Gray comprehensive assessment and optimal selection of water consumption forecasting model

A comprehensive assessing method based on the principle of the gray system theory and gray relational grade analysis was put forward to optimize water consumption forecasting models. The method provides a better accuracy for the assessment and the optimal selection of the water consumption forecasting models. The results show that the forecasting model built on this comprehensive assessing method presents better self-adaptability and accuracy in forecasting.

Gray Water Measurement and Feasibility of Retrieval Using Innovative Technology and Application in Water Resources Management in Isfahan-Iran

Reuse of wastewater for agriculture and green spaces purposes is significant.A mean yearly precipitation in Esfahan is 150 mm.The drinking water and agriculture usually used underground resources in the city.Gray water recycling is known as a suitable option today.Delivering all the water requirements of a home from refined water rises the cost of water.Whereas the essential water quality for garden,toilet and irrigation is less than drinking water.Therefore,the aim of this study is to analyze the evaluation of gray water and estimate the amount of recycle gray water which can use for drinking water with innovation method in Esfahan region in Iran.Previous studies did not measure the value of recycling gray water with new method of waste water treatment that can use for drinking purpose.In this study,gray water in Esfahan city is measured and technical aspects of its recycling is examined.Because of the lack of referable guidelines and official technical reports,studies from other similar countries applied in this study and on the basis of which the amount of recoverable gray water was calculated.Evaluations indicates that the overall recovery of gray water in Esfahan saves nine million cubic meters of water.The price of the rial of this value established on water is 190 billion Rials.Given the lack of water sources in Esfahan,the recycle of gray water seems to be a good option,however more research is required to select a recovery strategy.

Evaluation of Farmland Drainage Water Quality by Fuzzy–Gray Combination Method

The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.

Analysis of Gray Water Recycling by Reuse of Industrial Waste Water for Agricultural and Irrigation Purposes

Isfahan industrial province with its numerous industrial estates in its area and consequently the amount of wastewater produced by these settlements is very difficult to deal with.Therefore,the need for proper wastewater treatment and efficient management of industrial waste water from the industrial estates of this province should be seriously addressed and followed up by the authorities.The purpose of this study is the feasibility of reuse of wastewater from industrial settlements for agricultural and irrigation purposes.The present study is a descriptive cross-sectional study.In this study,the average values obtained from the sampling and the results of the experiments on waste water from the industrial waste water treatment plant in Isfahan,2017,have been used.Average values of BOD5,COD,TSS and so on were compared with the standards set by the Environmental Protection Agency and analyzed in Excel software.According to the results,the average values of COD,BOD5,TSS,SO4,pH and catalyst quality parameters were determined from wastewater effluents of 315,162,93,164(mg/L),8.3 and 32.5(NTU)respectively.The results of the study show that the average values of the quality parameters examined from the effluent of the treatment plant other than BOD5 and COD are within the standard range and the limit for agricultural and irrigation purposes,which may lead to undesirable environmental performance of these two parameters.

Assessment on the Water Resources Carrying Capacity in Karst Area Based on the Cosine Vector Included Angle

[Objective] The research aimed to assess the water resources carrying capacity in Guizhou Province based on the cosine vector included angle method. [Method] By using the cosine vector included angle method, the index weight was determined. The projection value of water resources carrying capacity in Guizhou Province was counted by using the multi-objective gray relational projection method. Moreover, the projection value which was counted by the index weight determined by the mean-variance method was as the control. [Result] The projection values which were obtained by two kinds of methods were very close, and the ordering result was consistent. [Conclusion] In the assessment of water resources carrying capacity, it was feasible to use the cosine vector included angle method to determine the index weight.

Influential Factors of Water Productivity of Maize in Oasis of Arid Areas——A Case Study of Linze County

[Objective] The aim was to research influential factors of water productivity of maize in oasis in arid areas. [Method] In middle reach of Heihe River in Linze County of Zhangye City, maize, a major crop in irrigated area in the oasis, was studied and nine influential factors were chosen through grey relation analysis. [Result] According to grey relation analysis, top five factors influencing water produc- tivity of maize during 1995-2009 were as follows： applied quantity of chemical fertil- izers〉labour input〉seeds〉mulch amount〉pesticide amount, which indicated that controllable factors, instead of uncontrollable ones, dominate in influence of water productivity of maize in oasis in arid areas. [Conclusion] With water resource limited, investment of controllable factors in high-efficient agricultural production should be the major strategy to improve water productivity of maize in oasis of arid areas.

Quantitative Study on the Relationship between Water Disaster and Grain Production of Hubei Province in the 1990s

The research explored variation coefficient of grains and analyzed the fluctuations of grains in Hubei in the 1990s in order to investigate quantitative cor- relation between grain production and water-related disaster. The conclusion is that the effective irrigated area and growing structure are major factors influencing grain production capacity, whose grey relational degrees were 0.91 and 0.85 with grain production, respectively. These indicated that water-related disasters have significant effects on grain yield in Hubei Province.

Water Status in Baghdad

Water is a strategically limited natural resource, and currently Iraq is in the grip of an extended drought period. It is needed to look for alternative water sources and work towards achieving high level of sustainability. Measurements for gray water samples were carried out including pH, EC （electrical conductivity）, TDS （total dissolved solids）, TS （total solids）, TSS （total suspended solids）, DO （dissolved oxygen）, BOD5 （biochemical oxygen demand）, COD （chemical oxygen demand）, alkalinity, chlorides （Cl）, calcium （Ca）, sodium （Na）, magnesium （Mg）, potassium （K）, lead （Pb）, TC （total coliforms）, TF （total fecal coliforms）, and nitrate （NO3）. The goals of this study are to estimate quantities of fresh water consumption and gray water generated in typical Baghdadian households, and to investigate gray water quality （physical, chemical and biological）. The major results can be summarized as follows： （1） The daily water consumption in Baghdad ranged from 75 Lpcd to 176 Lpcd with an average of 116 Lpcd; （2） the maximum daily consumption in Baghdad ranged from 124 Lpcd to 327 Lpcd with an average of 186 Lpcd; （3） the maximum hourly consumption in Baghdad ranged from 154 Lpcd to 900 Lpcd with an average of 308 Lpcd; （4） gray water generation in Baghdad ranged from 34 Lpcd to 139 Lpcd with an average of 68 Lpcd, and that gray water generated constituted 58% to 72% of total consumption.

Study on Entropy Weight Coefficient Method and Application for Water Quality Evaluation

In order to evaluate the quality of water environment, the conception of entropy is applied in information science, and the entropy weight model is built to evaluate comprehensively water quality. The indexes weights of water quality are determined by value of entropy. This kind of method is applied on evaluating water quality in the new water to be built. The result shows that the water quality in it which supply water is between grade Ⅲ and Ⅳ, and the result is similar to that of gray related method.

A method of remote sensing image water segmentation based on adaptive morphological elliptical structuring elements

The use of visible and infrared remote sensing images to calculate the water area is an effective means to grasp the basic situation of water resources,and water segmentation is the premise of statistics.Generally,the edge features of the water in the remote sensing images are complex.When the traditional morphology is used for image segmentation,it is easy to change the image edge and affect the accuracy of image segmentation because the fixed structuring elements are used to perform morphological operations on the image.To segment water in the remote sensing image accurately,a remote sensing image water segmentation method based on adaptive morphological elliptical structuring elements is proposed.Firstly,the eigenvalue and eigenvector of the image are estimated by linear structure tensor,and the elliptical structuring elements are constructed by the eigenvalue and eigenvector.Then adaptive morphological operations are defined,combining the close operation to eliminate the influence of dark detail noise on water without overstretching the water edge,so that the water edge can be maintained more accurately.Finally,on this basis,the water area can be segmented by gray slice.The experimental results show that the proposed method has higher segmentation accuracy and the average segmentation error is less than 1.43%.

Influencing Factors of Fabric-Skin Adhesion Based on Gray Correlation Analysis Method

Fabric-skin adhesion was objectively described by the indices of the maximum adhesion force F_(max) , the maximum separation distance L_(max) ,and adhesion work W as well as the adhesion force-separation distance curve. Firstly,gray correlation analysis method was adopted to investigate the correlation levels between adhesion indices,and secondly the relative importance of fabric structural parameters to fabric-skin adhesion,as well as the correlation levels between skin adhesion, water absorption, and wicking properties of the fabric. The results prove that W exhibits clear correlations with both F_(max) and L_(max) , yet the relevance between F_(max) and L_(max) is weak. Fabric adhesion indices are most associated with fabric mass and least with fabric thickness,whereas fabric wicking and water absorption present closest correlation with fabric thickness. Therefore, it is concluded that the relevance between fabric wicking, water absorption, and skin-adhesion properties are rather comprehensive than straight.

Application of Combined Prediction Model in Predicting Total Water Consumption in Ningxia

The gray GM( 1,1) prediction model and Logistic equation gray prediction model were established separately,and then the combined prediction model was established. Taking the water consumption in Ningxia Hui Autonomous Region from 2006 to 2012 as modeling data,the total water consumption of the whole region of Ningxia in 2018-2020 was analyzed and predicted. The results show that the accuracy of the three prediction models meets the accuracy requirements,but the gray GM( 1,1) and combined prediction models better conform to the actual situation and have better applicability.

Integrated Water Resources Carrying Capacity in Tongzhou District,Beijing City

目前,通州区已被定为北京市的新的发展中心,但水资源短缺和污染已经严重限制了当地的可持续发展。本文以可持续发展为原则,基于"自然—社会"水循环,提出了通州区水资源综合承载力量化模型。根据通州区的未来发展规划,设计了3种情景来提高该地区的水资源综合承载力。研究表明水资源短缺严重制约了通州区的城市化进程和可持续发展,外调水、本地区节水和控制污染是解决通州区水资源短缺的有效途径。

Effects of regulated deficit irrigation on soil salinity,physiological processes and fruit quality of gray jujube under desert conditions

Regulated deficit irrigation(RDI)was applied to gray jujube trees in an oasis region,to determine the effects of this irrigation system on soil salinity,gray jujube physiological processes,fruit yield,and fruit quality.Treatments consisted of severe,moderate and low deficit irrigation(irrigated with 85%,70%and 55%of CK,respectively)at the flowering stage to fruit set stage.During the other growth stages,all treatments were irrigated with 80%of pan evaporation,which was the same as that in control.The results indicated that soil salinity was enhanced during the periods of water stress,but the high value of soil salinity declined by 3.48%-37.27%,at each depth,after irrigation was resumed.RDI caused a decline in the photosynthetic rate,transpiration rate,and stomatal conductance,but enhanced the water use efficiency of the leaves.However,the leaf photosynthetic rate was effectively enhanced after the recovery of irrigation,especially in the moderate deficit irrigation treatment,which exceeded the control.This led to an improved fruit yield,which was 9.57%higher than that of the control.The deficit treatments caused a significant increase in the soluble solid content,soluble sugar content,single fruit weight and sugar/acid ratio.Enhanced vitamin C content,resulting from deficit treatments,has also been observed in the gray jujube.Therefore,this research shows that RDI provides some benefits in the production of gray jujube trees in desert conditions.