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Study on The Ecology System of Hani Terraced Paddy Fields 被引量:3
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作者 赵晓迪 赵荣 《Agricultural Science & Technology》 CAS 2014年第10期1793-1796,共4页
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
关键词 Hani terrace PADDY Ecology system Ecological civilization
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Research on Evaluation of Terrace Cultural Landscape Heritage Value from the Perspective of AVC——Take Three Famous Terraces in Southern China for Example 被引量:1
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作者 雷锦锦 罗盛锋 黄燕玲 《Agricultural Science & Technology》 CAS 2016年第12期2842-2846,2858,共6页
The objective evaluation to the terrace cultural landscape heritage value can provide targeted scientific basis for continuation of terrace culture landscape and establishment of protection measures. On the basis of f... The objective evaluation to the terrace cultural landscape heritage value can provide targeted scientific basis for continuation of terrace culture landscape and establishment of protection measures. On the basis of field investigation, expert consultation and literature review, combined with the AVC (Attraction、Vitality and Ca-pacity)theory and Analytic Hierarchy Process based on Fuzzy Comprehensive Evalu-ation, the terrace cultural landscape heritage protection evaluation system and eval-uation model, which selects 22 indicators from three levels including terrace culture landscape resources attraction, resources vitality and resources bearing capacity were structured. Based on col ection of data, material from field survey of China&#39;s most representative Yunnan Yuanyang Hani terrace, Hunan Ziquejie terrace and Longsheng Longji terrace and relevant mathematical calculation to determine evalua-tion index weights, organical y combined of qualitative with quantitative analysis, the diversity, reasonableness and accuracy of evaluation system is improved. Compre-hensive result of mathematical statistics showed that the rank of the cultural land-scape heritage value with the three most representative terraces in southern China is: γ(Hani)〉γ(Longji)〉γ(Ziquejie). 展开更多
关键词 Terrace cultural landscape heritage Value evaluation Analytic hierarchy process Fuzzy comprehensive evaluation
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Effects of Terracing and Agroforestry on Soil and Water Loss in Hilly Areas of the Sichuan Basin, China 被引量:16
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作者 J.H. ZHANG Z.A. SU G.C. LIU 《Journal of Mountain Science》 SCIE CSCD 2008年第3期241-248,共8页
Soil erosion in hilly areas of the Sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of ... Soil erosion in hilly areas of the Sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of terracing and agroforestry in farmland systems on soil and water conservation of slope fields in the hilly areas in Jianyang County, Sichuan Province, Southwestern China. A power function (Y = aXb) can statistically describe the relationship between water runoff (Y) and rainfall (X). The regression equation for the treatment of sloping terraces with crops (Plot 2) is remarkably different from that for the treatment of sloping terraces with grasses and trees (Plot 1) and the conventional up- and down-slope crop system (Plot 3) regarding equation coefficients, while regression equations are similar between Plot 1 and Plot 3. Water runoff amount and runoff coefficient of slope fields increased by 21.5~41.0 % and 27.5~69.7 % respectively, compared to those of sloping terraces, suggesting that terracing notably reduced the water runoff in the field. In the case of sloping terraces, lower amount of water runoff was observed on sloping terraces with crops than on sloping terraces with grasses and trees. Sediment yields on the slope fields in the normal year of rainfall distribution were notably higher (34.41~331.67 % and 37.06~403.44 % for Plot 1 and Plot 2, respectively) than those on sloping terraces, implying that terracing also plays a significant role in the reduction in soil erosion. It is suggested that terracing with crops is significantly effective for soil and water conservation in cultivatedfarmland, while the conventional practice of up- and down- slope cultivation creates high rates of water runoff and soil sediment transport. Terracing with grasses and fruit trees shows a less reduction in water runoff than terracing with crops, which was observed in the 3-year experiments. 展开更多
关键词 AGROFORESTRY sediment transport RUNOFF sloping terrace soil and water conservation
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Standards of Ecological Compensation for Traditional Ecoagriculture:Taking Rice-Fish System in Hani Terrace as an Example 被引量:33
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作者 LIU Mou-cheng XIONG Yin +3 位作者 YUAN Zheng MIN Qing-wen SUN Ye-hong Anthony M.Fuller 《Journal of Mountain Science》 SCIE CSCD 2014年第4期1049-1059,共11页
Traditional eco-agriculture provides many ecosystem services which are important for the local environment, especially in mountain areas. In order to encourage the farmers to engage in coo-agriculture, it is necessary... Traditional eco-agriculture provides many ecosystem services which are important for the local environment, especially in mountain areas. In order to encourage the farmers to engage in coo-agriculture, it is necessary to establish an eco-compensation mechanism for them. As the compensation standard is one of key issues in establishing eeo-compensation mechanism, this paper calculated the standard based on the farmers' willingness to accept (WTA) and the input-output analysis of eco-compensation. We took the traditional rice-fish eco-agriculture as the research object, conducting field surveys in Hani Terrace of Honghe County. Through the questionnaires in 2o11, we obtained the farmers' willingness to accept government compensation and market compensation. Then, the research evaluated the output of eco-compensation, the economic value of rice-fish paddy ecosystem services. Finally, under different market compensation standards, we compared the input and output of government compensation. The results show that, in 2011 the government should to pay farmers 7462 yuan.ha^-1·a^-1 to meet their willingness, but the output (ecological benefit) was only 7393 yuan.ha^-1·a^-1. However, whenthe rice price increases 1 yuan·kg-1 because of the limited use of chemicals in the next year, the government just has to pay farmers 4062 yuan.ha^-1·a^-1 and the surplus will be 3331 yuan.ha^-1·a^-1. 展开更多
关键词 Eco-compensation Eco-agriculture Ecosystem services Cultivation system Hani Terrace.
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Analysis of Comprehensive Benefits of Transforming Slope Farmland to Terraces on the Loess Plateau:A Case Study of the Yangou Watershed in Northern Shaanxi Province,China 被引量:9
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作者 XU Yong YANG Bo +2 位作者 TANG Qing LIU Guobin LIU Puling 《Journal of Mountain Science》 SCIE CSCD 2011年第3期448-457,共10页
De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess Plateau.There are different views about the defarming method,and also various... De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess Plateau.There are different views about the defarming method,and also various de-farming patterns have been put into practice.This paper takes the Yangou Watershed in Shaanxi Province of China as a case for studying the comprehensive benefits of transforming slope farmland to terraces.Based on the day-by-day meteorological data of the Yan'an station in 2005 and the data of terrain features,soil and land use data of the Yangou Watershed,the impact of transforming slope farmland on terraces were simulated and analyzed in aspects of yield increase and water-soil conservation under different topographic conditions with the aid of software WIN-YIELD.Furthermore,an empirical analysis was applied to study the effects of transforming slope farmland to terraces in the Yangou Watershed.The results show that:(1) The bigger the topographic gradient is,the more remarkable benefits it has in yield increase and water-soil conservation.(2) Farmland with slope below 5° could be retained,but farmland with slope above 15° should be converted to forest or grassland as soon as possible.(3) Transforming slope farmland to terraces has the same remarkable effects as the current policy of "Relieving and de-farming" in improving agricultural production conditions,safeguarding food security,raising permanent vegetation coverage rate,and preventing soil and water loss.Besides,it is more cost-effective than the policy of "Relieving and de-farming".It's strongly suggested that the policy of transforming slope farmland to terraces be carried out on the Loess Plateau without delay. 展开更多
关键词 Slope farmland TERRACE Comprehensive benefits Yangou Watershed Loess Plateau
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Soil Properties in Two Soil Profiles from Terraces of the Nam Co Lake in Tibet,China 被引量:4
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作者 WANG Liqiang YI Chaolu +2 位作者 Brigitta Sehiitt LIU Kexin ZHOU Liping 《Journal of Mountain Science》 SCIE CSCD 2009年第4期354-361,共8页
This article investigates the soil properties in two soil profiles from the terraces of the Nam Co Lake in Tibet,China. Profile 1,with a slope aspect to east,is 37 m,and profile 2,to southwest,is 32 m above the lake l... This article investigates the soil properties in two soil profiles from the terraces of the Nam Co Lake in Tibet,China. Profile 1,with a slope aspect to east,is 37 m,and profile 2,to southwest,is 32 m above the lake level. Twelve and nine layers were identified in profile 1 and profile 2,respectively,based on the color,texture,structure,moisture content,presence of carbonate,and root density. Grain sizes and measurements of water content,total organic carbon,total inorganic carbon,total carbon,pH value and electrical conductivity were all analyzed for each sample. The results show that soil is poorly developed because of sparse vegetation coverage and weak chemical weathering in the cold and arid area. The results also indicate that the soil properties are different between the two profiles and suggest that soil is better developed in profile 1 than in profile 2. These differences are ascribed to the dissimilarity of landform,vegetation and timing. Profile 1 faces to east as compared with profile 2 facing to southwest and gets less insolation and therefore less evaporation. Thus,vegetation grows better in profile 1 than in profile 2. Radiocarbon dating and OSL dating show that profile 1 underwent a longer soil forming process than profile 2,which is helpful for the soil development in profile 1. 展开更多
关键词 Soil property Soil genesis Environmental change Marine isotope stage 3 (MIS 3)
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Dating of the topmost terrace in the Jingxian Basin,Anhui Province:an indication of the establishment of the Qingyijiang River 被引量:2
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作者 HU Chun-sheng HU Chen-qi +3 位作者 LIU Shao-chen XU Guang-lai WU Li YANG Li-hui 《Journal of Mountain Science》 SCIE CSCD 2017年第3期549-557,共9页
On the northern fringe of Mt. Huangshan, many fiver terraces are developed at the junction between mountains and plains. The fiver terraces are most typical in the Jingxian Basin, Anhui Province, where the Qingyijiang... On the northern fringe of Mt. Huangshan, many fiver terraces are developed at the junction between mountains and plains. The fiver terraces are most typical in the Jingxian Basin, Anhui Province, where the Qingyijiang River, one of the longest tributaries of the lower Yangtze River, developed three staircase terraces. The topmost terrace (i.e., the T3 terrace) tread is 38 - 39 m above fiver level, and the top of the gravels is generally covered by 3 - 10.9 m of red clay deposits. Systematic magnetostratigraphy and electron spin resonance dating are used to research the timing of the establishment of the Qingyijiang River. The main results show that the topmost terrace developed no later than 900 kyr ago and that the appearance of the Qingyijiang River occurred correspondingly at least before 900 kyr ago on the northern fringe of Mt. Huangshan. In view of the almost synchronous age,the establishment of the Qingyijiang River was seemingly a response to the Mid-Pleistocene Revolution when the 100 kyr cycle commenced, and the Kunlun-Huanghe movement during the early- middle Pleistocene transition. In addition, the establishment of the Qingyijiang River possibly reflected the birth of the modem Yangtze River to some degree. Therefore the timing of the formation of the Yangtze River is restricted to no later than 900 kyr ago based on the appearance of the Qingyijiang River . 展开更多
关键词 Qingyijiang River Topmost terrace MAGNETOSTRATIGRAPHY Electron Spin Resonance dating Establishment timing Jingxian Basin
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Performance of Farmland Terraces in Maintaining Soil Fertility: A Case of Lake Maybar Watershed in Wello, Northern Highlands of Ethiopia 被引量:4
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作者 Shimeles Damene Lulseged Tamene Paul L.G. Vlek 《Journal of Life Sciences》 2012年第11期1251-1261,共11页
Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation measures to tackle the problem where farmland terracing i... Soil-erosion-induced land degradation is a great challenge in the Ethiopian highlands. Consequently, the government has invested in soil and water conservation measures to tackle the problem where farmland terracing is one of the commonly implemented measures in the country. The purpose of this study was to analyze the role of farmland terracing in maintaining soil fertility and to evaluate its performance within a terrace, across terrace age and slope of terrain. The study was conducted in the Lake Maybar watershed in Wello, northern Ethiopia. Composite topsoil samples were collected from plots representing four slope categories across the terrain and three positions within a terrace. The samples were analyzed for selected soil physico-chemical properties and statistically tested using ANOVA (analysis of variance). The study revealed that soil pH (△pH [H2O] = 0.6), exchangeable K+ (△K+ = 0.33 cmol(+)/kg) and clay (9%) content significantly increased towards the lower terrain position. Unlike other studies, all soil properties except bulk density (△ 0.40 g/cm3) showed non-significant differences within a terrace. Bench terrace formation reduced soil fertility gradients within a terrace for which it has been commented. Soil fertility also showed very slight change across terrace age, which indicates terracing reduced erosion-induced soil and nutrient loss. However, in order to optimize impact of farmland terracing on soil fertility maintenance, terracing should be complemented by fertility amendment considering site-specific conditions. 展开更多
关键词 Farmland terrace TERRAIN Wello Ethiopia soil degradation soil fertility.
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A discussion of the risks and benefits of using rock terracing to limit soil erosion in Guizhou Province
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作者 杰克.麦孔其 马焕成 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第1期41-47,83,共7页
The construction of stone terraces to minimise soil erosion is common throughout Guizhou. This technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While th... The construction of stone terraces to minimise soil erosion is common throughout Guizhou. This technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While they trap a greater thickness of soil on the slope they increase the risk of slope failures, reduce moisture and nutrient availability to plants, and thin more soil up slope. The stone risers also threaten long-term productivity. When a riser collapses debris is deposited over the terrace below making farming difficult. These breaches in the terrace focus surface runoff leading to gully formation and increased sediment transport down slope. Artificial drainage systems, often used in conjunction with terracing, compound the risk. These channels prevent precipitation from soaking into the soil. This limits groundwater and soil moisture recharge which reduces the availability of water for crops and the length of the growing season. The rapid drainage of water from the slope reduces the time of concentration of the catchment resulting in an increase in flood activity. Floods are caused by smaller rainstorm events. They arrive faster and peak quicker and higher than before the channels were constructed. Engineering solutions to soil erosion must therefore be used in conjunction with, and are not as a substitute for, good land management strategies. Furthermore, despite changes in land use practices, and the application of new technologies, there is a maximum amount of production that can be obtained from this land on a sustainable basis. 展开更多
关键词 Soil erosion Reafforestation TERRACING Sustainability LANDSLIDING Environmental management
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Effectiveness of Soil Conservation Methods in Preventing Red Soil Erosion in Southern China 被引量:2
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作者 ZHANG Guo-Hua XIE Chong-Bao +1 位作者 PI Xiao-Yu ZUO Chang-Qing 《Journal of Mountain Science》 SCIE CSCD 2015年第5期1281-1291,共11页
Rainfall, runoff(surface runoff and interflow) and soil loss were recorded from 2002 to2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground... Rainfall, runoff(surface runoff and interflow) and soil loss were recorded from 2002 to2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground(control check, CK),interplanting with soybean in spring or radish in autumn(I), level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace)(II), and level terraces of orchards with Bahia grass planted on the riser(III). The surface runoff and erosion in treatment II and III during the four years were low despite the occurrence of potentially erosive rains. By contrast, the CK plot had both the highest surface runoff coefficient and the highest sediment yield among all the plots. The surface runoff and soil erosion of the CK plot significantly differed from that of the treatment plots(p < 0.05). Additionally,Significant differences between the interflow of the CK plot and that of the treatment plots was found from April to August(p < 0.05). However, no significant differences between the CK and treatment plots were found from January to March and September to December. The order of the plots in terms of surface runoff coefficients and soil losses was: CK > I > III > II, whereas their order in terms of interflow was II > III > I > CK. The effects of treatment II were excellent, indicating that level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace) can be an excellent practice for soil and water conservation on sloping red soil land. Soil loss in southern China can be reduced through the widespread use of this approach. 展开更多
关键词 Red soil RUNOFF Soil erosion INTERFLOW
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Flora, life form characteristics, and plan for the promotion of biodiversity in South Korea's Globally Important Agricultural Heritage System, the traditional Gudeuljang irrigated rice terraces in Cheongsando 被引量:9
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作者 Hong Chul PARK Chaang Hveon OH 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1212-1228,共17页
The objectives of this study were to analyze the biodiversity of the Traditional Gudeuljang Irrigated Rice Terraces in Cheongsando, South Korea's representative GIAHS(Globally Important Agricultural Heritage Syste... The objectives of this study were to analyze the biodiversity of the Traditional Gudeuljang Irrigated Rice Terraces in Cheongsando, South Korea's representative GIAHS(Globally Important Agricultural Heritage System) site, with reference to position and land-use features, and to develop a plan to promote agricultural biodiversity in the region. We confirmed approximately 54,000 m2 of Gudeuljang paddy fields by an on-site survey. Of the Traditional Gudeuljang Irrigated Rice Terraces confirmed by onsite inspection, our survey showed that approximately 24,000 m2 are currently being used as paddy fields, approximately 15,000 m2 are being used as dry fields, and approximately 14,000 m2 are fallow. In terms of other non-agricultural land use, there was grassland, including graveyards; artificial arboreal land, such as orchards, rivers and wetlands, and man-made facilities, such as roads and residences. We also confirmed that the Traditional Gudeuljang Irrigated Rice Terraces had higher plant species diversity than conventional terraced rice paddies, and there was a difference in life form characteristics between the two types. Although the superficial topsoil structure is thesame for the Traditional Gudeuljang Irrigated Rice Terraces(TGIRTs) and conventional terraced rice paddies, it is thought that the differences in the subsurface structure of the TGIRTs contribute greatly to species and habitat diversity. However, the TGIRTs in Cheongsando are facing degeneration, due to damage and reduction in agricultural activity. The main cause is the reduction in the number of farming households due to an aging population in Cheongsando. In order to address this problem, we proposed a management plan, related to fallow paddy fields in South Korea, to initiate voluntary activities in the TGIRTs. 展开更多
关键词 Globally Important Agricultural Heritage System Rice terrace Agricultural biodiversity Topsoil structure Gudeuljang
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Effects of intense rainfall on stability of infinite terraced slope 被引量:5
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作者 马世国 韩同春 +2 位作者 徐日庆 吴渐 张杰 《Journal of Central South University》 SCIE EI CAS 2014年第4期1534-1545,共12页
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
关键词 intense rainfall infiltration infinite terraced slope stability safety factor
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Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan,China:an application of the fuzzy comprehensive evaluation model 被引量:10
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作者 LI Jing MIN Qingwen +3 位作者 LI Wenhua BAI Yanying YANG Lun Dhruba Bijaya G C 《Journal of Mountain Science》 SCIE CSCD 2016年第4期744-753,共10页
The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in... The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m^3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development. 展开更多
关键词 Fuzzy comprehensive evaluation model Water resources Hani Rice Terrace Water value Globally Important Heritage Systems(GIAHS)
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Distribution of Soil Enzyme Activities and Microbial Biomass Along a Latitudinal Gradient in Farmlands of Songliao Plain,Northeast China 被引量:26
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作者 LIU Xiu-Mei LI Qi +1 位作者 LIANG Wen-Ju JIANG Yong 《Pedosphere》 SCIE CAS CSCD 2008年第4期431-440,共10页
Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in fa... Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils (0-20 cm depth) were sampled in fields at 7 locations from north (Hallun) to south (Dashiqiao) in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass (MB) C and N, and MBC/MBN were significantly correlated with latitude (P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively), that is, increasing with the latitude. Significant positive correlations (P 〈 0.05) were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity (EC) (P 〈 0.05). MBC and MBN were positively correlated with the total C, C/N, and available P (P 〈 0.05). The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N (P 〈 0.05). The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient. 展开更多
关键词 farmlands HYDROLASES latitudinal gradient microbial biomass soil organic matter
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Comparison of River Terraces in the Middle Reach Valleys of the Yellow River and Analysis on the Multi-Gradational Features of Tectonism in the Formation of Terrace Series
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作者 XingChengqi DingGuoyu +5 位作者 LuYanchou ShenXuhui TianQinjian YinGongming ChaiZhizhang WeiKaibo 《Earthquake Research in China》 2003年第2期183-198,共16页
Where the Yellow River flows through the Haiyuan-Tongxin arc-form tectonic region on the northeastern side of the Qinghai-Xizang (Tibet) Plateau, as many as 10~21 basis and erosion terraces have been produced, among ... Where the Yellow River flows through the Haiyuan-Tongxin arc-form tectonic region on the northeastern side of the Qinghai-Xizang (Tibet) Plateau, as many as 10~21 basis and erosion terraces have been produced, among which the biggest altitude above river level is 401m and the formation age of the highest terrace is 1.57 Ma B.P. Based on comparative analysis of the Yellow River terraces located separately in the Mijiashan mountain, the Chemuxia gorge, the Heishanxia gorge and the other river terraces in the vast extent of the northern part of China, it has been found that the tectonic processes resulting in the formation of the terrace series is one of multi-gradational features, i.e., a terrace series can include the various terraces produced by tectonic uplifts of different scopes or scales and different ranks. The Yellow River terrace series in the study region can be divided into three grades. Among them, in the first grade there are 6 terraces which were formed separately at the same time in the vast extent of the northern part of China and represent the number and magnitude of uplift of the Qinghai-Xizang Plateau since 1.6 Ma B. P.; in the second grade there are 5 terraces which were separately and simultaneously developed within the Haiyuan-Tianjingshan tectonic region and represent the number and magnitude of uplift of this tectonic region itself since 1.6Ma B.P.; in the third grade there are 10 terraces which developed on the eastern slope of the Mijiashan mountain and represent the number and amplitude of uplift of the Haiyuan tectonic belt itself since 1.6Ma B.P. Comparison of the terrace ages with loess-paleosoil sequence has also showed that the first grade terraces reflecting the vast scope uplifts of the Qinghai-Xizang Plateau are very comparable with climatic changes and their formation ages all correspond to the interglacial epochs during which paleosoils were formed. This implies that the vast extent tectonic uplifts resulting in river down-cutting are closely related to the warm-humid climatic periods which can also result in river downward erosion after strong dry and cold climatic periods, and they have jointly formed the tectonic-climatic cycles. There exists no unanimous and specific relationship between the formation ages of the second and third grade terraces and climatic changes and it is shown that the formation of those terraces was most mainly controlled by tectonic uplifts of the Tianjingshan block and the Haiyuan belt. The river terraces in the study region, therefore, may belong to 2 kinds of formation cause. One is a tectonic-climatic cyclical terrace produced jointly by vast extent tectonic uplifts and climatic changes, and the terraces of this kind are extensively distributed and can be well compared with each other among regions. Another is a pulse-tectonic cyclical terrace produced by local tectonic uplifts as dominant elements, and their distribution is restricted within an active belt and can not be compared with among regions. 展开更多
关键词 Comparison of river terraces Terrace series Multi-gradational features of tectonic process Origin of terraces Climatic changes The middle reaches of the Yellow River
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New method for plugging channeling in oil field by nitrogen foam
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作者 杨朝蓬 高树生 +3 位作者 岳湘安 吕毓刚 睢宏刚 魏浩光 《Journal of Central South University》 SCIE EI CAS 2014年第2期677-683,共7页
In order to present a new method for plugging channeling in oil field,the injection modes and validity period of foam system which plugged the formation water layer were studied by means of the experimental model whic... In order to present a new method for plugging channeling in oil field,the injection modes and validity period of foam system which plugged the formation water layer were studied by means of the experimental model which simulated the real conditions of oil wells existing channeling.Above all,the influence factors including reservoir pressure,permeability,oil saturation and gas-to-liquid ratio were studied through dynamic experiment.Then,in light of the technology characteristics of foam injection in oil field,the comparison between gas-liquid and liquid-gas injection modes was studied.The result shows that the gas-liquid injection mode can ensure the foam injectivity and plugging performance.The plugging validity of nitrogen foam injected into the formation water layer was evaluated in different plugging pressure gradients by the dynamic method which is more reasonable than the static evaluation method in laboratory.The research demonstrates that the plugging validity period of foam decreases with plugging pressure gradient increasing.If the plugging pressure gradient is 0.15 MPa/m,the validity period is 160 h.Finally,a empirical equation and a plate about the plugging validity and the plugging pressure gradient were obtained for forecasting the validity period of foam. 展开更多
关键词 foam system plugging performance CHANNELING injection mode plugging validity
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Effect of absorption boundary layer on nonlinear flow in low permeability porous media 被引量:6
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作者 王学武 杨正明 +1 位作者 齐亚东 黄延章 《Journal of Central South University》 SCIE EI CAS 2011年第4期1299-1303,共5页
Taking low permeability cores of Daqing oilfield for example,the flow characteristics at low velocity were studied with the self-designed micro-flux measuring instrument.Considering the throat distribution and capilla... Taking low permeability cores of Daqing oilfield for example,the flow characteristics at low velocity were studied with the self-designed micro-flux measuring instrument.Considering the throat distribution and capillary model,the thickness of fluid boundary layer under different pressure gradients was calculated,and the mechanism and influencing factors of nonlinear percolation were discussed.The results show that the percolation curve of ultra-low rocks is nonlinear,and apparent permeability is not a constant which increases with pressure gradient.The absorption boundary layer decreases with the increase of pressure gradient,and changes significantly especially in low pressure gradient,which is the essence of nonlinear percolation.The absorption boundary layer is also found to be impacted by the surface property of rocks. 展开更多
关键词 low permeability reservoirs PERCOLATION absorption boundary layer capillary model
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Identifying Landscape Pattern Metrics for the Hani Terrace in Yunnan, China 被引量:8
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作者 徐远涛 闵庆文 +4 位作者 袁正 白艳莹 孙业红 李静 曹智 《Journal of Resources and Ecology》 CSCD 2013年第3期212-219,共8页
This study seeks to isolate a select group of landscape metrics particularly well-suited for describing the Hani Terrace in southwest of China.We examined the response of 47 landscape metrics to a large range of image... This study seeks to isolate a select group of landscape metrics particularly well-suited for describing the Hani Terrace in southwest of China.We examined the response of 47 landscape metrics to a large range of imagery grain sizes.Based on a correlation analysis,the original 47 metrics were placed into 21 groups such that all metrics within a group were strongly correlated with each other with a value of more than 0.9,and were represented by a single descriptor.Using these cross-sectional metrics in the context of principal components analysis,we found that five factors explained almost 93% of the total variation in the landscape pattern.The highest loadings for these five factors were the Splitting index (SPLIT),Patch area distribution (AREA_CV),Shannon's diversity index (SHDI),Euclidean nearest neighbor distance distribution (ENN_AM),and Total core area (TCA),respectively.Considering the real landscape,we added the Patch fractal dimension distribution (FRAC_MN) as the sixth landscape pattern metric.As the scale effect of landscape pattern metrics we design to investigate how a suite of commonly use landscape metrics respond to changing grain size.Based on the anlasis,we determined that the best domain of scale to characterise the Hani Terrace pattern metrics is between 40m and 45m.Through the fractal method,we found that the characteristic scale of the Hani Terrace is the same as the scale domain of metrics,among the 40m and 45m.We suggest that the majority of the patterns in the Hani Terrace landscapes,indeed for all those in southwest China,can be described effectively with these six metrics. 展开更多
关键词 landscape pattern metrics Hani Terrace factor analysis domain of scale characteristic scale
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Spatial Variability Analysis of Soil Nutrients Based on GIS and Geostatistics:A Case Study of Yisa Township, Yunnan, China 被引量:11
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作者 李静 闵庆文 +3 位作者 李文华 白艳莹 Dhruba Bijaya G.C. 袁正 《Journal of Resources and Ecology》 CSCD 2014年第4期348-355,共8页
Hani rice terraces system is one of the Globaly Important Agricultural Heritage Systems (GIAHS) pilot sites selected by FAO. Soil nutrients are an important symbol of soil fertility, and play an important role in th... Hani rice terraces system is one of the Globaly Important Agricultural Heritage Systems (GIAHS) pilot sites selected by FAO. Soil nutrients are an important symbol of soil fertility, and play an important role in the sustainable utilization of land. Based on geo-statistics and GIS, the spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen, available phosphorus and available potassium in the soil in Yisa (a town in Honghe County, Yunnan Province) was studied. The results show that the spatial variability of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium exhibited medium spatial variability, and the coefficients of variation are 12.54%, 40.14%, 40.00%, 34.89%, and 40.00% respectively. Available phosphorus exhibited strong spatial variability, and the coefifcient of variation is 102.13%. The spatial variation of pH, organic matter, total nitrogen, alkaline hydrolyzable nitrogen and available potassium fit the index mode, however, the spatial variation of available phosphorus ifts the spherical model. Total nitrogen, available phosphorus and available potassium were greatly affected by soil structural factors, while pH, organic matter and alkaline hydrolyzable nitrogen were affected by both structural and random factors. The spatial distribution of soil nutrients in Yisa was intuitively characterized by Kriging interpolation. It is very important to understand the spatial distribution of soil nutrients, which wil provide the guidance for adjusting agricultural management measures such as fertilization. 展开更多
关键词 spatial analysis geo-statistics soil nutrients KRIGING Hani rice terraces system GIAHS
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Values and Conservation of Honghe Hani Rice Terraces System as a GIAHS Site 被引量:18
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作者 张永勋 闵庆文 +1 位作者 焦雯珺 刘某承 《Journal of Resources and Ecology》 CSCD 2016年第3期197-204,共8页
Agri-cultural Heritage Systems(AHS) have not only various values but also important enlightening roles for modern agriculture.With agro-scientific and technological progress,the traditional agriculture that has last... Agri-cultural Heritage Systems(AHS) have not only various values but also important enlightening roles for modern agriculture.With agro-scientific and technological progress,the traditional agriculture that has lasted for thousands of years is declining gradually,thus is attached the importance of exploring and protecting our AHS.As a traditional agricultural system for 1300 years,the Honghe Hani Rice Terraces System(HHRTS) has many significant characteristics such as beautiful landscapes,distinctive rice varieties,ecologically clean agricultural production systems,systematic methods of managing water and soil and special ethnic culture.It was designated successively as a Globally Important Agricultural Heritage System(GIAHS) in 2010 and as a World Heritage(WH) in 2013.In this paper,taking HHRTS as an example,we analyzed the economic,ecological,aesthetic,cultural,and social values,as well as the research values,of the GIAHS.We conclude that the restrictions on increasing peasant earnings and improving their living standards are difficult with the low efficiency of traditional planting patterns and the single-industry structure of farming in rugged terrain.However,these restrictive factors are beneficial for developing some industries like green agriculture,organic agriculture or ecological food production because of the clean farmland environment.In the end,we propose the basic approaches to protect the Hani terraces agriculture system should include the local governments to encourage the development of ecotourism,organic agriculture and featuring agriculture by multi-mode economic compensation.It is very important for protecting terraces to coordinate benefits among corporations,governments and villagers by making reasonable policies of compensation. 展开更多
关键词 Honghe Hani Rice Terraces System Globally Important Agricultural Heritage Systems(GIAHS) cultural landscape multiple values eco-cultural compensation
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