Ecological Remediation Technology of Urban Landscape Water Body

Urban landscape water body is not only an important part of urban landscape construction,but also an important way to maintain landscape diversity and biodiversity,carrying the beautiful yearning of urban residents for natural life.A good state of urban landscape water body is crucial to the ecological environment of the city.However,due to the poor kinetic energy of urban landscape water body and the influence of various human factors,the quality of urban landscape water body often declines,and urban population is threatened by water security problems.Through the study of several water body ecological remediation technologies,relevant suggestions are put forward,in order to provide a reference for water pollution restoration and treatment in urban human settlement environment.

Extracting water body data based on SDWI and threshold segmentation:A case study in permafrost area surrounding Salt Lake in Hoh Xil,Qinghai-Tibet Plateau,China

There are a large number of lakes,rivers,and other natural water bodies distributed in the permafrost area of the Qinghai-Tibet Plateau(QTP).The changes in water bodies will affect the distribution of water resources in sur-rounding areas and downstream areas,resulting in environmental impact and bringing potential flood disasters,which will induce more serious issues and problems in alpine and high-altitude areas with a fragile habitat(such as the QTP in China).Generally,effective,reasonable,and scientific monitoring of large-scale water bodies can not only document the changes in water bodies intuitively,but also provide important theoretical reference for subsequent environmental impact prediction,and disaster prevention and mitigation in due course of time.The large-scale water extraction technology derived from the optical remote sensing(RS)image is seriously affected by clouds,bringing about large differences among the extracted water result products.Synthetic aperture radar(SAR)RS technology has the unique advantage characteristics of all-weather,all-day,strong penetration,and not being affected by clouds,which is hopeful in extracting water body data,especially for days with cloudy weather.The data extraction of large-scale water bodies based on SAR images can effectively avoid the errors caused by clouds that become prevalent at present.In this paper,the Hoh Xil Salt Lake on the QTP and its surrounding five lakes are taken as the research objects.The 2-scene Sentinel-1 SAR image data covering the whole area on 22 August 2022 was used to verify the feasibility of extracting water body data in permafrost zones.Furthermore,on 22 August 2022,the wealth here was cloudy,which made the optical RS images,e.g.,Sentinel-2 images full of clouds.The results show that:using the Sentinel-1 image and threshold segmentation method to extract water body data is efficient and effective with excellent results in permafrost areas.Concretely,the Sentinel-1 dual-polarized water index(SDWI),calculated by combining dual vertical–vertical(VV)polarized and verti-cal–horizontal(VH)polarized data is a useful index for water extraction and the result is better than each of the VV or VH polarized images.

Monitoring Surface Water Change in Northeast China in 1999–2020:Evidence from Satellite Observation and Refined Classification

As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable development.However,the long-term variation characteristics of surface water of different water body types in Northeast China remain rarely explored.This study investigated how surface water bodies of different types(e.g.,lake,reservoir,river,coastal aquaculture,marsh wetland,ephemeral water) changed during1999–2020 in Northeast China based on various remote sensing-based datasets.The results showed that surface water in Northeast China grew dramatically in the past two decades,with an equivalent area increasing from 24 394 km^(2) in 1999 to 34 595 km^(2) in 2020.The surge of ephemeral water is the primary driver of surface water expansion,which could ascribe to shifted precipitation pattern.Marsh wetlands,rivers,and reservoirs experienced a similar trend,with an approximate 20% increase at the interdecadal scale.By contrast,coastal aquacultures and natural lakes remain relatively stable.This study is expected to provide a more comprehensive investigation of the surface water variability in Northeast China and has important practical significance for the scientific management of different types of surface water.

Quantitative Evaluation of Heavy Metal Pollution and Its Influencing Factors in Water Bodies of Karst Areas

At present, there is relatively little research on the synergistic effects of heavy metals in soil, sediment, and bedrock on heavy metal pollution in water bodies. In this paper, heavy metals in soil, sediment, bedrock, and water of a typical karst watershed in southwest China were investigated. The results indicated that the average values of heavy metals in soil and sediment were relatively higher than those in bedrock except for Ni and As. During the research period, As and Cd were the main heavy metal elements polluting the soil and sediment in the study area, while water bodies were mainly polluted by Ni, As, and Cd. The pollution assessment indicated that there were instances of poor or very poor water quality in the study area during the study period;the soil as a whole was slightly polluted by Cd and As;sediment was subject to moderate Cd pollution and mild As pollution. Analysis of geochemical form for heavy metals showed that heavy metals in soil and sediment were mainly in residual form, and the proportions of exchangeable As and Cd were relatively high. Multiple statistical analysis showed that heavy metals in sediment, soil, and bedrock explained 23.8%, 16.8%, and 16.2% of the changes in heavy metals of water, respectively. The research results can provide scientific basis for the prevention and control of heavy metal pollution in water bodies.

Fractionation mechanism of stable isotope in evaporating water body

Under Rayleigh equilibrium condition, stable isotopic ratio in residual water increases with the decrease of the residual water proportion f exponentially, and the fractionation rate of stable isotopes is inversely proportional to temperature. However, under kinetic evaporation condition, the fi＇actionation of stable isotopes is not only related to the phase temperature but also influenced by the atmospheric humidity and the mass exchange between liquid and vapor phases. The ratio 6 in residual water will not change with f after undergoing evaporation of a long time for great relative humidity. The rate that the evaporating water body reaches isotopic steady state is mainly dependent on the relative humidity in atmosphere. The analysis shows that the actual mean linear variety rates, about -30.0, of the δ^18O in residual water versus the residual water proportion at Nagqu and Amdo stations are consistent with the simulated process under temperature of 20℃ and relative humidity of 50%. The distillation line simulated under Rayleigh equilibrium condition is analogous to the global meteoric water line （MWL） as the temperature is about 20℃. Under non-equilibrium condition, the slope and constant values of distillation line are directly proportional to temperature and relative humidity. According to the basic data, the simulated distillation line is very consistent with the actual distillation line of Qinghai Lake.

Landscape pattern dynamics of water body in Kaifeng city in the 20th century

Landscape spatial pattern mainly refers to the distribution of patches, which are different in size and shape in space owing to the interaction of various ecological activities. In landscape ecology study, landscape pattern has been one of the key study areas. Water body landscape plays an important role in the development history of a city, but at present city water body landscape in many cities has been destroyed, hence protecting water body in the city is becoming more and more important. In order to protect city water body landscape reasonably, the precondition is to probe the dynamics of water body landscape. Based on historical data and remote sensing data, six indexes including patch number, patch area, landscape dominance index, fractal dimension, patch density and connectivity index etc. were used to analyze landscape pattern dynamics of water body in Kaifeng city since the end of the Qing Dynasty (in the 20th century). The results showed: (1) Since the end of the Qing Dynasty, landscape area of water body in Kaifeng city increased first and then decreased from 1898 to 2002AD; the landscape dominant degree had the same changing tendency with the area. (2) Patch number of water body landscape in Kaifeng city had an increase from 1898 to 2002, but maximum area of patch, minimum area of patch and average area of patch decreased, which resulted in an increase in landscape fragment degree. (3) Connectivity index decreased and fractal dimension increased from 1898 to 2002. The reasons for these changes were the repeated overflows and flooding of the Yellow River and the influence of human activities.

Mechanism of combination membrane and electro-winning process on treatment and remediation of Cu^(2+) polluted water body

Mechanism of treatment and remediation of synthetic Cu^2＋ polluted water body by membrane and electro-winning combination process was investigated.The influences of electrolysis voltage,pH,and electrolysis time on the metal recovery effciencies were studied.Relationship between trans-membrane pressure drop（△P）,additions ratio,initial Cu^2＋ concentration on operating effciency,stability of membrane and the possibility of water reuse were also investigated.The morphology of membrane and electrodes were observed using scanning electron microscopy（SEM）,the composition of surface deposits was ascertained using combined energy dispersive X-ray spectroscopy（EDX） and atomic absorption spectrophotometer.The results showed that using low pressure reverse osmosis（LPRO）,Cu^2＋ concentration could increase from 20 to 100 mg/L or even higher in concentrated solutions and permeate water conductivity could be less than 20 μS/cm.The addition of sodium dodecy/sulfate sodium dodecyl sulfate improved Cu^2＋ removal effciency,while EDTA had little side influence.In electro-reduction process,using plante electrode cell,Cu^2＋ concentration could be further reduced to 5 mg/L,and the average current effciency ranged from 9% to 40%.Using 3D electrolysis treatment,Cu^2＋ concentration could be reduced to 0.5 mg/L with a current effciency range 60%-70%.

Development of a Model for Water and Heat Exchange Between the Atmosphere and a Water Body

A model for studying the heat and mass exchange between the atmosphere and a water body is developed, in which the phase change process of water freezing in winter and melting in summer and the function of the convective mixing process are taken into consideration. The model uses enthalpy rather than temperature as the predictive variable. It helps to set up governing equations more concisely, to deal with the phase change process more easily, and make the numerical scheme simpler. The model is verified by observed data from Lake Kinneret for a non-frozen lake in summer time, and Lake Lower Two Medicine for a frozen lake in winter time. Reasonably good agreements between the model simulations and observed data indicate that the model can serve as a component for a water body in a land surface model. In order to more efficiently apply the scheme in a climate system model, a sensitivity study of various division schemes with less layers in the vertical direction in the water body is conducted. The results of the study show that the division with around 10 vertical layers could produce a prediction accuracy that is comparable to the fine division with around 40 layers.

Automated Extraction for Water Bodies Using New Water Index from Landsat 8 OLI Images

The extraction of water bodies is essential for monitoring water resources,ecosystem services and the hydrological cycle,so analyzing water bodies from remote sensing images is necessary.The water index is designed to highlight water bodies in remote sensing images.We employ a new water index and digital image processing technology to extract water bodies automatically and accurately from Landsat 8 OLI images.Firstly,we preprocess Landsat 8 OLI images with radiometric calibration and atmospheric correction.Subsequently,we apply KT transformation,LBV transformation,AWEI nsh,and HIS transformation to the preprocessed image to calculate a new water index.Then,we perform linear feature enhancement and improve the local adaptive threshold segmentation method to extract small water bodies accurately.Meanwhile,we employ morphological enhancement and improve the local adaptive threshold segmentation method to extract large water bodies.Finally,we combine small and large water bodies to get complete water bodies.Compared with other traditional methods,our method has apparent advantages in water extraction,particularly in the extraction of small water bodies.

THE SUDDEN STARTING OF A FLOATING BODY IN DEEP WATER

This paper applies Lagrangian method to discuss the sudden starting of a floating hotly in deep water and the analytical'solutions are obtained. It is known from the numerical results that the disturbing domain extends and the dynamic pressure also increases when the breadth of the floating body keeps constant and its depth increases.

Stable isotopes and body composition in children: History, fundamentals, and clinical applications

The aim of this study was to gather information on the use of stable isotopes to measure total body water and body composition scan in children. We selected studies in the last 13 years, in addition to classical studies on the subject, indexed in the database PubMed, LILACS, BVS and SciELO. The body composition was characterized by the amount of bone tissue, muscle and adipose tissue, also including the organs as well as levels of body water. Your knowledge becomes increasingly important in light of the changes that occur in the nutritional status of various types of diseases in frameworks, such as diabetes mellitus, protein energy malnutrition, in cases of obesity and metabolic syndrome. The ability to accurately assess body fat mass especially in children is associated with the importance of effective strategies for prevention and treatment of childhood obesity. Historically, in addition to clinical applications, measurements of total body water were used to determine body composition in nutritional studies. To the knowledge of the body composition, the body water can be measured and used by the ingestion of a dose of labeled water. The measured isotope enrichment is a function of the amount of body water. The method of deuterium is particularly interesting for the assessment of body composition in children, due to its characteristics of collection and analysis.

Pollution control of urban black-odor water bodies

On the basis of on-the-spot investigation, the causes of urban black-odor water bodies and the problems existing in the treatment are analyzed, and the control techniques and management countermeasures for black-odor water bodies were put forward. The countermeasures include: treating from both the roots and the symptoms and combining multiple technologies; comprehensively managing and improve the monitoring systems; coordinating functions and implementing long-term management; opening information and innovating supervision platform; coordinating advance and promoting the construction of sponge city; diversified financing to form the market-oriented model of water pollution control.

Advances in Methods of Surface Water Extraction Based on MODIS Data

In recent years,remote sensing technology has been widely used to distinguish and extract water body information on the surface of land,investigate and analyze surface water resources,monitor and study ecological environment,monitor and assess floods. Remote sensing data provided by MODIS sensor carried on satellites in the United States Earth Observation System（ EOS） have high spatial and temporal resolution and spectral resolution,and images have a wide coverage range and are available for free. Moreover,they can be used for dynamic monitoring of changes in water body area on the earth quickly and efficiently. In this study,based on the analysis of spectral characteristics of water body,the characteristics of MODIS data and the methods of surface water extraction were introduced,and the advantages and disadvantages of various methods of water body extraction were analyzed by the comparison between the practical application effects of these methods.

Study on Development Law of Complex Fluvial Reservoir under Water

The Bozhong oilfield (Hereinafter referred to as BZ oilfield) is a typical representative of complex fluvial reservoirs in the Bohai Sea, located in the southern Bohai Sea, with an average porosity of 30.3% and an average permeability of 643 × 10-3 μm2, belonging to medium high porosity and permeability reservoir, the reservoir has good connectivity, and the average underground crude oil viscosity is 5 mPa·s. There are many plane fault blocks, and the longitudinal oil well section is long, so the oil-water relationship is very complex. With the further development of the oilfield, the vertical and horizontal oil-water movement law, residual oil distribution and potential are unclear, resulting in rapid bottom water coning, unbalanced injection and production in the oilfield, and increasingly prominent contradictions among layers, planes and layers in the oilfield. Through numerical simulation analysis and comparison of displacement law and recovery degree under different influence conditions, this paper studies the development effect of actual sand body under different influence conditions such as different well types, different development methods and well layout positions, and takes appropriate development methods for the oilfield, which is of great significance to improve the development effect of the oilfield.

Diversity and Adaptations of Immature Diptera in Semiaquatic Habitats at Shorelines of Hypersaline Lakes in the Crimea,with a Brief Review of Diptera in Mineralized Bodies of Water

The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in

Water Quality and Agricultural Sustainability in the Mantiqueira Ecological Corridor,Brazil

The presence of fecal coliforms is one of the determinants for classification of the quality of water bodies. The aim of this study was to evaluate the relationship between the water quality and surrounding land use in the area known as the Mantiqueira Ecological Corridor, which straddles the borders of the states of Sao Paulo, Rio de Janeiro and Minas Gerais, in Brazil. More particularly, we studied ten municipalities in Minas Gerais located in the region surrounding Serra do Papagaio State Park and Ibitipoca State Park. We established a classification of water bodies in the area surrounding the collection points in drainage basins based on the principles of sustainability. Using TM/Landsat 5 images, SPOTMap mosaics and the SRTM digital elevation model, we correlated land use classes with the environmental contamination index and topographic characteristics of the area studied. The presence of agriculture and urban areas heightened the differences in water quality classification in the comparison between the dry and rainy seasons, while in forested areas there was a greater equilibrium, with the same classification between the two seasons.

An Assessment of Land Cover Change in Gashaka-Gumti National Park, Nigeria

The paper assessed the land cover change in Gashaka-Gumti National Park between 1991 and 2021. To achieve this, LandSat data of years 1991, 2001, 2011 and 2021 were obtained from the United States Geological Survey online resource. The findings of the study revealed that there is decrease in the different land cover types over time as a result of anthropogenic activities of the enclave dwellers. The study observed that the continuous existence of enclaves within and around the Park constitutes a serious threat to the survival of the Park. The study recommended that the federal government should consider resettlement of the enclave dwellers to give way for the development of the Park.

Climate effects on an inland alpine lake in Xinjiang, China over the past 40 years

Inland lakes are important water resources in arid and semiarid regions. Understanding climate effects on these lakes is critical to accurately evaluate the dynamic changes of water resources. This study focused on the changes in Sayram Lake of Xinjiang, China, and addressed the effects of climate fluctuations on the inland lake based on long-term sequenced remote sensing images and meteorological data from the past 40 years. A geo- graphic information system （GIS） method was used to obtain the hypsometry of the basin area of Sayram Lake, and estimation methods for evaporation from rising temperature and water levels from increasing precipitation were proposed. Results showed that： （1）Areal values of Sayram Lake have increased over the past 40 years. （2） Both temperature and precipitation have increased with average increases of more than 1.8~C and 82 mm, respectively. Variation of the water levels in the lake was consistent with local climate changes, and the areal values show linear relationships with local temperature and precipitation data. （3） According to the hypsometry data of the basin area, the estimated lake water levels increased by 2.8 m, and the water volume increased by 12.9×108 m3 over the past 40 years. The increasing area of Sayram Lake correlated with local and regional climatic changes because it is hardly affected by human activities.

FWENet:a deep convolutional neural network for flood water body extraction based on SAR images

As one of the most severe natural disasters in the world,floods caused substantial economic losses and casualties every year.Timely and accurate acquisition of flood inundation extent could provide technical support for relevant departments in the field of flood emergency response and disaster relief.Given the accuracy of existing research works extracting flood inundation extent based on Synthetic Aperture Radar(SAR)images and deep learning methods is relatively low,this study utilized Sentinel-1 SAR images as the data source and proposed a novel model named flood water body extraction convolutional neural network(FWENet)for flood information extraction.Then three classical semantic segmentation models(UNet,Deeplab v3 and UNet++)and two traditional water body extraction methods(Otsu global thresholding method and Object-Oriented method)were compared with the FWENet model.Furthermore,this paper analyzed the water body area change situations of Poyang Lake.The main results of this paper were as follows:Compared with other five water body extraction methods,the FWENet model achieved the highest water body extraction accuracy,its F1 score and mean intersection over union(mIoU)were 0.9871 and 0.9808,respectively.This study could guarantee the subsequent research on flood extraction based on SAR images.

Three-Dimension Mathematical Model of Total Phosphor in the Reservoir and Application

Taking the transport of total phosphor pollutants in the Beijing Miyun reservoir for example,we have obtained three dimensional distributing regularity of total phosphor pollutants by the calculation of the linear interpolation value of each point between horizontal layers. The credibility analysis in allusion to this method was carried out and the programming scheme for realizing this method was set forth.