Agricultural heritage systems have the characteristics of ecological fragility and cultural sensitivity.For a long time,the conservation and sustainable development of agricultural heritage systems have received atten...Agricultural heritage systems have the characteristics of ecological fragility and cultural sensitivity.For a long time,the conservation and sustainable development of agricultural heritage systems have received attention from all sectors.However,there are few measurements of tourism disturbance(TD)and community resilience(CR)in agricultural heritage sites,and research on the relationship between the two is even more lacking.This study selects six villages in the Honghe Hani Rice Terraced System(HHRTS)as examples and constructs an evaluation system for TD and CR.Through questionnaires and in-depth interviews,it explores the response relationship between TD and CR of heritage site,and compares the response relationship of villages in different stages of tourism development.The results indicate that the heritage site's current response relationship between TD and CR shows a positive response type,and the development of tourism has brought positive responses and effects.There are differences in the interactive relationship between TD and CR among communities with different levels of tourism development.In communities with poor tourism development,CR is more susceptible to the impact of TD than other communities.The stability of the relationship between TD and CR response gradually tends to stabilize from poor,good,and moderate tourism development.展开更多
The interplay between human and ecological systems has evolved from traditional conservation approaches to integrated socio-ecological frameworks that emphasise the co-production of ecosystem services.This paper aims ...The interplay between human and ecological systems has evolved from traditional conservation approaches to integrated socio-ecological frameworks that emphasise the co-production of ecosystem services.This paper aims to inspire new research pathways to advance the Nature's Contributions to People(NCP)perspective by focusing on terraced agroecosystems as emblematic landscapes that exemplify this co-production.Informed by recent studies in sustainability science,and drawing on our experience in Mediterranean environments,we explore the transformative potential of these frameworks for understanding and managing terraced landscapes.Addressing their multifunctionality,the challenges they face,and their socio-cultural and ecological significance,we highlight the importance of bridging scientific insights with local knowledge and participatory practices.We examine the use of advanced biophysical assessments,mapping tools,and stakeholder-driven approaches to enhance field assessment,monitoring capabilities and tackle management challenges under changing socio-economic conditions.We stress the urgent need for education and capacity-building initiatives to counteract indigenous knowledge loss and sustain traditional practices.Looking to the future,we propose potential avenues for research and practice that integrate ecological,cultural,and governance dimensions,contributing to the long-term sustainability of terraced landscapes and informing broader efforts for sustainable land management in an era of rapid environmental change.展开更多
Agricultural terraces are significant for food provision,environmental stability and sustainable resource management.However,the spatiotemporal evolution of terraces and their influence on food productivity in mountai...Agricultural terraces are significant for food provision,environmental stability and sustainable resource management.However,the spatiotemporal evolution of terraces and their influence on food productivity in mountainous landscapes remain poorly understood.Taking the Chinese Loess Plateau(LP)as an example,this study conducted multitemporal mapping of terraces and sloping croplands over three decades(1990-2020),systematically assessing their impacts on food output through terrain gradient analysis.The results indicated that:(1)the terraced area expanded in the past 30 years,particularly across steeper terrain gradients(third to fifth gradients);(2)sloping croplands predominantly occupied gentle slopes(first to second gradients),exhibiting area reduction correlating with urbanization processes;(3)the food provision increased extensively,with yield decreasing from southeast to northwest and regions of high yielding mainly in terraced fields;(4)over time,the variation of food provision correlated positively with the area of sloping cropland at low gradients,while at higher gradients,the expansion of terraces dominated the increase in food provision;(5)spatial clustering analysis revealed significant food productivity associated with high-density terrace distribution across steeper slope gradients.Low yields could be attributed to improper terrace management.This study clarified the impact of long-term terrace patterns on food provision and offered large-scale perspectives for terrace-based agriculture to enhance food security.Furthermore,the findings underscore the imperative of integrated land management in topographically complex regions,informing evidence-based policymaking for rational allocation and optimal utilization of terrace resources.展开更多
The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has ...The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by＂forest-vil age-terrace-river＂, including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.展开更多
Many agricultural landscapes have been formed through the interaction and co-evolution of nature and people, and represent the living landscapes shaped over time through intensive and continuous human cultivation. Ter...Many agricultural landscapes have been formed through the interaction and co-evolution of nature and people, and represent the living landscapes shaped over time through intensive and continuous human cultivation. Terraced paddy fields are being re-evaluated to take into account the multiple functions they fill beyond only rice cultivation, particularly their contribution to the national biodiversity strategy of Japan. Since the 1990 s, terraced paddy fields have been considered a representative cultural landscape of Japan and, at the same time, multi-stakeholder conservation activities have been conducted throughout Japan to reverse the increasing abandonment of terraces. Shiroyone Senmaida is an outstanding cultural landscape and a major tourist attraction in Noto Peninsula, Ishikawa Prefecture, which was designated through an initiative by the Food and Agriculture Organization(FAO) as a Globally Important Agricultural Heritage Systems(GIAHS) pilot site in 2011. It is important to clarify tourist preference for terraced paddy field landscapes to contribute to future policy making toward improved agricultural landscape conservation. A key finding of this study is that tourists visiting toenjoy the agricultural landscape are also concerned on the sustainability of the farming methods and preferred to maintain the naturalness of the landscape. Respondents with higher educational levels and greater concern for the biological and traditional farming knowledge aspects of the rice terraces were also more inclined to favor sustainable farming practices. Tourists preferred to maintain the naturalness and rurality of the agricultural landscape, and indicated that construction of excessive tourist facilities would cause the landscape to deteriorate. It was suggested that the local community and surroundings, including rural settlements, hills, and forests, should also be conserved together with the scenic terrace.展开更多
Soil organic matter （SOM） content is one of the most important indicators of the sustainability of soil. To maintain sustainable soil utilization and management in fragile Hani terraced field, it is meaningful to in...Soil organic matter （SOM） content is one of the most important indicators of the sustainability of soil. To maintain sustainable soil utilization and management in fragile Hani terraced field, it is meaningful to investigate the effects of topography and land use type on SOM content. Descriptive statistics and geostatistics were used to analyze the data and the kriging method was applied to map the spatial patterns of SOM content. The results showed that the mean SOM content was 32.76 g/kg, with a variation coefficient of 40%. The SOM content was affected by elevation and land use type. As the increase of elevation, the SOM content in Hani terraced field also increased obviously. The SOM content in tea garden, which is almost at high elevation, was the highest in all six land use types, and the SOM content decreased in a following sequence： tea garden 〉 paddy field 〉 corn field 〉 banana garden 〉 cassava field 〉 sugarcane field. In addition, at the same elevation, the paddy field had the highest SOM content compared with other land use types. All these results demonstrate that paddy field is the most efficient and suitable land use type for SOM conservation at high, middle or low elevations in the fragile Hani terraced field. In order to protect soil quality and maintain the sustainable agricultural development, it is necessary to maintain or even to enlarge the area of paddy field in Yuanyang county, Yunnan Province, China.展开更多
For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulo...For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.展开更多
Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat tr...Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.展开更多
Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion.This paper introduces a new system based on rainwater harvesting and ...Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion.This paper introduces a new system based on rainwater harvesting and recycling technology,which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer inputs.The new system consists of three subsystems：1） A plough layer with the dual function of crop cultivation and rainwater harvesting; 2） A tank below the plough layer for storing water; 3） An irrigation-drainage subsystem.The plough layer and the storage tank,both treated for reducing seepage,are connected through the irrigation and drainage system.Results showed that,compared with the traditional paddy fields,rice evapotranspiration（ and crop coefficient） in the test field remained at a similar level,while the irrigation amount was reduced by 44.3% under the condition of basin irrigation,and the drainage amount decreased by 86.6%,and the non-point source pollution was reduced to 67.7%~87.9%,and the rainwater utilization efficiency increased by 30% and reached 95.4%,and crop yield of middle-season rice reached 9,975 kg/hm2,which was only 0.4% lower than that in the traditional paddy field in the terms of dry matter.The new technology sheds light on new possibilities for transformation of hilly sloping land.展开更多
A debris flow,with terraced fields as the source area,broke out on June 25th,2018 in the Xiaotuga area of Yunnan Province,China,and this kind of debris flow is rarely recorded.Two purposes in this study:(1)the influen...A debris flow,with terraced fields as the source area,broke out on June 25th,2018 in the Xiaotuga area of Yunnan Province,China,and this kind of debris flow is rarely recorded.Two purposes in this study:(1)the influence of flow drag force on slope stability;(2)back-analyze the movement process of debris flow.First,the geological background and movement of this debris flow were described based on a field investigation.Then,drag force,calculated by the laminar flow theory,is added to the slope stability calculation model,which elaborates the initiation process of this disaster.Moreover,dynamic simulation software(DAN3D)was used to simulate the kinematic process of the debris flow with a variety of combination models.The study shows that the terrace area can quickly produce surface runoff and create a drag force under rainfall conditions,which is the essential reason for the initiation of debris flow.In addition,the use of the FVV(Frictional-Voellmy-Voellmy)model is found to provide the best performance in simulating this type of debris flow,which reveals that it lasts approximately 200 s and that the maximum velocity is 12 m/s.展开更多
The presence of roads in high steep agricultural systems is often linked with landslides occurrence.This research aims to model multi-temporal overland flow dynamics in a shallow landslides-prone terraced landscape(no...The presence of roads in high steep agricultural systems is often linked with landslides occurrence.This research aims to model multi-temporal overland flow dynamics in a shallow landslides-prone terraced landscape(northern Italy).The combined use of Remotely Piloted Aircraft Systems(RPAS)and photo-grammetric techniques(e.g.,Structure from Motion-SfM)allowed to elaborate multi-temporal high-resolution Digital Elevation Models(DEMs).Hydrological analyses of water flow's depth alterations due to the road presence were carried out adopting the SIMulated Water Erosion model(SIMWE),focusing on different scenarios considering the presence of the road and assuming its absence through a specific DEM smoothing procedure.The possibility to perform multi-temporal hydrological simulations at a hillslope scale so as to analyse the role played by the road in overland flows alteration is still a challenge to be investigated.Results proved the role played by the road in water flows change above the two observed shallow landslides,with respective maximum water depth values equal to 0.18 m and 0.14 m.On the contrary,no-road simulations not revealed significant water flows deviations towards landslides,with water depth values around 0 m,underlining that the absence of the road would avoid relevant changes in water flow paths toward the collapsed surfaces.This work could be a solid starting point for analyse road impact on runoff dynamics and hillslopes stability also at a wider scale,as well as for planning efficient mitigation intervention so as to reduce the occurrence of similar future scenarios.展开更多
Conventional geotechnical software limits the use of the strength reduction method(SRM)based on the Mohr–Coulomb failure criterion to analyze the slope safety factor(SF).The use of this constitutive model is impracti...Conventional geotechnical software limits the use of the strength reduction method(SRM)based on the Mohr–Coulomb failure criterion to analyze the slope safety factor(SF).The use of this constitutive model is impractical for predicting the behavior of all soil types.In the present study,an innovative numerical technique based on SRM was developed to determine SF using the finite element method and considering the extended Cam–clay constitutive model for clayey gravel soil as opposed to the Mohr–Coulomb model.In this regard,a novel user subroutine code was employed in ABAQUS to reduce the stabilizing forces to determine the failure surfaces and resist and drive shear stresses on a slope.After validating the proposed technique,it was employed to investigate the performance of terraced slopes in the context of a case study.The impacts of geometric parameters and different water table elevations on the SF were examined.The results indicated that an increase in the upper and lower slope heights led to a decrease in SF,and a slight increase in the horizontal offset led to an increase in the SF.Moreover,when the water table elevation was lower than the toe of the terraced slope,the SF increased because of the increase in the uplift force as a resistant component.展开更多
These two paintings depict the living environment of Hani and Yi ethnic nationalities which inhabit the Ailao Mountains in Southwest China. The paintings, while realistic, display some slightly decorative techniques. ...These two paintings depict the living environment of Hani and Yi ethnic nationalities which inhabit the Ailao Mountains in Southwest China. The paintings, while realistic, display some slightly decorative techniques. The communities live harmoniously, building terraced fields and展开更多
Transportation as a means to support industrial development can impact the economic development of important agricultural heritage sites. Because the central towns in mountainous areas have weak economic interactions ...Transportation as a means to support industrial development can impact the economic development of important agricultural heritage sites. Because the central towns in mountainous areas have weak economic interactions with each other, an appropriate method is needed to evaluate their transportation accessibility. This paper takes the Honghe Hani Rice Terraced System(HHRTS) as a study area and develops a model to determine shortest time-distances from central towns in the study area to the nearest high-grade city as a way to evaluate transportation accessibility(TA). We then analyze the relationship between the accessibility of these towns and their economies. The study finds that the TA of the central towns in HHRTS is not good as a whole. More than 70% of the towns are more than 1 hour away from their nearest high-grade city. Of the four counties in the study area, Yuanyang County has the best traffic conditions, while Lvchun County has the worst traffic conditions. The central towns in the northern and middle regions have better TA than those in the west, southwest and east margin regions. The small-scale rural economy has little dependence on the transportation network, while secondary industries are obviously impacted by the transportation network. In the future, to support the integrated development of industries in HHRTS, traffic conditions in each town should be improved appropriately according to the industrial orientation of the town, but excessive investments to construct roads irrespective of eco-environmental impacts and economic benefits should be avoided. Especially in the case of ecologically vulnerable towns, the building high-grade roads should be banned.展开更多
In the terraced fields in Honghe Hani and Yi Autonomous Prefecture,southwest China’s Yunnan Province,the morning mist drifts up from the valleys while the tiered ridges spread like the fingerprints of the earth.
This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace...This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace abandonment. Logit and Tobit models are employed to conduct empirical analysis and it is found that terrace abandonment increases sequentially among the new, middle, and old generations, confirming that intergenerational differences significantly influence whether farmers abandon terraces and the terrace abandonment scale. Village characteristics and government subsidies significantly influence farmers' terrace abandonment. An increase in the number of migrant workers in the village increases terrace abandonment among new and middle generation farmers, whereas an increase in the distance from the village to the county significantly increases terrace abandonment among old generation farmers. An increase in the village's total population significantly reduces terrace abandonment among new generation farmers. An increase in government subsidies significantly reduces terrace abandonment among middle and old generation farmers. The impact of intergenerational differences on terrace abandonment is more pronounced in low-altitude areas. To reduce terrace abandonment, it is necessary to promote terrace transfer, develop characteristic agriculture, improve terrace farming subsidies, and propose targeted strategies for the different generations of farmers.展开更多
French photographer Yann Layma first captured a moment at the Honghe Hani Rice Terraces in 1993.The tiered fields climbed like stairways into the sky.Glints of water appeared and disappeared through drifting clouds.Ha...French photographer Yann Layma first captured a moment at the Honghe Hani Rice Terraces in 1993.The tiered fields climbed like stairways into the sky.Glints of water appeared and disappeared through drifting clouds.Hani farmers could be seen quietly tending the land.Deeply moved,Layma spent six months producing Mountain Sculptors-a collection that included a film,a photo album,a travel diary,and nearly 10,000 photographs.展开更多
AS twilight descended,a screen rose.Locals and tourists converged spontaneously on the open-air cinema on the second-floor terrace of Chang’an Mills shopping plaza,in the iconic Shougang Park,Beijing.If anything riva...AS twilight descended,a screen rose.Locals and tourists converged spontaneously on the open-air cinema on the second-floor terrace of Chang’an Mills shopping plaza,in the iconic Shougang Park,Beijing.If anything rivals the magic of a summer night sky,it’s the jovial atmosphere brought about by the silver screen.展开更多
The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present ...The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.展开更多
Lattice distortion of materials has a profound impact on their electronic and magnetic properties,which can generate local magnetic states in intrinsically non-magnetic systems.Here we report on the realization of a o...Lattice distortion of materials has a profound impact on their electronic and magnetic properties,which can generate local magnetic states in intrinsically non-magnetic systems.Here we report on the realization of a one-dimensional(1D)magnetic stripe in monolayer H-NbSe_(2)sustained by strain along the terraces of the graphene/SiC substrates.The strength of this tensile strain is widely tunable by the height-to-width ratio of the terraces.Increasing the tensile strength leads to the shifts and splitting of the Nb 4d bands crossing the Fermi energy,generating spin polarization in a 1D magnetic stripe along the terrace.Simultaneously,the charge-densitywave signature of strained H-NbSe_(2)is significantly suppressed.Such a magnetic stripe can be locally quenched by an individual Se-atom defect via the defect-induced Jahn-Teller distortion and charge density redistribution.These findings provide a different route to achieving and manipulating 1D magnetism in otherwise non-magnetic systems,offering a new way for spintronic devices.展开更多
基金funded by the Natural Science Foundation of China(Grant No.41971264)。
文摘Agricultural heritage systems have the characteristics of ecological fragility and cultural sensitivity.For a long time,the conservation and sustainable development of agricultural heritage systems have received attention from all sectors.However,there are few measurements of tourism disturbance(TD)and community resilience(CR)in agricultural heritage sites,and research on the relationship between the two is even more lacking.This study selects six villages in the Honghe Hani Rice Terraced System(HHRTS)as examples and constructs an evaluation system for TD and CR.Through questionnaires and in-depth interviews,it explores the response relationship between TD and CR of heritage site,and compares the response relationship of villages in different stages of tourism development.The results indicate that the heritage site's current response relationship between TD and CR shows a positive response type,and the development of tourism has brought positive responses and effects.There are differences in the interactive relationship between TD and CR among communities with different levels of tourism development.In communities with poor tourism development,CR is more susceptible to the impact of TD than other communities.The stability of the relationship between TD and CR response gradually tends to stabilize from poor,good,and moderate tourism development.
基金supported by the projects REACT4MED—Inclusive Outscaling of Agro-Ecosystem Restoration Actions for the Mediterranean,which is part of the PRIMA Programme supported by the European Union under Horizon 2020(Grant No.2122,Horizon 2020)SELINA—Science for Evidence-based and Sustainable Decisions about Natural Capital,funded by the European Union’s Horizon Europe Research and Innovation Programme(Grant No.101060415)。
文摘The interplay between human and ecological systems has evolved from traditional conservation approaches to integrated socio-ecological frameworks that emphasise the co-production of ecosystem services.This paper aims to inspire new research pathways to advance the Nature's Contributions to People(NCP)perspective by focusing on terraced agroecosystems as emblematic landscapes that exemplify this co-production.Informed by recent studies in sustainability science,and drawing on our experience in Mediterranean environments,we explore the transformative potential of these frameworks for understanding and managing terraced landscapes.Addressing their multifunctionality,the challenges they face,and their socio-cultural and ecological significance,we highlight the importance of bridging scientific insights with local knowledge and participatory practices.We examine the use of advanced biophysical assessments,mapping tools,and stakeholder-driven approaches to enhance field assessment,monitoring capabilities and tackle management challenges under changing socio-economic conditions.We stress the urgent need for education and capacity-building initiatives to counteract indigenous knowledge loss and sustain traditional practices.Looking to the future,we propose potential avenues for research and practice that integrate ecological,cultural,and governance dimensions,contributing to the long-term sustainability of terraced landscapes and informing broader efforts for sustainable land management in an era of rapid environmental change.
基金supported by the National Natural Science Foundation of China(Grants No.U21A2011,41971129)the National Key Research and Development Program of China(Grant No.2022YFF1300403)the Distinguished Membership Project of the Youth Innovation Promotion Association of CAS(Grant No.Y201812)。
文摘Agricultural terraces are significant for food provision,environmental stability and sustainable resource management.However,the spatiotemporal evolution of terraces and their influence on food productivity in mountainous landscapes remain poorly understood.Taking the Chinese Loess Plateau(LP)as an example,this study conducted multitemporal mapping of terraces and sloping croplands over three decades(1990-2020),systematically assessing their impacts on food output through terrain gradient analysis.The results indicated that:(1)the terraced area expanded in the past 30 years,particularly across steeper terrain gradients(third to fifth gradients);(2)sloping croplands predominantly occupied gentle slopes(first to second gradients),exhibiting area reduction correlating with urbanization processes;(3)the food provision increased extensively,with yield decreasing from southeast to northwest and regions of high yielding mainly in terraced fields;(4)over time,the variation of food provision correlated positively with the area of sloping cropland at low gradients,while at higher gradients,the expansion of terraces dominated the increase in food provision;(5)spatial clustering analysis revealed significant food productivity associated with high-density terrace distribution across steeper slope gradients.Low yields could be attributed to improper terrace management.This study clarified the impact of long-term terrace patterns on food provision and offered large-scale perspectives for terrace-based agriculture to enhance food security.Furthermore,the findings underscore the imperative of integrated land management in topographically complex regions,informing evidence-based policymaking for rational allocation and optimal utilization of terrace resources.
基金Supported by Project of Ministry of Human Resources and Social Security~~
文摘The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by＂forest-vil age-terrace-river＂, including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.
文摘Many agricultural landscapes have been formed through the interaction and co-evolution of nature and people, and represent the living landscapes shaped over time through intensive and continuous human cultivation. Terraced paddy fields are being re-evaluated to take into account the multiple functions they fill beyond only rice cultivation, particularly their contribution to the national biodiversity strategy of Japan. Since the 1990 s, terraced paddy fields have been considered a representative cultural landscape of Japan and, at the same time, multi-stakeholder conservation activities have been conducted throughout Japan to reverse the increasing abandonment of terraces. Shiroyone Senmaida is an outstanding cultural landscape and a major tourist attraction in Noto Peninsula, Ishikawa Prefecture, which was designated through an initiative by the Food and Agriculture Organization(FAO) as a Globally Important Agricultural Heritage Systems(GIAHS) pilot site in 2011. It is important to clarify tourist preference for terraced paddy field landscapes to contribute to future policy making toward improved agricultural landscape conservation. A key finding of this study is that tourists visiting toenjoy the agricultural landscape are also concerned on the sustainability of the farming methods and preferred to maintain the naturalness of the landscape. Respondents with higher educational levels and greater concern for the biological and traditional farming knowledge aspects of the rice terraces were also more inclined to favor sustainable farming practices. Tourists preferred to maintain the naturalness and rurality of the agricultural landscape, and indicated that construction of excessive tourist facilities would cause the landscape to deteriorate. It was suggested that the local community and surroundings, including rural settlements, hills, and forests, should also be conserved together with the scenic terrace.
基金supported by the National Natural Science Foundation of China (Grant No. 70973143)Natural Science Foundation of Zhejiang Province, China (Grant No. Y5110259)
文摘Soil organic matter （SOM） content is one of the most important indicators of the sustainability of soil. To maintain sustainable soil utilization and management in fragile Hani terraced field, it is meaningful to investigate the effects of topography and land use type on SOM content. Descriptive statistics and geostatistics were used to analyze the data and the kriging method was applied to map the spatial patterns of SOM content. The results showed that the mean SOM content was 32.76 g/kg, with a variation coefficient of 40%. The SOM content was affected by elevation and land use type. As the increase of elevation, the SOM content in Hani terraced field also increased obviously. The SOM content in tea garden, which is almost at high elevation, was the highest in all six land use types, and the SOM content decreased in a following sequence： tea garden 〉 paddy field 〉 corn field 〉 banana garden 〉 cassava field 〉 sugarcane field. In addition, at the same elevation, the paddy field had the highest SOM content compared with other land use types. All these results demonstrate that paddy field is the most efficient and suitable land use type for SOM conservation at high, middle or low elevations in the fragile Hani terraced field. In order to protect soil quality and maintain the sustainable agricultural development, it is necessary to maintain or even to enlarge the area of paddy field in Yuanyang county, Yunnan Province, China.
基金Project(51178423)supported by the National Natural Science Foundation of China
文摘For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.
基金Project(51305388)supported by the National Natural Science Foundation of ChinaProject(BJ2014055)supported by the Youth Talent Projects of Colleges in Hebei Province,ChinaProject(2016M590211)supported by China Postdoctoral Science Foundation
文摘Because of the mixed grain and coarse grain structure, the long heat treatment cycle and large energy conservation in the heavy cylinder heat treatment process, the up ladder type and terraced type normalizing heat treatment of heavy cylinder after rolling were put forward. The microstructure and mechanical properties of 2.25Cr1Mo0.25 V steel after the up ladder type normalizing, terraced type normalizing and isothermal type normalizing were studied. Experimental results show that： 1） For the grain refinement, the twice terraced type normalizing is better than the up ladder type and isothermal type normalizing, and the average grain size is 18 μm; 2） The yield strength, tensile strength and-30℃ charpy impact energy after twice terraced type normalizing are 681 MPa, 768 MPa and 181 J, respectively, and the mechanical properties are better than those of the up ladder type and isothermal type normalizing; 3） Compared with the isothermal type normalizing, the holding time of terraced type normalizing can be shortened by 30%, which greatly reduces the energy consumption.
基金partly supported by Non-profit Industry Financial Program of MWR(Grant No.201301012)
文摘Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion.This paper introduces a new system based on rainwater harvesting and recycling technology,which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer inputs.The new system consists of three subsystems：1） A plough layer with the dual function of crop cultivation and rainwater harvesting; 2） A tank below the plough layer for storing water; 3） An irrigation-drainage subsystem.The plough layer and the storage tank,both treated for reducing seepage,are connected through the irrigation and drainage system.Results showed that,compared with the traditional paddy fields,rice evapotranspiration（ and crop coefficient） in the test field remained at a similar level,while the irrigation amount was reduced by 44.3% under the condition of basin irrigation,and the drainage amount decreased by 86.6%,and the non-point source pollution was reduced to 67.7%~87.9%,and the rainwater utilization efficiency increased by 30% and reached 95.4%,and crop yield of middle-season rice reached 9,975 kg/hm2,which was only 0.4% lower than that in the traditional paddy field in the terms of dry matter.The new technology sheds light on new possibilities for transformation of hilly sloping land.
基金supported by the National Natural Science Foundation of China(No.42077277)。
文摘A debris flow,with terraced fields as the source area,broke out on June 25th,2018 in the Xiaotuga area of Yunnan Province,China,and this kind of debris flow is rarely recorded.Two purposes in this study:(1)the influence of flow drag force on slope stability;(2)back-analyze the movement process of debris flow.First,the geological background and movement of this debris flow were described based on a field investigation.Then,drag force,calculated by the laminar flow theory,is added to the slope stability calculation model,which elaborates the initiation process of this disaster.Moreover,dynamic simulation software(DAN3D)was used to simulate the kinematic process of the debris flow with a variety of combination models.The study shows that the terrace area can quickly produce surface runoff and create a drag force under rainfall conditions,which is the essential reason for the initiation of debris flow.In addition,the use of the FVV(Frictional-Voellmy-Voellmy)model is found to provide the best performance in simulating this type of debris flow,which reveals that it lasts approximately 200 s and that the maximum velocity is 12 m/s.
文摘The presence of roads in high steep agricultural systems is often linked with landslides occurrence.This research aims to model multi-temporal overland flow dynamics in a shallow landslides-prone terraced landscape(northern Italy).The combined use of Remotely Piloted Aircraft Systems(RPAS)and photo-grammetric techniques(e.g.,Structure from Motion-SfM)allowed to elaborate multi-temporal high-resolution Digital Elevation Models(DEMs).Hydrological analyses of water flow's depth alterations due to the road presence were carried out adopting the SIMulated Water Erosion model(SIMWE),focusing on different scenarios considering the presence of the road and assuming its absence through a specific DEM smoothing procedure.The possibility to perform multi-temporal hydrological simulations at a hillslope scale so as to analyse the role played by the road in overland flows alteration is still a challenge to be investigated.Results proved the role played by the road in water flows change above the two observed shallow landslides,with respective maximum water depth values equal to 0.18 m and 0.14 m.On the contrary,no-road simulations not revealed significant water flows deviations towards landslides,with water depth values around 0 m,underlining that the absence of the road would avoid relevant changes in water flow paths toward the collapsed surfaces.This work could be a solid starting point for analyse road impact on runoff dynamics and hillslopes stability also at a wider scale,as well as for planning efficient mitigation intervention so as to reduce the occurrence of similar future scenarios.
文摘Conventional geotechnical software limits the use of the strength reduction method(SRM)based on the Mohr–Coulomb failure criterion to analyze the slope safety factor(SF).The use of this constitutive model is impractical for predicting the behavior of all soil types.In the present study,an innovative numerical technique based on SRM was developed to determine SF using the finite element method and considering the extended Cam–clay constitutive model for clayey gravel soil as opposed to the Mohr–Coulomb model.In this regard,a novel user subroutine code was employed in ABAQUS to reduce the stabilizing forces to determine the failure surfaces and resist and drive shear stresses on a slope.After validating the proposed technique,it was employed to investigate the performance of terraced slopes in the context of a case study.The impacts of geometric parameters and different water table elevations on the SF were examined.The results indicated that an increase in the upper and lower slope heights led to a decrease in SF,and a slight increase in the horizontal offset led to an increase in the SF.Moreover,when the water table elevation was lower than the toe of the terraced slope,the SF increased because of the increase in the uplift force as a resistant component.
文摘These two paintings depict the living environment of Hani and Yi ethnic nationalities which inhabit the Ailao Mountains in Southwest China. The paintings, while realistic, display some slightly decorative techniques. The communities live harmoniously, building terraced fields and
基金The International Exchange and Cooperation Project of Ministry of Agriculture "Conservation of Globally Important Agricultural Heritage Systems(GIAHS)in China in 2018"The Third-party Monitor and Assessment on Honghe Hani Rice Terraces Systems in 2018
文摘Transportation as a means to support industrial development can impact the economic development of important agricultural heritage sites. Because the central towns in mountainous areas have weak economic interactions with each other, an appropriate method is needed to evaluate their transportation accessibility. This paper takes the Honghe Hani Rice Terraced System(HHRTS) as a study area and develops a model to determine shortest time-distances from central towns in the study area to the nearest high-grade city as a way to evaluate transportation accessibility(TA). We then analyze the relationship between the accessibility of these towns and their economies. The study finds that the TA of the central towns in HHRTS is not good as a whole. More than 70% of the towns are more than 1 hour away from their nearest high-grade city. Of the four counties in the study area, Yuanyang County has the best traffic conditions, while Lvchun County has the worst traffic conditions. The central towns in the northern and middle regions have better TA than those in the west, southwest and east margin regions. The small-scale rural economy has little dependence on the transportation network, while secondary industries are obviously impacted by the transportation network. In the future, to support the integrated development of industries in HHRTS, traffic conditions in each town should be improved appropriately according to the industrial orientation of the town, but excessive investments to construct roads irrespective of eco-environmental impacts and economic benefits should be avoided. Especially in the case of ecologically vulnerable towns, the building high-grade roads should be banned.
文摘In the terraced fields in Honghe Hani and Yi Autonomous Prefecture,southwest China’s Yunnan Province,the morning mist drifts up from the valleys while the tiered ridges spread like the fingerprints of the earth.
基金Key Program of National Natural Science Foundation of China,No.41930757National Natural Science Foundation of China,No.42371285。
文摘This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace abandonment. Logit and Tobit models are employed to conduct empirical analysis and it is found that terrace abandonment increases sequentially among the new, middle, and old generations, confirming that intergenerational differences significantly influence whether farmers abandon terraces and the terrace abandonment scale. Village characteristics and government subsidies significantly influence farmers' terrace abandonment. An increase in the number of migrant workers in the village increases terrace abandonment among new and middle generation farmers, whereas an increase in the distance from the village to the county significantly increases terrace abandonment among old generation farmers. An increase in the village's total population significantly reduces terrace abandonment among new generation farmers. An increase in government subsidies significantly reduces terrace abandonment among middle and old generation farmers. The impact of intergenerational differences on terrace abandonment is more pronounced in low-altitude areas. To reduce terrace abandonment, it is necessary to promote terrace transfer, develop characteristic agriculture, improve terrace farming subsidies, and propose targeted strategies for the different generations of farmers.
文摘French photographer Yann Layma first captured a moment at the Honghe Hani Rice Terraces in 1993.The tiered fields climbed like stairways into the sky.Glints of water appeared and disappeared through drifting clouds.Hani farmers could be seen quietly tending the land.Deeply moved,Layma spent six months producing Mountain Sculptors-a collection that included a film,a photo album,a travel diary,and nearly 10,000 photographs.
文摘AS twilight descended,a screen rose.Locals and tourists converged spontaneously on the open-air cinema on the second-floor terrace of Chang’an Mills shopping plaza,in the iconic Shougang Park,Beijing.If anything rivals the magic of a summer night sky,it’s the jovial atmosphere brought about by the silver screen.
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF2023S1A5A2A01077716)。
文摘The timing and mechanisms of fluvial terrace formation along the Yangtze River in the Yichang region provide critical insights into the interplay between tectonics,climate,and river evolution.In this study,we present new cosmogenic nuclide isochron burial ages for the fifth(T5)and fourth(T4)terraces,yielding ages of 0.49±0.05 Ma and 0.35±0.04 Ma,respectively.By integrating our data with existing 14C and ESR ages for lower terraces,we reconstruct a detailed incision history,showing~85 m of river downcutting since the Middle Pleistocene.Incision rates varied over time,with a notable acceleration after 0.1 Ma coinciding with the Gonghe movement of the Tibetan Plateau,highlighting the role of tectonic uplift in driving fluvial incision.The formation of the fifth terrace is associated with the Kunlun–Huanghe uplift,while the development of the fourth terrace corresponds to the phase of regional uplift in the Qinling Mountains.Sedimentological evidence further indicates that terrace formation was influenced by both climatic and tectonic controls:while T4 aggraded during a glacial period,T5 formed during the interglacial MIS 13 under strong monsoonal conditions—demonstrating that major aggradation can occur during warm phases.However,sustained incision required tectonic forcing,as climatic transitions alone were insufficient to drive deep bedrock erosion.Our results also constrain the longdebated integration of the Three Gorges.The 0.49 Ma age for T5 provides a robust minimum age for the hydrological connection between the Sichuan and Jianghan Basins.This timing,combined with the earlier formation of the"First Bend of the Yangtze"(Eocene–Miocene),contradicts the classical east-towest headward erosion model.Instead,geomorphic analysis of the gorges—showing diachronous valley development from east to west—supports a progressive,bottom-to-top integration,initiated in the Xiling Gorge and culminating in the incision of the Qutang Gorge.This sequence aligns with knickpoint migration driven by base-level fall and regional tectonic uplift.We conclude that the evolution of the Yangtze River through the Three Gorges is the result of a complex interplay between climate,tectonics,and base-level dynamics,with terraces serving as key archives of landscape response to these forces.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1402602,2022YFA1402502,2021YFA1400103,2020YFA0308802,and 2024YFA1611300)the National Natural Science Foundation of China(Grant Nos.92163206,12274026,12321004,12304205,11934003,12393831,and U2230402)+1 种基金Beijing Association for Science and Technology Youth Talent Lift Program,MCIN/AEI/10.13039/501100011033(Grant No.PID2022-140845OB-C66)FEDER Una manera de hacer Europa。
文摘Lattice distortion of materials has a profound impact on their electronic and magnetic properties,which can generate local magnetic states in intrinsically non-magnetic systems.Here we report on the realization of a one-dimensional(1D)magnetic stripe in monolayer H-NbSe_(2)sustained by strain along the terraces of the graphene/SiC substrates.The strength of this tensile strain is widely tunable by the height-to-width ratio of the terraces.Increasing the tensile strength leads to the shifts and splitting of the Nb 4d bands crossing the Fermi energy,generating spin polarization in a 1D magnetic stripe along the terrace.Simultaneously,the charge-densitywave signature of strained H-NbSe_(2)is significantly suppressed.Such a magnetic stripe can be locally quenched by an individual Se-atom defect via the defect-induced Jahn-Teller distortion and charge density redistribution.These findings provide a different route to achieving and manipulating 1D magnetism in otherwise non-magnetic systems,offering a new way for spintronic devices.
