Effects of drip and flood irrigation on carbon dioxide exchange and crop growth in the maize ecosystem in the Hetao Irrigation District,China

Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.

Research on the Public Perception of Yangzhou Historical and Cultural Districts Based on Network Review Text Analysis

The historical and cultural districts of a city serve as important cultural heritage and tourism resources.This paper focused on four such districts in Yangzhou and performed semantic analysis on online public comments using ROST CM6 software.According to the high frequency words,attention preference of district site elements,activities and feelings in Yangzhou historical and cultural districts were analyzed.Through the analysis of semantic network and public emotional tendency,the relationship between the protection and utilization of Yangzhou historical and cultural districts and the perception and demand of users were discussed,and some suggestions for the protection,utilization and renewal of historical and cultural districts were put forward.

Identifying the Hydrochemical Characteristics,Genetic Mechanisms and Potential Human Health Risks of Fluoride and Nitrate Enriched Groundwater in the Tongzhou District,Beijing,North China

Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.

Properties and Characterization of Two Clays Raw Material from Mountain District (West of Côte d’Ivoire) for Use in Low-Carbon Cements

This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.

Optimization of Agricultural Industrial Structure in Changping District of Beijing Based on Grey Relational Analysis

In the economic development of Beijing,although the share of the total amount of agricultural industry in the overall economy is relatively low,it has an important impact on the daily life of residents,social stability and the development of other industries.Changping District,as an important agricultural production base of Beijing,its agricultural development has an indispensable strategic significance for the stability and growth of the entire regional economy.Therefore,it is very important to study the structure of agricultural industry in Changping District.Based on the detailed analysis of the agricultural industrial structure of Changping District,this paper uses the grey relation theory to analyze the different industries in the agricultural industrial structure of Changping District,including planting,forestry,animal husbandry,fishery and agricultural,forestry,service industries,in order to reveal the impact of these industries on the agricultural industrial structure of Changping District.Through this study,it comes up with specific and feasible suggestions for the optimization of agricultural industrial structure in Changping District,and provides valuable reference for the agricultural development of other areas in Beijing.

Improving the Quality of Public Space in Old Residential Areas Based on Superposition and Intervention:A Case Study of Baihuazhou District of Nanchang City

With the development of cities,China has entered an era of stock planning.The functions of old residential areas in urban development can no longer meet the needs of residents in the new era for a better life,and new standards have been put forward for the quality of public spaces for living.This paper analyzes and sorts out the characteristics and problems of the public space in the old residential areas of Baihuazhou district.Combining superposition and intervention techniques,the spatial,historical,cultural and other characteristic elements of the residential areas are preserved to the greatest extent.The public space in the old residential areas of Baihuazhou District is updated and reconstructed in order to achieve the goal of improving the quality of its public space.

Analysis of Characteristics and Meteorological Influencing Factors of Air Pollution in Luojiang District,Deyang City

Based on the monitoring data of ambient air quality and meteorological observation data,the characteristics and meteorological influencing factors of air pollution in Luojiang District of Deyang City from 2018 to 2022 were analyzed.The results show that from 2018 to 2022,the main air pollutants affecting the air quality of Luojiang District of Deyang City were PM_(2.5) and PM_(10),and the primary pollutant on heavy pollution days was basically PM_(2.5).PM_(2.5) and PM_(10) pollution showed obvious seasonal differences,and PM_(2.5) concentration exceeded the limit mainly in spring and winter,among which it was the most serious in early spring,especially in January and February,followed by December.PM_(10) exceeding the standard had a high seasonal correlation with PM_(2.5) exceeding the standard,mainly in spring and winter,among which it was the most serious in winter,especially in December,followed by January.PM_(2.5) and PM_(10) pollution showed an overall weakening trend.PM_(2.5) and PM_(10) concentration were closely related to meteorological factors such as temperature,relative humidity,wind speed,precipitation and air pressure,and were mainly affected by rainfall.

Study on Methods of Evaluating Visual Landscapes in Historic and Cultural Districts

This paper with the purpose of protecting visual landscape environment in historical and cultural districts,analyzes categories and characteristics of historical and cultural districts from the perspective of visual landscape,finally with the assessment basis of "landscape picture" proposes the classification of areas of 5 different levels,that is,the optimal viewing gallery,the secondary viewing gallery,the optimal viewing surface,the secondary viewing surface,and the common viewing surface,explores an approach of evaluating pollution indexes in historic and cultural districts by comprehensively evaluating "landscape pictures" in those areas of different levels.

Analysis on Vapour Field for the Drought Causes in Beijing,Tianjin and Hebei Districts in Recent Years

The monthly variation,temporal-spatial distribution,transportation characteristics of vapour field at middle and lower atmosphere and their effects on drought in Beijing,Tianjin and Hebei districts were studied,which have a guiding significance on predicting climate and arranging agricultural production in the district.

Analysis of Landscape Culture in the New Era of Residential Districts

The culture in the era of planned economy, commodity economy and new residential districts were respectively analyzed, including cultural life, landscape culture, ecological culture and traditional culture.

Planning & Construction of Residential Districts in Hangzhou City from the Aging Perspective

Through questionnaire investigation,interviews and field survey,residence status of the citizens and residence expectations of the elderly in Hangzhou city were investigated.The contradictions between planning & construction of residential districts in Hangzhou and the aging of population were preliminarily analyzed.From the angles of psychological and behavioral characteristics of the elderly,many requirements of the elderly were reasonably taken into account in the planning & construction of residential districts.Through improving conditions of activity places and residence organizations of the elderly,leisure functions of the elderly in residential districts were perfected to provide references for the future planning & construction of residential districts for population aging.

Energy-saving Architectural Designs for Relocation Residential Districts in North Jiangsu Province of China

By investigating present relocation residential districts for peasants whose houses are removed for the unified planning of rural areas in north Jiangsu Province, as well as residents' feelings about the environment of residential district, main architectural structures and energy consumption conditions, the indoor thermal environment, use of main heating and cooling facilities, residents' satisfaction on the acoustical and luminous environment, major space-enclosing structures and calculation of energy-saving designs are analyzed, and suggestions are given for the architectural design of relocation residential districts in the study area. It is stressed that the relationship between energy conservation and architectural layout, orientation, lighting, ventilation, selection of enclosing-structure materials, facade, color and style should be properly handled in the planning, and the focus is to control building orientation and shape coefficient, on the basis of which energy-saving designs of windows, exterior walls and roofs can be done. Energy consumption of present residential buildings is calculated and analyzed to bring forth new ideas to the energy-saving designs for relocation residential districts in north Jiangsu Province, and establish an architectural energy-saving system suitable for climatic and natural conditions of north Jiangsu to instruct the energy-saving designs of relocation residential districts in the study area.

Landscape Planning Principles and Techniques for Residential Districts

Landscape design principles for residential districts were analyzed in this study,it was stressed that local features should be demonstrated,actual conditions of the site respected;functional demands of residential districts should be clarified;landscape designs and architectural designs should be organically combined;central landscapes should be highlighted,sense of hierarchy and enclosure created;human-concerned and ecological principles should be followed.On this basis,landscape design techniques for residential districts were discussed from the perspectives of artistic conception and plant furnishing.In terms of plant furnishing,spatial processing,linear changes and changes of seasonal aspects were emphasized,and plants with environmental and economic benefits were suggested.By doing this,this study aimed at contributing to the future planning and construction of residential districts.

Current Use and Coordinated Development of Traditional Residential Districts from the Perspective of Human Settlement—A Case Study of Nanyuan Dormitory Area of Anhui Agricultural University

In view of China's rapid urbanization,Nanyuan Dormitory Area of Anhui Agricultural University was studied as a representative of traditional living quarters with harmonious neighborhood relationship to discuss current use and coordinated development of traditional residential districts from the perspective of human settlement.Problems in the dormitory area were analyzed,neighboring environment,regional characteristics,cultures and all relevant elements were fully considered to build a favorable human settlement by following the coordinated development of human settlement and economy.Renovation strategies on the basis of maintaining original favorable human settlement were discussed from the perspectives of space ecology,dwelling environment,facilities and humanistic environment,so as to provide new concepts for the sustainable development of urban traditional residential districts and the construction of favorable human settlement.

Status quo and Existing Problems of Seismic Prevention Planning in Counties and Districts——a Case Study of Hongsibao District, Wuzhong City,Ningxia Hui Autonomous Region

This paper introduced domestic and overseas status, the historical evolution and the development history of earthquake disaster reduction planning. The urgencies and realistic significance were analyzed to carry out earthquake disaster reduction planning for districts or countries in the northwest. With Hongsibao District in Wuzhong City, Ningxia Province as an example, this article analyzed in detail the present situation and the special problems of earthquake disaster reduction planning in Northwest China. The relevant solving measures were put forward in order to offer a reference for the scientific establishment and effective implementation of earth- quake disaster reduction planning in Northwest China. The foundation of earthquake disaster reduction in the Hongsibao District is still very weak, there is a single earthquake monitoring means, the emergency rescue system is not complete, the working mechanism is not perfect, and the lack of funding for the work of earthquake disaster reduction.

Reform of Green Spaces in Old Residential Districts——A Case Study of the Old Wujie Residential District of Urumqi Railway Bureau in China

Taking green space reform in the Old Wujie Residential District of Urumqi Railway Bureau for example, current situation of green spaces in old residential districts of Urumqi City was introduced, and problems were summarized as "limited plant species, simple plant furnishings; improper planting location; conflicts between plant and pipe layout; serious competition leading to poor growth of plants; small ratio of green space, worn infrastructure; backward management level, and poor protection consciousness of residents". In view of these problems, relevant suggestions were given to improve infrastructure and plant furnishings in the study district, and to provide reference for green space reform in old residential districts in northwest China.

Preliminary research to determine stressdistricts form focal mechanism solutions in Southwest China and its adjacent area

The method of sliding direction fitting is used to determine stress districts, taking the shear stress directions andratios of shear stress to stress on fault planes given by focal mechanism solutions as the criteria to select focalmechanism solutions of one region and sorting out the ear'thquakcs controlled by different tectonic stfess fields,and then determining the stress districts from epicenter distribution of eanhquakes. We call this method as step bystep convergence method. By inversion analyzing of 297 focal mechanism solutions, we consider that SouthwestChina and its adjacent area can be divided into 5 stress districts, and we worked out directions of the three principal stresses and values of shape factor gi in 5 stress districts.

Land use scenario simulation of mountainous districts based on Dinamica EGO model

Mountainous area makes up 22% of global land, and rational land use in this area is important for sustainable development. Mentougou district has been positioned as an ecological conservation development zone of Beijing and significant land use changes have taken place since 2004. With the combination of GIS and Dinamica EGO(Environment for Geoprocessing Objects) model, the quantitative structure and spatial distribution of land use in Mentougou from 2006 to 2014 are analyzed in this paper. Considering topography has influence on the action mode of driving factors, the research area is divided into two parts based on elevation, mountainous area above 300 m, plain and shallow mountainous area below 300 m. Based on cellular automata theory, the probability of land use change is calculated by Weights of Evidence method and the spatial distribution of land use is simulated by means of two complementary spatial transition functions: Expander and Patcher. Land use pattern of Menougou in 2030 for three kinds of scenarios: trend development, rapid development and ecological protection are simulated. The comparison shows that the trend development scenario is more reasonable based on social, economic and environmental considerations and other scenarios provide a reference for improving irrational land use.

Resources Conditions of Coalbed Methane Districts in China

The China National Administration of Coal Geology accomplished an assessment of coalbed methane resources of China in 1988. The total amount of coalbed methane resources in China is 14336.944 billion m3, occurring in recoverable coal seams and beneath weathering zones, with coalbed methane content equal to or higher than 4 m3 per ton and buried depths smaller than 2000 m, among which there are 967.51 billion m3 of predicted reserves and 13369.434 billion m3 of future reserves. The resources in coal reservoirs with methane content of more than 8 m3 per ton are 12444.087 billion m3, and those with methane content between 4 to 8 m3 per ton are 1892.856 billion m3. There are 35 districts in which the resources abundance is higher than 150 million m3/km2, 49 districts with the abundance between 50 million and 150 million m3/km2, and 31 districts with the abundance less than 50 million m3/km2. There is 9256.078 billion m3 of methane occurring in coal seams with buried depths less than 1500 m, and 5080.866 billion m3 in coal seams with buried depths between 1500 and 2000 m. There are 28 large-scale districts in which coalbed methane resources are more than 100 billions m3, 28 medium-scale districts with coalbed methane resources between 20 billion and 100 billion m3 and 59 small-scale districts with resources amount less than 20 billion m3. The Jincheng area is one of the most favourable districts for coalbed methane resources in China.

Evaluation of reclamation land productivity in mining districts

In order to evaluate the productivity of reclamation lands in mining districts, field investigation and spatial information technique were adopted to investigate influence factors of land. Based on the collected data of each land, membership grade of each factor was obtained based on Fuzzy logic, and combined weight of each factor was got by analytica1 hierarch process and Delphi method. According to membership grades and combined weights of all factors, integrated fertility index (IFI) of every land was calculated to reflect levels of the productivity of reclamation lands in mining districts. Experimental results show that spatial information technique is an efficient method in field data collection, while lack of evaluation data. By means of quantificational analysis of this method, IFI is appropriate to describe the productive capacity level of reclamation lands.