Water Balance Parameters Research Articles

Synergistic impact of climate and land use land cover change dynamics on the hydrological regime of Loktak Lake catchment under CMIP6 scenarios

Study region: Loktak Lake catchment, north-eastern Himalayan ranges, IndiaStudy focus: Assessing the potential synergistic impact of land use land cover (LULC) and climate change on water resources is crucial for watershed management especially in the data-scarce vulnerable wetlands. Using the SWAT hydrological model, the current study seeks to quantify the combined impacts of LULC and climate change on the water balance parameters of the Loktak Lake catchment. This study simulates the hydrological regime of the Loktak Lake catchment based on future climate and changes to LULC dynamics using four GCM models in combination with SWAT models under two alternative scenarios.New hydrological insights for the region: The findings showed that under the SSP 126 and SSP 585 scenarios, the annual mean temperature is anticipated to increase by a maximum of 1.7°C and 3.74°C, respectively, by the 2050 s and 2090 s, while the annual precipitation similarly shown a rising trend for both the scenarios for the mid and far future. The mean annual streamflow is projected to increase by 48.84 cumecs (31.65 %) and 57 cumecs (36.89 %) by the 2050 s and 2090 s decades, respectively, while the water yield will rise by 200.65 mm (30.25 %) and 216.1 mm (32.57 %) in comparable decades. The outcomes of this study might provide a scientific foundation for ecological protection as well as water resource management and development in response to the potential future risk due to climate change in the Loktak Lake catchment.

Enhancing water balance assessment in urban areas through high-resolution land cover mapping: Case study of Debrecen, Hungary

Land cover (LC) mapping in urban areas is one of the core applications in remote sensing (RS), and it plays an important role in modern urban planning and management. In order to support up-to-date simplified water balance calculation, LC modelling needs to be developed for precise and high-resolution operations to monitor rapidly expanding urban areas. This study provides a spatial decision support tool for urban water balance calculations considering hydrological parameters at pixel scale. The study is aimed to create a high-resolution LC map for more precise water balance calculations to identify and link the most important parameters, such as crop coefficient, for estimating crop evapotranspiration, runoff coefficients, and infiltration rate. Meteorological data from 2016 to 2019 were involved in evapotranspiration estimation. The study site is Debrecen, a city in northeast Hungary with a population of about 200,000. By integrating Landsat 8 imagery, Google Earth (GE), and Corine Land Cover (CLC), a LC map of 30 m resolution was created with 81.2 % overall accuracy (OA) and a coefficient of kappa greater than 0.78. For the classification of Landsat 8, seven classes were assigned (forests, sealed surfaces, areas with crop cover, grassland, semi-sealed surfaces, bare ground and surface water bodies). Classification results were validated by 101 ground truth samples using other satellite images and aerial photographs. Water balance parameters (i.e. surface runoff, infiltration and evapotranspiration) were then defined and calculated at a pixel scale and for larger areas. The technique developed in this study can also be utilized in other urban areas.

Dehydration and tomato spotted wilt virus infection combine to alter feeding and survival parameters for the western flower thrips, Frankliniella occidentalis

Dehydration and tomato spotted wilt virus (TSWV) infection substantially impact the feeding of western flower thrips, Frankliniella occidentalis. Until now, the dynamics between these biotic and abiotic stresses have not been examined for thrips. Here, we report water balance characteristics and changes in other biological parameters during infection with TSWV for the western flower thrips. There were no apparent differences in water balance parameters during TSWV infection of male or female thrips. Our results show that, although water balance characteristics of western flower thrips are minimally impacted by TSWV infection, the increase in feeding and activity when dehydration and TSWV are combined suggests that virus transmission could be increased under periods of drought. Importantly, survival and progeny generation were impaired during TSWV infection and dehydration bouts. The negative impact on survival and reproduction suggests that the interactions between TSWV infection and dehydration will likely reduce thrips populations. The opposite effects of dehydration on feeding/activity and survival/reproduction for virus infected thrips suggest the impact of vectorial capacity will likely be minor for TSWV transmission. As water stress significantly impacts insect-plant-virus dynamics, these studies highlight that all interactions and effects need to be measured to understand thrips-TSWV interactions in their role as viral vector to plants.

Temporal Gap‐Filling of 12‐Hourly SMAP Soil Moisture Over the CONUS Using Water Balance Budgeting

AbstractTemporal gaps in satellite‐based soil moisture (SM) products are a persistent issue. This study presents an entirely observation‐based method to derive volumetric SM content for filling gaps in Soil Moisture Active Passive (SMAP) retrievals. Using a water balance equation, 12‐hr topsoil water amount variations are determined based on observed precipitation from the Global Precipitation Measurement Mission (inflow) and a hydrologic loss function (outflow) built on SMAP dry‐downs. A temporally seamless SM product, composed of SMAP dry‐downs and precipitation‐driven moisture approximations, was generated as a secondary outcome in determining optimal water balance parameters. This data set maintains the original SMAP SM dynamics with a median Pearson correlation (R) of 0.69 and an unbiased root‐mean‐square error (ubRMSE) of 0.05 m3/m3. Using these parameters and available SMAP observations, a 12‐hourly SM product was produced over the conterminous United States. Validated against in situ measurements, this 12‐hourly SM product exhibits good performance with a median R of 0.63 and captures most SM peaks induced by heavy rainfall. A time series examination revealed the produced 12‐hourly SM product closely corresponds to in situ SM variations and outperforms two other SMAP‐based 12‐hourly SM products gap‐filled using temporal linear interpolation and a three‐dimensional smoothing approach, especially during sparse SMAP data periods. The proposed scheme's validity is further verified by the comparable performance of the exclusive filled‐on SM estimates. Utilizing the 12‐hourly SM data set and its paired hydrologic losses could enhance the quantification connections among the hydrologic components and benefit the understanding of land‐surface hydrology.

How to measure field soil water balance parameters?

The article provides a methodological, computational, and instrumental assignment that aids in identifying the various elements that makeup soil water balance. Reputable publications have published a large number of studies in the last ten years that discuss the computation of the soil water balance under various cropping patterns using various establishment procedures and Resource Conservation Technologies (RCTs). However, the computational and instrumental aspects of this work have received little attention. Because they lack the necessary fundamental (instrumental/methodological) competence, prospective scientists and students are unwilling to take on soil water balance calculation problems at the master's or doctoral levels, which generates misunderstandings. A thorough analysis of all the elements of soil water balance-irrigation, precipitation, evaporation, transpiration, drainage, seepage, and changes in the soil moisture profile-was included in this collection. To determine the soil water balance, all the factors are important. Although the instrumental part is well known, the computational and methodological parts are equally important. Scientists are currently attempting to find ways to save water and increase water productivity, as well as to better understand current patterns of water usage and the repercussions of activities. If one is fully versed in the instrumental, methodological, and computational aspects required to ascertain the components of soil water balance, one may also discuss the effects of a particular RCT on raising water and land productivity in a region with differing agroclimatic conditions.

Interpreting effective hydrologic depth estimates derived from soil moisture remote sensing: A Bayesian non-linear modeling approach

The water balance equation (WBE) describes how net water inflows into a system relate to storage changes over a time span (dt). This equation is fundamental in hydrologic studies, helping to determine water supply and elucidate the terrestrial water cycle. For land surface, the WBE links water fluxes like precipitation (P), evapotranspiration, drainage and surface runoff to soil moisture (SM) changes within a discrete soil layer (dSM). While traditional focus has been on the precision of the WBE-estimated fluxes, there has been increased recent interest in fitting the WBE using remotely-sensed P and SM data to infer water balance parameters, particularly the ΔZ that associates net fluxes and dSM within dt. However, obtaining physically interpretable WBE parameters like ΔZ is a potentially ill-posed problem due to simplifying assumptions imbedded in a WBE implementation, missing hydrologic constraints, and accuracy and revisit limitations in available remotely-sensed data. In addition, WBE parameters obtained from classical maximum likelihood estimation approaches can vary significantly. Here, using a Bayesian non-linear modeling approach, we demonstrate how these factors can impede the identification of useful ΔZ estimates. Specifically, we find that ΔZ estimates are likely to be spuriously biased due to limitations in the temporal resolution and accuracy of satellite-based dSM estimates – as well as the neglect of other hydrological components in the WBE. Maps showcasing the lower and upper bounds of the 94 % HDI from our Bayesian model further elucidate these biases. Results suggests that estimates of ΔZ are effective in nature and great care should be exercised when attempting to interpret them physically. Instead, they should be defined as effective parameters reflecting the characteristics of their fitted remotely-sensed data sets. Drawing from current progress, accurate ΔZ estimates, informed by more advanced remote sensing techniques and precise WBE, will enhance our understanding of terrestrial water cycle.

Assessment of the level of annual intake of tritium into the air from the surface of the lake Kyzyltash

Сайт «Озёра России». URL: https://ozera.info/lakes/ about/gvr/list-lakes/kyzyl-tash (Дата обращения 25.03.2022 г.) Екидин А.А., Антонов П.Л., Жуковский М.В. Оценка загрязнения атмосферы тритием при испарении воды с поверхности промышленных водоемов // Вопросы радиационной безопасности. 2012. № 3. С. 3-10. Андреева М.А. Озера среднего и Южного Урала. Челябинск, 1975. 270 с. Толстикова В.С. Кузнецов В.Н. Ядерное наследие на Урале: исторические оценки и документы. Екатеринбург, 2017. 400 с. Баторшин Г.Ш., Мокров Ю.Г., Алексахин А.И. Концепция вывода из эксплуатации водое мов-хранилищ ЖРО ФГУП «ПО «Маяк». VII Международный промышленный форум «АТОМЭКО – 2013». М., 2013. Радиационная обстановка на территории России и сопредельных государств в 2020 г. Ежегодник. Обнинск, 2021. 239 с. Чеботина М.Я., Николин О.А., Смагин А.И., Мурашова Е. Тритий в водоёмах производственного и комплексного назначения в районе ПО «Маяк» на Урале // Водное хозяйство России. 2011. № 4. С. 75-84. Vostrotin V.V., Yanov A.Y., Finashov L.V. Tritium in environmental objects in the area affected by FSUE Mayak Production Association in 2014-15 // Journal of Radiological Protection. 2021. Vol. 41, № 2. P. S56-S66. DOI 10.1088/1361-6498/ abe8c8. Иванов Н.Н. Об определении величины испаряемости // Известия Всесоюзного географического общества. 1954. Т. 86, № 2. вып. 1. С. 189–196. Сайт компании ООО «Расписание Погоды». URL: https:// rp5.ru. (Дата обращения 25.03.2022). Busigin A., Kalyanam K.M., Sood S.K. Estimation of the tritium release rate from a spill of tritiated water // Fusion Technology. 1992. Vol. 21, No 2P2. P. 512-517. DOI: 10.13182/FST92-A29798. Yoshinori S. Lake water mixing and tritium balance in lake Chuzenji // Geographical Review of Japan. 1983. Vol. 56-10. P. 667-678. The paper presents the results of research of the levels of tritium volume activity in lake Kyzyltash, a water storage reservoir for liquid radioactive waste from Mayak Production Association. Insufficient knowledge of the ways of migration of tritium from the reservoir and their quantitative assessment in modern conditions does not allow to fully objectively assess and predict the impact of the object of “nuclear heritage” on the population of Ozersk and the environment. The research was aimed at obtaining scientific results, which will be the starting point for the formation of a tritium monitoring program for industrial reservoirs by Mayak Production Association. The purpose of the study was assessement of the dynamics of tritium volume activity in the lake Kyzyltash, assessment of water balance parameters and the level of tritium intake into the air from its surface during the ice-free period. A total of 33 water samples were collected. The average tritium volume activity in 2021 made 1,57Е+04 Bq/l, SD – 1,1Е+03 Bq/l that more than 2 times exceeds the intervention level. A trend of decrease in the average monthly tritium volume activity in the reservoir during the observation period was revealed. In the course of calculations, it was stated that in the course of evaporation during the ice-free period the 196 TBq of tritium entered the air from lake Kyzyltash surface that is comparable with releases from all the Russia facilities (179 TBq) except Mayak Production Association. The obtained values of evaporated tritium make 13% from atmospheric tritium releases of Mayak Production Association in 2020. A total of ~12,2 million m3 had evaporated from the water reservoir surface in the study period. The model of dependence of tritium volume activity from time in lake Kyzyltash in 2021 and using of exponentially decreasing function allowed defining water balance of lake Kyzyltash in the ice-free period with 6,3 million m3 deficiency. Research of the model parameters allow prediction of sanitary and hygienic characteristics of the water reservoir from the point of view of radiation safety and calculation of water balance of the reservoir in certain periods of time.

OSTRICH-CROPGRO multi-objective optimization methodology for calibration of the growing dynamics of a second-generation transgenic soybean tolerant to high temperatures and dry growing conditions

CONTEXTCurrent estimates show that the impact of climate change on agriculture will result in yield losses in major crops of 8–43%, mainly due to a combination of drought and heat. Second-generation transgenic crops are expected to mitigate these constraints. Soybean HaHB4 is a second-generation transgenic crop tolerant to high temperatures and dry growing conditions created in Argentina carrying the sunflower HaHB4 gene. Soybean HaHB4 has been approved in Argentina, the United States, Brazil, Paraguay, Canada and China. OBJECTIVEThis study presents a robust methodology to calibrate the CROPGRO-soybean model for the growth and development of soybean HaHB4. The approach consists of a holistic treatment of calibration parameters, objective functions, model responses and measured data. Based on the differences between transgenic and controls obtained in field trials, the proposed methodology includes species parameters related to those physiological traits that present the most significant differences, i.e. heat and drought tolerance with no yield penalties, increased light interception and photosynthetic rate, increased crop biomass and crop yield and improved water use efficiency. METHODSWe define multiple objective functions as a way of handling multiple simulated responses in the calibration procedure. For this, we connect CROPGRO with the OSTRICH software toolkit. Adjustments for initial water content in the soil profile, soil root growth factor and root depth progression were made using soft data procedures. The basic procedure for automatic calibration was modified by considering a semi-automated calibration process. The calibration sequence considers phenological development, water balance, biomass and yield parameters. RESULTS AND CONCLUSIONSWe observed good accuracy in the calibrated simulation of soybean HaHB4 development at all phenological stages, with RMSE = 1.62 days. The soil water balance reached RMSE = 27.4 mm. An acceptable biomass simulation at maturity was reached, with RMSE = 34% of average observed values. The grain yield was well predicted, with RMSE = 636 kg/ha. To verify the robustness of the calibrated model we evaluated it for grain yield prediction in fourteen field experiments for different growing seasons, water conditions and locations across the Argentine Pampas. The model accurately simulated grain yield with RMSE = 408 kg/ha, d-index = 0.93 and R2=0.77. SIGNIFICANCEThis study provides a calibration procedure for climate-resilient cultivars that are still missing for long-term studies on climate change impacts. The importance of modelling a climate-resilient crop in the framework of the soil–plant-atmosphere system is a step towards ensuring food security.

Involvement of Nitric Oxide in Methyl Jasmonate-Mediated Regulation of Water Metabolism in Wheat Plants under Drought Stress

Drought is a serious challenge that causes significant crop loss worldwide. The developmental processes of plants are regulated by phytohormones and signaling molecules that crosstalk together in signaling cascades. We suppose that nitric oxide (NO) is a secondary messenger of the JAs signaling pathway, as 10−7 M methyl jasmonate (MeJA) pretreatment regulates NO accumulation in wheat plants under drought stress, modulated by 12% polyethylene glycol (PEG), and in control plants. This study aimed to compare 2 × 10−4 M nitric oxide donor sodium nitroprusside (SNP) and MeJA pretreatments in regulating growth and water balance parameters at the vulnerable initial first-leaf stage of wheat growth. The application of 12% PEG decreased transpiration intensity twofold, relative water content (RWC) by 7–9%, and osmotic potential of cell sap by 33–40% compared with those of control plants. Under drought, MeJA- and SNP-pretreated plants decreased transpiration intensity by 20–25%, RWC by 3–4%, and osmotic potential of cell sap by 16–21% compared with those of control plants, and enhanced the proline content by 25–55% compared with MeJA- and SNP-untreated plants. Our results suggest that pretreatment with MeJA as well as SNP could mitigate drought stress in wheat plants. Similarities in MeJA- and SNP-induced shifts in plant water balance suggested that NO is a mediator of MeJA-induced regulation of wheat water content during water deficit.

The role of the apelin/APJ system in water homeostasis regulation

Water balance in the body is achieved by balancing renal and non-renal water losses with corresponding water intake. It is under the control of both the central nervous system, which integrates many parameters of water and electrolyte balance in the body, including inducing important adaptive behavioral responses, and three hormonal systems: vasopressinergic, renin-angiotensin-aldosterone and apelinergic. A lot of research is devoted to the regulation of water-electrolyte metabolism. However, this process is still quite difficult to understand, especially since more and more of its regulators are being discovered over time. One of them is the hormone apelin, an endogenous ligand for the APJ receptor. As is known, the receptor is highly expressed in many organs, such as the brain, heart, liver and kidneys, lungs, and has multidirectional effects.This literature review discusses the main characteristics and features of the regulation of these systems in relation to water-electrolyte metabolism, as well as issues of intersystem interaction and modulation of the effects of apelin.

Water balance in Japanese male kendo college athletes during training: a pilot study assessing seasonal differences with adjusted energy expenditure.

Due to various factors, water balance may vary across seasons. These effects may be particularly prominent in athletes and dependent upon energy expenditure during training. Japanese male kendo college athletes participated in this study during their training sessions. The participants were observed for three days each season, i.e., in spring, summer, and winter. The energy expenditure of the participants during training was monitored using the heart rate method. Data regarding the total amount of sweating, rate of sweating, amount of water intake, and rate of water intake were collected for each season and the differences were assessed using analysis of covariance, with energy expenditure as the covariate. The water balance parameter values observed during a kendo training session in summer were the highest, whereas these values were significantly reduced in winter. Energy expenditure was the highest in spring. The amount of sweating per energy expenditure varied seasonally, reaching as high as 2.14 g/kcal in summer. After adjusting for the influence of energy expenditure, the amount of sweating, amount of water intake, and water intake rate varied significantly by seasons, with the highest values in summer (P<0.001). The sweating rate was high in all the seasons, but the highest rate was observed in summer, followed by spring and then winter. There was a significant difference in the sweating rate in each season (P<0.001). The rehydration rate was 28% in spring, 39% in summer, and 22% in winter. After adjusting for the influence of energy expenditure, seasonal differences in water balance were observed in Japanese male kendo college athletes during training. These results suggest that water intake is essential after training in any season to maintain the water balance of the body.

Water balance and urinary parameters of lambs fed diets containing cactus cladodes varieties

AbstractThe water balance and urinary parameters of lambs fed diets containing cactus cladodes varieties were evaluated. Thirty-six uncastrated male Santa Inês lambs (22.0 ± 2.9 kg initial body weight) were distributed in a completely randomized design, with three treatments and 12 replicates. The animals were fed a control diet (Tifton-85 hay as exclusive roughage), Miúda or Orelha de Elefante Mexicana (OEM) cactus-based diets. Urine samples were collected 45 days after the introduction of the tested diets, and voluntary water intake was measured over 10 days, during the experimental period. Diets containing Miúda or OEM cactus caused a reduction of 68.35 and 77.03% in voluntary water intake, respectively. In addition, the Miúda cactus cladodes caused urinary alkalinization (pH = 8.14) and reduction in the urinary excretion index (UEI) and on the fractional excretion rate (FER) of total calcium (Ca). The diets with OEM cactus cladodes caused higher oxalates intake (6.21 g/day) and increase in urinary volume. Regardless of the variety, there was a reduction in the urinary concentrations of urea, creatinine, total proteins, Ca, phosphorus (P), UEI of urea and P, as well as in FER of P, compared to the control diet. Urinary Mg content and UEI of uric acid and Mg increased and FER of P decreased by diets supplemented with different varieties of cactus cladodes. In conclusion, the cactus cladodes increased water intake and retention, and diuresis in lambs, altered urine parameters, without compromising kidney function.

Analysis of the spatial and temporal variability of direct rainfall in Lake Tana, Ethiopia

The Blue Nile’s source, Lake Tana, is the biggest lake in Ethiopia and offers multiple services to local, regional, and international communities. The first step to effectively, efficiently, and sustainably utilizing the services that the lake may provide is to understand its water balance using accurate estimations of its water balance parameters, including direct rainfall. Direct rainfall to Lake Tana is one of the most important water balance terms of the Lake that needs a precise estimate. This study tries to analyze the spatial and temporal variability of direct rainfall to the Lake and estimate the mean annual and mean monthly direct rainfall amount to the lake using sufficient data and appropriate methodologies. 30 years (1986–2015) monthly and mean annual data from 13 meteorological stations were collected and used to analyses the spatial and temporal variability. Spatial and statistical tools were used for data processing, analysis, and presentation. Five interpolation techniques:- Thiessen polygon, spline, isohyetal, inverse distance weighting, and Kriging were considered and their performances were assessed and compared using evaluation criteria. The results indicate that the Isohytal method is slightly better than the other four methods and it is also easy to implement in a geographic information system (GIS) with Geostatic Analysis in ArcGIS. Further, the analysis has shown that the mean annual direct rainfall to Lake Tana is 1313.43 mm with a standard deviation of 259.01. Besides, it has been seen that there is a significant spatial and temporal variability of direct rainfall on Lake Tana. In terms of spatial variability, the Lake gets maximum direct rainfall in its southeastern part with an annual mean value of 1720 mm and a minimum value in its northwest parts with an annual mean value of 860 mm. In terms of Temporal variability, maximum direct rainfall is estimated in July as 374.11 mm in the Summer season and the minimum is less than 12.3 mm depth in December, January, February, and March in Winter.

ESTIMATION OF WATER BALANCE OF BARSACHHU WATERSHED IN CHUKHA BHUTAN USING REMOTE SENSING AND GIS

The water balance of a watershed is critical for the estimation of the water budget to meet the present and future domestic and economic demand and supply of water. Water balance parameters like precipitation, temperature, evapotranspiration soil moisture content deficit and surplus determine the water budget of a watershed which is further influenced by factors like land use, soil types, seasonal variation and other environmental factors. This paper intends to estimate the water balance of the Barsachhu watershed using Thornthwaite and Mather (TM) model. The use of Remote Sensing data and GIS as a tool were used in deriving the required data in executing the model. The study indicates that the monthly soil moisture content (deficit or surplus) is substantially influenced by the change in monthly rainfall, temperature and land use land cover pattern. April to October remain water surplus months while November to March remains a period of deficit. The soil moisture content has a different response to different land use in the Barsachhu watershed. The maximum annual moisture deficit and surplus of the basin are 126.27 mm and 2430.79 mm respectively and is observed in built-up areas. The runoff coefficient of the Barsachhu watershed computed from the runoff simulation of the TM model is 0.63.

Estimation of Water Balance Parameters in Rogerm Catchment Area, Mangesh, Duhok Governorate, Kurdistan Region of Iraq

The analysis of some hydrological elements of the water balance of Rogerm catchment area which is in Mangesh subdistrict, Duhok Governorate about 45 km north-west of Duhok was conducted. The aimed area is around 179.5 km². The historical record of rainfall data in Mangesh Agricultural office stations were used to calculate the water balance parameters for the period 2012-2013 to 2020-2021. The average amount of rain is almost 783.5 mm, it falls through 56 days of eight rainfall months/year. The biggest amount of rain falls in March, it reaches 158.4 mm. In winter the rain is denser and it reaches 47.7% from the total of the rainy year. 46.1% of the total amount of rain falls during two days, which cause the surface runoff. Water surplus was between 77% - 78% and 18% ground water recharge of the total annual rainfall. The probability of return period of the water surplus each two years may be 50% from (565-907 mm/year) and 50% from (363-530 mm/year) consequently, while maximum and minimum probability of return period is (907 mm/year) and (363 mm/year) consequently of the water surplus for the coming year are 10% and 90% consequently

Using Stable Water Isotope Composition (δ18O and δ2H) to Track the Interannual Responses of Arctic and Tropical Andean Water Bodies to Rising Air Temperatures

AbstractLakes in the Arctic and tropical Andes are experiencing some of the largest temperature increases on the planet with coeval marked limnological changes, but little data exist on water balance parameters from these regions. Here, we present a unique data set of water stable isotope composition (δ18O and δ2H) from a suite of 49 water bodies in the Canadian Arctic (Resolute Bay, Cornwallis Island, and Cape Herschel, Ellesmere Island) and the tropical Andes (Cajas National Park, Ecuador) spanning various years from 2009 to 2016. We show that an increase in air temperature over the study period resulted in evaporative enrichment of water isotopes in most Arctic sites highlighting the significance of evaporative losses to small Arctic ponds during the prolonged ice‐free summers now experienced in this part of the world. Exceptions include some Arctic waterbodies that received abundant snowmelt and large, ice‐covered lakes less prone to evaporation. Data from the Andean lakes indicated evaporative effects were minimal due to abundant precipitation. These data, in combination with limnological records and paleolimnological research from each region, provide a holistic view on how freshwater ecosystems are responding to recent warming in climatically sensitive Arctic and Andean environments.

AquaCrop Simulation of Winter Wheat under Different N Management Practices

AquaCrop is a well-known water-oriented crop model. The model has been often used to simulate various crops and the water balance in the field under different irrigation treatments, but studies that relate AquaCrop to fertilization are rare. In this study, the ability of this model to simulate yield and the water balance parameters was investigated in a wheat field under different nitrogen management practices. During the 2015–2016 and 2016–2017 growing seasons, meteorological data were provided from a nearby meteorological station, and the evolution of soil water content and final yields were recorded. The model showed a very good performance at simulating the soil water content evolution in the root zone. Notwithstanding its simplicity, AquaCrop based on a semi-quantitative approach for fertility performed well at the field level for the final yield estimation under different nitrogen treatments and field topography variation. Although the correlation coefficient between simulated and measured final yields was high, increased values of variations were observed in the various zones of this experimental field (−50% to +140%). The model appears to be an efficient tool for evaluating and improving the management practices at the field level. The experiments were conducted in Thessaly, which is the largest plain and the main agricultural area of Greece. Thessaly, however, has a strong negative water balance, which has led to a strong decrease in the level of the aquifer and, at the same time, to sea intrusion. There is also a significant risk of contamination of the groundwater aquifer due to increased use of agrochemicals. This analysis is particularly important for Thessaly due to the need for improvement of agricultural practices in this area, to decrease the pressure of agricultural activities on natural resources (soil, water) and reverse the consequences of current management.

Viewpoint: Irrigation water management in a space age

AbstractClimate change and rapid population growth are already putting increasing demand and pressure on the world's freshwater resources. Irrigated agriculture is responsible for about 70% of global freshwater withdrawals, consuming the most amount of water. However, the diverted water in irrigation systems is often not utilized efficiently because of poor water management at different spatial scales, resulting in a system efficiency of only 30–50% in most Asian countries. Typically, improving water management in irrigated areas requires accurate information on various water balance parameters while also considering a changing climate across different spatial scales. There have been technical limitations in getting accurate and reliable information on various key water balance parameters with the conventional approaches used in the recent past. In the twenty‐first century, considerable advances have been made in using satellite imagery, including processing and geospatial algorithms, to estimate hydro‐meteorological fluxes and relevant components at different spatial scales. This paper provides a perspective on the application of innovative and non‐conventional approaches to water resources management in the Murray Darling basin, Australia, the Indus basin, Pakistan and the Amu Darya basin, Uzbekistan. Examples of the state‐of‐the‐art tools described in this paper include: (i) using geoinformatics to monitor the diagnostic and operational performance of large irrigation schemes; (ii) quantifying groundwater and surface water to better manage these two resources using geoinformatics; (iii) forecasting irrigation supply and demand at high spatial and temporal scales using hydrological modelling based on the nodal network; (iv) forecasting crop yield production by satellite remote sensing. The approaches in this study clearly demonstrate that new monitoring and planning tools and methods are highly effective in improving irrigation water management in the ‘space age’ (for the purposes of this paper, space age refers to a period in which earth observation satellites are available to accurately monitor agricultural practices and water balance parameters such as soil moisture and evapotranspiration). The application of these innovative tools can assist in strategizing, diagnosing, monitoring and improving the performance of irrigation systems to grow more crop per drop of water while minimizing environmental impacts and dealing with climate change impacts.

Intake, digestibility, water balance, ruminal dynamics, and blood parameters in sheep fed diets containing extra-fat whole corn germ

We evaluated the effects of replacing ground corn with extra-fat whole corn germ (EFCG; 0%, 25%, 50%, 75%, and 100%) on the intake and concentration of soluble nutrients of dry matter and its components, ingestive behavior, water balance, ruminal dynamics, and blood parameters in sheep. Five rumen-fistulated sheep with an average body weight of 67.56 ± 9.13 kg were assigned to a 5 × 5 Latin square experimental design. The experimental period lasted five consecutive 22-day periods divided into 14-day adaptation and 8-day sampling periods. The diets were composed of corn silage and cactus cladodes as roughage and soybean meal, ground corn, EFCG, urea, and mineral premix as concentrate. The forage: concentrate ratio was 70:30. There were no differences in nutrient intake, except for ether extract. However, the concentration of digestible crude protein (CP; P = 0.038) and ether extract (EE; P < 0.001) increased. The replacement levels did not influence ingestive behavior, nor rumination efficiencies. Water intake and excretion were unaffected, except for excretion by feces (P = 0.040), which decreased. There was no effect of treatments on the dry matter (DM), neutral detergent fiber (NDF), and indigestible neutral fiber detergent (NDF) pools; however, the pool of EE (P < 0.001) increased. The rates of passage (Kp), ingestion (Ki), and degradation (Kd) of DM and aNDF, as well as the passage rate (Kpi) of iNDF, were uninfluenced. Levels of cholesterol (P < 0.001) and triglycerides (P = 0.001) increased. It was concluded that ground corn can be fully replaced by EFCG without affecting intake and concentration of digestible dry matter and its components, water balance, ingestive behavior, rumen dynamics, and glucose and fructosamine serum concentrations. On the other hand, the replacement increased ether extract intake and consequently, cholesterol and triglyceride serum concentrations. Therefore, we recommend total replacement of ground corn by EFCG in diets for sheep. However, further investigations are needed on animal performance and sensory and biochemical characteristics of meat and milk.

Interplay between abiotic (drought) and biotic (virus) stresses in tomato plants.

With climate warming, drought becomes a vital challenge for agriculture. Extended drought periods affect plant–pathogen interactions. We demonstrate an interplay in tomato between drought and infection with tomato yellow leaf curl virus (TYLCV). Infected plants became more tolerant to drought, showing plant readiness to water scarcity by reducing metabolic activity in leaves and increasing it in roots. Reallocation of osmolytes, such as carbohydrates and amino acids, from shoots to roots suggested a role of roots in protecting infected tomatoes against drought. To avoid an acute response possibly lethal for the host organism, TYLCV down‐regulated the drought‐induced activation of stress response proteins and metabolites. Simultaneously, TYLCV promoted the stabilization of osmoprotectants' patterns and water balance parameters, resulting in the development of buffering conditions in infected plants subjected to prolonged stress. Drought‐dependent decline of TYLCV amounts was correlated with HSFA1‐controlled activation of autophagy, mostly in the roots. The tomato response to combined drought and TYLCV infection points to a mutual interaction between the plant host and its viral pathogen.