. We evaluated variation in salinity tolerance and water use strategies in an introduced halophytic shrub, Tamarix spp by measuring gas exchange rates, biomass accumulation and turgor loss points. We hypothesized that salinity tolerance is not uniformly expressed, with high salinity ecotypes expressing more conservative water use traits that maximize hydraulic safety over high conductance rates. We studied two populations of Tamarix spp. along the lower Colorado River, where groundwater salinity differed by nearly sixfold. Cuttings collected from the sites were grown in a greenhouse with five salinity levels from 0 to 32 parts per thousand (ppt), imposing increasing water limitation. In situ measurements of leaf water potentials (Ψ) and branch xylem anatomy were taken on ecotypes sourced from high‐ and low‐salinity sites. In the greenhouse, biomass and gas exchange rates were evaluated over the 0–32 ppt salinity gradient, and a separate dry down experiment was performed to determine turgor loss points and stomatal responses to drying soils. In the greenhouse, the low salinity population accumulated 72% more biomass when grown at 4 ppt compared to 16 ppt, while the high salinity population produced 50% more biomass when grown at 16 ppt. Net carbon assimilation was greater at lower salinities in the low salinity population but independent of salinity in the high salinity population. The high salinity population had a lower turgor loss point and exhibited greater stomatal control relative to the low salinity population. Synthesis. Results provide evidence for divergence of traits related to plant water use across salinity gradients in this recently introduced halophyte. Local adaptation to increased salinity has implications in aridland riparian ecosystems, where water management or drought may lead to altered soil salinities. The interaction of trait variation within Tamarix spp. and increasing salinity is likely to favour its continued dominance.

High-Resolution Analysis of Growth and Transpiration of Quinoa Under Saline Conditions.

The Plantarray 3.0 phenotyping platform® was used to monitor the growth and water use of the quinoa varieties Pasto and selRiobamba under salinity (0–300 mM NaCl). Salinity reduced the cumulative transpiration of both varieties by 60% at 200 mM NaCl and by 75 and 82% at 300 mM NaCl for selRiobamba and Pasto, respectively. Stomatal conductance was reduced by salinity, but at 200 mM NaCl Pasto showed a lower reduction (15%) than selRiobamba (35%), along with decreased specific leaf area. Diurnal changes in water use parameters indicate that under salt stress, daily transpiration in quinoa is less responsive to changes in light irradiance, and stomatal conductance is modulated to maximize CO2 uptake and minimize water loss following the changes in VPD (vapor pressure deficit). These changes might contribute to the enhanced water use efficiency of both varieties under salt stress. The mechanistic crop model LINTUL was used to integrate physiological responses into the radiation use efficiency of the plants (RUE), which was more reduced in Pasto than selRiobamba under salinity. By the end of the experiment (eleven weeks after sowing, six weeks after stress), the growth of Pasto was significantly lower than selRiobamba, fresh biomass was 50 and 35% reduced at 200 mM and 70 and 50% reduced at 300 mM NaCl for Pasto and selRiobamba, respectively. We argue that contrasting water management strategies can at least partly explain the differences in salt tolerance between Pasto and selRiobamba. Pasto adopted a “conservative-growth” strategy, saving water at the expense of growth, while selRiobamba used an “acquisitive-growth” strategy, maximizing growth in spite of the stress. The implementation of high-resolution phenotyping could help to dissect these complex growth traits that might be novel breeding targets for abiotic stress tolerance.

Quantitative Evaluation of the Trade-Off Growth Strategies of Maize Leaves under Different Drought Severities

The leaf is one of the most drought-sensitive plant organs. Investigating how leaf traits change and their trade-off growth during a drought would contribute to developing targeted drought-resistance measures. We investigated changes in five key maize leaf traits (leaf area, dry mass, effective number, water content, and specific weight) and their trade-off growth based on a drought simulation experiment. We also developed an indicator (0, 1) to quantitatively evaluate drought severity. The results showed a trade-off growth between different leaf traits of maize plants under drought conditions. Maize maintained relatively high leaf water content to maintain high leaf metabolic activity until drought severity was greater than 0. When drought severity was (0, 0.48), maize tended to adopt rapid growth strategy by maintaining regular leafing intensity and investing more energy into leaf area rather than specific leaf weight so that more energy could be absorbed. When the drought severity exceeded 0.48, maize conserved its resources for survival by maintaining relatively lower metabolic activity and thicker leaves to minimize water loss. The results provide an insight into the acclimation strategies of maize under drought, and contribute to targeted drought prevention and relief measures to reduce drought-induced risks to food security.