Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in China from 2000 to 2020

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

Analysis of Land Degradation in Ethiopia and Countermeasures

In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper depicts the land degradation status and causes,through an integrated assessment,and some measures to alleviate the problem are proposed.

Measurement and Spatial Distribution of Urban Land Use Compactness in Chaoyang District of Beijing,China

China is in the process of rapid urbanization,and wise land use is critical to the long-term sustainability of Chinese cities.Promotion of a compact city is typically believed to be helpful for sustainable land use management.However,given the fact that Chinese cities are characterized by high population densities,the applicability of a more compact solution to expand cities in China remains questionable;there is little evidence to support the many claims in its favor.In seeking to provide empirical data to explore the application of compact city theory in China,one of the key problems researchers face is the task of measuring the urban compactness,in order to objectively investigate the current characteristics of urban compactness.To meet this need,indices were developed for measuring the urban land use compactness,by which the spatial distribution characteristics of urban land use compactness were identified and applied to the Chaoyang District of Beijing.The conclusions can be made as follows:(1) comprehensive land use compactness in Chaoyang District has increased during the period of 2001-2007,especially the population density;(2) the spatial distribution of land use compactness has the characteristics of a ring structure,which shows a decreasing trend with its distance to the city center;(3) there is a strong positive correlation between urban land use compactness and location.The better the location is,the higher the land use compactness is.

A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality

Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.

Safeguard Measures for Implementation of New Round of Land Consolidation Planning

We conduct a comprehensive analysis of the current situation of security system for implementation of China's land consolidation planning. The prominent problems in the process of implementing safeguard measures for planning are summarized as follows: the guiding ideology for planning formulation is imperfect; the legal basis is weak, and administrative means are not sound; the economic security mechanism is not brought into full play, and the social security measures still need to be further deepened; the technical safeguard measures are short. From laws and regulations, administrative management, economic security, social supervision, technology management and other aspects, we establish the scientific security system for implementation of land consolidation planning; put forth the recommendations for guaranteeing the implementation of planning in China.

Analysis on the Influencing Factors and Control Measures of "Non-Grain Conversion" of Cultivated Land in Agricultural Land Transfer

Through the method of literature analysis,this paper analyzes the present situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land in China,summarizes the influencing factors and consequences of the phenomenon of"non-grain conversion"of cultivated land in the transfer of agricultural land,and finally puts forward some measures.The study found that costs and benefits are the fundamental factors affecting the"non-grain conversion"of cultivated land in agricultural land transfer,and other main factors include government and policy guidance,industrial and commercial capital to the countryside,labor transfer and so on.The"non-grain conversion"of cultivated land in the transfer of agricultural land is a serious threat to China s food security,leading to the decline of the quality of agricultural land and the destruction of the ecological environment,as well as the risk of breach of contract in"industrial and commercial capital to the countryside".Based on the understanding of the influencing factors of non-grain conversion,this paper puts forward the following measures:strengthening the control of the use of cultivated land in agricultural land transfer;implementing accurate subsidies for grain cultivation and ensuring the benefit of grain growers;adopting grain planting incentive mechanism to increase grain enthusiasm;strengthening media publicity and education to enhance food security awareness.The improvement of the current situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land will be of great significance to the protection of agricultural land and food security in China.

The Type of Low-yielding Fields,Using Direction and Land Fertility Building Measures in Suiping County

Using the evaluation indicator system for arable land fertility in Suiping County,this paper analyzes some factors influencing agricultural production,such as physical and chemical properties of soil,site conditions,soil management,and soil nutrients concerning various types of low-yielding fields in the county. In accordance with the dominant soil constraint factors and main direction of improvement,the lowyielding fields in the county are divided into four types: irrigation improvement type,waterlogging drainage type,barren soil fertilization and barrier layer type. Finally this paper offers specific guidance on the construction of arable land.

Sustainable Utilization of Arable Land Resources in Karst Area:A Case Study of Anshun City of China

Aiming at utilization status of arable land resources in Anshun City,a Karst area,quantitative and qualitative analyses were performed from the viewpoints of quality,quantity and benefits of arable land.And the benefits of arable land were analyzed with multiple linear regression.Finally,the sustainable utilization of arable land resources was discussed,and several protection measures were pointed out.

Research on Plant Landscape Design in the Reconstruction of Urban Green Land——A Case Study of Green Land Reconstruction of Yangliu River in Wenjiang City of China

In modern green land planning, it should highlight the application of native plants and the construction of urban three-dimensional greening. By taking green land reconstruction of Yangliu River of Wenjiang City as an example, the site condition and design concept have been analyzeds; and furthermore, reconstruction schemes have been explained in detail based on five themes. It has emphasized composing landscape based on sections, enriching plant levels, improve forest canopy line and enrich tour space. Plants on green lands can be moved, adjusted, transformed, added and supplemented.

STUDY ON URBAN LAND SAVING IN THE ECONOMICDEVELOPED COASTAL REGION OF CHINA

In the initial period of industrialization a great deal of land is needed for Chinese industry development as well as land resource per person of China is much lower than the average value in the world, thus it is necessary to save land in Chinese urban constrUction. This paper mainly discussed the features of urban land use in economic developed coastal cities: one is that the index of urban land per person in middle-small cities was higher than in large cities; another is that urban land has not been used highly and strongly; the third is that the industrial land occupied an irrationally large percentage of whole urban land; the final is that rural enterprises took up a quantity of land. Thereafter, this paper put forward five land-saving measures: first, to adopt the idea of saving land; next, to adjust the land-use structure when redeveloping the old city and alternate some land use when adjusting the industry structure of the city; the third, to develop the system of payment for using land and the management of urban planning; finally to enhance the effective regional plan and the urban landuse plan.

AutoCAD Land Development Desktop在测绘工程中的应用

鉴于AutoCADLandDevelopmentDesktop与现今很多的土木工程设计软件相兼容,本文结合实际测绘工作经验,对该软件的主要功能模块进行较为详细的说明,针对具体工程测量中遇到的数据采集、组织、检查以及土方量计算等方面的问题提出了解决方法,同时指出了在使用该软件过程应该注意的问题。

LAND RESOURCES OF INNER MONGOLIA AND THEIR RATIONAL UTILIZATION

1. The Characteristics of land resources in Inner Mongolia1.1 The vast expance of land Accounting for 12.5 per cent of the Total area of China, the land area in InnerMongolia is 1.183 million square kilometer. The land of per person in Inner Mongolia,which was 5.5 hectares, was 6.5 times of per person in China in 1990.

Occurrence and Epidemic Dynamics and Control Countermeasures of Important Sugarcane Diseases in Rainy and Humid Season

The rainy and humid season from July to September is the crucial period for elongation and jointing and yield performance of sugarcane,and also a peak occurrence and damage period of many important sugarcane diseases. In order to prevent large-area outbreak of sugarcane diseases and ensure safe growth in late stage,the occurrence dynamics of important sugarcane diseases in the rainy and humid season was analyzed and discussed from the aspects of three epidemic outbreak elements of plant diseases: host plant,pathogen and environmental condition. Moreover,the corresponding control ideas and technical countermeasures were put forward according to the epidemic characteristic of sugarcane diseases and the actual sugarcane production.

Research Advances of Effects of Land Use Pattern on Greenhouse Gas Fluxes in Grassland Ecosystem

The grassland is the largest terrestrial ecosystem in China,and greenhouse gas fluxes such as CO2,CH4 and N2O play an important role in the global climate change. The differences in grazing,cultivation and management measures will affect greenhouse gas emissions in grassland ecosystem. Studies suggest that reclamation will lead to increased CO2 fluxes,and fertilization will lead to increased N2 O fluxes; no grazing in summer can reduce greenhouse gas emissions,but impacts of grazing and management measures on greenhouse gas fluxes have not yet reached the same conclusion. The different results may be related to local natural conditions,management measures and research methods. Future research should be focused on unity and standardization in these areas,making the results scientific and comparable,and finally providing the basis for emission reduction of greenhouse gases in grassland ecosystem.

Effects of Anti-wind Erosion with Peanut Stubbles in Sandy Lands during Fallow Period

[Objective] The aim was to select a cultivation method suitable for sandy lands in Liaoning Province. [Method] The research explored effects of autumn plowing, autumn rotary cultivation, autumn ridging, and rotary cultivation before spring sowing on physical and chemical properties. [Result] By autumn plowing, surface soils were seriously eroded, more water was evaporated, and more nutrients lost; by autumn rotary cultivation, surface soils were seriously eroded also, reducing wa- ter content and nutrients; by autumn ridging, surface soils were slightly eroded, so that evaporation was light and fewer nutrients lost; by rotary cultivation before spring sowing, soil erosion was the lightest, with more water and nutrients maintained. [Conclusion] It is effective for improving anti-wind erosion by no-tillage during fallow period and land reclamation before sowing in semi-dry areas.

Characteristics of Rainstorm and Flood Disaster in Shaoyang City and Flood Protection Countermeasures

Based on ground meteorological observation data at 10 representative stations of Shaoyang City during 1951-2017 and rainfall data at over 220 automatic weather stations during 2005-2017,statistical analysis on rainstorm and flood disaster in Shaoyang was conducted. Occurrence characteristics and rule of rainstorm and flood disaster were found,and disaster situation was evaluated and analyzed. The results showed that（ 1）there was almost local rainstorm and flood in Shaoyang City every year,with strong seasonal characteristic.（ 2） The loss caused by rainstorm and flood disaster was the most serious in various meteorological disasters.（ 3） Rainstorm and flood disaster generally had the sudden and devastating characteristics. Via the analysis and research on rainstorm and flood disaster,defense measure and countermeasure of rainstorm and flood were proposed,which could provide scientific decision basis for party and government leading flood relief,and had important guidance significance for preventing and mitigating disasters by government agencies.

Integrated visual navigation based on angles-onlymeasurements for asteroid final landing phase

Visual navigation is imperative for successful asteroid exploration missions.In this study,an integrated visual navigation system was proposed based on angles-only measurements to robustly and accurately determine the pose of the lander during the final landing phase.The system used the lander's global pose information provided by an orbiter,which was deployed in space in advance,and its relative motion information in adjacent images to jointly estimate its optimal state.First,the landmarks on the asteroid surface and markers on the lander were identified from the images acquired by the orbiter.Subsequently,an angles-only measurement model concerning the landmarks and markers was constructed to estimate the orbiter's position and lander's pose.Subsequently,a method based on the epipolar constraint was proposed to estimate the lander's inter-frame motion.Then,the absolute pose and relative motion of the lander were fused using an extended Kalman filter.Additionally,the observability criterion and covariance of the state error were provided.Finally,synthetic image sequences were generated to validate the proposed navigation system,and numerical results demonstrated its advance in terms of robustness and accuracy.

MC-LRF based pose measurement system for shipborne aircraft automatic landing

Due to the portability and anti-interference ability,vision-based shipborne aircraft automatic landing systems have attracted the attention of researchers.In this paper,a Monocular Camera and Laser Range Finder(MC-LRF)-based pose measurement system is designed for shipborne aircraft automatic landing.First,the system represents the target ship using a set of sparse landmarks,and a two-stage model is adopted to detect landmarks on the target ship.The rough 6D pose is measured by solving a Perspective-n-Point problem.Then,once the rough pose is measured,a region-based pose refinement is used to continuously track the 6D pose in the subsequent image sequences.To address the low accuracy of monocular pose measurement in the depth direction,the designed system adopts a laser range finder to obtain an accurate range value.The measured rough pose is iteratively optimized using the accurate range measurement.Experimental results on synthetic and real images show that the system achieves robust and precise pose measurement of the target ship during automatic landing.The measurement means error is within 0.4in rotation,and 0.2%in translation,meeting the requirements for automatic fixed-wing aircraft landing.

COVID-19 transmission and control in land public transport:A literature review

Land public transport is an important link within and between cities,and how to control the transmission of COVID-19 in land public transport is a critical issue in our daily lives.However,there are still many inconsistent opinions and views about the spread of SARS-CoV-2 in land public transport,which limits our ability to implement effective interventions.The purpose of this review is to overview the literature on transmission characteristics and routes of the epidemic in land public transport,as well as to investigate factors affecting its spread and provide feasible measures to mitigate the infection risk of passengers.We obtained 898 papers by searching the Web of Science,Pubmed,and WHO global COVID database by keywords,and finally selected 45 papers that can address the purpose of this review.Land public transport is a high outbreak area for COVID-19 due to characteristics like crowding,inadequate ventilation,long exposure time,and environmental closure.Different from surface touch transmission and drop spray transmission,aerosol inhalation transmission can occur not only in short distances but also in long distances.Insufficient ventilation is the most important factor influencing long-distance aerosol transmission.Other transmission factors(e.g.,interpersonal distance,relative orientation,and ambient conditions)should be noticed as well,which have been summarized in this paper.To address various influencing factors,it is essential to suggest practical and efficient preventive measures.Among these,increased ventilation,particularly the fresh air(i.e.,natural ventilation),has proven to effectively reduce indoor infection risk.Many preventive measures are also effective,such as enlarging social distance,avoiding face-to-face orientation,setting up physical partitions,disinfection,avoiding talking,and so on.As research on the epidemic has intensified,people have broken down many perceived barriers,but more comprehensive studies on monitoring systems and prevention measures in land public transport are still needed.

Torrent Control and Stabilization through Bio-engineering Measures in North Western Himalayan Region

The study revealed that low cost bio-engineering measures using local grass （Saccharum munja）, shrubs （Vitex negundo and Ipomea spp.） and trees （Acacia nilotica and Acacia catechu） along with loose boulder structures （spurs, check dams and gully plugs） of suitable design and dimensions were very effective in channelizing the torrent water flow towards central line and its stabilization. In the catchment, small to medium sized gullies were treated with gully plugging by erecting loose boulder check dams along with suitable vegetative barriers ofSaccharum munja and Ipomea spp. to stop their further advancement. Different treatments of these combinations trapped the sediment to the tune of 5-15 tonnes and it was stabilized at the spur tails. In this, attractive type spur trapped the maximum sediment. The D-50 analysis of sediment deposited was also carried out and the value varied from 3.1-3.7 mm, implying deposition of higher percentage of finer fertile soil proportion and its stabilization. The mechanical as well as vegetative measures helped in the channelization of water course towards the central line to the tune of 10-80 m. The stream banks were stabilized by plantations and put to use under agro forestry systems. Different treatments in catchment, with regard to their efficacy to reduce runoff, ground water recharge, sediment and channel morphology resulted in reclamation of 43 ha area of the torrent bed.