Water and nitrogen footprint assessment of integrated agronomic practice management in a summer maize cropping system

The footprints of water and nitrogen(WF and NF)provide a comprehensive overview of the type and quantity of water consumption and reactive nitrogen(Nr)loss in crop production.In this study,a field experiment over two years(2019 and 2020)compared three integrated agronomic practice management(IAPM)systems:An improved management system(T2),a high-yield production system(T3),and an integrated soil-crop management system(ISCM)using a local smallholder farmer’s practice system(T1)as control,to investigate the responses of WF,Nr losses,water use efficiency(WUE),and nitrogen use efficiency(NUE)to IAPM.The results showed that IAPM optimized water distribution and promoted water use by summer maize.The evapotranspiration over the whole maize growth period of IAPM increased,but yield increased more,leading to a significant increase in WUE.The WUE of the T2,T3,and ISCM treatments was significantly greater than in the T1 treatment,in 2019 and 2020respectively,by 19.8-21.5,31.8-40.6,and 34.4-44.6%.The lowest WF was found in the ISCM treatment,which was 31.0%lower than that of the T1 treatment.In addition,the ISCM treatment optimized soil total nitrogen(TN)distribution and significantly increased TN in the cultivated layer.Excessive nitrogen fertilizer was applied in treatment T3,producing the highest maize yield,and resulting in the highest Nr losses.In contrast,the ISCM treatment used a reduced nitrogen fertilizer rate,sacrificing grain yield partly,which reduced Nr losses and eventually led to a significant increase in nitrogen use efficiency and nitrogen recovery.The Nr level in the ISCM treatment was34.8%lower than in the T1 treatment while NUE was significantly higher than in the T1 treatment by 56.8-63.1%in2019 and 2020,respectively.Considering yield,WUE,NUE,WF,and NF together,ISCM should be used as a more sustainable and clean system for sustainable production of summer maize.

Shallow sub-lakes are essential for sustaining the successful wintering of waterbirds in Poyang Lake,China

For migratory waterbirds,the quality of wintering habitat is related to spring migration and successful breeding in the next year.The availability of food resources in the habitat is critical and varies within water levels.Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years,the wintering waterbird populations have remained relatively stable.Hence,the mechanism of maintaining the stability is worth exploring.This study aimed to compare the distribution of vegetation and herbivorous wa-terbirds in 2015-2016 and 2016-2017,focusing on three shallow sub-lakes and one main lake are.The results showed that the emergence of tubers and the growth of Carex spp.provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level.Shallow sub-lakes supported almost all of the tuber-eating waterbirds(1.42-1.62×10^(5))and most geese(1.34-1.53×10^(6)).However,the main lake area,covered with Persicaria hydropiper,did not provide adequate and accessible food.This resulted in almost no distribution of tuber-eating waterbirds,with only a few geese congregating in early winter.Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake.Therefore,we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

Review on the Impact of Climate Change on Great Lakes Region’s Agriculture and Water Resources

This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technological advances since the 19th century. From 1900 to 2010, temperatures in the Midwest rose by an average of 1.5 degrees Fahrenheit, which would also lead to an increase in greenhouse gas emissions. Precipitation is also expected to increase due to increased storm activity and changes in regional weather patterns. This paper explores the impact of these changes on urban and agricultural areas. In urban areas such as the city of Chicago, runoff from the increasing impervious surface areas poses challenges to the drainage system, and agriculture areas are challenged by soil erosion, nutrient loss, and fewer planting days due to excessive rainfall. Sustainable solutions such as no-till agriculture and the creation of grassland zones are discussed. Using historical data, recent climate studies and projections, the paper Outlines ways to enhance the Midwest’s ecology and resilience to climate change.

Operational guidance for aeration and flow augmentation for the Chicago Area Waterway System—A case study

The Chicago Area Waterway System(CAWS)is a 133.9 km branching network of navigable waterways controlled by hydraulic structures,in which the majority of the flow is treated wastewater effluent and there are periods of substantial combined sewer overflows.The CAWS comprises a network of effluent dominated streams.More stringent dissolved oxygen(DO)standards and a reduced flow augmentation allowance have been recently applied to the CAWS.Therefore,a carefully calibrated and verified one-dimensional flow and water quality model was applied to the CAWS to determine emission-based real-time control guidelines for the operation of flow augmentation and aeration stations.The goal of these guidelines was to attain DO standards at least 95%of the time.The“optimal”guidelines were tested for representative normal,dry,and wet years.The finally proposed guidelines were found in the simulations to attain the 95%target for nearly all locations in the CAWS for the three test years.The developed operational guidelines have been applied since 2018 and have shown improved attainment of the DO standards throughout the CAWS while at the same time achieving similar energy use at the aeration stations on the Calumet River system,greatly lowered energy use on the Chicago River system,and greatly lowered discretionary diversion from Lake Michigan,meeting the recently enacted lower amount of allowed annual discretionary diversion.This case study indicates that emission-based real-time control developed from a well calibrated model holds potential to help many receiving water bodies achieve high attainment of water quality standards.

Analysis on Residents’ Satisfaction and Its Influencing Factors with Water Environment Management: Based on the Data from Xiaoqing River

Xiaoqing River is one of the key rivers in the Yellow River Basin, and its management satisfaction is the content that the government should consider when formulating policies. This paper concentrates on residents’ satisfaction of water environment management in Jinan section of Xiaoqing River, using questionnaires to find out the problems and effects of Xiaoqing River management. Based on the correlation analysis of the questionnaire data, the results show that five factors including the impact of water pollution, understanding of Xiaoqing River governance, willingness to participate in Xiaoqing River governance, policy publicity, and government regulation have a positive impact on the satisfaction of Xiaoqing River water environment governance. Finally, the paper puts forward some countermeasures and suggestions to increase residents’ satisfaction from five aspects, such as increasing publicity efforts, paying attention to the cultivation of public participation consciousness, etc.

Payment for Water-Related Ecosystem Services as a Strategic Watershed Management Approach

Payments for ecosystem services (PES) have been created worldwide to assist watershed management and improve or maintain water quality. Considering their importance, we conducted a holistic review of payment for water-related ecosystem services to understand how this instrument has been applied in watershed management worldwide. First, we identified the watershed management actions considered by the PES programs and the challenges of implementing water-related PES. After we identified the methods and criteria used to define priority areas for water-related PES. Our review considered articles published on the Web of Science from 2011 to 2022. We found 236 articles relating PES to water resources, highlighting the main water conservation strategies: native vegetation conservation, native vegetation restoration, and implementing best agricultural practices. The method most frequent was interview, followed by the use of technologies, document analysis, and hydrological models. Another significant result was that priority areas for receiving PES are mainly riparian zones, areas near or with native vegetation cover, areas with higher erosion potential, steep areas, and areas with socially vulnerable communities. This review was crucial to identify efficient water resource conservation strategies and potential challenges in the implementation and development of PES programs.

The Management of Environment Cost Caused by Ballast Water

According to classical economic theory,external cost is the indirect,and uncompensated,social or environmental cost caused to an uninvolved third party that arises as an effect of another party’s activity.In light of this,the environmental cost caused by ballast water is considered as a negative externality.This paper aims to contribute by proposing that the environmental cost caused by ballast water can be determined through questionnaires,and that the imposition of a Pigouvian retributive tax is required to compensate for the environmental damage caused.The paper proceeds as follows.Firstly,ballast water management is discussed.Second,the environmental cost is discussed and it is asserted that it is important to have clear regulations and to update them frequently to prevent or minimize ballast water’s negative impact on the environment.Finally,it is suggested that the environmental cost caused by ballast water can be determined by questionnaires and,more specifically,by the WTP(Willingness to Pay)method,and that a special Pigouvian corrective taxation which can internalize this cost should be imposed.

Transdisciplinary research for supporting the integration of ecosystem services into land and water management in the Tarim River Basin,Xinjiang,China

There is a growing need for both science and practice domains to collaboratively and systematically seek knowledge-based strategies for sustainable development. In recent years, transdisciplinary research has emerged as a new approach that enables joint problem solving among scientists and stakeholders in various fields. In this paper, we aim to introduce transdisciplinary research for supporting the integration of the concept of eco- system services into land and water management in the Tarim River Basin, Xinjiang, Northwest China. While a large number of ecosystem service studies have helped to raise the awareness for the value of nature in China, a number of challenges remain, including an improved understanding of the relationships between ecosystem structure, functions and services, and the interaction of the various ecosystem services. A meaningful valuation of ecosystem services also requires the consideration of their strong spatial heterogeneity. In addition, ways to introduce the con- cept of ecosystem services into decision-making in China need to be explored. Thus, successful integration of the concept of ecosystem services into actual land and water management requires a broad knowledge base that only a number of scientific disciplines and stakeholders can provide jointly, via a transdisciplinary research process. We regard transdisciplinary research as a recursive process to support adaptive management that includes joint knowledge generation and integration among scientists and stakeholders. System, target, and transformation knowledge are generated and integrated during the process of （1） problem （re）definition, （2） problem analysis and strategy development, and （3） evaluation of the impact of the derived strategy. Methods to support transdisciplinary research comprise participatory modelling （actor-based modelling and Bayesian Networks modelling） and partici- patory scenario development. Actor-based modelling is a semi-quantitative method that is based on the analysis of problem perspectives of individual stakeholders as depicted in perception graphs. With Bayesian Networks, com- plex problem fields are modelled probabilistically in a simplified manner, using both quantitative data and qualitative expert judgments. These participatory methods serve to integrate diverse scientific and stakeholder knowledge and to support the generation of actually implementable management strategies for sustainable development. For the purpose of integrating ecosystem services in land and water management in the Tarim River Basin through trans- disciplinary research, collaboration among scientists and institutional stakeholders from different sectors including water, agriculture, forestry, and nature conservation is required. The challenge is to adapt methods of transdisci- plinary research to socio-cultural conditions in China, particularly regarding ways of communication and deci- sion-making.

New Attempt for Building Rural Water Environment Management System Based on the Investigation and Analysis of Water Environment in Xianxia Town, Yudu County

Water environment is a part of ecological environment, and conservation of water environment has always been a focus of public attention in China, but water environment management in the vast countryside has been stuck in bottleneck. Based on the fi eld investigation in Xianxia Town, Yudu County, Ganzhou City, Jiangxi Province, this paper explored the current situation of local water environment and the management diffi culties, then introduced the holistic view to integrate the linkage of government, market and society, proposed the universality of the individual case, and the new attempt centering on urban-rural integrated water environment management system with public participation mechanism, management subjects' benefit balance and coordination system, marketing operation mechanism and economic incentive mechanism as the extension.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

The Basin Water Resources Management System and Its Innovation in China

Water provides the origin of human survival and prosperity,and the basic resource for the maintenance of terrestrial eco-systems,their biodiversity,productivity and ecological services.With China’s recent,rapid growth both in population and economic development,the water shortage has become one of the most constraints on its ecological restoration and socio-economic development,especially in the arid inland regions of northwest China.At first glance,this water shortage in China appears to be a resource crisis.But second,an in-depth analysis reveals that the water shortage crisis arises mainly resulting from the poor water management system and operating mechanism that cannot facilitate fair allocation and efficient utilization of water resources both regionally and nationally and thus is viewed as a crisis of water manage-ment.The solution of China’s water shortage and low-efficient utilization problem will,in particular,require a fundamen-tal and substantial reform or innovation of the existing water management system and operating mechanism.In this paper,we address explicitly the problems existed in the current water management system,explore the basic theory of water re-sources management and provide some insights into the way how to establish a river basin based integrated water re-sources management system in China.

Planning,Protection and Construction of Ancient Villages in Jiangxi under the Background of New Urbanization: Taking the Water Management System of Mingkou Village in Leping City,Jiangxi Province as an Example

Urbanization is an inevitable trend of economic development. It is an important indicator that reflects the industrialization and modernization of a country. In the long-term urbanization process in China, due to the excessive emphasis on the status of the city and one-sided emphasis on urban development, a serious of urban diseases such as population congestion and environmental damage have been caused. Meanwhile, neglected rural areas have exposed social problems such as aging and hollowing out, making the urban-rural dual structure more prominent. Currently, China s economic and social development has reached a new stage, and the realization of urban-rural integration is a major measure to comprehensively develop the national economy and social undertakings. Vigorously developing the rural areas and revitalizing the countryside has become a national policy. Traditional ancient villages are treasures in the vast rural areas. They should be more protected and developed to eliminate the urban-rural gap, thereby passing down and carrying forward the essence of traditional culture and enhancing China s national confidence and cultural confidence. Focusing on the protection and planning of ancient villages, combined with the current policy background of new urbanization, based on field research on Mingkou Village, Leping City, Jiangxi Province, protective development strategies are put forward for ancient villages and their water management from the perspective of water management in ancient villages to arouse people s attention to the protection of ancient villages.

Reviews of the research on water resources management system at home and abroad

The reform of the system of water resource management abroad has started since the 50s of last century, it has left us a lot of experiences in many aspects with the innovation of system, such as the legal environment in water resources, water rights, water market theory, and the ＂participation＂ management of water resources, these experiences has been promoted in more than 40 developing countries. Based on analyzing the theory and experiences of water resources management both at home and abroad, especially the theory and experiences of agricultural water resources management, this paper puts forward the main problems waiting for further investigation in China＇s water resources management and provides some reference and inspiration for the innovation of the system of water resource management in China.

Contribution of Geographic Information Systems for the Management of Water Resources： Case of Groundwater Resources of the Plain of Mascara （Algeria）

The plain of Mascara includes groundwater resources, heavily exploited for the needs of the population, industry and agriculture. However, this resource is under threat from the point of view of quality and quantity. The degradation of water quality comes from water discharges untreated （domestic and/or industrial） and from the irrational use of fertilizers and pesticides in agriculture. The decrease in reserves is due to the effects of intensive exploitation. Several studies on the water resources of the plain generated a mass of very important data. In most cases, these data are disparate at different institutions managers （water resources, environment, etc.）, and are found recorded in paper documents, difficult to exploit. For this reason, it would be essential to use reliable new techniques, namely the GIS （geographic information systems）. The implementation of the GIS of the plain of Mascara （with extension to all the sub-basin of Wadi Fekan） must permit to organize the data and transform it into information. Integration, crossing and superposition of the data with other variables may contribute to spatial analysis and generate very important thematic maps. The GIS constitutes a very effective decision aid tool for the management, exploitation, preservation and protection of water resources. The exploitation possibilities of GIS are multiple, direct or indirect. We give an example as the coupling with a groundwater flow model that may be the subject of additional work.

AN INSTRUCTURAL SYSTEM MODEL OF COASTAL MANAGEMENT TO THE WATER RELATED HAZARDS IN CHINA

Coastal lowlands have large areas of hazard impact and relatively low capacity of prevention to the water related hazards,which have been indicated by the wide_spread flood hazards,high percentages of land with high flood vulnerability.Increasing population pressure and the shift of resources exploitation from land to sea will force more and more coastal lowlands to be developed in the future,further enhancing the danger of water_related hazards.In this paper,the coastal lowlands in the northern Jiangsu province,China,were selected as a case study.The Interpretation Structural Model (ISM) was employed to analyze the direct and indirect impacts among the elements within the system,and thereby,to identify the causal elements,middle linkages,their expressions,and relations.

Evaluating the Effects of Sustainable Chemical and Organic Fertilizers with Water Saving Practice on Corn Production and Soil Characteristics

The rapidly growing world population,water shortage,and food security are promising problems for sustainable agriculture.Farmers adopt higher irrigation and fertilizer applications to increase crop production resulting in environmental pollution.This study aimed to identify the long-term effects of intelligent water and fertilizers used in corn yield and soil nutrient status.A series of field experiments were conducted for six years with treatments as:farmer accustomed to fertilization used as control(CON),fertilizer decrement(KF),fertilizer decrement+watersaving irrigation(BMP1);combined application of organic and inorganic fertilizer+water-saving irrigation(BMP2),and combined application of controlled-release fertilizer(BMP3).A significant improvement was observed in soil organic matter(14.9%),nitrate nitrogen(106.7%),total phosphorus(23.9%),available phosphorus(26.2%),straw yield(44.8%),and grain yield(54.7%)with BMP2 treatment as compared to CON.The study concludes that integrating chemical and organic fertilizers with water-saving irrigation(BMP2)is a good approach to increasing corn productivity,ensuring water safety and improving soil health.The limitations of the current study include the identification of fertilizer type and its optimum dose,irrigation water type,and geographical position.

A review of science–policy interface for water governance in the Caspian Sea

Science and policy have been interlinked for decades and perform essential nexus conditions in the governing aspects of environmental scenarios.This review paper examines the present challenges in the science–policy interface in terms of water governance in the Caspian Sea and identifies effective conditions that may be used in the current context to enhance the mechanism.The evaluation of the science–policy link in the water policy of the Caspian Sea reveals a gap between knowledge producer and governance system,impeding the translation of scientific information into action.Complicated and context-dependent solutions make it challenging to establish effective science–policy processes in the Caspian Sea water governance settings.Establishing a common governing authority,implementing water and resource management regulations,and protecting the natural environment through legal frameworks are crucial steps to address these concerns and ensure sustainable development.Collaboration among coastal states is essential in environmental,economic,and social aspects of regional development.However,the lack of a comprehensive approach,coherent activities,and effective utilization of national and regional power has hindered efforts to halt the environmental degradation of the Caspian Sea.Local governments need to recognize their responsibility to protect and utilize the Caspian Sea for present and future generations,considering both environmental and human security.The interlinkage of the Caspian Sea water governance with the Organization for Economic Co-operation and Development(OECD)water governance principles offers a framework for policymakers to assess gaps and make necessary amendments to existing mechanisms.Effective science–policy interaction,engagement of diverse stakeholders,institutionalizing agreements,and addressing collective action issues are critical for successful water governance.

Integrated water risk early warning framework of the semi-arid transitional zone based on the water environmental carrying capacity (WECC)

Water risk early warning systems based on the water environmental carrying capacity(WECC)are powerful and effective tools to guarantee the sustainability of rivers.Existing work on the early warning of WECC has mainly concerned the comprehensive evaluation of the status quo and lacked a quantitative prejudgement and warning of future overload.In addition,existing quantitative methods for short-term early warning have rarely focused on the integrated change trends of the early warning indicators.Given the periodicity of the socioeconomic system,however,the water environmental system also follows a trend of cyclical fluctuations.Thus,it is meaningful to monitor and use this periodicity for the early warning of the WECC.In this study,we first adopted and improved the prosperity index method to develop an integrated water risk early warning framework.We also constructed a forecast model to qualitatively and quantitatively prejudge and warn about the development trends of the water environmental system.We selected the North Canal Basin(an essential connection among the Beijing-Tianjin-Hebei region)in China as a case study and predicted the WECC in 25 water environmental management units of the basin in 2018–2023.We found that the analysis of the prosperity index was helpful in predicting the WECC,to some extent.The result demonstrated that the early warning system provided reliable prediction(root mean square error of 0.0651 and mean absolute error of 0.1418),and the calculation results of the comprehensive early warning index(CEWI)conformed to the actual situation and related research in the river basin.From 2008 to 2023,the WECC of most water environmental management units in the basin had improved but with some spatial differences:the CEWI was generally poor in areas with many human disturbances,while it was relatively good in the upstream regions with higher forest and grass covers as well as in the downstream areas with larger water volume.Finally,through a sensitivity analysis of the indicators,we proposed specific management measures for the sustainability of the water environmental system in the North Canal Basin.Overall,the integrated water risk early warning framework could provide an appropriate method for the water environmental administration department to predict the WECC of the basin in the future.This framework could also assist in implementing corresponding management measures in advance,especially for the performance evaluation and the arrangement of key short-term tasks in the River Chief System in China.

Water System Condition and Asset Replacement Prioritization

The goal of asset management is to identify and track the maintenance and replacement of assets that have reached their useful life. For that reason, gathering data and collecting information is a critical step when developing an asset management plan. Such data gathering includes physical and operational properties of the assets as well as collecting and tracking important events during the lifespan of the asset (i.e., pipe breaks, replacement year, maintenance performed, etc.). Critical factors in the asset management plan may be overlooked when there is no data or poor quality data. However, many utilities lack the resources for examining buried infrastructure and lack good quality work order data, so other methods of data collection are needed. The concept for this paper was to develop a means to acquire data on the assets for a condition assessment to identify pipes that were most likely to break and those with the highest consequences for same. Three utilities were used as examples. It was found that for buried infrastructure, much more information was known than anticipated but the actual predictions relied on only a few factors related to pipe type. However, there is a need to track the consequences, in this case breaks, which would indicate a failure. The latter would be useful for predicting future maintenance needs and the most at-risk assets, but is often missing in utility systems as many utilities do not adequately track breaks sufficiently. In this case two utilities were analyzed and predication on a third was developed.