Land use intensity dynamics in the Andhikhola watershed, middle hill of Nepal

Land use intensity is a valuable concept to understand integrated land use system, which is unlike the traditional approach of analysis that often examines one or a few aspects of land use disregarding multidimensionality of the intensification process in the complex land system. Land use intensity is based on an integrative conceptual framework focusing on both inputs to and outputs from the land. Geographers’ non-stationary data-analysis technique is very suitable for most of the spatial data analysis. Our study was carried out in the northeast part of the Andhikhola watershed lying in the Middle Hills of Nepal, where over the last two decades, heavy loss of labor due to outmigration of rural farmers and increasing urbanization in the relatively easy accessible lowland areas has caused agricultural land abandonment. Our intention in this study was to ascertain factors of spatial pattern of intensity dynamism between human and nature relationships in the integrated traditional agricultural system. High resolution aerial photo and multispectral satellite image were used to derive data on land use and land cover. In addition, field verification, information collected from the field and census report were other data sources. Explanatory variables were derived from those digital and analogue data. Ordinary Least Square(OLS) technique was used for filtering of the variables. Geographically Weighted Regression(GWR) model was used to identify major determining factors of land use intensity dynamics. Moran’s I technique was used for model validation. GWR model was executed to identify the strength of explanatory variables explaining change of land use intensity. Accordingly, 10 variables were identified having the greatest strength to explain land use intensity change in the study area, of which physical variables such as slope gradient, temperature and solar radiation revealed the highest strength followed by variables of accessibility and natural resource. Depopulation in recent decades has been a major driver of land use intensity change but spatial variability of land use intensity was highly controlled by physical suitability, accessibility and availability of natural resources.

Agricultural land use intensity study in Taibus Banner, and its determinants： a case Inner Mongolia, China

Based on rural household survey data from Taibus Banner, in the Inner Mongolia Autonomous Region, China, this study separately categorizes agricul- tural land use intensity into labor intensity, capital intensity, the intensity of labor-saving inputs, and the intensity of yield-increasing inputs, and then analyzes their determinants at the household level. The findings reveal that within the study area： （1） labor intensity is higher and capital intensity is lower than in the major grain-producing and economically developed areas of eastern and central China; （2） the most widely planted crops are those with the lowest labor intensity （oats） and capital intensity （benne）; （3） there are marked differences in agricultural land use intensity among households; a major factor affecting land use decision-making is the reduced need for labor intensity for those households with high opportunity costs, such as those with income earned from non-farming activities which alleviates financial constraints and allows for increased capital intensity. As a result, these households invest more in labor-saving inputs; （4） households with a larger number of workers will allocate adequate time to manage their land and thus they will not necessarily invest more in labor-saving inputs. Those households with more land to manage tend to adopt an extensive cultivation strategy. Total income has a positive impact on capital intensity and a negative impact on labor intensity. House- holds that derive a higher proportion of their total income through farming are more reliant upon agriculture, which necessitates significant labor and yield-increasing inputs. Finally, the authors contend that policy makers should clearly recognize the impacts of non-farming employment on agricultural land use intensity. In order to ensure long- term food security and sustainable agricultural develop-ment in China, income streams from both farming and non- farming employment should be balanced.

Evaluating rural sustainable land use from a system perspective based on the ecosystem service value

Rural sustainable land use(RSLU) is important to China’s implementation of the UN 2030 Agenda for Sustainable Development Goals and the goals of rural revitalization strategy in China. Research on RSLU is key to understanding the impact of human activities on rural sustainability. This paper explored the evaluation method of RSLU from a system perspective based on the ecosystem service value(ESV). Three systems were proposed for consideration when conducting this evaluation method. One was the sustainability of the land system, the other was the sustainability of the ecoeconomic system, and the rest was the sustainability of the land-eco-economy system. Indicators including(1) land use intensity and land system stability,(2) gross domestic production(GDP), ESV, and the eco-economic harmony degree(EEHD), and(3) coupling degree and coupling coordination degree were used to analyze the sustainability of the land, eco-economic, and landeco-economic systems, respectively. An empirical research on Yanhe ecovillage was conducted and the study period extended from 2008 to 2020. The results showed that forest land had always accounted for more than 81.20% of the total area in Yanhe eco-village from 2008 to 2020, which greatly influenced land system stability and restricted economic development. This feature contrasted with RSLU. The total ESV of Yanhe eco-village declined by 1.60×106CNY during 2008–2020 because of land use changes. The EEHD was –0.01, which presented that there was a very slight unharmonious between ecology and economy. The coupling degree and coupling coordination degree showed that the development between the land and ecoeconomic systems exhibited a coupling coordination relationship. The results indicated that ecology and economy in Yanhe eco-village will change significantly in response to land use changes in rural areas, which further revealed the dynamic linkage between human beings and nature. Moreover, opposite variation tendencies in land system stability and ESV revealed that the contradiction between the high stability of the land system and well development of the eco-economic system. The results of this study implied that it is necessary and useful to integrate ESV into land management to achieve RSLU.

Evaluation and Obstacle Diagnosis of Low-carbon Intensive Land Use in Kaifeng City

Low carbon intensive use of urban land is an important trend to achieve regional high quality development.In this study,with Kaifeng municipal district as an example,the catastrophe progression model was used to estimate and analyze the low-carbon intensive use level of urban land in Kaifeng City from 2011 to 2020,and the obstacle factors in the process of low-carbon intensive land use in Kaifeng City were revealed by using the obstacle degree model.The results showed that during the study period,the low-carbon intensive use of land in Kaifeng City showed a slow,fluctuating and declining trend,and the overall situation was in a generally intensive state.The land input level and land output level were on the rise,while the low-carbon level of land and the degree of land use were on the decline.Currently,the main obstacle factors restricting the low-carbon intensive use of land in Kaifeng City were the carbon structure coefficient of land use,energy consumption per square kilometer,carbon emissions per square kilometer,carbon emissions per capita,and non-agricultural land use efficiency.In the future,it is necessary to further improve the land use structure and promote the high-quality development of Kaifeng City.

Interaction of Land Demand and Supply Effects in Intensive Land Use: a Simulation Study for Chengdu,China

Intensive land use( ILU) policies affect the demand and supply of land. These policies promote efficient land use, and demands for land must therefore be evaluated in terms of the level of land-use intensity. If the demand is considered excessive, ILU policies act like a "valve"to restrict the land supply. Drawing on data from Chengdu,China,where developable land is scarce,we construct a model using system dynamics( SD) to simulate two scenarios: ILU development and non-ILU development. The results show that when ILU leads to positive land-use efficiency,land supply will exceed demand,resulting in an appropriate level of real demand for the current population level and GDP. Thus,artificial demand( inflated by investors) is reduced. By contrast,when non-ILU leads to negative land-use efficiency,land demand will exceed supply. In this scenario,artificial demand is higher than real demand.

Use of Data Mining to Support the Development of Knowledge Intensive CAD

In order to compete in the global manufacturing mar ke t, agility is the only possible solution to response to the fragmented market se gments and frequently changed customer requirements. However, manufacturing agil ity can only be attained through the deployment of knowledge. To embed knowledge into a CAD system to form a knowledge intensive CAD (KIC) system is one of way to enhance the design compatibility of a manufacturing company. The most difficu lt phase to develop a KIC system is to capitalize a huge amount of legacy data t o form a knowledge database. In the past, such capitalization process could only be done solely manually or semi-automatic. In this paper, a five step model fo r automatic design knowledge capitalization through the use of data mining is pr oposed whilst details of how to select, verify and performance benchmarking an a ppropriate data mining algorithm for a specific design task will also be discuss ed. A case study concerning the design of a plastic toaster casing was used as an illustration for the proposed methodology and it was found that the avera ge absolute error of the predictions for the most appropriate algorithm is withi n 17%.

Performance Assessment of the Overall Building Envelope Thermal Performance-Building Envelope Performance(BEP)Metric

Today,to describe the thermal performance of the building envelope and its components we use a variation of metrics;such as,R-value,ACH(air exchange rate per hour),SHGC(solar heat gain coefficient)of windows,U-factor etc.None of these performance indicators is meant to represent the overall thermal performance.In this paper,such a metric is introduced,the BEP(building envelope performance)value.Unlike the thermal resistance,typically expressed as an R-value,the BEP-value considers additional elements of heat transfer that affect the energy demand of the building because of exterior and interior(solar)thermal loads:conductive and radiant heat transfer,and air infiltration.To demonstrate BEP’s utility,validation studies were carried out by comparing the BEP-value to theoretical results using whole building energy simulation tools such as EnergyPlus and WUFI Plus.Results show that BEP calculations are comparable to calculations made using these simulation tools and that unlike other similar metrics,the BEP-value accounts for all heat transfer mechanisms that are relevant for the overall energy performance of the building envelope.The BEP-value thus allows comparing envelopes of buildings with different use types in a fair and realistic manner.

Use of acoustic intensity measurements in underwater acoustics (Modern state and prospects)

This paper discusses scalar and vector characteristics of underwater ambient noise which were explored by the authors and their colleagues in different regions of the Earth Ocean.The measurements presented were performed in 6 Hz - 1000 Hz band, at depths up to 1000 m and wind speeds less than 15 m/s. The following questions are addressed: ratio between edsotropic (coherent) and isotropic (diffusive) parts of ambient noise; noise energy transport and its cotmection with surface waves propagation direction; noise energy flow cancenation by opposite energy flow of signal; signal-to-noise ratio for combined receiver in dynamic noise field. It follows from the results presellted, that further development of underwater intensity measurements opens new opportunities for investigations in the fields of underwater acoustics and oceanology.

Impact of COVID-19 on the energy consumption of commercial buildings:A case study in Singapore

Numerous studies have demonstrated that commercial activities have significantly reduced during COVID-19,while there are few studies disclosing the consequent impacts on the energy consumption of commercial build-ings.This study explores the changes in energy consumption of different types of commercial buildings in Sin-gapore under the impact of the pandemic,using commercial building energy performance data from 2017 to 2020(n=540).The sampled buildings include 93 hotel buildings,303 office buildings,106 retail buildings,and 38 mixed developments.The analysis mainly used linear regression and paired sample t-test.The results showed that relative to 2019,the mean energy use intensity(EUI)of sampled commercial buildings decreased by 56.77 kWh/m^(2)in the pandemic year(2020),a plunge of 19.9%.The extent to which the EUI of each type of commercial building is affected by the pandemic is found as:mixed development>retail>office>hotel.The study also identi-fied the factors that significantly influenced the EUI of commercial buildings before and during the pandemic.The results of the study complement existing knowledge about the factors influencing energy consumption in com-mercial buildings by considering the impact of the pandemic and furthermore contribute to the improvement of energy management in commercial buildings by providing directions for building energy efficiency approaches.

Comprehensive assessment on the ecological stress of rapid land urbanization per proportion, intensity, and location

Aiming at assessing the ecological stress of land urbanization comprehensively,three perspectives are considered and combined,i.e.the amount effect with the proportion of construction lands as the indicator,the intensity effect per the density of environmental pollutant emissions,and the location effect based on their spatial distribution in the heterogeneous landscape.The quantitative results of Southern Jiangsu case in Eastern China show the single-perspective ecological stress are spatially different;the proportion effect is higher in city propers which are more densely populated and industrialized.However,the intensity effect is more significant for units along the Yangtze river where heavy industries are gathered,while the location effect is higher in“ecologically suitable”regions.As the integration of proportion,intensity,and location effects,the comprehensive stress differs across Southern Jiangsu and are also different with the single-perspective results.Dominant stressors of each unit are spatially distinct,which benefits policymakers in targeting their objectives as per primary influencing factors.It is concluded that the comprehensive assessment could efficiently reveal the spatial differentiation of the ecological effects of land urbanization and also the differentiated role of different factors for each unit.

Quantitative measuring and influencing mechanism of urban and rural land intensive use in ChinaQuantitative measuring and influencing mechanism of urban and rural land intensive use in China

Land use issue is an important constraining force to limit economic sustainable development of China. Urban and rural rapid expansion depletes valued land resources under the background of rapid urbanization. An extensive use pattern might cause a serious waste of land resources. The study on influencing mechanism of land intensive use （LIU） in China at the county level is a key tool for effective LIU practice and policy-making. This paper uses OLS model, Spatial Panel Lagged model and Spatial Panel Error model to quantitatively analyze the influencing mechanisms of five class factors and 17 variables supported by GIS （Geographic Information System） and MATLAB. And a comprehensive data set was devel- oped including physical geography and socio-economic information of 2286 counties. Meanwhile, the spatiotemporal pattern of LIU has discussed by means of GIS. The results show that Spatial Panel Data models are slightly superior to OLS model in terms of signifi- cance and confidence level. Regression results of these models indicate that industrialization, urbanization, economic development level, location, transportation and policy have significant impact on LIU of counties. The variables of physical geography are less significant than socio-economic variables. An ignored variable of historical factor, however, became the best significant factor. In the future, the LIU at the county level should take advantage of the new situation by enhancing favorable factors and reducing disadvantageous ones, which can be acquired by improving the entire level and quality of industrialization and urbanization. We argued that an efficient and complete land market and operating system should be built to reflect market-oriented activities at the first place, then, differential LIU regulation policies and measurements should be optimized according to regional differences. In the meantime, we should pay close attention to the carrying capacity of local resources and environments when conducting LIU practices.

Development of evaluation model for intensive land use in urban centers

Starting with exptoration from the perspective of urban spaces, this research was conducted by anatyzing the functionat areas--urban centers with the most hightighted contradictions in terms of intensive land use in order to devetop an evatuation model for intensive land use in urban centers. Based on quantitative research methods, and taking into account three aspects of intensive use, i.e., buitdings, lands and traffic as wetl as muttiple evaluation factors, this paper conducted the research horizontatty by means of quantitative and comparative studies on each individual factor, devetoped the evatuation model for intensive rand use in urban centers, and anatyzed the driving forces of intensive land use from the aspects of buitdings, land use, roads, etc.

Holistic identification and assessment of environmental risks of arable land use in two grain producing areas of China

Taking two typical grain producing areas of southern(Dongting Lake Region)and northern China(Shandong Province)as examples,this study used fault tree analysis and parametric estimation to provide a comparative analysis for environmental risks of intensive arable land use.The results show that(1)in the risks of eutrophication,toxicity,soil structure,greenhouse effect and air pollution,the greenhouse effect was the most prominent with the highest discharge;(2)the Dongting Lake Region discharged less pollutants annually than did Shandong Province,while surpassing Shandong in cumulative pollutant discharge in 2007-2018;(3)the spatial distribution of environmental risk in the Dongting Lake Region was mostly concentrated in the northern area,whereas that in Shandong Province displayed a scattered pattern;(4)in the Dongting Lake Region,Yueyang,Changde,and Yiyang were high environmental risk cities in 2007-2018,whereas in Shandong Province,Zaozhuang,Heze,Liaocheng,and Dezhou exhibited higher comprehensive environmental risk indexes in 2007-2008,while Rizhao replaced them in 2018.The results indicated that ago-production material use must be controlled,reasonable zoning for areas posing environmental risks must be employed and cities with high environmental risk must be dynamically monitored to prevent the intensification of environmental risks of arable land use.

中国土地利用强度及其承载力研究（英文）

Land use intensity quantifies the impacts of human activities on natural ecosystems, which have become the major driver of global environmental change, and thus it serves as an essential measurement for assessing land use sustainability. To date, land-change studies have mainly focused on changes in land cover and their effects on ecological processes, whereas land use intensity has not yet received the attention it deserves and for which spa- tially-explicit representation studies have only just begun. In this paper, according to the de- gree and reversibility of surface disturbance by human activities, there are four main classes of land use intensity： artificial land, semi-artificial land, semi-natural land, and natural land. These were further divided into 22 subclasses based on key indicators, such as human pop- ulation density and the cropping intensity. Land use intensity map of China at a 1-km spatial resolution was obtained based on satellite images and statistical data. The area proportions of artificial land, semi-artificial land, semi-natural land, and natural land were 0.71%, 19.36%, 58.93%, and 21%, respectively. Human and economic carrying capacity increased with the increase of land use intensity. Artificial land supports 24.58% and 35.62% of the total population and GDP, using only 0.71% of the total land, while semi-artificial land supported 58.24% and 49.61% of human population and GDP with 19.36% of China＇s total land area.

中国农地利用变化及其驱动因素--文献述评

Understanding the manifestations and underlying drivers of agricultural land use change in China is of great importance for both domestic and global food security. However, little is known about the holistic pattern of agricultural land use change across China, especially from the perspective of intensity since the evidence has been gathered mainly through case studies at local levels. This study conducts a systemic review of agricultural land use change and its underlying drivers in China by aggregating 169 relevant case studies from 123 publications. The cases related to intensification and disintensification, which are the two types of agricultural land use change, are generally equal, accounting for 50% of the total number of cases. Intensification and disintensification can be further divided into the same three categories: expansion/contraction of agricultural land, changes in agricultural land use activities and changes in land management intensity. Demographic, economic, technological, and institutional drivers, together with location factors, are frequently noted as significant underlying drivers, while sociocultural drivers and farm(er) characteristics are less frequently recognized. Finally, three major land use change trajectories are summarized mainly concerning rising labor costs and the concomitant increase in off-farm employment, the ecological improvement policy, and advances in agricultural technology.

Thermal performance of a lightweight building with phase change material under a humid subtropical climate

The use of phase change materials(PCMs)in building enclosures is an efficient way to reduce the heat gain and/or loss in summer and winter.It was evident that the thermal performance of buildings with PCMs was affected by the outdoor air temperature significantly.However,the influence of humidity,which was serious in the humid subtropical climate was unclear.To explore the effect of PCMs under a humid subtropical climate,the thermal performance of a lightweight building outfitted with PCMs with a melting temperature of 25°C was investigated.The actual outdoor air temperature with a humidity of 40-90 RH%and wind velocity of 2-6 m/s blowing from the east,west,south,and north was assumed for the performance assessment.A simulated model was developed using EnergyPlus and verified against experimental data.The energy savings by using PCMs was reduced from 3.9%to 2.6%when the outdoor humidity increased from 40 to 90 RH%in summer.However,the savings was not obvious in winter.Annual energy savings decreased from 1.64%to 1.32%with humidity increasing from 40 to 90 RH%.For annual condition,the average energy savings was reduced from 1.43%to 0.92%when the wind speed increased from 2 m/s to 6 m/s.From an economic point of view,the investment payback period was less than 10 years when the PCM price was lower than 18.0 Yuan/kg.

栽培陆地使用紧张的时间空间的差别分析基于在中国的波伊昂·莱克·埃科科诺米克地区的 emergy

Taking the emergy requirements of the five input indexes as the foundation, this paper analyzes the total temporal and spatial changes in cultivated land use intensity in the Poyang Lake Eco-economic Zone from 2000 to 2010. The results are obtained as follows： （1） Over a period of 10 years, the cultivated land use intensity has increased exponentially in the Poyang Lake Eco-economic Zone; agricultural machinery intensity has been the largest proportion of the total inputs, comprising more than 99.50% and increasing year by year, which indicates that agricultural mechanization is a basic trend in agricultural development in the Poyang Lake Eco-economic Zone. （2） The total number of counties belonging to the moderate- and low- intensity cultivated land use categories is the largest, while the number of counties belonging to the high-intensity cultivated land use and extensive cultivated land use categories is the smallest. （3） This zone can be divided into five areas： an eastern area of high-intensity cultivated land use, a central and eastern area of low-intensity cultivated land use, a central area of low-intensity cultivated land use, a southern area of moderate-intensity cultivated land use, and a northern area of moderate-intensity cultivated land use. （4） The counties which had a coordinated development between cultivated land use intensity and their socio-economic development level increase year by year, and the socio-economic development level had increasingly obvious effects on the cultivated land use intensity. Finally, this paper presents suggestions for the development of cultivated land use intensity in the Poyang Lake Eco-economic Zone, especially for different levels of intensity among counties.

Wheat yield convergence and its driving factors in countries along the Belt and Road

Improving the wheat yield of countries along the Belt and Road(BR)plays a core role in ensuring global food security.However,little attention has been paid to the wheat yield variation and the determinants across these countries.This paper analyzes wheat yield convergence in countries along the BR using the club-convergence test.The empirical results show that instead of one convergence for all countries along the BR,the wheat yields are converging into three clubs.Furthermore,we investigate the impact of climate change and agricultural production technology on wheat yield convergence,and find that countries along the BR with a one degree Celsius increase in temperature are 36.5%(32.7%)more likely to converge to the high-level yield club.This may be related to the lower frequency of frost and higher photosynthetic capacity of wheat.We also find that a one kilogram increase in fertilizer application per hectare will result in a 0.4%(0.5%)higher probability of countries along the BR converging to the high-level yield club.Countries along the BR should pay more attention to coordinating production technologies and climate change to ensure food security.