Exploring the combination of biochar‐amended soil and automated irrigation technology for water regulation and preservation in green infrastructure

Biochar is a carbon sink material with the potential to improve water retention in various soils.However,for the long‐term maintenance of green infrastructure,there is an additional need to regulate the water contents in the covers to maintain vegetation growth in semiarid conditions.In this study,biochar‐amended soil was combined with subsurface drip irrigation,and the water preservation characteristics of this treatment were investigated through a series of one‐dimensional soil column tests.To ascertain the best treatment method specific to semiarid climatic conditions,the test soil was amended with 0%,1%,3%,and 5%biochar.Automatic irrigation devices equipped with soil moisture sensors were used to control the subsurface water content with the aim of enhancing vegetation growth.Each soil column test lasted 150 h,during which the volumetric water contents and soil suction data were recorded.The experimental results reveal that the soil specimen amended with 3%biochar is the most water‐saving regardless of the time cost.Soil with a higher biochar content(e.g.,5%)consumes a more significant amount of water due to the enhancement of the water‐holding capacity.Based on the experimental results,it can be concluded that the appropriate ratio can be determined within 1%–3%,which can reduce not only the amount of irrigated/used water but also the time cost.Such technology can be explored for water content regulation in green infrastructure and the development of barriers for protecting the environment around deep underground waste containment.

Contract Mechanism of Water Environment Regulation for Small and Medium Sized Enterprises Based on Optimal Control Theory

The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.

Using Rn-222 to Study Human-Regulated River Water-Sediment Input Event in the Estuary

The implementation of the water sediment regulation scheme(WSRS)is a typical example of artificially controlling land-source input.During WSRS,the water discharge of the Yellow River will increase significantly,and so will the input of terri-genous materials.In this study,we used a natural geochemical tracer 222Rn to quantify terrestrial inputs under the influence of the 2014 WSRS in the Yellow River Estuary.The results indicated that during WSRS the concentration of 222Rn in the estuary increased by about four times than in the period before WSRS.The high-level 222Rn plume disappeared quickly after WSRS,indicating that 222Rn has a very short‘memory effect’in the estuary.Based on the investigation conducted from 2015 to 2016,the concentration of 222Rn tended to be stable in the lower reaches of the Yellow River.During WSRS,the concentrations of 222Rn in the river water in-creased sharply at about 3–5 times greater than in the non-WSRS period.Based on the 222Rn mass balance model,the fluxes of 222Rn caused by submarine groundwater discharge(SGD)were estimated to be(3.5±1.7)×10^(3),(11±3.9)×10^(3),and(5.2±1.9)×10^(3)dpm m^(-2)d^(-1)in the periods before,during,and after WSRS,respectively.This finding indicated that SGD was the major source of 222Rn in the Yellow River Estuary,which can be significantly increased during WSRS.Furthermore,the SGD-associated nutrient fluxes were estimated to be 9.8×10^(3),2.5×102,and 1.1×10^(4)μmolm^(-2)d^(-1)for dissolved inorganic nitrogen,phosphorus,and silicon,respectively,during WSRS or about 2–40 times greater than during the non-WSRS period.

Recent advances in elaborate interface regulation of BiVO_(4)photoanode for photoelectrochemical water splitting

Bismuth vanadate(BiVO_(4))is an excellent photoanode material for photoelectrochemical(PEC)water splitting system,possessing high theoretical photoelectrocatalytic conversion efficiency.However,the actual PEC activity and stability of BiVO_(4)are faced with great challenges due to factors such as severe charge recombination and slow water oxidation kinetics at the interface.Therefore,various interface regulation strategies have been adopted to optimize the BiVO_(4)photoanode.This review provides an in-depth analysis for the mechanism of interface regulation strategies from the perspective of factors affecting the PEC performance of BiVO_(4)photoanodes.These interface regulation strategies improve the PEC performance of BiVO_(4)photoanode by promoting charge separation and transfer,accelerating interfacial reaction kinetics,and enhancing stability.The research on the interface regulation strategies of BiVO_(4)photoanode is of great significance for promoting the development of PEC water splitting technology.At the same time,it also has inspiration for providing new ideas and methods for designing and preparing efficient and stable catalytic materials.

Brazilian’s Legal Framework and Water Regulation

The legal framework of water regulation can assume different characteristics according to each country’s reality.The preservation and conservation of water and ecosystems depend on rules configuration in the Constitution and legal prescriptions.This manuscript presents the Brazilian legal framework and water regulation.The analysis confirms that in the Brazilian system water is regulated as environmental resource and environmental good.From a descriptive methodology,the article explains how the Brazilian legal system works.The article also remarks on the regulation of multiple uses of water,approaching the legal regulation among industrial,agricultural,and human consumption of water.The aim of the paper is to explain normative regulation of water in Brazil,including the court’s activities in cases of discharges of sewage directly into the rivers.

SOIL SALINITY CONTROI,REGARDING SUBSURFACE WATER REGULATION IN NORTH CHINA PLAIN

The North China Plain (NCP) lying along the eastern coastal area withgeogriaphical coordinates 100°to 120°and 30° to 40°W, is one of the mostimportan agncultural ngons in China. A problem in soil salmization has beenfound in vast areas along the lower reaches of the Yellow hiver and north of it. After30 years of work on saline soil amelioration, 2.0 million ha has been improved,accounting for over 60 percen of the total ongnal saline soil area. Ths achievetnenthas ban obtained in close relation to water conservancy work. The author analyzessalthezation amelioration by using measures concerning subsuffoce water regulation.Ih addition to water conservancy measures, thes paper also descnbes acomprehensive way to ameliorate salthezation in northem NCP. Finally, the authorstresses the necessity of combining all measures together into a whole system forsolving salinization problems in northem NCP.

Effects of water application intensity of microsprinkler irrigation on water and salt environment and crop growth in coastal saline soils

Laboratory and field experiments were conducted to investigate the effects of water application intensity（WAI） on soil salinity management and the growth of Festuca arundinacea（festuca） under three stages of water and salt management strategies using microsprinkler irrigation in Hebei Province, North China. The soil water content（è） and salinity of homogeneous coastal saline soils were evaluated under different water application intensities in the laboratory experiment. The results indicated that the WAI of microsprinkler irrigation influenced the è, electrical conductivity（ECe） and p H of saline soils. As the WAI increased, the average values of è and ECe in the 0–40 cm profile also increased, while their average values in the 40–60 cm profile decreased. The p H value also slightly decreased as depth increased, but no significant differences were observed between the different treatments. The time periods of the water redistribution treatments had no obvious effects. Based on the results for è, ECe and p H, a smaller WAI was more desirable. The field experiment was conducted after being considered the results of the technical parameter experiment and evaporation, wind and leaching duration. The field experiment included three stages of water and salt regulation, based on three soil matric potentials（SMP）, in which the SMP at a 20-cm depth below the surface was used to trigger irrigation. The results showed that the microsprinkler irrigation created an appropriate environment for festuca growth through the three stages of water and salt regulation. The low-salinity conditions that occurred at 0–10 cm depth during the first stage（-5 k Pa） continued to expand through the next two stages. The average p H value was less than 8.5. The tiller number of festuca increased as SMP decreased from the first stage to the third stage. After the three stages of water and salt regulation, the highly saline soil gradually changed to a low-saline soil. Overall, based on the salt desalinization, the microsprinkler irrigation and three stages of water and salt regulation could be successfully used to cultivate plants for the reclamation of coastal saline land in North China.

Effect of Water and Sediment Regulation on Lower Yellow River

According to the results of the water and sediment regulations of the Yellow River in year 2002—2007,the effect of erosion and deposition on the lower reaches,the amount and distribution of erosion and deposition in the river mouth area,the adjustment of river regime,the effect of river regulation projects and changes of flowing capacity of the channel are analyzed.It is revealed that the water and sediment regulation is efficient to reduce deposition and improve the flowing capacity and the conditions of sediment transport.

ANALYSIS AND CALCULATION OF REGULATED WATER RESOURCES OF GROUNDWATER RESERVOIR

Groundwater reservoir is a kind of important engineering, which can optimize water resources arran- gement by means of artificial regulation. Regulated water is the blood and value performance of groundwater reservoir. To resolve the problem of real-time quantification of regulated water, the paper analyzed sources and compositions of regulated water in detail. Then, under the conditions of satisfying water demand inside research area, the paper analyzed quantity available and regulation coefficient of different regulated water and established a formula to calculate regulated water. At last, based on a pore groundwater reservoir in the middle reaches of the Yinma River, Jilin Province, the paper calculated regulated water with the formula and the result shows that the method is feasible. With some constraint conditions, the formula can be adopted in other similar areas.

Promoting the production of salinized cotton field by optimizing water and nitrogen use efficiency under drip irrigation

Cotton is the main economically important crop in Xinjiang,China,but soil salinization and shortage of water and nutrients have restricted its production.A field experiment was carried out in the salinity-affected arid area of Northwest China from 2018 to 2019 to explore the effects of nitrogen and water regulation on physiological growth,yield,water and nitrogen use efficiencies,and economic benefit of cotton.The salinity levels were 7.7(SL)and 12.5 dS/m(SM).Drip irrigation was used with low,medium and adequate irrigation levels representing 60%,80%and 100%of cotton crop water demand,respectively,and three nitrogen applications,i.e.,206,275 and 343 kg/hm^(2),accounting for 75%,100%and 125%of local N application,respectively were used.The multi-objective optimization based on spatial analysis showed that,at SL salinity,water use efficiency(WUE),nitrogen use efficiency(NUE),economic benefit and yield simultaneously reached more than 85%of their maxima at 379.18-398.32 mm irrigation and 256.69-308.87 kg/hm^(2).At SM salinity,WUE,yield and economic benefit simultaneously reached more than 85%of their maxima when irrigation was 351.24-376.30 mm and nitrogen application was 230.18-289.89 kg/hm^(2).NUE,yield and economic benefit simultaneously reached their maxima at 428.01-337.72 mm irrigation,and nitrogen application range was 222.14-293.93 kg/hm^(2).The plants at SL salinity had 21.58%-46.59%higher WUE rates,14.91%-34.35%higher NUE rates and 20.71%-35.34%higher yields than those at SM salinity.The results are of great importance for the nutrient and water management in cotton field in the arid saline area.

Mechanism of Photothermal Energy on the Growth and Yield of Rice under Water Level Regulation

The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.

New Developments in Water Efficiency

An overview of significant new developments in water efficiency is presented in this paper. The areas covered will be legislative, regulatory, new programs or program wrinkles, new products, and new studies on the effectiveness of conservation programs. Examples include state and local level efficiency regulations in Texas; the final results of the national submetering study for apartments in the US; the US effort to adopt the IWA protocols for leak detection; new water efficient commercial products such as ET irrigation controllers, new models of efficient clothes washers, and innovative toilet designs.

Response of the distributary channel of the Huanghe River estuary to water and sediment discharge regulation in 2007

The water and sediment discharge regulation （WSDR） project, which has been performed since 2002 before flood season every year, is of great significance to the river management in China. Until 2007, six experiments have been fulfilled to evaluate the effect of the project on the natural environment. To fill the gap of investigations, a study on flood and suspended sediment transportation and channel changing along the distributary channel of the Huanghe （Yellow） River was conducted during the WSDR project period in 2007. The lower channel was scoured rapidly and the channel became unobstructed gradually several days after the flood peak water was discharged from the Xiaolangdi Reservoir. Within four days after the flood peak at 3 000 m3/s entered the distributary, the channel in the river mouth area was eroded quickly. Both the mean values of area and depth of the main channel were tripled, and the maximum flood carrying capacity increased to 5 500 m3/s or more. Then, the river channel was silted anew in a very short time after completion of the WSDR. Favored by the WSDR project, the fiver status in April 2008 became better than that of the year before. The adjustment ranges of main channel parameters were about 30%, 10%, and 10% at sections C2, Q4, and Q7, respectively. The process of rapid erosion-deposition was more active 15 km away in the channel from the fiver mouth due to the marine influence. It is reasonable for discharging sediment at concentration peak from Xiaolangdi Reservoir at the end of the flood peak. As a result, the sediment peak reached the river mouth about two days later than that of the water current. In addition, the WSDR project has improved the development of the estuarine wetland. Wetland vegetation planted along the river banks restrained the water flow as a strainer and improved the main channel stability. It is suggested to draw water at mean rate of 150 m3/s from the Huanghe River during flood periods, because at the rate the water in the wetland would be stored and replenished in balance. Moreover, we believe that cropland on the river shoal of the lower Huanghe River should be replaced by wetland. These activities should achieve the Huanghe River management strategy of ＂To concentrate flow to scour sediment, stabilize the main channel, and regulate water and sediment＂.

Study on the Operation Mechanism and Effect of the Yellow River Water and Sediment Regulation System

In order to scientifically deal with the problems of less water and more sediment in the Yellow River and the uncoordinated relationship between water and sediment,it is necessary to establish a perfect water and sediment regulation system.Through the calculation of the sediment transport capacity of the Yellow River and the application of the water and sediment regulation system,it is found that the sediment transport efficiency of the Yellow River will increase with the increase of water flow,and there will be an obvious inflection point near the flat discharge.The joint regulation of the backbone reservoir group can discharge the large discharge close to the minimum flat discharge of the downstream river,which improves the sediment transport capacity of the river and alleviates the problem of sediment deposition.In this paper,through the introduction of the Yellow River water and sediment regulation project system,regulation indicators and mechanisms,the author discusses in detail the Yellow River water and sediment regulation scheme and its operation effect,hoping to provide help promote the improvement of the Yellow River governance effect.

＂One-for-several＂ rotor VVVF Technique apply to water injection station

In the process of oilfield water injection volume of injection allocation often appear with the pump displacement situation does not match, the widespread adoption of stator frequency technology allows the pump displacement and volume of injection allocation phase matching. But the technology in pump class load application speed range is limited, there is still a reflux valve control blind area,＂ turn off undead＂ problem. ＂ One-for-several＂ rotor frequency Technique in water injection station application, solved the control blind area problem, the full realization of the variable frequency close return voltage injection, at the same time, the successful implementation of the slip power efficient feedback. Stable water injection pressure of the system, and the electric energy is saved, satisfy the oilfield high efficiency, fine water needs, has a high application value.

Hydrological Services by Mountain Ecosystems in Qilian Mountain of China: A Review

Hydrological service is a hot issue in the current researches of ecosystem service, particularly in the upper reaches of mountain rivers in dry land areas, where the Qilian Mountain is a representative one. The Qilian Mountain, where forest, shrubland and grassland consist of its main ecosystems, can provide fresh water and many other ecosystem services, through a series of eco-hydrological process such as precipitation interception, soil water storage, and fresh water provision. Thus, monitoring water regulation and assessing the hydrological service of the Qilian Mountain are meaningful and helpful for the healthy development of the lower reaches of arid and semi-arid areas. In recent 10 years, hydrological services have been widely researched in terms of scale and landscape pattern, including water conservation, hydrological responses to afforestation and their ecological effects. This study, after analyzing lots of current models and applications of geographical information system（GIS） in hydrological services, gave a scientific and reasonable evaluation of mountain ecosystem in eco-hydrological services, by employing the combination of international forefronts and contentious issues into the Qilian Mountain. Assessments of hydrological services at regional or larger scales are limited compared with studies within watershed scale in the Qilian Mountain. In our evaluation results of forest ecosystems, it is concluded that long-term observation and dynamic monitoring of different types of ecosystem are indispensable, and the hydrological services and the potential variation in water supplement on regional and large scales should be central issues in the future research.v

Assessment and regulation of ocean health based on ecosystem services: Case study in the Laizhou Bay, China

The ecosystem-based management of nearshore waters requires integrated assessment of ocean health and scientific guidance on artificial regulations to promote sustainable development. Quantitative approaches were developed in this paper to assess present and near-term ocean health based on ecosystem services. Results of the case study in the Laizhou Bay of China showed that the index score of ocean health was 0.785 6 out of 1.0 at present and was expected to range from 0.555 1 to 0.804 1 in the near-term future depending on different intensities of artificial regulation of negative pressures. Specifically, the results of ocean health at present mainly indicated that cultural services and provisioning services performed essentially perfectly while supporting services and regulating services functioned less well. It can be concluded that this nearshore ecosystem would partially lose supporting and regulating services in the near-term future if the increasing pressures were not wellregulated but that all of these categories of ecosystem services could be slightly improved if the negative pressures were fully controlled. Additionally, it is recommended that publicity and education on ecosystem services especially on cultural services and regulating services should be further strengthened. The analytical process and resulting quantification provide flexible tools to guide future development of regulations so as to facilitate ecosystem-based management in the coastal zone.

Physiological responses and adjustment mechanisms of the dominate species of natural vegetation of Eastern Tengger Desert

Reaumuria soongorica and Salsola passerina have significant differences in ecophysiological characteristics, which change with the environmental variations. Although they live together for a long period of time, their adaptive mechanisms to environmental stresses are very different. As two extreme xerophytes, Reaumuria soongorica and Salsola passerina differ significantly from other psammophytes in ecophysiological characteristics; they can survive in lower water potential, and can even grow in piedmont areas. Low water potential may be related to the existence of osmosis-regulating substance, such as praline, which can strengthen the capacity of water absorption. Compared to other psammophytes, Reaumuria soongorica and Salsola passerina have a higher degree of photo-inhibition under the same condition, and the photo-inhibition can lead to destruction of the photosynthetic pigment, nevertheless, this photo-inhibition can be repaired under suitable conditions in the morning and evening.

Multiscale cellulose-based fireproof and thermal insulation gel materials with water-regulated forms

Different forms of construction materials(e.g.,paints,foams,and boards)dramatically improve the quality of life.With the increasing environmental requirements for buildings,it is necessary to develop a comprehensive sustainable construction material that is flexible in application and exhibits excellent performance,such as fireproofing and thermal insulation.Herein,an adjustable multiform material strategy by water regulation is proposed to meet the needs of comprehensive applications and reduce environmental costs.Multiform gels are constructed based on multiscale cellulose fibers and hollow glass microspheres,with fireproofing and thermal insulation.Unlike traditional materials,this multiscale cellulose-based gel can change forms from dispersion to paste to dough by adjusting its water content,which can realize various construction forms,including paints,foams,and low-density boards according to different scenarios and corresponding needs.

The influence of water regulation on vegetation in the lower Heihe River

Water regulation has been carried out by the Heihe River Bureau since 2000, which aims to address the existing eco-environmental problems in the lower Heihe River. In the past nine years, great changes in spatial-temporal distribution of water resources took place in the lower Heihe River. In order to objectively evaluate the influence of water regulation on the eco-environment, the changes of groundwater table, typical vegetation, landscape types as well as East Juyan Lake have been analyzed in the lower Heihe River, by means of field surveys and remote sensing. These results indicate that there are obvious effects of water regulation on the eco-environment, which has been improved toward sustainability in the lower Heihe River.