The influences of canopy temperature measuring on the derived crop water stress index

Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.

Satellite-measured water vapor isotopologues across the Tianshan Mountains,central Asia

The satellite-based water vapor stable isotope measurements have been widely used in modern hydrological and atmospheric studies.Their use is important for arid areas where the precipitation events are limited,and below-cloud evaporation is strong.This study presents the spatial and temporal characteristics of water vapor isotopologue across the Tianshan Mountains in arid central Asia using the NASAAura Tropospheric Emission Spectrometer(TES).The near-surface water vapor stable isotopes are enriched in summer and depleted in winter,consistent with the seasonality of precipitation isotopes.From the surface to 200 hPa,the isotope values in water vapor show a decreasing trend as the atmospheric pressure decreases and elevation rises.The vapor isotope values in the lower atmosphere in the southern basin of the Tianshan Mountains are usually higher than that in the northern basin,and the seasonal difference in vapor isotopes is slightly more significant in the southern basin.In addition,bottom vapor isotopologue in summer shows a depletion trend from west to east,consistent with the rainout effect of the westerly moisture path in central Asia.The isotopic signature provided by the TES is helpful to understand the moisture transport and below-cloud processes influencing stable water isotopes in meteoric water.

Evaluation of Dosimetric Impact of Uncertainty of Measurement in Estimating External Radiotherapy Dose

Cancer is a major societal public health and economic problem, responsible for one in every six deaths. Radiotherapy is the main technique of treatment for more than half of cancer patients. To achieve a successful outcome, the radiation dose must be delivered accurately and precisely to the tumor, within ± 5% accuracy. Smaller uncertainties are required for better treatment outcome. The objective of the study is to investigate the uncertainty of measurement of external radiotherapy beam using a standard ionization chamber under reference conditions. Clinical farmers type ionization chamber measurement was compared against the National Reference standard, by exposing it in a beam 60Co gamma source. The measurement set up was carried out according to IAEA TRS 498 protocol and uncertainty of measurement evaluated according to GUM TEDDOC-1585. Evaluation and analysis were done for the identified subjects of uncertainty contributors. The expanded uncertainty associated with 56 mGy/nC ND,W was found to be 0.9% corresponding to a confidence level of approximately 95% with a coverage factor of k = 2. The study established the impact of dosimetry uncertainty of measurement in estimating external radiotherapy dose. The investigation established that the largest contributor of uncertainty is the stability of the ionization chamber at 36%, followed by temperature at 22% and positioning of the chamber in the beam at 8%. The effect of pressure, electrometer, resolution, and reproducibility were found to be minimal to the overall uncertainty. The study indicate that there is no flawless measurement, as there are many prospective sources of variation. Measurement results have component of unreliability and should be regarded as best estimates of the true value. .

Laser Measurement and Intensity Evaluation of Intake Swirl in Engine Using a Water Analog

The intake swirl in the cylinder was induced by a swirler which was fixed in one of two intake ports. In order to understand the characteristics of the intake swirl, a transparent water analog was designed which simulated 150 type single cylinder engine. At the same time, the particle image velocimetry was used to measure the flow fields induced by various swirlers in the analog. After measurement, a new method was presented to evaluate the intensity of the intake swirl. Then, when the measured sections, the lifts of valve and the swirlers were different, the calculated results of the flow field were compared.

Cause of over Water Quality Standard and Control Measures of State-controlled Sections in Northern Water-deficient Area of Jiangsu

Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology.

Image-based Water Level Measurement Method under Stained Ruler

This paper propoes the water level measuring method based on the image, while the ruler used to indicate the water level is stained. The contamination of the ruler weakens or eliminates many features which are required for the image processing. However, the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features. As the color differeaces are embossed, only the region of the ruler is limited to eliminate the noise, and the average image is produced by using several continuous frames. A histogram is then produced on the height axis of the produced intensity average image. Local peaks and local valleys are detected, and the section between the peak and valley which have the greatest change is looked for. The valley point at this very moment is used to detect the water level. The detected water level is then converted to the actual water level by using the mapping table. The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.

Liquid holdup measurement with double helix capacitance sensor in horizontal oil-water two-phase flow pipes

This paper presents the characteristics of a double helix capacitance sensor for measurement of the liquid holdup in horizontal oil–water two-phase flow. The finite element method is used to calculate the sensitivity field of the sensor in a pipe with 20 mm inner diameter and the effect of sensor geometry on the distribution of sensitivity field is presented. Then, a horizontal oil–water two-phase flow experiment is carried out to measure the response of the double helix capacitance sensor, in which a novel method is proposed to calibrate the liquid holdup based on three pairs of parallel-wire capacitance probes. The performance of the sensor is analyzed in terms of the flow structures detected by mini-conductance array probes.

A modified soil water content measurement technique using actively heated fiber optic sensor

Soil water content measurement is critical in practical engineering.The actively heated fiber Bragg grating optic sensor(FBGS)has great potential of multi-point measurement for soil water content measurement in field.In this study,the effect of heating time on the measurement accuracy is discussed,and modifications are made for actively heated fiber optic(AHFO)sensors.The results demonstrate that if an integration data analysis method is used,the accuracy and reliability of soil water content measurement with AHFO sensors will be improved.Both a short fiber length and a short-term heating pattern are effective and can help to reduce soil disturbance.With the proposed integration method,a short heating time is guaranteed for measuring the soil water content.Such improvements will reduce the thermal disturbance to soil sample and improve the reliability of measurement.

An integrated measurement and modeling methodology for estuarine water quality management

This paper describes research undertaken by the authors to develop an integrated measurement and modeling methodology for water quality management of estuaries. The approach developed utilizes modeling and measurement results in a synergistic manner. Modeling results were initially used to inform the field campaign of appropriate sampling locations and times, and field data were used to develop accurate models. Remote sensing techniques were used to capture data for both model development and model validation. Field surveys were undertaken to provide model initial conditions through data assimilation and determine nutrient fluxes into the model domain. From field data, salinity re- lationships were developed with various water quality parameters, and relationships between chlorophyll a concentrations, transparency, and light attenuation were also developed. These relationships proved to be invaluable in model development, particularly in modeling the growth and decay of chlorophyll a. Cork Harbour, an estuary that regularly experiences summer algal blooms due to anthropogenic sources of nutrients, was used as a case study to develop the methodology. The integration of remote sensing, conventional fieldwork, and modeling is one of the novel aspects of this research and the approach developed has widespread applicability.

Current Situation and Comprehensive Control Measures of Water Environment in the Chaohu Lake

Based on the analysis of current situation of water environment in the Chaohu Lake,general ideas and measures of controlling the water environment were proposed. In respect of control ideas,controlling outbreaks of blue-green algae should be as one of control goals; it is needed to combine reducing the quantity of blue-green algae with decreasing eutrophication level to make the decrease in the quantity of blue-green algae larger than their natural increase until outbreaks of blue-green algae are eliminated; all kinds of techniques should be combined closely,integrated and innovated,and corresponding safeguard measures should be adopted. In respect of control measures,controlling sources of pollution and intercepting pollutants are basic measures,of which improving sewage treatment capacity and standard greatly is a key measure,and actively controlling pollution from large-scale livestock and poultry breeding is one of main measures; rivers polluted heavily should be controlled,and using microorganisms to purify small and moderate rivers can be as one of preferred techniques; blue-green algae should be dredged deeply to reducing their quantity; water should be transferred from the Yangtze River to the Chaohu Lake or the Hauihe River to purify water bodies and increase environmental capacity; reed wetland should be restored on a large scale to increase vegetation coverage from 5% to 20%; dredging should be combined with the elevation of basement of restored reed wetland.

Simulation results of the online tritiated water measurement system

Currently,the liquid scintillation method is widely used to measure the activity of tritiated water in the primary circuit of nuclear power plants,which leads to the continuous production of radioactive waste during measurement.In addition,the real-time activity information of tritiated water cannot be obtained.To solve this problem,herein we present an online tritiated water measurement method based on plastic scintillators that used the optical transport process in the Geant 4 software toolkit to build a model of plastic scintillation detection for tritiated water.Through simulation,the basic geometric dimensions of the detector were determined.In this dimension,using one detector to measure for 3 h,when the tritiated water activity was 100 Bq/L,its resolution was 16%(16 Bq/L).In addition,calculations were performed for the presence of other background signals to obtain the minimum detectable concentration.

Measurement of water holdup in oil-in-water emulsions in wellbores using microwave resonance sensor

In this study,we propose a new method for water holdup measurement of oil-in-water emulsions with a microwave resonance sensor(MRS).The angle and length of the electrode plate are optimized by HFSS simulation software.Using a vector network analyzer(VNA),a static calibration experiment is conducted,and the resonant frequency distribution of oil-in-water emulsions is analyzed within an 80%–100%water holdup range.In addition,we observe and analyze the micron-sized oil bubble structure in the emulsifi ed state with an optical microscope.On this basis,a dynamic experiment of oil-in-water emulsions with high water cut and low velocity in a vertical upward pipe is conducted.S_(21) response curves of the MRS are obtained by the VNA under diff erent working conditions in real time.Finally,we analyze the relationship between the resonant frequency and water cut.Experimental results show that the MRS has an average resolution of 0.096%water cut for high water cut oil-in-water emulsions within the frequency range of 2.2–2.8 GHz.

Soil and water loss in the Lancang River-Mekong River watershed (in Yunnan section, China) and its control measures

According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.

Integrating water use systems and soil and water conservation measures into a hydrological model of an Iranian Wadi system

Water resources are precious in arid and semi-arid areas such as the Wadis of Iran. To sustainably manage these limited water resources, the residents of the Iranian Wadis have been traditionally using several water use systems(WUSs) which affect natural hydrological processes. In this study, WUSs and soil and water conservation measures(SWCMs) were integrated in a hydrological model of the Halilrood Basin in Iran. The Soil and Water Assessment Tool(SWAT) model was used to simulate the hydrological processes between 1993 and 2009 at daily time scale. To assess the importance of WUSs and SWCMs, we compared a model setup without WUSs and SWCMs(Default model) with a model setup with WUSs and SWCMs(WUS-SWCM model). When compared to the observed daily stream flow, the number of acceptable calibration runs as defined by the performance thresholds(Nash-Sutcliffe efficiency(NSE)≥0.68, –25%≤percent bias(PBIAS)≤25% and ratio of standard deviation(RSR)≤0.56) is 177 for the Default model and 1945 for the WUS-SWCM model. Also, the average Kling–Gupta efficiency(KGE) of acceptable calibration runs for the WUS-SWCM model is higher in both calibration and validation periods. When WUSs and SWCMs are implemented, surface runoff(between 30% and 99%) and water yield(between 0 and 18%) decreased in all sub-basins. Moreover, SWCMs lead to a higher contribution of groundwater flow to the channel and compensate for the extracted water by WUSs from the shallow aquifer. In summary, implementing WUSs and SWCMs in the SWAT model enhances model plausibility significantly.

Online dynamic measurement of saturation-capillary pressure relation in sandy medium under water level fluctuation

An online dynamic method based on electrical conductivity probe, tensiometer and datataker was presented to measure saturation-capillary pressure （S-p） relation in water-light nonaqueous phase liquid （LNAPL） two-phase sandy medium under water level fluctuation. Three-electrode electrical conductivity probe （ECP） was used to measure water saturation. Hydrophobic tensiometer was obtained by spraying waterproof material to the ceramic cup of commercially available hydrophilic tensiometer. A couple of hydrophilic tensiometer and hydrophobic tensiometer were used to measure pore water pressure and pore LNAPL pressure of the sandy medium, respectively. All the signals from ECP and tensiometer were collected by a data taker connected with a computer. The results show that this method can finish the measurement of S-R relation of a complete drainage or imbibition process in less than 60 min. It is much more timesaving compared with 10-40 d of traditional methods. Two cycles of water level fluctuation were produced, and four saturation-capillary pressure relations including two stable residual LNAPL saturations of the sandy medium were obtained during in 350 h. The results show that this method has a good durable performance and feasibility in the porous medium with complicated multiphase flow. Although further studies are needed on the signal stability and accuracy drift of the ECP, this online dynamic method can be used successfully in the rapid characterization of a LNAPL migration in porous media.

A policy and technical measures for controlling soil and water loss in the Loess Plateau of China

Loess Plateau is the most serious region of soil and water loss in China and the world. The sediment carried into the Yellow River amounts to 1.6 billion tons every year. This paper reviews the factors and reasons for erosion in this area, and puts forward a comprehensive controlling policy on the basis of the principles of ecology and practise of Chinese scientists for 40 years. In conformity with the policy, a number of technical measures for controlling soil and water loss are suggested.

The Preliminary Study on the Converting Measures between the Four Waters in Wet and Low-lying Farmland

Most of China's wetland areas are located in the Sanjiang Plain.This area has 207×10 4 hm 2 of wet and low lying farmland,of which 59% is cropped.During the 1970s and 1980s,the Chinese government organized intensive scientific research into potential changes to existing natural resources conditions for these farmlands.The aim was to change the water resources regime to one that was beneficial to crop production.Arterial drainage,field drainage and appropriate sub soil treatments were required.The relation between plant products industry and the Four Waters distribution,also the main measures of the Four Waters converting in wet and low lying farmland were discussed in the paper.

Benefit measurement of the soil and water conservation for ecological forestry engineering

Data were collected from Three-north Region, Middle and upper reaches region of Yangtze River and Coastal region. By analysis of factors influencing soil erosion, the longitude, latitude, annual precipitation, and the slope degree were selected as regional independent variables and canopy density and stock litter were selected as independent variables, and integral diffusing models were established for evaluation of the benefit of soil and water conservation of forest. By solving the parameters of models using the package of STATISTICA, the Power function between independent variables and dependent variables was set up. The soil conservation amount of forest and economic values were estimated using the contrast method for the ecological forestry engineering of the above three areas.

Method of Predicting Water Content in Crude Oil Based on Measuring Range Automatic Switching

Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error of water content in crude oil proposed in this paper is based on switching measuring ranges of on-line water content analyzer automatically.Measuring precision on data collected from oil field and analyzed by in-field operators can be impressively improved by using back propogation （BP） neural network to predict water content in output crude oil.Application results show that the difficulty in accurately measuring water-oil content ratio can be solved effectively through this combination of on-line measuring range automatic switching and real time prediction,as this method has been tested repeatedly on-site in oil fields with satisfactory prediction results.

Estimation of Glacier Melt Water Contribution for Human Consumption in the Royal Andes Considering Temperature Measurement Errors

Glaciers from the West side of the Royal Andes are an important source of fresh water for some of the most important Bolivian cities like El Alto. Temperature is an important datum for hydrological modelling and for glacier melt estimation. All temperature measurement devices have some degree of uncertainty due to systematic errors;thus, any temperature measurement has some errors. It is important to estimate the influence of such errors on the results from hydrological models and the estimation of melt water. The present study estimates the melt water contribution from the glaciers Tuni and Huayna West as a source of water supply for human consumption of El Alto considering the errors from temperature measurements. The hydrologic response of the basins was simulated with a hydrologic model. The glacier melt contribution was estimated as the difference between the discharge from the current scenario (with glaciers) and the discharge from a scenario without glaciers. Several volumes of melt water were estimated considering the temperature measurement and its possible errors. The uncertainty of such melt water volume was addressed by performing a Monte Carlo analysis of the possible melt water. The melt water contribution from glacier Tuni and Huayna West during the hydrologic year 2011-2012 was between 1.37 × 106 m3 and 1.72 × 106 m3. Such water volume is enough to meet the yearly water demand of between 6.81% and 8.55% of El Alto.