In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,a...In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.展开更多
To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection ...To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection in the core grain pro- duction region. Based on the deep analysis on the land resources characteristics and problems using the combined method of literature review method with qualita- tive and quantitative analysis, we constructed the land resource security system for different categories according to the land use principles of optimization, intensivism, improvement, and overall planning, and proposed the corresponding supporting mea- sures. The results showed that controlling the new increase, promoting the reclama- tion and improvement of land are the basis for land resource security, clearing the idle, improving the utilization rate of stock are the core of the efficient use of land resources, and establishing a unified urban and rural construction land market is the key to promoting the economical and intensive utilization of land resources, provid- ing scientific basis for the sustainable utilization of land resources in the core grain production regions.展开更多
Fenlong green ecological agriculture technology (Fenlong technology), a new smash ridging farming method developed by Guangxi Academy of Agdcultural Sciences, has been elected as the recommended cultivation techniqu...Fenlong green ecological agriculture technology (Fenlong technology), a new smash ridging farming method developed by Guangxi Academy of Agdcultural Sciences, has been elected as the recommended cultivation technique by the Ministry of Agriculture of China. It replaces the traditional plowshare with spiral drill, and its tilth depth is twice deeper than that by tractor tilthing. It also extends soil nutrient, moisture, oxygen and microorganism, the so-called "Four pools". Soil nutrient, oxygen, microorganism, light and rainfall use ratio is increased by 10%-100%, creating a platform for natural increase of more than 10% of crop yield. Its application to over 20 kinds of crops in 21 provinces has proved that the yield increases 10-30% with quality enhancing 5% and double water retaining capacity but no more input. When the application area of Fenlong could reach 67 million hm2, the amount of fertilizer can be reduced by 40-50 billion kg, saving 120-150 billion Yuan. In this paper, we put forward the strategy of "4+1" (arable, saline-alkali soil, grasslands, Sponge City + rivers) green development in China, and deepened the Fenlong cultivated tilled layer from 16.5 cm to 35 cm for 67 million hm2 arable land, ridged 13.3 million hm2 of saline-alkali soil for 35 cm, and also 35 cm for 67 million hm2 degraded steppe, which could have the following 3 effects: first, the 147 million hm2 of land with Fenlong cultivation could increase loosing soil to 315.491 billion m3, in* creasing by 159.26% for 120 million hm2 of arable land with the average tilled layer of 16.5 cm, which has loosing soil of only 198.1 billion m3, that is, the space of the land increases 1.6 times. Second, every hectare of plowland could store up to 450 m3/hm2 of natural rainfall, and the unused 60 m3 of saline-alkali soil and grasslands could store water of 102 billion m3, showing an increase of over 88.89% for the current plowland storage of 54 billion m3 at now, that is, double the natural rainfall storage capacity. Third, the two multiple increase of natural resources application can bring trillions of resource activation, environmental cleaning, food security, citizens, health, economic, ecological and social benefits, and makes the Chinese nation move forward in green development. Its application in "big scientific research" and "One Belt And One Road" will contribute Chinese strength to the world.展开更多
Although understood differently in different parts of the world, conservation tillage usually includes leaving crop residues on the soil surface to reduce tillage. Through a global review of long-term conservation til...Although understood differently in different parts of the world, conservation tillage usually includes leaving crop residues on the soil surface to reduce tillage. Through a global review of long-term conservation tillage research, this paper discusses the long-term effect of conservation tillage on sustainable land use, nutrient availability and crop yield response. Research has shown several potential benefits associated with conservation tillage, such as potential carbon sequestration, nutrient availability, and yield response. This research would provide a better perspective of the role of soil conservation tillage and hold promise in promoting application of practical technologies for dryland farming systems in China.展开更多
Land-use change is an important aspect of global environment change. It is,in a sense, the direct result of human activities influencing our physical environment. Supported bythe dynamic serving system of national res...Land-use change is an important aspect of global environment change. It is,in a sense, the direct result of human activities influencing our physical environment. Supported bythe dynamic serving system of national resources, including both the environment database and GIStechnology, this paper analyzed the land-use change in northeastern China in the past ten years(1990 ― 2000). It divides northeastern China into five land-use zones based on the dynamic degree(DD) of land-use: woodland/grassland ― arable land conversion zone, dry land ― paddy fieldconversion zone, urban expansion zone, interlocked zone of farming and pasturing, and reclamationand abandoned zone. In the past ten years, land-use change of northeastern China can be generalizedas follows: increase of cropland area was obvious, paddy field and dry land increased by 74. 9 and276. 0 thousand ha respectively; urban area expanded rapidly, area of town and rural residenceincreased by 76. 8 thousand ha; area of forest and grassland decreased sharply with the amount of1399. 0 and 1521. 3 thousand ha respectively; area of water body and unused land increased by 148. 4and 513. 9 thousand ha respectively. Besides a comprehensive analysis of the spatial patterns ofland use, this paper also discusses the driving forces in each land-use dynamic zones. The studyshows that some key biophysical factors affect conspicuously the conversion of different land-usetypes. In this paper, the relationships between land-use conversion and DEM, accumulated temperature(≥10℃) and precipitation were analysed and represented. We conclude that the land-use changes innortheast China resulted from the change of macro social and economic factors and local physicalelements. Rapid population growth and management changes, in some sense, can explain the shaping ofwoodland/grassland ― cropland conversion zone. The conversion from dry land to paddy field in thedry land ― paddy field conversion zone, apart from the physical elements change promoting theexpansion of paddy field, results from two reasons: one is that the implementation of market-economyin China has given fanners the right to decide what they plant and how they plant their crops, theother factor is originated partially from the change of dietary habit with the social and economicdevelopment. The conversion from paddy field to dry land is caused primarily by the shortfall ofirrigation water, which in turn is caused by poor water allocation managed by local governments. Theshaping of the reclamation and abandoned zone is partially due to the lack of environmentprotection consciousness among pioneer settlers. The reason for the conversion from grassland tocropland is the relatively higher profits of farming than that of pasturing in the interlocked zoneof farming and pasturing. In northeastern China, the rapid expansion of built-up areas results fromtwo factors: the first is its small number of towns; the second comes from the huge potential forexpansion of existing towns and cities. It is noticeable that urban expansion in the northeasternChina is characterized by gentle topographic relief and low population density. Physiognomy,transportation and economy exert great influences on the urban expansion.展开更多
The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestio...The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households' behavior. This paper selected I l factors covering four aspects of rural households' family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households' questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang (Yangtze) River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households' behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.展开更多
Tropical Asia is a region comprising South and Southeast Asia and under strong influence of the Asianmonsoon climate. It is characterized by an extremely high population density and by high land use intensity.Paddy ri...Tropical Asia is a region comprising South and Southeast Asia and under strong influence of the Asianmonsoon climate. It is characterized by an extremely high population density and by high land use intensity.Paddy rice cultivation is the most important form of agriculture in the greater part of the region. Soilresources of tropical Asia have a specific feature in comparison with tropical Africa and America. Ultisolsdominate in uplands, and lowland soils like Inceptisols and Histosols are relatively abundant. The latterpoint is made clearer if we take the landforms of the region with a vast extent of lowlands into consideration.Geologically, tropical Asia with the Himalayan orogeny and active volcanism exhibits a conspicuous contrastto tropical Africa and America with the dominance of the shield structure. This along with the monsoonclimate should have determined the basic features of landforms and soil, and accordingly all the agriculturaland social characteristics of tropical Asia today. Although paddy rice cultivation in the lowland is highlysustainable, upland cultivation in extensive Ultisol areas tends to be handicapped by low fertility and higherodibility of the soil, resulting in low sustainability. Land shortage is compelling people to exploit slopelandsin hills and mountains, on the one hand, and thus far unutilized coastal lowlands, on the other. Both ofthese new reclamations are facing to serious land degradation problems today. Tropical Asia will continueto be the most densely populated region of the world with ever-increasing population. In order to meet theincreasing food demand lowland rice cultivation should be intensified by the infrastructure development toease the stresses on slopelands and vulnerable coastal lowlands. At the same time, upland crop productionin Ultisol areas should be stabilized and enhanced, providing integrated nutrient management and measuresfor soil conservation.展开更多
The problem of price scissors difference between industrial products and agricultural products is one of the important problems in China. It impacts not only the living standard improvement of farmers but also the eco...The problem of price scissors difference between industrial products and agricultural products is one of the important problems in China. It impacts not only the living standard improvement of farmers but also the economic value of cultivated land, furthermore results in the direct and indirect loss of cultivated land resources. China's cultivated land area has decreased dramatically in recent years. An important reason for the decrease is the relatively low cost of cultivated land occupancy, which results from the distortion of economic value of cultivated land due to the existence of scissors difference. This study firstly analyzed the dynamic change of scissors difference and calculated the absolute and relative magnitude of scissors difference from 1997 to 2002, then computed the economic value of cultivated land before and after scissors difference adjustment in 2002, and finally discussed the inverted scissors difference. Results suggest that the scissors difference has a remarkable impact on the economic value of cultivated land, and the adjustment of scissors difference even inverted scissors difference to the economic value of cultivated land is indisoensable.展开更多
The studies of driving forces of regional land use change (LUC) are to reveal the real motivation behind the LUC and its interacting mechanism, so as to simulate and predict the process of LUC. Presently, studies root...The studies of driving forces of regional land use change (LUC) are to reveal the real motivation behind the LUC and its interacting mechanism, so as to simulate and predict the process of LUC. Presently, studies rooting from different natural and socio-economic backgrounds and from different scales have deepened the people’s understanding and cognition to driving forces of regional LUC. Biophysical driving forces are relatively stable, and have the cumulating effects. Human driving forces are relatively active, and are main driving forces of short-term regional LUC. Existing regional LUC models can answer the three main problems: which contribution (why), which location (where) and what rate (when). But, regional land use system is defined as the self-organized system, usually affected by the cri- tical value area and sudden change, and controlled by different stages. To reduce the impact of critical threshold and break on land use system, the studies of LUC driving forces will aim at following priority areas: data linkage between remote sensing and no-remote sensing data; underlying driving force identification; driving factor quantification; driving factor scale dependence; and driving process integration simulation.展开更多
Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The natur...Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The nature of sustainable use of land resource is to retain the quantity and productivity of land resource from generation to generation.The evaluation of sustainable use of land resource is an important method to ensure land use to get onto the sustainable track. Furthermore, building index system is the key of the evaluation. In view of tendency of the evaluation indexes chosen so widely, the evaluation indexes should include only three kinds in the researches on the evaluation of sustainable use of land resource. The first is the stock and structure index of land resource, viz. Areas quantity structure of land resources. In China, it is especially paid attention to the per person index of land quantity and rate between cultivated land and farmland. The second is the productive index of land, which includes the productivity, potentiality, stability and renewal situation of land. The third is the sustained index of land environment. On the evaluation research of area level, we should lay particular emphasis on statistic indexes. With a case of Guangxi Zhuang Autonomous Region in China, the evaluation index system of sustainable land use in county area has been built in this thesis. Using the weighted average method to calculate the means of sustainable land use in each county, according to the land using situation, all counties in the autonomous region have been divided into three types. (1) Sustainable Pattern contains 18 counties, which have higher land resource productivity, stronger sustained abilities of land environment .The economic benefits of land using in these counties are obviously higher. These counties have gotten highly intensive farming, and they are all in the good circumstance. (2) Basically Sustained Pattern contains 48 counties, which productivity of land resource is of middle level. In part of counties and cities, the stock of land resource inclines to lower level, but their land using potentialities are still greater. Through changing land using pattern, these counties can rapidly enter in a good circumstance. (3) Critically Sustained Pattern contains 14 counties, which are mostly in the karst mountain areas. They have less stock of land resource, lower productivity and more extensive cultivation. The productivity of land renewing has been hindered, so it urgently need to be renovated. At last, the writers have explored the basic ways of sustainable use of land resource in Guangxi, China — (1) Retain the stock of land resource and strictly manage farmland uses. (2) Strengthen the value accounting of land resource, and control the farmland occupation of non agricultural construction. (3) Depend on technology advanced, optimize the land using structure, and promote the productive level. (4) Carry out land management all round, and improve the ecological environment of land resource. (5) Enhance evaluation researche and land monitoring, and promote the sustainable utilization level of land resource.展开更多
The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological res...The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone.展开更多
Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants (HOCs). The major factors limiting phytoremediation are the mass transfer, ra...Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants (HOCs). The major factors limiting phytoremediation are the mass transfer, rate of plant uptake, and microbial biodegradation of HOCs. This article discusses the potential of surfactants to enhance desorption, plant uptake, and biodegradation of HOCs in the contaminated sites. Positive effects of surfactants on phytoremediation have been recently observed in greenhouse studies. The presence of some nonionic surfactants including polyoxyethylene sorbltan monooleate (Tween 80) and polyoxyethylene(23)dodecanol (Brij35) at relatively low concentrations resulted in significant positive effects on phytoremediation for pyrene-contaminated soil. However, the anionic surfactant (sodium dodecyl sulfate, SDS) and the cationic surfactant (cetyltrimethylammonium bromide, CTMAB) were not useful because of their phytotoxicity or low efficiency for surfactant-enhanced phytoremediation (SEPR). The mechanisms of SEPR for HOC-contaminated sites were evaluated by considering experimental observations. In view of concerns about the cost effectiveness and toxicity of surfactants to plants, more research is needed to enhance the use of SEPR technology.展开更多
New Zealand is highly dependent on its soil resource for continued agricultural production. To avoiddepleting this resource, there is a need to identify soils and associated land management practices wherethere is a r...New Zealand is highly dependent on its soil resource for continued agricultural production. To avoiddepleting this resource, there is a need to identify soils and associated land management practices wherethere is a risk of soil degradation. Environmental integrity and ecosystem services also need to be maintained.Accordingly, to ensure sustainable production, the on- and off-site environmental impacts of land managementneed to be identified and managed. We developed a structural vulnerability index for New Zealand soils. Thisindex ranks soils according to their inherent susceptibility to physical degradation when used for agricultural(pasture, forestry and cropping) purposes. We also developed a rule-based model to assess soil compactionvulnerability by characterising the combined effects of resistance and resilience. Other soil attributes havebeen appraised using seven chemical, physical and biological indicators of soil quality. These indicators havebeen applied in a nation-wide project involving data collection from over 500 sites for a range of land uses.These soil quality data can be interpreted via the World Wide Web - through the interactive decision-support tool SINDI. The land-use impact model is a framework to assess agricultural land management andenvironmental sustainability, and may be applied to land units at any scale. Using land resource data andinformation the model explicitly identifies hazards to land productivity and environmental integrity. It utilisesqualitative expert and local knowledge and quantitative model-based evaluations to assess the potentialenvironmental impacts of land-management practices. The model is linked to a geographic informationsystem (GIS), allowing model outputs, such as the environmental impacts of site-specific best managementpractices, to be identified in a spatially explicit manner. The model has been tested in New Zealand in anarea of pastoral land use. Advantages of this risk identification model include: utilising current knowledge ofthe causes and effects of land-management practices on soil degradation; linking land management practiceto both on- and off-site environmental consequences; identifying important gaps in local knowledge; andproviding spatially explicit information on the environmental impact of land-management practices.展开更多
Based on Tupu theory, this paper studied the dynamic changes, conversion modes, expansion intensity and landscape attributes of the saline-alkali lands in Changling County, Zhenlai County and Da'an City of the wes...Based on Tupu theory, this paper studied the dynamic changes, conversion modes, expansion intensity and landscape attributes of the saline-alkali lands in Changling County, Zhenlai County and Da'an City of the western Jilin Province in 1980-2000 with the help of GIS. The results show that the saline-alkali land rather sharply increased in Da'an during 1995-2000; the main conversion processes in the three counties were from grassland to saline-alkali land and from saline-alkali land to grassland; and the typical shapes, spatial expansion speed and mode, and landscape attributes of the saline-alkali land were different in the three counties, which were closely related to local topography, predominant wind orientation, water resources distribution, etc. The corresponding spatial expansion mode was marginality in Changling, random in Zhenlai and more kernels in Da'an, respectively. Landscape attributes also responded to the spatial-temporal dynamic changes of the saline-alkali land and the landscape indices of Da'an fluctuated greatly. The frame of this research may provide fundamental reference for landscape analysis and give some suggestions for regional sustainable development.展开更多
The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practic...The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practices. The values of abundance, species richness, diversity and evenness were significantly larger in OT and ON than in CT, indicating that the abundance and diversity in organic farming fields were greater than those in conventional farming. The community structure of enchytraeid genera was different between OT and ON. Enchytraeus was the most abundant in OT, while Fridericia in ON. The abundance of oribatids in OT was similar to that in ON, while the species richness and diversity in the former were smaller. These results suggested that no-tillage practice under organic management might contribute to the improvement in quality of soil mesofauna.展开更多
Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. I...Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.展开更多
A micro-level analysis on man-land system is important in understanding the content of human geography in rural areas, particularly in the different regions. This paper is based on a survey undertaken in the three vil...A micro-level analysis on man-land system is important in understanding the content of human geography in rural areas, particularly in the different regions. This paper is based on a survey undertaken in the three villages of Wugou Village, Hutuo Village, and Xiaonan Village of Gongyi City, ltenan Province in April 2003. The survey covers three types of economic and social activities from 214 households. Data collected include 120 attributes for each household. By using theories from the relevant disciplines such as geography, mathcmatics, physics, ecology, and system sciences, this paper develops a framework employing the concept of system entropy in the status function of the man-land system. In this framework, the entropy change is used to show the evolution of the system, and the entropy flow to express the flow among the spatial parts of the system. Following the framework, and using a large set of household data from surveys, the paper makes a quantitative analysis of the village-level man-land system from a micro-perspective. After a theoretical investigation, the corresponding strategies in the paper are then put forward in order to adjust the unbalanced trend of the village man-land system from both perspectives of small-area and individual actors.展开更多
Languages and linguistic resources transport from one locality to another,adapting to the norms,customs,and regulations of a new locality.This process involves translocalization.Translocalization emphasizes the moveme...Languages and linguistic resources transport from one locality to another,adapting to the norms,customs,and regulations of a new locality.This process involves translocalization.Translocalization emphasizes the movement of linguistic resources against the backdrop of globalization and the combination or reframing of resources from different localities.This research explores the extent to which translocalization is reflected by the linguistic landscapes of three distinct commercial areas in Guangzhou,China.It goes on to discuss how translocalization works together with social rescaling to incur the movement of linguistic resources and to result in distinct linguistic landscapes of the three commercial areas.It concludes that some languages or linguistic resources,such as English,pinyin and traditional Chinese writing,are transported to local contexts for the purpose of rescaling,whereas other languages or dialects,like Cantonese,might gradually lose their function of rescaling and retain its function in indexing local identity and solidarity.This study calls for more attention to the local resources and contexts in linguistic landscape studies.It argues for the indexical function of linguistic resources in social rescaling and city planning.展开更多
文摘In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.
文摘To solve the contradiction between supply and demand of land, the con- struction of land resource security guarantee system is an important part to coordi- nate the economic development and cultivated land protection in the core grain pro- duction region. Based on the deep analysis on the land resources characteristics and problems using the combined method of literature review method with qualita- tive and quantitative analysis, we constructed the land resource security system for different categories according to the land use principles of optimization, intensivism, improvement, and overall planning, and proposed the corresponding supporting mea- sures. The results showed that controlling the new increase, promoting the reclama- tion and improvement of land are the basis for land resource security, clearing the idle, improving the utilization rate of stock are the core of the efficient use of land resources, and establishing a unified urban and rural construction land market is the key to promoting the economical and intensive utilization of land resources, provid- ing scientific basis for the sustainable utilization of land resources in the core grain production regions.
文摘Fenlong green ecological agriculture technology (Fenlong technology), a new smash ridging farming method developed by Guangxi Academy of Agdcultural Sciences, has been elected as the recommended cultivation technique by the Ministry of Agriculture of China. It replaces the traditional plowshare with spiral drill, and its tilth depth is twice deeper than that by tractor tilthing. It also extends soil nutrient, moisture, oxygen and microorganism, the so-called "Four pools". Soil nutrient, oxygen, microorganism, light and rainfall use ratio is increased by 10%-100%, creating a platform for natural increase of more than 10% of crop yield. Its application to over 20 kinds of crops in 21 provinces has proved that the yield increases 10-30% with quality enhancing 5% and double water retaining capacity but no more input. When the application area of Fenlong could reach 67 million hm2, the amount of fertilizer can be reduced by 40-50 billion kg, saving 120-150 billion Yuan. In this paper, we put forward the strategy of "4+1" (arable, saline-alkali soil, grasslands, Sponge City + rivers) green development in China, and deepened the Fenlong cultivated tilled layer from 16.5 cm to 35 cm for 67 million hm2 arable land, ridged 13.3 million hm2 of saline-alkali soil for 35 cm, and also 35 cm for 67 million hm2 degraded steppe, which could have the following 3 effects: first, the 147 million hm2 of land with Fenlong cultivation could increase loosing soil to 315.491 billion m3, in* creasing by 159.26% for 120 million hm2 of arable land with the average tilled layer of 16.5 cm, which has loosing soil of only 198.1 billion m3, that is, the space of the land increases 1.6 times. Second, every hectare of plowland could store up to 450 m3/hm2 of natural rainfall, and the unused 60 m3 of saline-alkali soil and grasslands could store water of 102 billion m3, showing an increase of over 88.89% for the current plowland storage of 54 billion m3 at now, that is, double the natural rainfall storage capacity. Third, the two multiple increase of natural resources application can bring trillions of resource activation, environmental cleaning, food security, citizens, health, economic, ecological and social benefits, and makes the Chinese nation move forward in green development. Its application in "big scientific research" and "One Belt And One Road" will contribute Chinese strength to the world.
基金Project supported by the National Natural Science Foundation of China (No.40571151)the Beijing Key Lab of Resources Environment and GIS at Capital Normal Universitythe National High Technology Research and Development Program of China (863 Program) (Nos. 2002AA2Z4311 and 2002AA2Z4021).
文摘Although understood differently in different parts of the world, conservation tillage usually includes leaving crop residues on the soil surface to reduce tillage. Through a global review of long-term conservation tillage research, this paper discusses the long-term effect of conservation tillage on sustainable land use, nutrient availability and crop yield response. Research has shown several potential benefits associated with conservation tillage, such as potential carbon sequestration, nutrient availability, and yield response. This research would provide a better perspective of the role of soil conservation tillage and hold promise in promoting application of practical technologies for dryland farming systems in China.
文摘Land-use change is an important aspect of global environment change. It is,in a sense, the direct result of human activities influencing our physical environment. Supported bythe dynamic serving system of national resources, including both the environment database and GIStechnology, this paper analyzed the land-use change in northeastern China in the past ten years(1990 ― 2000). It divides northeastern China into five land-use zones based on the dynamic degree(DD) of land-use: woodland/grassland ― arable land conversion zone, dry land ― paddy fieldconversion zone, urban expansion zone, interlocked zone of farming and pasturing, and reclamationand abandoned zone. In the past ten years, land-use change of northeastern China can be generalizedas follows: increase of cropland area was obvious, paddy field and dry land increased by 74. 9 and276. 0 thousand ha respectively; urban area expanded rapidly, area of town and rural residenceincreased by 76. 8 thousand ha; area of forest and grassland decreased sharply with the amount of1399. 0 and 1521. 3 thousand ha respectively; area of water body and unused land increased by 148. 4and 513. 9 thousand ha respectively. Besides a comprehensive analysis of the spatial patterns ofland use, this paper also discusses the driving forces in each land-use dynamic zones. The studyshows that some key biophysical factors affect conspicuously the conversion of different land-usetypes. In this paper, the relationships between land-use conversion and DEM, accumulated temperature(≥10℃) and precipitation were analysed and represented. We conclude that the land-use changes innortheast China resulted from the change of macro social and economic factors and local physicalelements. Rapid population growth and management changes, in some sense, can explain the shaping ofwoodland/grassland ― cropland conversion zone. The conversion from dry land to paddy field in thedry land ― paddy field conversion zone, apart from the physical elements change promoting theexpansion of paddy field, results from two reasons: one is that the implementation of market-economyin China has given fanners the right to decide what they plant and how they plant their crops, theother factor is originated partially from the change of dietary habit with the social and economicdevelopment. The conversion from paddy field to dry land is caused primarily by the shortfall ofirrigation water, which in turn is caused by poor water allocation managed by local governments. Theshaping of the reclamation and abandoned zone is partially due to the lack of environmentprotection consciousness among pioneer settlers. The reason for the conversion from grassland tocropland is the relatively higher profits of farming than that of pasturing in the interlocked zoneof farming and pasturing. In northeastern China, the rapid expansion of built-up areas results fromtwo factors: the first is its small number of towns; the second comes from the huge potential forexpansion of existing towns and cities. It is noticeable that urban expansion in the northeasternChina is characterized by gentle topographic relief and low population density. Physiognomy,transportation and economy exert great influences on the urban expansion.
基金Under the auspices of the National Natural Science Foundation of China (No. 70373029)
文摘The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households' behavior. This paper selected I l factors covering four aspects of rural households' family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households' questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang (Yangtze) River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households' behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.
文摘Tropical Asia is a region comprising South and Southeast Asia and under strong influence of the Asianmonsoon climate. It is characterized by an extremely high population density and by high land use intensity.Paddy rice cultivation is the most important form of agriculture in the greater part of the region. Soilresources of tropical Asia have a specific feature in comparison with tropical Africa and America. Ultisolsdominate in uplands, and lowland soils like Inceptisols and Histosols are relatively abundant. The latterpoint is made clearer if we take the landforms of the region with a vast extent of lowlands into consideration.Geologically, tropical Asia with the Himalayan orogeny and active volcanism exhibits a conspicuous contrastto tropical Africa and America with the dominance of the shield structure. This along with the monsoonclimate should have determined the basic features of landforms and soil, and accordingly all the agriculturaland social characteristics of tropical Asia today. Although paddy rice cultivation in the lowland is highlysustainable, upland cultivation in extensive Ultisol areas tends to be handicapped by low fertility and higherodibility of the soil, resulting in low sustainability. Land shortage is compelling people to exploit slopelandsin hills and mountains, on the one hand, and thus far unutilized coastal lowlands, on the other. Both ofthese new reclamations are facing to serious land degradation problems today. Tropical Asia will continueto be the most densely populated region of the world with ever-increasing population. In order to meet theincreasing food demand lowland rice cultivation should be intensified by the infrastructure development toease the stresses on slopelands and vulnerable coastal lowlands. At the same time, upland crop productionin Ultisol areas should be stabilized and enhanced, providing integrated nutrient management and measuresfor soil conservation.
文摘The problem of price scissors difference between industrial products and agricultural products is one of the important problems in China. It impacts not only the living standard improvement of farmers but also the economic value of cultivated land, furthermore results in the direct and indirect loss of cultivated land resources. China's cultivated land area has decreased dramatically in recent years. An important reason for the decrease is the relatively low cost of cultivated land occupancy, which results from the distortion of economic value of cultivated land due to the existence of scissors difference. This study firstly analyzed the dynamic change of scissors difference and calculated the absolute and relative magnitude of scissors difference from 1997 to 2002, then computed the economic value of cultivated land before and after scissors difference adjustment in 2002, and finally discussed the inverted scissors difference. Results suggest that the scissors difference has a remarkable impact on the economic value of cultivated land, and the adjustment of scissors difference even inverted scissors difference to the economic value of cultivated land is indisoensable.
基金Under the auspices of the National Natural Science Foundation of China (No. 49771073) and Key Project of ChineseAcademy of Sciences (No. KZ952-J1-203)
文摘The studies of driving forces of regional land use change (LUC) are to reveal the real motivation behind the LUC and its interacting mechanism, so as to simulate and predict the process of LUC. Presently, studies rooting from different natural and socio-economic backgrounds and from different scales have deepened the people’s understanding and cognition to driving forces of regional LUC. Biophysical driving forces are relatively stable, and have the cumulating effects. Human driving forces are relatively active, and are main driving forces of short-term regional LUC. Existing regional LUC models can answer the three main problems: which contribution (why), which location (where) and what rate (when). But, regional land use system is defined as the self-organized system, usually affected by the cri- tical value area and sudden change, and controlled by different stages. To reduce the impact of critical threshold and break on land use system, the studies of LUC driving forces will aim at following priority areas: data linkage between remote sensing and no-remote sensing data; underlying driving force identification; driving factor quantification; driving factor scale dependence; and driving process integration simulation.
文摘Sustainable use of natural resources is different from sustainable development. As the most important natural resource, sustainable use of land resource is the essential guarantee of sustainable development. The nature of sustainable use of land resource is to retain the quantity and productivity of land resource from generation to generation.The evaluation of sustainable use of land resource is an important method to ensure land use to get onto the sustainable track. Furthermore, building index system is the key of the evaluation. In view of tendency of the evaluation indexes chosen so widely, the evaluation indexes should include only three kinds in the researches on the evaluation of sustainable use of land resource. The first is the stock and structure index of land resource, viz. Areas quantity structure of land resources. In China, it is especially paid attention to the per person index of land quantity and rate between cultivated land and farmland. The second is the productive index of land, which includes the productivity, potentiality, stability and renewal situation of land. The third is the sustained index of land environment. On the evaluation research of area level, we should lay particular emphasis on statistic indexes. With a case of Guangxi Zhuang Autonomous Region in China, the evaluation index system of sustainable land use in county area has been built in this thesis. Using the weighted average method to calculate the means of sustainable land use in each county, according to the land using situation, all counties in the autonomous region have been divided into three types. (1) Sustainable Pattern contains 18 counties, which have higher land resource productivity, stronger sustained abilities of land environment .The economic benefits of land using in these counties are obviously higher. These counties have gotten highly intensive farming, and they are all in the good circumstance. (2) Basically Sustained Pattern contains 48 counties, which productivity of land resource is of middle level. In part of counties and cities, the stock of land resource inclines to lower level, but their land using potentialities are still greater. Through changing land using pattern, these counties can rapidly enter in a good circumstance. (3) Critically Sustained Pattern contains 14 counties, which are mostly in the karst mountain areas. They have less stock of land resource, lower productivity and more extensive cultivation. The productivity of land renewing has been hindered, so it urgently need to be renovated. At last, the writers have explored the basic ways of sustainable use of land resource in Guangxi, China — (1) Retain the stock of land resource and strictly manage farmland uses. (2) Strengthen the value accounting of land resource, and control the farmland occupation of non agricultural construction. (3) Depend on technology advanced, optimize the land using structure, and promote the productive level. (4) Carry out land management all round, and improve the ecological environment of land resource. (5) Enhance evaluation researche and land monitoring, and promote the sustainable utilization level of land resource.
基金Foundation item:Under the auspices of the Special Scientific Research of the Ministry of Land and Resources of China(No.201411009)
文摘The agro-pastoral ecotone has been recognized as the main distribution area of reserved land resource for cultivation. Accordingly, clarifying this assumption, as well as concerting land reclamation and ecological restoration, is important to ensure food security and environmental improvement in the agro-pastoral ecotone. We selected Horqin Left Back Banner(HLBB) as the subject of our case study. The landscape ecological security pattern of this area was determined using the minimum cumulative resistance model. Over-cultivation, quantity of reserved land resource for cultivation, and changes in landscape indexes before and after land use adjustment were then analyzed. Over-cultivation is a serious problem in the agro-pastoral ecotone. Reserved land resource for cultivation is less than that considered previously, and the area of reserved land resource for cultivation in HLBB only accounts for 11.50% of total uncultivated land. With regard to changes in landscape indexes, the adjusted land use pattern is effective for anti-desertification. The compensation standard for abandoned cultivated land should be improved and the comprehensive results of ‘Grain for Green' should be evaluated to further implement ecological restoration in the agro-pastoral ecotone.
基金the National Natural Science Foundation of China (No.20507009)the Program for New Century Excellent Talents in University (NCET) of the Ministry of Education of China,the Natural Science Foundation of Jiangsu Province for Outstanding Young Scientist (No.BK2006518)and the International Foundation for Science (No.C/3958-1).
文摘Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants (HOCs). The major factors limiting phytoremediation are the mass transfer, rate of plant uptake, and microbial biodegradation of HOCs. This article discusses the potential of surfactants to enhance desorption, plant uptake, and biodegradation of HOCs in the contaminated sites. Positive effects of surfactants on phytoremediation have been recently observed in greenhouse studies. The presence of some nonionic surfactants including polyoxyethylene sorbltan monooleate (Tween 80) and polyoxyethylene(23)dodecanol (Brij35) at relatively low concentrations resulted in significant positive effects on phytoremediation for pyrene-contaminated soil. However, the anionic surfactant (sodium dodecyl sulfate, SDS) and the cationic surfactant (cetyltrimethylammonium bromide, CTMAB) were not useful because of their phytotoxicity or low efficiency for surfactant-enhanced phytoremediation (SEPR). The mechanisms of SEPR for HOC-contaminated sites were evaluated by considering experimental observations. In view of concerns about the cost effectiveness and toxicity of surfactants to plants, more research is needed to enhance the use of SEPR technology.
基金Project supported by the Foundation for Science,Research and Technology,New Zealand(Contract CO9X0016)by the New Zealand Ministry for the Environment Sustainable Management Fund(Contract 5089)and by the following Regional Councils of New Zealand:
文摘New Zealand is highly dependent on its soil resource for continued agricultural production. To avoiddepleting this resource, there is a need to identify soils and associated land management practices wherethere is a risk of soil degradation. Environmental integrity and ecosystem services also need to be maintained.Accordingly, to ensure sustainable production, the on- and off-site environmental impacts of land managementneed to be identified and managed. We developed a structural vulnerability index for New Zealand soils. Thisindex ranks soils according to their inherent susceptibility to physical degradation when used for agricultural(pasture, forestry and cropping) purposes. We also developed a rule-based model to assess soil compactionvulnerability by characterising the combined effects of resistance and resilience. Other soil attributes havebeen appraised using seven chemical, physical and biological indicators of soil quality. These indicators havebeen applied in a nation-wide project involving data collection from over 500 sites for a range of land uses.These soil quality data can be interpreted via the World Wide Web - through the interactive decision-support tool SINDI. The land-use impact model is a framework to assess agricultural land management andenvironmental sustainability, and may be applied to land units at any scale. Using land resource data andinformation the model explicitly identifies hazards to land productivity and environmental integrity. It utilisesqualitative expert and local knowledge and quantitative model-based evaluations to assess the potentialenvironmental impacts of land-management practices. The model is linked to a geographic informationsystem (GIS), allowing model outputs, such as the environmental impacts of site-specific best managementpractices, to be identified in a spatially explicit manner. The model has been tested in New Zealand in anarea of pastoral land use. Advantages of this risk identification model include: utilising current knowledge ofthe causes and effects of land-management practices on soil degradation; linking land management practiceto both on- and off-site environmental consequences; identifying important gaps in local knowledge; andproviding spatially explicit information on the environmental impact of land-management practices.
基金Under the auspices of National Natural Science Foundation of China (No. 40401003)Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX3-SW-356)fund for Scholarship of Dean of Chinese Academy of Sciences
文摘Based on Tupu theory, this paper studied the dynamic changes, conversion modes, expansion intensity and landscape attributes of the saline-alkali lands in Changling County, Zhenlai County and Da'an City of the western Jilin Province in 1980-2000 with the help of GIS. The results show that the saline-alkali land rather sharply increased in Da'an during 1995-2000; the main conversion processes in the three counties were from grassland to saline-alkali land and from saline-alkali land to grassland; and the typical shapes, spatial expansion speed and mode, and landscape attributes of the saline-alkali land were different in the three counties, which were closely related to local topography, predominant wind orientation, water resources distribution, etc. The corresponding spatial expansion mode was marginality in Changling, random in Zhenlai and more kernels in Da'an, respectively. Landscape attributes also responded to the spatial-temporal dynamic changes of the saline-alkali land and the landscape indices of Da'an fluctuated greatly. The frame of this research may provide fundamental reference for landscape analysis and give some suggestions for regional sustainable development.
文摘The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practices. The values of abundance, species richness, diversity and evenness were significantly larger in OT and ON than in CT, indicating that the abundance and diversity in organic farming fields were greater than those in conventional farming. The community structure of enchytraeid genera was different between OT and ON. Enchytraeus was the most abundant in OT, while Fridericia in ON. The abundance of oribatids in OT was similar to that in ON, while the species richness and diversity in the former were smaller. These results suggested that no-tillage practice under organic management might contribute to the improvement in quality of soil mesofauna.
基金Under the auspices of National Natural Science Foundation of China(No.41171155,40801069)National Science and Technology Major Project of China:Water Pollution Control and Governance(No.2012ZX07505-003)
文摘Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.
基金Under the auspices of Key Program of National Natural Science Foundation of China (No.40535025), Planning Itemof Youthful Cadreman Teachers of University in Henan Province (No. DOC2005-461), the Social Science of Henan EducationalDepartment (No. 2005-ZX-238) and Key Program of Henan University's Fund (No. 04ZDRW009)
文摘A micro-level analysis on man-land system is important in understanding the content of human geography in rural areas, particularly in the different regions. This paper is based on a survey undertaken in the three villages of Wugou Village, Hutuo Village, and Xiaonan Village of Gongyi City, ltenan Province in April 2003. The survey covers three types of economic and social activities from 214 households. Data collected include 120 attributes for each household. By using theories from the relevant disciplines such as geography, mathcmatics, physics, ecology, and system sciences, this paper develops a framework employing the concept of system entropy in the status function of the man-land system. In this framework, the entropy change is used to show the evolution of the system, and the entropy flow to express the flow among the spatial parts of the system. Following the framework, and using a large set of household data from surveys, the paper makes a quantitative analysis of the village-level man-land system from a micro-perspective. After a theoretical investigation, the corresponding strategies in the paper are then put forward in order to adjust the unbalanced trend of the village man-land system from both perspectives of small-area and individual actors.
基金supported by MOE Project of Humanities and Social Sciences for Young Researchers(Project No.:16YJC740023)Project of Humanities and Social Sciences in Universities and Colleges in Guangdong Province[Project No.:2016WTSCX033]the support from the Chinese MOE Research Project of Humanities and Social Science(Project No.:16JJD740006)conducted by the Center for Linguistics and Applied Linguistics,Guangdong University of Foreign Studies.
文摘Languages and linguistic resources transport from one locality to another,adapting to the norms,customs,and regulations of a new locality.This process involves translocalization.Translocalization emphasizes the movement of linguistic resources against the backdrop of globalization and the combination or reframing of resources from different localities.This research explores the extent to which translocalization is reflected by the linguistic landscapes of three distinct commercial areas in Guangzhou,China.It goes on to discuss how translocalization works together with social rescaling to incur the movement of linguistic resources and to result in distinct linguistic landscapes of the three commercial areas.It concludes that some languages or linguistic resources,such as English,pinyin and traditional Chinese writing,are transported to local contexts for the purpose of rescaling,whereas other languages or dialects,like Cantonese,might gradually lose their function of rescaling and retain its function in indexing local identity and solidarity.This study calls for more attention to the local resources and contexts in linguistic landscape studies.It argues for the indexical function of linguistic resources in social rescaling and city planning.