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The morphological characteristics of gully systems and watersheds in Dry-Hot Valley, SW China 被引量:1
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作者 Zhen Xu Fachao Qin +4 位作者 Bin Zhang Qingchun Deng Hui Liu Jie Jin Liangtao Shi 《Acta Geochimica》 EI CAS CSCD 2018年第6期854-866,共13页
Gully systems and watersheds are geomorphic units with clear boundaries that are relatively independent of basin landscapes and play an important role in natural geography. In order to explore the morphological charac... Gully systems and watersheds are geomorphic units with clear boundaries that are relatively independent of basin landscapes and play an important role in natural geography. In order to explore the morphological characteristics of gully systems and watersheds in the Dry-Hot Valley [South West(SW) China], gullies are interpreted from online Google images with high resolution and watersheds are extracted from digital elevation model at a scale of 1:50,000. The results show that:(1) There are17,382 gullies(with a total area of 1141.66 km2) and 42 watersheds in the study area.(2) The average gully density of the study area(D) is 4.29 km/km2, gully frequency(F) is 14.39 gullies/km2, the branching ratio(B) is 5.13, the length ratio(L) is 3.12, and the coefficient of the main and tributary gullies(M) is 0.06. The degree of gully erosion isstrong to extremely strong, the main development intensity of gully erosion ranges from intense to moderate, and the type of gully system is tributary.(3) The watershed areas(A) are between 0.39 and 96.43 km2, the relief ratio(R) is from 0.10 to 0.19, the circularity ratio(C) is from 0.30 to0.83, the texture ratio(T) is from 0.82 to 39.35, and the dominant geomorphological texture type is fine.(4) There is a quantitative relationship between F and D:F = 0.624 D2(R =0.84) and T is closely related to D, F, M(R2[ 0.7). A,R and C are related to M(R2[ 0.5). The development of gully systems is the result of coupling effects between multiple factors. In this area, the degree of erosion and the condition of the main and tributary gullies can be controlled by the degree of topographic breakage in the watershed, which provides some theoretical basis for the evaluation of gully erosion by the latter. In addition, the scale, relief, and shape have a significant impact on the locations of the main and tributary gullies. For tributary gullies, attention should be paid to the interception and control of runoff and sediment in the small confluence branches in order to prevent gully expansion and head advance. These features can inform the development of targeted measures for the control of soil erosion. 展开更多
关键词 MORPHOLOGICAL characteristics Quantitative RELATIONSHIPS GULLY system WATERSHED dry-hot VALLEY
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Industrial Poverty Alleviation Model in Deep Poverty-stricken Villages in the Dry-hot Valley of Jinsha River: A Case Study of Poverty Alleviation in the Green Prickleyash Planting Industry in Laopingzi Village,Luquan County 被引量:1
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作者 Meiqi SHAO Zisheng YANG 《Asian Agricultural Research》 2019年第6期59-63,70,共6页
Industrial poverty alleviation is the core of poverty alleviation in rural areas of China,and it is the fundamental way for the rural poor to achieve stable income and poverty alleviation. Laopingzi Village,Jiaopingdu... Industrial poverty alleviation is the core of poverty alleviation in rural areas of China,and it is the fundamental way for the rural poor to achieve stable income and poverty alleviation. Laopingzi Village,Jiaopingdu Town,Luquan County,Kunming County,Yunnan Province,located in the dry-hot valley area of Jinsha River,has become a typical deep poverty-stricken village due to its special natural conditions.In recent years,in the battle to win the fight against poverty,the people of Laopingzi Village have achieved a virtuous cycle of the ecological environment and an access to get rid of poverty and get rich through vigorously developing green prickleyash planting industry. By the end of 2018,the incidence of poverty in Laopingzi Village Committee dropped from 45. 62% in 2014 to 1. 11%,and the green prickleyash planting industry had achieved remarkable results in poverty alleviation. This article summarizes the specific practices of developing the green prickleyash planting industry in the village,analyzes the main results and successful experiences of the mode and discusses the inspiration of the implementation of green prickleyash cultivation on industrial poverty alleviation,so as to provide an effective practical example for the development and poverty alleviation of poverty-stricken areas. 展开更多
关键词 INDUSTRIAL poverty alleviation Green prickleyash Characteristic PLANTING Mode DEEP POVERTY-STRICKEN VILLAGE dry-hot valley area of Jinsha River
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Poverty Alleviation Mode by Developing Sorghum Planting Industry in Dry-hot Valley Areas of Jinsha River in China:Taking Luquan Yi and Miao Autonomous County of Yunnan Province as an Example
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作者 Renyi YANG Zisheng YANG 《Asian Agricultural Research》 2019年第10期57-61,共5页
There are many state-level poverty-stricken counties in the dry-hot valley areas of Jinsha River in China,with a wide range of poverty and extreme degree of poverty.The industry-supporting poverty alleviation ranks fi... There are many state-level poverty-stricken counties in the dry-hot valley areas of Jinsha River in China,with a wide range of poverty and extreme degree of poverty.The industry-supporting poverty alleviation ranks first in the"five batches"of China's targeted poverty alleviation strategy.The practice of planting in Luquan County since 2017 shows that the valleys and slopes on the dry-hot valley areas of Jinsha River with an altitude above 1800 m have wide land suitable for sorghum planting,and suitable for introduction and planting.In recent years,the county has adopted the mode of enterprise+government+cooperative+poor household,introduced the Langzhitang wine factory,developed sorghum planting with large-scale,industrialized and specialized features to achieve stable income growth for the poor,and significant results have been achieved.Based on many field surveys,household surveys,and interviews with county and village leaders,this paper analyzes the specific practices and main effects of the county's poverty alleviation model by developing sorghum planting industry,aiming to provide necessary reference for the targeted poverty alleviation and poverty alleviation in similar areas of Yunnan Province and other provinces. 展开更多
关键词 dry-hot valley area Industry-supporting POVERTY alleviation SORGHUM PLANTING POVERTY MODE Luquan COUNTY
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Livelihood Capital and Livelihood Diversification for Different Farmers in Yuanjiang Dry-Hot River Valley
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作者 Wenjuan ZHAO Shilong YANG Xiao WANG 《Asian Agricultural Research》 2016年第3期17-21,26,共6页
Under the analytical framework of sustainable livelihoods,we establish the evaluation indicator system for farmers' livelihood capital,to evaluate the current livelihood capital and livelihood diversification for ... Under the analytical framework of sustainable livelihoods,we establish the evaluation indicator system for farmers' livelihood capital,to evaluate the current livelihood capital and livelihood diversification for different farmers in the Dai nationality region of Xinping County in the Yuanjiang dry-hot river valley area,and discuss the relationship between livelihood capital and livelihood diversification. Studies have shown that the mode dominated by agriculture,supplemented by non-agricultural activities,combined with breeding,is the commonly used livelihood strategy for farmers in this region. As farmers change from pure agriculture to non-agriculture,their total livelihood capital and nonagricultural livelihood diversification index will increase,while agricultural livelihood diversification index will decrease. In the meantime,their livelihood activities gradually shift from agricultural to non-agricultural ones,which is mainly reflected in the combination of both agricultural and non-agricultural activities. Regression analysis on livelihood capital and livelihood diversification shows that natural and physical capital is the basis of realizing agricultural livelihood diversification. Farmers with rich natural and physical capital will prefer agricultural livelihood strategies. While financial and human capital is the driving force for farmers' transition from pure agriculture to non-agriculture. 展开更多
关键词 LIVELIHOOD CAPITAL LIVELIHOOD DIVERSIFICATION Regression analysis Yuanjiang dry-hot VALLEY
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Simulation of Morphological Development of Soil Cracks in Yuanmou Dry-hot Valley Region, Southwest China 被引量:8
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作者 XIONG Donghong YAN Dongchun +4 位作者 LONG Yi LU Xiaoning HAN Jianning HAN Xueqin SHI Liangtao 《Chinese Geographical Science》 SCIE CSCD 2010年第2期112-122,共11页
Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the ... Soil cracking is an important process influencing water and solutes transport in the Yuanmou Dry-hot Valley region of Southwest China. Studying the morphological development of soil cracks helps to further reveal the close relationship between the soil cracking process and water movement in such semi-arid regions. Here we report regular changes on surface morphology of soil cracks with decreasing water in four different soils (Typ-Ustic Ferrisols,Ver-Ustic Ferrisols,Tru-Ustic Vertisols and Typ-Ustic Vertisols) through simulation experiments. Our results indicate the following: 1) Different soils ultimately have different development degrees of soil cracks,according to their various values of crack area density. Soil cracks in Typ-Ustic Ferrisols can only develop to the feeble degree,while those in the other three soils are capable of developing into the intensive degree,and even into the extremely intensive degree. 2) Soil crack complexity,as expressed by the value of the area-weighted mean of crack fractal dimension (AWMFRAC),is found to continuously decrease as a whole through the whole cracking process in all the studied soils. 3) Soil crack connectivity shows a uniform trend in the studied soils,that is to say,connectivity gradually increases with soil crack development. 展开更多
关键词 元谋干热河谷地区 土壤水分 裂缝形态 中国西南 模拟实验 形态发育 裂纹形态 半干旱地区
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A novel model to assess soil productivity in the dry-hot valleys of China 被引量:3
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作者 DUAN Xing-wu HAN Xu +2 位作者 HU Jin-ming FENG De-tai RONG Li 《Journal of Mountain Science》 SCIE CSCD 2017年第4期705-715,共11页
Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We develope... Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We developed a new empirical soil productivity model based on field investigations of soil erosion, soil physicochemical properties, and crop yields in the dry-hot valleys(DHVs) in China. We found that soil p H, and organic matter and available potassium contents significantly affected crop yields under eroded conditions of the DHVs. Moreover, available potassium content was the key factor affecting soil productivity. We then modified an existing soil productivity model by adding the following parameters: contents of effective water, potassium, organic matter, and clay, soil p H, and root weighting factor. The modified soil productivity model explained 63.5% of the crop yield. We concluded that the new model was simple, realistic, and exhibited strong predictability. In addition to providing an accurate assessment of soil productivity, our model could potentially be applied as a soil module in comprehensive crop models. 展开更多
关键词 土壤生产力 干热河谷地区 评估模型 中国 速效钾含量 土壤PH值 生产力模型 作物产量
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Responses of Dodonaea viscosa growth and soil biological properties to nitrogen and phosphorus additions in Yuanmou dry-hot valley 被引量:4
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作者 WANG Xue-mei YAN Bang-guo +3 位作者 ZHAO Guang ZHAO Ji-xia SHI Liang-tao LIU Gang-cai 《Journal of Mountain Science》 SCIE CSCD 2018年第6期1283-1298,共16页
Nitrogen(N) and phosphorus(P) are limited nutrients in terrestrial ecosystems, and their limitation patterns are being changed by the increase in N deposition. However, little information concerns the plant growth and... Nitrogen(N) and phosphorus(P) are limited nutrients in terrestrial ecosystems, and their limitation patterns are being changed by the increase in N deposition. However, little information concerns the plant growth and the soil biological responses to N and P additions among different soils simultaneously, and these responses may contribute to understand plant-soil interaction and predict plant performance under global change. Thus, this study aimed to explore how N and P limitation changes in different soil types, and reveal the relationship between plant and soil biological responses to nutrient additions. We planted Dodonaea viscosa, a globally distributed species in three soil types(Lixisols, Regosols and Luvisols) in Yuanmou dry-hot valley in Southwest China and fertilized them factorially with N and P. The growth and biomass characters of D. viscosa, soil organic matter, available N, P contents and soil carbon(C), N, P-related enzyme activities were quantified. N addition promoted the growth and leaf N concentration of D. viscosa in Lixisols; N limitation in Lixisols was demonstrated by lower soil available N with higher urease activity. P addition promoted the growth and leaf P concentration of D. viscosa in Luvisols; severe P limitation in Luvisols was demonstrated by a higher soil available N: P ratio with higher phosphatase activity. Urease activity was negatively correlated with soil available N in Nlimited Lixisols, and phosphatase activity was negatively correlated with soil available P in P-limited Luvisols. Besides, the aboveground biomass and leaf N concentration of D. viscosa were positively correlated with soil available N in Lixisols, but the aboveground biomass was negatively correlated with soil available P. Our results show similar nutrient limitation patterns between plant and soil microorganism in the condition of enough C, and the nutrient limitations differ across soil types. With the continued N deposition, N limitation of the Lixisols in dry hot valleys is expected to be alleviated, while P limitation of the Luvisols in the mountaintop may be worse in the future, which should be considered when restoring vegetation. 展开更多
关键词 土壤类型 植物生长 生物性质 磷酸 山谷 干燥 生物资源
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Planar morphology and controlling factors of the gullies in the Yuanmou Dry-hot Valley based on field investigation 被引量:3
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作者 DENG Qingchun MIAO Fang +5 位作者 ZHANG Bin LUO Mingliang LIU Hui LIU Xiaojiao QIN Fachao LIU Gangcai 《Journal of Arid Land》 SCIE CSCD 2015年第6期778-793,共16页
The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding ... The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding their controlling factors, this study, utilizing a total station and GPS RTK, measured the shoulder lines and channel curves of 112 gullies in six sites of the Yuanmou Dry-hot Valley and then mapped them by Arc GIS software and calculated nine parameters. The results showed that the channel lengths range from 10.88 to 249.11 m; the widths range from 6.20 to 40.99 m; the perimeters range from 54.11 to 541.67 m; the gully areas range from 153.02 to 6,930.30 m2; the left-side areas range from 92.93 to 4,027.20 m2; and the right-side areas range from 63.65 to 3,539.77 m2. The slightly sinuous and straight gullies account for 73.21% of the total gullies; the quantity of the right skewed gullies is 8.93% greater than that of the left skewed ones based on the symmetry ratio; the shape ratios range from 1.12 to 1.40 and the morphology ratios from 0.038 to 1.294; the fractal dimension is 1.192. Gullies in different sites have diverse planar characteristics. Except for the symmetry index, which was close to a negatively skewed distribution, all of the other parameters had the characteristic of positively skewed distribution. The gully area is related to the length and width, but the gully length has a weak correlation with the width. The evolutionary stage, topographic conditions, strata, soil properties, and piping erosion played very important roles in the gully planar morphology. This study could provide useful information for controlling gully erosion and safeguarding human habitation and engineering buildings. 展开更多
关键词 元谋干热河谷区 平面形态 控制因素 野外调查 基础 通道长度 侵蚀速率 演化阶段
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Anthropogenic Impacts on the Sediment Flux in the Dry-hot Valleys of Southwest China—an Example of the Longchuan River 被引量:3
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作者 ZHOUYue LUXixi +1 位作者 HUANGYing ZHUYunmei 《Journal of Mountain Science》 SCIE CSCD 2004年第3期239-249,共11页
The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper... The sediment flux data, measured from a dry-hot valley of the Longchuan River, a tributary of the lower Jinsha River, were analyzed with Mann-Kendall test, Seasonal Mann-Kendall test and Sen’s test. In both the upper reaches (Xiaohekou) and the lower reaches (Xiaohuangguayuan), the sediment fluxes showed a significant increase from 1970 to 2001, despite the fact that the water discharge did not change significantly during the period and numerous reservoir constructions which contribute to the trap of sediment. This can be attributed to the intensification of human activities, especially the activities related to land surface disturbances such as deforestation and afforestation, expansion of agriculture land, and road constructions. This increase is more significant in the lower reaches of the river observed at the place of Xiaohuangguayuan due to the dry-hot climate. The profound increase in sediment flux has significant implications for effective management of the sedimentation problems of the on-going Three Gorges Reservoir. 展开更多
关键词 人为影响 泥石流 干热流域 森林破坏 造林活动 道路建设
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Effects of vegetation coverage and seasonal change on soil microbial biomass and community structure in the dry-hot valley region 被引量:3
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作者 WU Han XIONG Dong-hong +5 位作者 XIAO Liang ZHANG Su YUAN Yong SU Zheng-an ZHANG Bao-jun YANG Dan 《Journal of Mountain Science》 SCIE CSCD 2018年第7期1546-1558,共13页
Soil microorganisms are sensitive indicator of soil health and quality. Understanding the effects of vegetation biomass and seasonal change on soil microorganisms is vital to evaluate the soil quality and implement ve... Soil microorganisms are sensitive indicator of soil health and quality. Understanding the effects of vegetation biomass and seasonal change on soil microorganisms is vital to evaluate the soil quality and implement vegetation restoration. This study analyzed the soil phospholipid fatty acids(PLFAs) in fresh and withered Kudzu(Pueraria montana var. lobata) vegetation conditions in different seasons. The results showed that vegetation biomass and seasonal change significantly affected microbial biomass and its community structure. Both fresh and withered Kudzu cover significantly increased soil microbial biomass, and the growth effect of microbes in the soil with fresh Kudzu cover was more obvious than that with withered Kudzu cover. Compared with the dry season, the rainy season significantly increased the microbial biomass and the B/F(the ratio of bacterial to fungal PLFAs) ratio but dramatically reduced the G+/G-(the ratio of gram-positive to gram-negative bacteria PLFAs). Kudzu cover and seasonal change had a significant effect on microbial structure in soil covered by higher vegetation biomass. Furthermore, soil temperature and moisture had different correlations with specific microbial biomass in the two seasons. Our findings highlight the effect of Kudzu vine cover on the soil microenvironment and soil microhabitat, enhancing the soil quality in the Dry-hot Valley of Jinsha River, Southwest China. 展开更多
关键词 土壤微生物 生物资源 土壤健康 植被恢复 季节 山谷 干燥 社区
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Morphology and controlling factors of the longitudinal profile of gullies in the Yuanmou dry-hot valley 被引量:3
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作者 DING Lin QIN Fa-chao +6 位作者 FANG Hai-dong LIU Hui ZHANG Bin SHU Cheng-qiang DENG Qing-chun LIU Gang-cai YANG Qian-qian 《Journal of Mountain Science》 SCIE CSCD 2017年第4期674-693,共20页
The morphology of the gully longitudinal profile(GLP) is an important topographic index of the gully bottom associated with the evolution of the gullies.This index can be used to predict the development trend and eval... The morphology of the gully longitudinal profile(GLP) is an important topographic index of the gully bottom associated with the evolution of the gullies.This index can be used to predict the development trend and evaluate the eroded volumes and soil losses by gullying. To depict the morphology of GLP and understand its controlling factors, the Global Positioning System Real-time Kinematic(GPS RTK) and the total station were used to measure the detail points along the gully bottom of 122 gullies at six sites of the Yuanmou dry-hot Valley. Then, nine parameters including length(Lt), horizontal distance(Dh), height(H), vertical erosional area(A), vertical curvature(Cv), concavity(Ca), average gradient(Ga), gully length-gradient index(GL), normalized gully length-gradient index(Ngl), were calculated and mapped using CASS, Excel and SPSS.The results showed that this study area is dominated by slightly concave and medium gradient GLPs, and the lithology of most gullies is sandstone and siltstone.Although different types of GLPs appear at different sites, all parameters present a positively skewed distribution. There are relatively strong correlations between several parameters: namely Lt and H, Dh and H, Lt and A, Dh and A, H and GL. Most GLPs, except three, have a best fit of exponential functions with quasistraight shapes. Soil properties, vegetation coverage,piping erosion and topography are important factors to affect the GLP morphology. This study provides useful insight into the knowledge of GLP morphology and its influential factors that are of critical importance to prevent and control gully erosion. 展开更多
关键词 纵剖面形态 元谋干热河谷 控制因素 沟谷 全球定位系统 地形指数 平均梯度 CASS
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Sap flow characteristics of three afforestation species during the wet and dry seasons in a dry-hot valley in Southwest China 被引量:2
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作者 Xiaofei Wang Jianfeng Liu +2 位作者 Yongyu Sun Kun Li Chunhua Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期51-62,共12页
Assessing and using tree species(exotic or native) with superior tolerance to environmental stresses(such as drought and high temperature) play an important role in afforestation practices. In the present study, stem ... Assessing and using tree species(exotic or native) with superior tolerance to environmental stresses(such as drought and high temperature) play an important role in afforestation practices. In the present study, stem sap flow characteristics and responses to ambient meteorological factors of three tree species, Albizzia kalkora(native), Azadirachta indica(exotic), and Acacia auriculaeformis(exotic), in a dry-hot valley(Yuanmou, Yunnan Province, China) were investigated using thermal dissipation probes. The diurnal dynamics of sap flow in three studied species displayed an obvious circadian rhythm during the wet and dry seasons, with the exception of A.indica during the dry season. The sap flow velocity(SFV)in A. kalkora and A. auriculaeformis was significantly positively correlated with photosynthetically active radiation(PAR), air temperature, vapour pressure deficit(VPD)and wind speed, but negatively correlated with atmosphericrelative humidity over the two seasons. The cross-correlation analysis also revealed that the SFV of the three species was significantly correlated with PAR and VPD(P<0.001). Additionally, stem sap flow lagged behind PAR but ahead of VPD, and the diurnal sap flow was more dependent on PAR than on VPD. However, we found that the dominant climatic factor influencing the stem sap flow differed between daytime and nighttime. PAR was more influential than other meteorological factors during the daytime, while VPD or other factors were more influential overnight. When the nighttime refilling ability of the three tree species was compared, our results suggest that A.indica has higher drought resistance and better for afforestation of the studied region. 展开更多
关键词 造林树种 树干液流 干热河谷 中国西南 季节 干燥 潮湿 特征
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IMPACT OF WATER ENVIRONMENTAL CHARACTERISTICS IN DRY-HOT VALLEY OF JINSHA RIVER ON SOIL DESERTIFICATION 被引量:1
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作者 刘刚才 刘淑珍 《Chinese Geographical Science》 SCIE CSCD 1999年第2期93-96,共4页
Withthesocialdevelopment,humanbeingshadtopaymuchatentiontothecrisisofenvironmentastotheeconomiccrisis.Waterd... Withthesocialdevelopment,humanbeingshadtopaymuchatentiontothecrisisofenvironmentastotheeconomiccrisis.Waterdeficiencyanddeser... 展开更多
关键词 DESERTIFICATION DRY HOT VALLEY of the Jinsha RIVER WATER environment
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Effects of Land Use Change on the Ecosystem Services Value in the Dry-Hot Valley 被引量:1
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作者 ZHOU Hongyi XIONG Donghong +1 位作者 YANG Zhong HE Xiubin 《Wuhan University Journal of Natural Sciences》 CAS 2007年第4期743-748,共6页
The objective of the study reported here was to determine whether LANDSAT TM images could be used to quantify changes in land-use and ecosystem services in Yuanmou County. The sizes of six land use/land cover(LUCC) ca... The objective of the study reported here was to determine whether LANDSAT TM images could be used to quantify changes in land-use and ecosystem services in Yuanmou County. The sizes of six land use/land cover(LUCC) categories were estimated in Yuanmou County according to the LANDSAT TM images in the summer of 1986 and 2005. Coefficients published by Xie Gaodi and co-workers in 2003 were used to value changes in ecosystem services delivered by each land use/land cover category,and the ecosystem services sensitivity analysis was conducted to de-termine the effect of manipulating these coefficients on the estimated values. The im-portant results are summarized as followings. ① The estimated size of cultivated land,pasture land,water area and unused land decreased by 6.39%,1.35%,2.25% and 10.67% respectively between 1986 and 2005. By contrast,the estimated size of forest land and construction land increased by about 2.23% and 71.15% respectively between 1986 and 2005. ② The total ecosystem services value(EVS) of the study area in-creased from 2 142 132 609.46 yuan to 2 146 416 621.00 yuan,with the net increase of 4 284 011.54 yuan during the 20-year time period. ③ The coefficient sensitivity(CS) of the study are less than unity in all cases(CS ∧1) . This indicates that the total eco-system values estimated for the study area are relatively inelastic with respect to the ecosystem service coefficients. While this implies that our estimates are robust and the coefficient is reasonable,highly under or over valued coefficients can substantially affect the veracity of estimated changes in ecosystem service values overtime even when the CS are less than unity(CS ∧1) . 展开更多
关键词 土地使用 土地覆盖 生态系统 服务评估 云南 干热河谷地区
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Impacts of reforestation on woody species composition,species diversity and community structure in dry-hot valley of the Jinsha River,southwestern China
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作者 GONG Zhi-lian TANG Ya 《Journal of Mountain Science》 SCIE CSCD 2016年第12期2182-2191,共10页
To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with... To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with adjacent wastelands,natural shrub grassland and a natural forest as references.Species importance value,species richness,species heterogeneity and Sorenson similarity index between plantations and the natural forest were analyzed.Results indicated that compared to wastelands and natural shrub grassland,reforestation improved species diversity and community structure,and more forest woody species found suitable habitats in plantations.Species diversity in understory of plantations and Sorenson similarity index were significantly negatively correlated with stem density in mature plantations(26-31 years old).Higher species diversity and Sorenson similarity index existed in mature sparse plantations due to lower stem density and more tree species planted initially.In contrast,reference natural forest,with species heterogeneity of 2.28 for shrub layer,showed the highest species diversity.It would take a long time for species composition and diversity to recover through reforestation in a dry-hot valley.Therefore,it was essential to protect remnant natural forests strictly and reforest with suitable management such as lower stem density and increasing genetic diversity of trees planted. 展开更多
关键词 金沙江干热河谷 物种多样性 植树造林 中国西南部 群落结构 木本植物 植物组成 相似性指数
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Seasonal Dynamics of the Soil Moisture in Yuanmou Dry-Hot Valley of Yunnan
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作者 Yuanjiao Zhao Wenhua Su +2 位作者 Guangfei Zhang Fengtao Cui Rui Zhou 《Meteorological and Environmental Research》 CAS 2013年第4期56-58,共3页
[Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining comple... [Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining completed research about soil moisture in dry season, data in rainy and dry seasons were contrasted to study seasonal dynamics of the soil moisture in the zone. [Result] Soil moisture in rainy season increased with the depth of soil, but would decrease within 1.0 m below the root layer. The soil moisture of grassland was higher than that of the woodland, while soil moisture of the savanna was higher than that of the woodland but lower than that of the grassland. In addition, compared with soil moisture in dry season, it is clear that to avoid forming permanent soil desiccation, based on soil and hydrology conditions in Yuanmou, it is better to plant grass not tree in Yuanmou when we do something about ecological restoration. [Conclusion] The research had certain guidance significance for planting agricultural and economic crops and carrying out ecological restoration in Yuanmou Dry-Hot Valley. 展开更多
关键词 元谋干热河谷 土壤水分 季节动态 云南 土壤含水量 稀树草原 生态恢复 土壤深度
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苹果丁冷冻-热风联合干燥体积收缩机制 被引量:1
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作者 任广跃 朱乐雯 +3 位作者 段续 刘文超 李格格 卫新雨 《农业工程学报》 EI CAS CSCD 北大核心 2024年第2期63-71,共9页
为降低冻干苹果能耗,同时获得具有良好外观的脱水产品,该研究将冷冻-热风联合干燥应用于苹果脱水加工,并从水分迁移角度探究此过程中产品的收缩机制。选取4个水分转换点(干基含水率分别为1.00、0.76、0.53和0.33 g/g)对苹果进行联合干... 为降低冻干苹果能耗,同时获得具有良好外观的脱水产品,该研究将冷冻-热风联合干燥应用于苹果脱水加工,并从水分迁移角度探究此过程中产品的收缩机制。选取4个水分转换点(干基含水率分别为1.00、0.76、0.53和0.33 g/g)对苹果进行联合干燥处理,并对脱水产品的收缩率、质构特性、微观结构、孔隙分布及样品在热风干燥阶段的水分迁移与分布进行测定及分析。结果表明,联合干燥样品的收缩情况显著(P<0.05)优于单一热风干燥样品,且转换点对样品收缩率影响较大(收缩率6%~45%),当转换点干基含水率低于0.53 g/g时,联合干燥样品没有出现明显的体积收缩现象。随着转换点干基含水率的升高,样品的收缩程度增大,并出现不同程度的中心塌陷,且孔隙率逐渐减小,但相应能耗降低。产品收缩主要发生在热风干燥过程的升速阶段,在此阶段样品自由水含量大幅减少,结合水与不易流动水未发生明显改变,样品内部水分在湿度差的作用下向表面迁移,这是导致联合干燥样品发生体积收缩的关键机制。该研究结果可为冷冻-热风联合干燥高效生产良好外观的脱水苹果提供数据支撑及理论参考。 展开更多
关键词 冷冻干燥 热风干燥 联合干燥 收缩 水分迁移 微观结构
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横断山区典型流域次降水事件水沙特征分析
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作者 郭乾坤 黄婷婷 +2 位作者 单志杰 秦伟 宁堆虎 《中国水土保持科学》 CSCD 北大核心 2024年第1期27-34,共8页
横断山区干热河谷高温低湿,植被稀疏,水土流失现象较为严重,是金沙江、澜沧江和怒江等大江大河泥沙的主要源区。干热河谷地区水土流失多由次强降水事件造成,因此在该区域基于次降水事件尺度开展水沙特征研究,对于评价降雨和下垫面对流... 横断山区干热河谷高温低湿,植被稀疏,水土流失现象较为严重,是金沙江、澜沧江和怒江等大江大河泥沙的主要源区。干热河谷地区水土流失多由次强降水事件造成,因此在该区域基于次降水事件尺度开展水沙特征研究,对于评价降雨和下垫面对流域产流产沙的相对贡献、指导未来水土保持实践具有重要意义。基于金沙江一级支流龙川江流域小黄瓜园水文站1966—2018年实测水沙数据,运用Mann-Kendall方法划分基准期和变化期,并基于2期次降水事件,对比分析降雨等级相同、暴雨覆盖面积比例等级相同、降雨量和降雨空间分布相似等3种情况下,2期水沙特征及变化原因。结果表明:1)小黄瓜园1966—2018年径流量和输沙量呈现明显下降趋势,其中2008年为突变年份;2)水土保持措施主导下的下垫面变化是变化期径流输沙减少的主要原因。长期以来龙川江流域实施的水土保持工程有效地改变下垫面的情况,减流减沙效果明显。应进一步加强横断山区等地形复杂地区次降水事件尺度水沙变化研究,更好地指导水土保持优化配置与管理。 展开更多
关键词 次降水事件 水土保持措施 下垫面 水沙特征 干热河谷 龙川江流域
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干热区紫花苜蓿的生产性能和营养价值评价
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作者 龙会英 张德 《草业科学》 CAS CSCD 北大核心 2024年第1期117-125,共9页
在云南省干热河谷区,以不同紫花苜蓿(Medicago sativa)品种(系)作为研究对象,应用方差和灰色关联度的分析方法对其生产性能及营养成分进行综合评价。结果表明,8个品种(系)的一级分枝数和水分有明显差异。所有参试材料在2018年和2020年... 在云南省干热河谷区,以不同紫花苜蓿(Medicago sativa)品种(系)作为研究对象,应用方差和灰色关联度的分析方法对其生产性能及营养成分进行综合评价。结果表明,8个品种(系)的一级分枝数和水分有明显差异。所有参试材料在2018年和2020年每年可刈割8次,2019年为9次。6号苜蓿品种‘南苜701-特克拉’的年均干草产量最高,达到29589.96 kg·hm^(-2),显著高于5号‘四季旺’和8号‘德钦’(P<0.05)。在2018年,8个苜蓿品种(系)产量在4个季度中从高到低的排列顺序为第3季度>第2季度>第4季度>第1季度。所有供试材料的粗纤维、粗脂肪、粗灰分、全钙、无氮浸出物差异均不显著(P>0.05)。8号品种‘德钦’的粗蛋白含量(21.43%)、粗灰分(10.16%)和全磷含量(0.25%)均最高,粗纤维含量最低(18.36%)。经灰色关联度分析表明,‘热引41号紫花苜蓿’‘德钦’‘多叶’和‘WL525HQ’的综合表现较好,在该地区具有较高的推广利用价值。 展开更多
关键词 紫花苜蓿 生产性能 产量性状 灰色关联度 营养价值 综合评价 干热河谷
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蒸汽烫漂与热风干燥箱流场优化设计及仿真
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作者 陈忠加 赵宇轩 +2 位作者 卢丰源 孙敏 王青春 《农业工程学报》 EI CAS CSCD 北大核心 2024年第6期60-71,共12页
农产品的烫漂与干燥是农产品加工的关键技术。农产品蒸汽烫漂与热风干燥箱是集烫漂与干燥一体的新型农产品绿色保质低碳智能干燥技术装备。农产品蒸汽烫漂与热风干燥箱内部流场均匀性直接影响着农产品烫漂与干燥效果。为提高其内部速度... 农产品的烫漂与干燥是农产品加工的关键技术。农产品蒸汽烫漂与热风干燥箱是集烫漂与干燥一体的新型农产品绿色保质低碳智能干燥技术装备。农产品蒸汽烫漂与热风干燥箱内部流场均匀性直接影响着农产品烫漂与干燥效果。为提高其内部速度均匀性与温湿度均匀性,同时减少冷凝现象发生,采用计算流体力学(computational fluid dynamics,CFD)方法建立蒸汽烫漂与热风干燥箱模型,对其送风方式和送风口数量进行研究。结果表明:侧送侧回的送风方式在速度场以及温湿度场的均匀性总体优于上送下回,能量利用系数提高约18%,箱内壁面冷凝面积小于上送下回。仿真研究表明,当送风口数量为4个时,箱内的温度场和相对湿度场均匀性更好,能量利用系数最高。试验表明,蒸汽烫漂与热风干燥箱的试验值和仿真值最大温度偏差为2.3℃,相对湿度误差不超过1.3%,误差在合理范围内,仿真结果可靠,研究结果可为农产品低碳智能干燥新技术的研究提供参考。 展开更多
关键词 农产品 干燥设备 蒸汽烫漂 热风干燥 计算流体力学
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