Search

The degradation of water quality has been observed worldwide, and inputs of nitrogen (N), along with other nutrients, play a key role in the process of contamination. The quantification of N loading from non-point sources at a watershed scale has long been a challenge. Process-based models have been developed to address this problem. Because N loading from non-point sources result from interactions between biogeo-chemical and hydrological processes, a model framework must include both types of processes if it is to be useful. This paper reports the results of a study in which we integrated two fundamental hydrologic features, the SCS (Soil Conservation Service) curve function and the MUSLE (Modified Universal Soil Loss), into a biogeochemical model, the DNDC. The SCS curve equation and the MUSLE are widely used in hydrological models for calculating surface runoff and soil erosion. Equipped with the new added hydrologic features, DNDC was substantially enhanced with the new capacity of simulating both vertical and horizontal movements of water and N at a watershed scale. A long-term experimental watershed in Southwest China was selected to test the new version of the DNDC. The target watershed's 35.1 ha of territory encompass 19.3 ha of croplands, 11.0 ha of forest lands, 1.1 ha of grassplots, and 3.7 ha of residential areas. An input database containing topographic data, meteorological conditions, soil properties, vegetation information, and management applications was established and linked to the enhanced DNDC. Driven by the input database, the DNDC simulated the surface runoff flow, the subsurface leaching flow, the soil erosion, and the N loadings from the target watershed. The modeled water flow, sediment yield, and N loading from the entire watershed were compared with observations from the watershed and yielded encouraging results. The sources of N loading were identified by using the results of the model. In 2008, the modeled runoff-induced loss of total N from the watershed was 904 kgNyr-1, of which approximately 67% came from the croplands. The enhanced DNDC model also estimated the watershed-scale N losses (1391 kgNyr-1) from the emissions of the N-containing gases (ammonia, nitrous oxide, nitric oxide, and dinitrogen). Ammonia volatilization (1299 kgNyr-1) dominated the gaseous N losses. The study indicated that process-based biogeochemical models such as the DNDC could contribute more effectively to watershed N loading studies if the hydrological components of the models were appropriately enhanced. [ABSTRACT FROM AUTHOR]

Daily PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 µm) samples were collected at an urban site in Chengdu, an inland megacity in southwest China, during four one-month periods in 2011, with each period in a different season. Samples were subjected to chemical analysis for various chemical components ranging from major water-soluble ions, organic carbon (OC), element carbon (EC), trace elements to biomass burning tracers, anhydrosugar levoglucosan (LG) and mannosan (MN). Two models, ISORROPIA-II thermodynamic equilibrium model and positive matrix factorization (PMF) model, were applied to explore the likely chemical forms of ionic constituents and to apportion sources for PM2.5. Distinctive seasonal patterns of PM2.5 and associated main chemical components were identified and could be explained by varying emission sources and meteorological conditions. PM2.5 showed a typical seasonality of waxing in winter and waning in summer, with an annual mean of 119 μg m-3. Mineral soil concentrations increased in spring whereas biomass burning species elevated in autumn and winter. Six major source factors were identified to have contributed to PM2.5 using the PMF model. These were secondary inorganic aerosols, coal combustion, biomass burning, iron and steel manufacturing, Mo-related industries, and soil dust, and they contributed 37 ± 18%, 20 ± 12%, 11 ± 10%, 11 ± 9%, 11 ± 9%, and 10 ± 12%, respectively, to PM2.5 masses on annual average, while exhibiting large seasonal variability. On annual average, the unknown emission sources that were not identified by the PMF model contributed 1 ± 11% to the measured PM2.5 mass. Various chemical tracers were used for validating PMF performance. Antimony (Sb) was suggested to be a suitable tracer of coal combustion in Chengdu. Results of LG and MN helped constrain the biomass burning sources, with wood burning dominating in winter and agricultural waste burning dominating in autumn. Excessive Fe (Ex-Fe), defined as excessive portion in measured Fe that cannot be sustained by mineral dust, is corroborated to be a straightforward useful tracer of iron and steel manufacturing pollution. In Chengdu, Mo/Ni mass ratios were persistently higher than unity, and considerably distinct from those usually observed in ambient airs. V/Ni ratios averaged at only 0.7. Results revealed that heavy oil fuel combustion should not be a vital anthropogenic source, and additional anthropogenic sources for Mo are yet to be identified. Overall, the emission sources identified in Chengdu could be dominated by local sources located in the vicinity of Sichuan, a result differed from those found in Beijing and Shanghai, wherein cross-boundary transport is significant in contributing pronounced PM2.5. These results provided implications for PM2.5 control strategies. [ABSTRACT FROM AUTHOR]

In Dechen (Bde chen) County, Yunnan Province, a Tibetan county of the People's Republic of China, prominent lay Buddhist practitioners work to resist and mitigate the impacts of agrochemical pollution and climate change on sacred landscapes. In this region of northwest Yunnan officially renamed and dubbed "Shangri-La" by the local and national state for tourism purposes, and in alignment of this name with the term Shambala, a place of divine serenity in Tibetan Buddhism, the protagonists in this paper insist that chemical futures and pollution are only adding to the creation of a "fake" Shangri-La, and that more than human- and nature-centric views are necessary in building a more ecologically sound future. This paper ethnographically analyses these activities and motivations in the context of ecocentric views surrounding indigenous Tibetan more-than-human spirit worlds. I ask what drives rural Tibetan grape-growers to pursue an ecologically friendly agenda. Motivations include observation of chemical degradation on land, Buddhist ethics, local land worship, and conceptions that being a local Tibetan should revolve around the preservation of sacred landscapes and mountain gods and spirits rather than purely economic profit and development. A critical variable, however, is that lay Buddhists holding these beliefs are exceptions, with most villages showing more concern for the economic benefits of new cash agricultures over sacred landscapes and spirits. I argue that while many villagers are willing to ignore the long-term vitality of the sacred landscape in favour of economic prosperity and view new economic activities as morally acceptable within Tibetan spirituality, some individuals insist that preserving the local landscape is paramount to a sustainable future both locally and across Greater China. [ABSTRACT FROM AUTHOR]

Copyright of Antipode is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the rise of "Internet + Education," blended learning has become a new trend in higher education. This study aims to explore how behavioral willingness and self-efficacy affect the learning effect of college students in this new learning mode. The Unified Theory of Acceptance and Use of Technology (UTAUT2) was used to construct a theoretical model, and data on the blended learning effectiveness of 167 college students from a university in Southwest China were collected through questionnaires, and the theoretical assumptions and model were verified using Structural Equation Modeling (SEM) in Smart PLS software. It was found that in blended learning, performance expectation, effort expectation, hedonic motivation and facilitation all significantly and positively affect college students' behavioral intention of blended learning, which in turn positively affects the effect of blended learning, among which hedonic motivation is a more important influencing factor in the behavioral intention of blended learning. Self-efficacy also has a significant positive effect on blended learning effects. Finally, the study proposes countermeasures for teaching improvement from three aspects: teachers' teaching design, students' motivation and behavior, and optimization of e-learning platform content and function. [ABSTRACT FROM AUTHOR]

Southwest China is located in the southeastern margin of the Tibetan Plateau and it is a region of high seismic activity. Historically, strong earthquakes that occurred here usually generated lots of landslides and brought destructive damages. This paper introduces several earthquake triggered landslide events in this region and describes their characteristics. Also, the historical data of earthquakes with a magnitude of 7.0 or greater, having occurred in this region, is collected and the relationship between the affected area of landslides and earthquake magnitude is analysed. Based on the study, it can be concluded that strong earthquakes, steep topography as well as fragile geological environment, are the main reasons responsible for serious landslides in southwest China. At the same time, it is found that the relationship between the area affected by landslides and the earthquake magnitude in this region are consistent with what has been obtained worldwide. Moreover, in this paper, it is seen that the size of the areas affected by landslides change enormously even under the same earthquake magnitude in the study region. While at the same tectonic place or fault belt, areas affected by landslides presented similar outline and size. This means that local geological conditions and historical earthquake background have an important influence on landslides distribution, and they should be considered when assessing earthquake-triggered landslide hazards at Grade 1 according to ISSMGE. [ABSTRACT FROM AUTHOR]

With its rapid development, the rural area of Southwest China has been puzzled by the waste management problem, especially for increasing solid waste and water pollution from the domestic waste. Therefore, in order to efficiently and effectively manage the domestic waste in the rural area of Southwest China, 22 villages were selected randomly to analyse the characteristics of domestic waste, the influence factors of characteristics and resident’s willingness of participation in domestic waste management by questionnaires, field samplings and laboratory tests. The results of the rural area of Southwest China indicated that the generation of domestic waste was 178 g d−1 per capita and it was mainly composed of kitchen waste, inert waste, plastics and paper with a total proportion of 81.98%. The waste bulk density, moisture, ash, combustible and lower calorific value were 107 kg m−3, 37.04%, 25.73%, 37.23% and 8008 kJ kg−1, respectively. These characteristics were influenced by the topography, the distance from towns or cities, the villagers’ ethnicities and income sources to some extent. Moreover, the distance of 50–800 m between each collection facility and the disposal fee of around ¥5.00 per household per month could be accepted. The working hours of participation in waste management is suggested as 5 hours per day with the income of ¥1000 per capita per month. Based on the outcome of this survey, a waste management system consisting of classified collection, centralised treatment and decentralised treatment was proposed. It is important to ensure financial viability and practical considerations of this system. [ABSTRACT FROM PUBLISHER]

Highlights • A multi-objective model is formulated to balance benefit and reliability of hydropower. • PMOPSO combines the merits of small population, parallel computing and MOPSO. • Parallel technology is used to improve execution efficiency and population diversity. • Domain knowledge is adopted to enhance the feasibility of particles during evolution. Abstract Due to the expanding system scale and increasing operational complexity, the cascade hydropower reservoir operation balancing benefit and firm output is becoming one of the most important problems in China’s hydropower system. To handle this problem, this paper presents a parallel multi-objective particle swarm optimization where the swarm with large population size is divided into several smaller subswarms to be simultaneously optimized by different worker threads. In each subtask, the multi-objective particle swarm optimization is adopted to finish the entire evolutionary process, where the leader particles, external archive set and computational parameters are all dynamically updated. Besides, a novel constraint handling strategy is used to identify the feasible search space while the domination strategy based on constraint violation is used to enhance the convergence speed of swarm. The presented method is applied to Lancang cascade hydropower system in southwest China. The results show that PMOPSO can provide satisfying scheduling results in different cases. For the variation coefficient of generation in 30 independent runs, the presented method can bettered the serial algorithm with about 66.67% and 61.29% reductions in normal and dry years, respectively. Hence, this paper provides an effective tool for multi-objective operation of cascade hydropower system. [ABSTRACT FROM AUTHOR]

It is essential to determine rockmass mechanical parameters in stability assessment. The structural z is the main factor in this regard, and we know little about the relationship between mechanical parameters and multiple structure planes. In this paper, we have conducted a series of numerical tests to obtain mechanical parameters for a dam foundation in Southwest China. The biaxial numerical test was performed based on the discrete element method. This numerical test considers the spacing, types, dip angles, and size effect. We established a relationship of mechanical parameters between small size lab samples and large size field samples. We forecasted the strength parameters for a spillway slope in Southwest China. The dip angle has a significant effect on the slope strength and stability. In this case, the rockmass fracture stress-dip angle curve forms a U-shaped distribution. The X-shaped double structure plane demonstrates severe strength weakening relative to a single structure plane. As structure plane spacing reaches a certain level, its influence on rockmass strength diminishes. The elementary volume of the rockmass for dam foundation analysis is about 4 m × 4 m × 4 m. [ABSTRACT FROM AUTHOR]

Abstract: Xiaojiang Hao, who obtained Master Degree from Kunming Institute of Botany (KIB), Chinese Academy of Sciences (CAS) in 1985, and Doctor in Pharmacy degree in Pharmacy from Institute for Chemical Research, Kyoto University, in 1990, was born in Chongqing in July, 1951. In 1991, he returned to KIB, CAS, as an Associate professor and served as the chair of the Department of Phytochemistry. In 1994, he was promoted to a full professor at the current institute. He served as the Deputy Director of KIB and the Director of Open Laboratory of Phytochemistry from 1995 to 1997, and the Director of KIB from 1997 to 2005. Professor Hao has published more than 450 peer-reviewed SCI papers, which have been cited over 6000 times. He has obtained one PCT patent and 23 patents in China. Due to his tremendous efforts, one candidate drug, phenchlobenpyrrone, has entered the Phase II clinical trail for the treatment of Alzheimer’s disease. Moreover, he won the First Prize of Natural Sciences in Yunnan Province for three times, and Ho Leung Ho Lee Fund Science and Technology Innovation Award in 2017.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Copyright of Yellow River is the property of Editorial Board of Yellow River and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The post-Mao era (1976–present) has seen a number of great changes in China. Two of these – the revival of religion and the emergence of a nascent, but powerful environmental movement – have come together in a unique way in the revitalisation ofdongbareligion among the Naxi nationality (pop. 300,000) of northwest Yunnan and southwest Sichuan provinces. This paper examines the relations between indigenous Naxi and outside tourists (mainly Han from other parts of China) through multiple lenses, including traditional Naxi cosmologies and theories of kinship and hospitality, as well as contemporary ideas concerning tourism development and environmental protection. The aim is to show that: (1) Naxi theories of alterity occur at multiple levels simultaneously – gods/demons vs. humans, kin vs. non-kin, native vs. stranger, host vs. guest, etc. – but that a unified logic underlies the relations, transactions, and interpenetration of these groups and (2) this logic is a productive force in its own right, that is, capable of harnessing new situations to it, even as it itself evolves as novel meanings are engendered in the process of intentional action. In all of this, one figure stands out: thedongba, a traditional shaman-priest viewed as a kind of mediator or facilitator in interactions and exchanges involving a wide range of human and non-human subjects. [ABSTRACT FROM PUBLISHER]

Generalized inversion is one of the important steps in the quantitative interpretation of gravity data. With appropriate algorithm and parameters, it gives a view of the subsurface which characterizes different geological bodies. However, generalized inversion of gravity data is time consuming due to the large amount of data points and model cells adopted. Incorporating of various prior information as constraints deteriorates the above situation. In the work discussed in this paper, a method for fast nonlinear generalized inversion of gravity data is proposed. The fast multipole method is employed for forward modelling. The inversion objective function is established with weighted data misfit function along with model objective function. The total objective function is solved by a dataspace algorithm. Moreover, depth weighing factor is used to improve depth resolution of the result, and bound constraint is incorporated by a transfer function to limit the model parameters in a reliable range. The matrix inversion is accomplished by a preconditioned conjugate gradient method. With the above algorithm, equivalent density vectors can be obtained, and interpolation is performed to get the finally density model on the fine mesh in the model domain. Testing on synthetic gravity data demonstrated that the proposed method is faster than conventional generalized inversion algorithm to produce an acceptable solution for gravity inversion problem. The new developed inversion method was also applied for inversion of the gravity data collected over Sichuan basin, southwest China. The established density structure in this study helps understanding the crustal structure of Sichuan basin and provides reference for further oil and gas exploration in this area. [ABSTRACT FROM AUTHOR]

Cambrian in Sichuan basin developed thick black shale, varies carbonate and clastic rock, which deposited in different sedimentary environment. Sichuan basin in the upper Yangtze platform contained a record of environment during the Cambrian. Detail facies analyses of Cambrian enable us to discuss the sedimentary environment and palaeogeographic setting. Sedimentation commenced in the Early Cambrian with the deposition of shelf facies (Qiongzhusi Formation and Canglangpu Formation). At this stage, thick shale and clastic rock deposited in Sichuan basin. At the end of the Early Cambrian, a carbonate platform developed in upper Yangtze platform, and Sichuan basin was located in restricted platform (Longwangmiao Formation). In the Middle Cambrian, tidal flat and restricted platform developed in Sichuan basin (Douposi Formation), because of continuous regression. During the Late Cambrian, Sichuan basin was located in carbonate platform again (Xixiangchi Formation). There are three types of sedimentary system in the Cambrian of Sichuan basin: clastic sedimentary system, clastics-carbonate mixed sedimentary system and carbonate sedimentary system. Vertically, the basin shows the evolutionary character of clastic-carbonate sedimentary systems. The three sedimentary systems correspond to three "transgression-regression" cycles of the Cambrian. The transgression in the initial period of the Early Cambrian led to the formation of clastic sedimentary system in the Qiongzhusi Formation of Lower Cambrian. The transgression in the later period of the Early Cambrian led to the formation of clasticcarbonate mixed sedimentary system in the Middle-Lower Cambrian. The transgression in the initial period of the Late Cambrian led to the formation of carbonate sedimentary system in the Xixiangchi Formation of Upper Cambrian. With the end of Late Sinian continental rifting ended, Sichuan basin entered a stable evolutionary stage of the craton basin, while the paleo-land developed in the north and southwest. In Qiongzhusi-Canglangpu period, the basin developed onshore-shelf sedimentary facies from west to east; In Longwangmiao-Xixiangchi period, the basin developed tidal flat-platform-slope sedimentary facies from west to east. [ABSTRACT FROM AUTHOR]

order to study the relative importance of acidic aroma components in flue-cured tobacco, 146 samples of flue-cured tobacco leaves from a growing area in southwest China were selected for investment, n-Butyric acid, isovalerie acid, valeric acid, 3-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, capric acid contents and sense quality of all samples were tested in the paper. Then grey preference analysis was used to evaluate the relative importance of each acid based on aroma, taste and buming characteristics of sense quality. The results showed that hexanoic acid had the most influence on aroma, taste and burning characteristics and capric acid took the second place in acidic aroma components. Heptanoic Acid had the least influence on aroma, taste and burning characteristics. [ABSTRACT FROM AUTHOR]

Reconstructing ancient diets and the use of animals and plants augment our understanding of how humans adapted to different environments. Yunnan Province in southwest China is ecologically and environmentally diverse. During the Neolithic and Bronze Age periods, this region was occupied by a variety of local culture groups with diverse subsistence systems and material culture. In this paper, we obtained carbon (δ13C) and nitrogen (δ15N) isotopic ratios from human and faunal remains in order to reconstruct human paleodiets and strategies for animal exploitation at the Bronze Age site of Shilinggang (ca. 2500 Cal BP) in northwest Yunnan Province. The δ13C results for human samples from Shilinggang demonstrate that people’s diets were mainly dominated by C3-based foodstuffs, probably due to both direct consumption of C3 food and as a result of C3 foddering of consumed animals. Auxiliary C4 food signals can also be detected. High δ15N values indicate that meat was an important component of the diet. Analysis of faunal samples indicates that people primarily fed pigs and dogs with human food waste, while sheep/goats and cattle were foddered with other food sources. We compare stable isotope and archaeobotanical data from Shilinggang with data from other Bronze Age sites in Yunnan to explore potential regional variation in subsistence strategies. Our work suggests that people adopted different animal utilization and subsistence strategies in different parts of Yunnan during the Bronze Age period, probably as local adaptations to the highly diversified and isolated environments in the region. [ABSTRACT FROM AUTHOR]

Cooperation theories assume that interacting individuals can change their strategies under different expected payoffs, depending on their social status or social situations. When looking at sex differences in cooperation, the existing studies have found that the genders cooperate at similar frequencies. However, the majority of the data originate within Western human societies. In this paper, we explore whether there are gender differences in cooperation in China. An Iterated Prisoner’s Dilemma game with a punishment option was used to gather data about Southwest Chinese subjects in a culture in which men have a hierarchical advantage over women. Results indicate that men invested into partners significantly more than women did (34% ♂ vs. 24% ♀) while women, in turn, were more likely to defect (65% ♀ vs. 50% ♂). In this region, women have customarily held less economic power and they are used to obtain a payoff typically lower than men. We suggest that the women’s willingness to invest in cooperation has decreased throughout evolutionary time, providing us with an illustration of a culturally-driven shift towards a disparity in gender cooperation interests. [ABSTRACT FROM AUTHOR]

In post-socialist China, the village's collective management over community farmland, forestry, and other resources has been greatly undermined since China's reform and opening up in the early 1980s. The subsequent rural-urban migration has further dismantled rural communities. Efforts have been made to revitalise the countryside, yet little success has been achieved. This paper closely examines one community reconstruction case that experienced two development stages: village committee-led internal development based on collective management of community resources, and tourism development externally subsidised by the government. Unsuccessful as it is, the case shows the vital role of collective resource management in comparison to external subsidies and investment in community reconstruction. It also suggests that a strong community leadership can initiate the process of community reconstruction, but a lack of mobilisation and participation of community members creates underlying issues that threaten its sustainability. [ABSTRACT FROM AUTHOR]

To study the stability of fill roadbeds for railway-private sidings at the Anning refinery in southwest China, a series of triaxial creep tests of compacted red clay was carried out using an SLB-1 stress–strain controlled triaxial shear permeability tester. In this paper, under different confining pressures, stress levels and drainage conditions, the creep characteristics of the red clay compaction were studied. The results showed that the creep characteristics of compacted red clay were significantly affected by confining pressure, stress level and drainage conditions, and the compacted red clay showed the characteristic of creep attenuation. The stress–strain isochronal curves indicated obvious nonlinear characteristics, which formed a cluster of curves with the uniformization procedure, whereas under drainage conditions, the stress–strain isochronal curves presented a certain linear relationship. Moreover, according to the stress–strain curves, the long-term strength of the compacted red clay was 0.54–0.72 times the instantaneous strength. Furthermore, taking the triaxial creep test of the compacted red clay under a confining pressure of 300 kPa as an example, the data were analyzed, and a new empirical creep model was established. Compared with the Burgers model and the Singh–Mitchell model, the calculated curve of the new empirical creep model is in good agreement with the experimental curve. The new model, which has fewer parameters that are easier to get, has the advantage of a higher accuracy. The new empirical model can better reflect and predict the creep characteristics of compacted red clay in the filling roadbeds of the special railway line at the Anning factory refinery in southwest China. [ABSTRACT FROM AUTHOR]

Entrepreneurial behavior has been substantially addressed in entrepreneurship literature, but the mechanisms by which social capital influences entrepreneurial behavior among college students remain unclear, especially the potential mediating and moderating interplay among them. Therefore, drawing on social capital theory and the Stimulus-Organism-Response (S-O-R) model, this study proposed a moderated mediation model of social capital on entrepreneurial behavior. Sample data were collected via questionnaires from entrepreneurial team members participating in the Innovation and Entrepreneurship Competition in Southwest China. Results showed that (1) social capital has a positive impact on entrepreneurial behavior; (2) entrepreneurial passion partially mediates the relationship between social capital and entrepreneurial behavior; and (3) entrepreneurial risk perception positively moderates the relationship between entrepreneurial passion and behavior and thus enhances the mediating effect of entrepreneurial passion. This study provides insights into the internal mechanism of social capital on entrepreneurial behavior and also offers practical guidance for individuals, universities, and governments. [ABSTRACT FROM AUTHOR]

Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies. [ABSTRACT FROM AUTHOR]

Gully erosion is one of the major contributors to severe land degradation in the Yuanmou Dry-hot valley region of Southwest China. Planting vegetation in gully beds has proven to be an effective measure in controlling the development of gullies. However, the inner mechanism for this process remains unclear. In this paper, in situ scouring experiments were performed to reveal the influence of grass belt position on the hydraulic properties of runoff in gully beds. The results demonstrate that (1) grass belt position can have a significant effect on reducing runoff erosivity (runoff shear stress, stream power) and sediment content in gully beds, and that the reduction may be strengthened as the distance between the gully headwall and grass belt (DHG) decreases; (2) grass belts could play a positive role in enhancing the surface resistance and increasing flow energy consumption, as resistance and flow energy consumption increase as DHG increases; and (3) there were similar trends in the temporal variations within the hydraulic properties, which changed sharply in the early stage of the experiment and then tended to stabilize, with their time to stability continuously increasing as DHG decreased. [ABSTRACT FROM AUTHOR]

This paper presents a highly robust numerical model to simulate water-sediment mixture flows in practical field studies. The model is composed of an integrated algorithm combining the finite element characteristic splitting method and finite volume Godunov scheme. The former maintains the generality and stability of the numerical algorithm, while the latter ensures the conservation and accuracy of the model. The proposed model is first tested by three benchmark flow problems including flood flow in a pool, dam break over a mobile bed, and morphological process of a dam removal. Then, the model is applied to two practical field case studies to demonstrate its potential engineering values. The first case study is related to the damage of the Polo Hydropower Plant by a sediment flooding event. The second one is the investigation of a well-known 2013 dam-break flooding that happened in the Tangjiashan Mountain. It is shown that the simulated water and sediment flows are in good agreement with the documented laboratory and field data, and the numerical model is capable of providing useful information on the flow predictions, thus making further engineering measures to mitigate these disasters. [ABSTRACT FROM AUTHOR]

Various approaches have been developed for identifying statistically homogeneous regions or structural domains in a jointed rock mass based on joint orientations or the other joint parameters; however, few studies have been conducted by integrating both. In this paper, nine parameters are considered for this identification, namely: orientation, spacing, aperture, roughness, trace length, trace type, filling, groundwater condition, and weathering. A statistical parameter, known as the correlation coefficient, is used to quantify the degree of the similarity between the joint parameters collected from four adjacent adits at the Songta dam site on the upper reaches of the Nu River in southwest China. Based on the analytic hierarchy process, the weights of the parameters are obtained. The overall homogeneity of the rock mass around the studied regions is determined based on the homogeneity index. [ABSTRACT FROM AUTHOR]

This paper develops a new routing algorithm for improving simulation capacity of physically-based hydrological models applied to sparsely-gauged river basins. The study area is the Lhasa River basin, a large plateau basin with an area of 26,225 km2 in southwest China. In the basin, observations from three hydrological stations are available, and the observed hourly rainfall and summer stream flow data (12 June to 30 September) for the period of 1998-2000 obtained from the three stations were used. TOPMODEL, with its original routing algorithm, which is a distance-related delay function, was applied to the Lhasa River basin. To improve the routing algorithm using a unit hydrograph function and a linear reservoir method, this study proposed a new algorithm; the results revealed that the new algorithm improved the simulation of the variation of hourly stream flow. In addition, to evaluate the influence of rainfall spatial variation on runoff generation, observed rainfall series from the three gauges were used to simulate runoff individually, and it was found that there are significant differences among the three simulated hourly stream flow series. [ABSTRACT FROM AUTHOR]

This paper presented the reactivated mechanism of Badu landslide according to site investigations, monitoring, finite element and limit equilibrium analyses. Finite element analysis incorporating a stability analysis with the finite element stress-based method revealed a large railway cut triggered a localized slide in the upper part of Badu landslide rather than a global failure, and piles in three rows were effective in stabilizing the reactivated zone. Monitoring results and the limit equilibrium analysis showed that the landslide underwent multi-instabilities rather than a global failure due to a rise in groundwater table in rainy season. The mechanism of reactivated Badu landslide was finally proposed, i.e., 'grading creeping-sliding' mechanism, which helped designers to propose the most suitable mitigation measures to stabilize the landslide. [ABSTRACT FROM AUTHOR]

The paddy fields and water storage facilities are seriously damaged by the coal mine subsiding in the hilly post-mining and subsidence-stable areas in China, which make the farmers there being suffered greatly from the lack of water for traditional rice cultivation and daily life. The purpose of this paper is to find a method to restore the damaged paddy fields, thereby promoting sustainable development of land resources, and alleviating the contradiction between people and land, as well as creating a more inhabitable environment. The research methodology included field experiments, cultivated observation, and field investigation. This paper selected the Songzao Mining Area as the research area, and focused on the restoration technologies of damaged paddy fields, through the following four different measures at three experimental fields: (1) Traditional repeated cattle plowing (CK); (2) Water retention agent with repeated cattle plowing (W&C); (3) Film without holes under tilth depth (FO); and (4) Film with holes under tilth depth (FW). At last, a contrastive analysis of the four measures was made according to the results of the experiments. The results show that the use of water retaining agent with repeated cattle plowing (W&C) can be the most appropriate method to restore the damaged paddy field in the hilly post-mining and subsidence-stable area in southwest China. Compared with the other three measures, its water productivity is the maximum (0.81 kg/m3), and the net income is the highest (1 403 $/hm2). What's more, it is simple, short time-consuming, and low cost, which is benefit to generalize the use of this restoration technology [ABSTRACT FROM AUTHOR]

Identification and management the 'critical risk areas' where hotspot lead exposures are a potential risk to human health, become a major focus of public health efforts in China. But the knowledge of health risk assessment of lead pollution at regional and national scales is still limited in China. In this paper, under the guidance of 'sources-pathways-receptors' framework, regional human health risk assessment model for lead contamination was developed to calculate the population health risk in Yunnan province. And the cluster and AHP (analytic hierarchy process) analysis was taken to classify and calculate regional health risk and the decomposition of the regional health risk in the greatest health risk region, respectively. The results showed that Yunnan province can be divided into three areas. The highest health risk levels, located in northeastern Yunnan, including Kunming, Qujing, Zhaotong region. In those regions, lead is present at high levels in air, food, water and soil, and high population density which pose a high potential population risk to the public. The current study also reveals that most regional health risk was derived from the child receptors (age above 3 years) 4.3 times than the child receptors (age under 3years), and ingestion of lead-contaminated rice was found to be the most significant contributor to the health risk (accounting for more than 49 % health risk of total). This study can provide a framework for regional risk assessment in China and highlighted some indicators and uncertainties. [ABSTRACT FROM AUTHOR]

In this paper the concentration distribution of lead (Pb), arsenic (As) and zinc (Zn) in seven coal samples taken from Southwest China were analysed by applying the sequential extraction method. The results showed that the total concentrations of these trace elements in different samples varied significantly, as did their distribution within some specific fractions. The highest percentages of these three elements are contained in the exchangeable and sulphide-bound fractions, which tend to be released into the atmosphere and therefore pose a threat to the environment and human health because of their high mobility and toxicity. The As concentration in the exchangeable fraction was only as high as 19·07 mg kg−1 in the Shuikuang sample, while in the other samples it was below the detection limit. The concentration in the sulphide-bound fraction accounted for 55·26%; thereby indicating a large amount of pyrite because of its sulphophile affinity. Most fractions of As and Zn were contained in the residual fraction. [ABSTRACT FROM AUTHOR]

A soil–rock mixture (SRM) is a type of heterogeneous geomaterial, and the particle distribution of SRM can be described by fractal theory. At present, it is difficult to quantify the fractal dimension of a particle size distribution and understand the scale effect in SRMs. In this study, the fractal theory and discrete element method (DEM) were introduced to solve this problem. First, the particle gradation of SRM was dealt with by using fractal theory. The fractal structure of particle distribution was studied, and a method of calculation of the fractal dimension is presented in this paper. Second, based on the fractal dimension and relative threshold, the particle gradations of SRMs at different scales were predicted. Third, numerical direct shear tests of SRM at different scales were simulated by using the DEM. The scale effects of shear displacement, shear zone, and shear strength parameters were revealed. Last, taking the maximum particle size of 60 mm as the standard value, the piece-wise functional relationship between shear strength parameters and particle size was established. The results are as follows: for SRM in a representative engineering area, by plotting the relationship between particle cumulative mass percentage and particle size, we can judge whether the SRM has a fractal structure; in Southwest China, the frequency of the fractal dimension of the SRM is in the normal distribution, and the median fractal dimension is 2.62; the particle gradations of SRMs at different scales calculated by fractal dimension and relative threshold can expand the study scope of particle size analysis; when the particle size is less than 70 mm, the strength parameters show a parabolic trend with the particle size increases, and if not, a nearly linear trend is found. The proposed method can describe the fractal characteristics of SRM in a representative engineering area and provides a quantitative estimation of shear strength parameters of SRM at different scales. [ABSTRACT FROM AUTHOR]

Relay cropping of Poaceae and Fabaceae promotes high yield and land-use efficiency by allowing a double harvest. However, it is difficult to increase yield synergistically because of the reduced photosynthetic abilities of legume leaves under the shade of graminoids. Leaf photosynthetic capacity in relay cropping systems is associated with ecological niche differentiation and photosynthetic compensation after restoration of normal light. We conducted a field experiment in southwest China in 2020-2021 to evaluate the effects of three cropping patterns: maize-soybean relay cropping (IMS), monoculture maize (MM), and monoculture soybean (SS), and N application levels: no N application (NN:0 kg N ha-1 ), reduced N (RN: 180 kg N ha-1 ), and conventional N (CN: 240 kg N ha-1 ). Compared to monocropping, relay cropping increased the stay-green traits of maize and soybean by 13% and 89%, respectively. Relay cropping prolonged the leaf stay-green duration in the maize and soybean lag phase by almost 4 and 8 days, respectively. Relay cropping maize (IM) increased the leaf area index (LAI) by 79.4% to 88.5% under NN and 55.5% to 148% under RN. Relay cropping soybean (IS) increased the LAI from 115% to 437% at days 40 to 50 after anthesis. IM increased yield by 65.6%. IS increased yield by 9.7%. HI and system yield were at their highest values under RN. In the relay cropping system, reduced N application extended green leaf duration, increased photosynthesis inside the canopy at multiple levels, ultimately increases soybean yield synergistically. [ABSTRACT FROM AUTHOR]

Since the 1980s, Hong Kong triad societies have evolved from hierarchical, pyramidal organizations to loose, compartmentalized syndicates that retain a modicum of hierarchy. Changes in triad organization and modus operandi occurred in response to stringent anti-organized crime measures enacted in Hong Kong. However, organizational evolution has facilitated triad transplantation to China and improved triads’ ability to engage in transnational crime. Triads have exploited favorable circumstances in China: prevalent corruption, rapid urbanization, and high demand for illicit goods and services. This paper includes two case studies of the Sun Yee On triad. The first examines Sun Yee On's localized activity by tracing the evolution of one Shenzhen area chapter. The second case study examines Sun Yee On's role as a supplier of methamphetamine precursor chemicals to Mexico's Sinaloa cartel. Sun Yee On exemplifies how modern triads have become hybridized, assuming attributes of both local Chinese organized crime and transnational criminal networks. [ABSTRACT FROM PUBLISHER]

Tianqiao carbonate-hosted Pb-Zn deposit, controlled by NW-trending F thrust fault and NW-trending Tianqiao anticline, is located in the eastern part of Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province, southwestern Yangtze Block, southwest China. Ore bodies in this deposit are hosted in the Devonian-Carboniferous carbonate rocks, and ore minerals include sphalerite, galena and pyrite, while the gangue minerals are dominated by calcite and dolomite. Using high-precision solid thermal ionization mass spectrometry (TIMS), this paper reports the strontium isotopic compositions (0.7119 to 0.7167) of sulfide samples from the Tianqiao deposit in order to trace the origin of hydrothermal fluids. Compared with the country rocks, the calculated Sr/Sr values of sulfide range from 0.7118 to 0.7130, higher than those of the age-corrected Devonian to Permian sedimentary rocks (0.7073 to 0.7101) and the Middle Permian Emeishan flood basalts (0.7078 to 0.7039), but lower than those of the age-corrected Proterozoic basement rocks (such as the Kunyang and Huili Groups, Sr/Sr=0.7243 to 0.7288). This implies a mixed strontium source between the older basement rocks and the younger cover sequences. Together with geologic and previous isotopic evidences, we considered that the fluids' mixing is a possible mechanism for sulfide precipitation in the Tianqiao deposit. [ABSTRACT FROM AUTHOR]

In this paper, the coupled WRF/SSiB model, accompanied by a Karst Rocky Desertification (KRD) map of the Guizhou Karst Plateau (GKP) of China, was applied to detect how the changed vegetation and soil characteristics over the GKP modify the energy balance at the land surface. The results indicated that land degradation led to reduced net radiation by inducing more upward shortwave and longwave radiation, which were associated with increasing surface albedo and temperature, respectively. The KRD also resulted in changed surface energy partitioning into sensible and latent heat fluxes. The latent heat flux at land surface was reduced substantially due to the higher surface albedo and stomatal resistance, the lower Leaf Area Index (LAI) and roughness length in the degradation experiment, while the sensible heat flux increased, mainly because of the higher surface temperature. Furthermore, the moisture flux convergence was reduced, owing to the lower atmospheric heating and the relative subsidence. However, compared with the reduced evaporation, the decrease in moisture flux convergence contributed much less to the reduced precipitation. Precipitation strongly affects soil moisture, vegetation growth and phenology, and thus evaporation and convective latent heating, so when precipitation was changed, a feedback loop was created. [ABSTRACT FROM AUTHOR]

Karst terrains are generally regarded as a fragile and vulnerable environment. China's karst is mainly developed in pre-Triassic, old-phase, hard, compact carbonate rock. The lack of soil cover in bare karst land can enhance desertification. Its underground drainage system can aggravate both drought and flooding problems; the interconnected surface and subsurface conditions allow for easy contamination by pollutants. Moreover, karst terrains quite often suffer from a series of engineering problems, such as water infiltrating into mines or transportation tunnels, leakage from reservoirs, and failure of building foundations. As resources and energy exploitation intensified in recent years, karst areas in Southwest China faced some severe geo environmental problems. In order to find out how the problems action and evolution in recent years, field and laboratory investigations were conducted in Guangxi autonomous region, Guizhou, Yunnan, Guangdong, Hunan, Hubei provinces, and Chongqing municipality. About 100 experts from the Provincial Geological Survey and graduate students took part in this project. Several symposiums were held during those 3 years. Besides the in situ survey, data were collected from hydrogeological survey results since 2000 when the new round of land resources investigation began. After analyzing these data, rock desertification, drought and flooding, and contamination and engineering geological environmental problems were considered the most prevalent problems in karst areas in Southwestern China. The status of each problem is elaborated upon in this paper and should be considered for future sustainable development. [ABSTRACT FROM AUTHOR]

Southwest China's Yunnan province has been affected throughout history by climate-induced water stresses, with the 2009 drought as a recent example. To deal with such stresses, mountain farmers have developed many local coping strategies. This paper provides case studies of these coping mechanisms in three mountain communities in Baoshan Municipality, Yunnan province. To minimize water-related environmental and economic vulnerabilities, our results show that upland farmers employ strategies both individually and collectively, which vary according to agroecological zone, economics, and historical period. Climate change is also emerging as an ongoing environmental challenge. We explore China's options for introducing and implementing adaptation policies that link with farmer strategies to respond more effectively to water stresses induced by climate change and other forces. [ABSTRACT FROM AUTHOR]

This paper presents an evaluation of the spatio-temporal patterns of hydrologic alteration induced by dam construction and precipitation variability in the Lancang River Basin of southwest China from 1957 to 2000. Analyses were conducted using the linear regression method, the Mann-Kendall test, and the Range of Variability Approach. The results indicate that there was considerable variation in the average monthly precipitation between the pre- and post-dam periods in the Lancang River Basin. Second, the magnitude of monthly runoff was strongly related to precipitation, which showed an up-down annual variation, and was significantly altered by dam construction and precipitation variability. In the modified series (hydrologic series with the precipitation impacts removed), runoff deviations between the pre- and post-dam periods became larger. Third, the extreme runoff cycles were influenced by dam construction and precipitation variability downstream from the dam, and the monthly maximum runoff increased from the pre-dam to post-dam period at all hydrologic stations. Fourth, the degree of hydrologic alteration (DHA) indicates that the precipitation variability not only affected the hydrologic regime of unregulated river reach but also modified the negative impacts of dam construction, which could provide a modest mitigation of the hydrologic alterations induced by dam construction, possibly decreasing the level of DHA. Last, the overall degree of hydrologic alteration in the observed series reached 25.2, 25.3, and 29.1 % for the upstream, midstream, and downstream areas, respectively. These results show that the hydrologic regimes of the Lancang River during the 1957-2000 period were affected by damming and precipitation variability, but the hydrologic alteration was relatively low in the upstream areas of the river without a dam. [ABSTRACT FROM AUTHOR]

In many societies, dialectometry has revealed strong correlations between geographic distances and dialect differences (e.g., Gooskens, 2005; Heeringa & Nerbonne, 2001; Nerbonne, 2009, 2010). But what happens when dialectometry is applied to a small, clan-based society such as the indigenous Sui people of rural southwest China? The Sui results show a strong correlation between dialect difference and geographic distance, thus supporting Nerbonne and Kleiweg's (2007) Fundamental Dialectological Postulate. A new culturally specific computation, “rice paddy distance,” also provides a strong correlation with dialect differences. However, the study finds that some dialectometry patterns of larger societies are not “compressible” into small societies such as Sui. Clan exogamy also poses challenges for dialectometry. Nonetheless, the overall results show that basic principles of dialect variation in space can be generalized cross-culturally, even across very different cultures. This paper also suggests a “lower limit” for dialectology, that is, the smallest distance where regional dialectology may be relevant, all other things being equal. [ABSTRACT FROM AUTHOR]

Soil hydraulic properties such as soil infiltration rate and hydraulic conductivity are closely linked to runoff generation and infiltration processes but little is known about them on karst hillslopes. The objectives of this paper were to investigate the change in soil stable infiltration rate ( q) and near-saturated hydraulic conductivity ( K) in different slope positions and to understand their relationship with rock fragment content and soil texture within the topsoil in subtropical karst regions of southwest China. Tension infiltrometers (20 cm in diameter) were used to measure q and K at pressure head of −20 mm on hillslopes 1 (a disintegrated landslide failure) and 2 (an avalanche slope). The change of q and K was great and they mostly had a moderate variability with coefficient of variations (CV) between 0.1 and 1.0 in the different slope positions. On average, q ranged from 0.43 to 4.25 mm/min and K varied from 0.75 to 11.00 mm/min. These rates exceed those of most natural rainfall events, confirming that overland flow is rare on karst hillslopes. From bottom to top, q and K had a decrease-increase-decrease trend due to the presence of large rock outcrops (>2 m in height) on hillslope 1 but had an increasing trend on hillslope 2 with less complex landform. They tended to increase with increase in total rock fragment content (5-250 mm) within the topsoil as well as slope gradient on both hillslopes. Pearson correlation analysis suggested that higher coarse pebble (20-75 mm), cobble (75-250 mm), and sand (2-0.05 mm) contents as well as total rock fragment content could significantly facilitate water infiltration into soils, but higher clay (<0.002 mm) content could restrict water movement. This result indicated that rock fragment, sand, and clay contents may remarkably affect water flow in the topsoil layers, and should be considered in hydrological modeling on karst hillslopes in subtropical regions. [ABSTRACT FROM AUTHOR]

Farming plot reconstruction engineering is important in mitigating cultivated land fragmentation and promoting intensified production in hilly mountainous regions. As an anthropogenic disturbance, farming plot reconstruction and subsequent agricultural intensification have considerable effects on cultivated land, ecological environments, and pedogenesis. Although researchers have given considerable attention to changes in the physical and nutrient properties of soil in reconstructed farming plots, the connection between soil engineering and anthropogenic pedogenesis is often neglected. In this paper, we compared samples obtained during farming plot reconstruction engineering and agricultural intensification in terms of different soil properties. The results indicated that reconstruction changed the soil profile patterns from A–C to A–B–C, thereby significantly increasing the soil thickness, bulk density, clay content, pH, soil organic carbon, total nitrogen, C/N ratio, and cation exchange capacity. The geochemical composition notably varied in topsoil; the chemical index of alteration (CIA) and the chemical index of weathering (CIW) decreased markedly, and the Na 2 O/K 2 O ratio (Na/K) increased slightly. After a period of agricultural intensification, the physical and chemical properties of soil improved gradually with a high coefficient of variation. However, the soil exhibited Mg and Ca leaching and K and Na accumulation, and the intensity of chemical weathering was not significantly stronger with higher CIA values, higher CIW values, and lower Na/K ratios. These changes indicated that the anthropogenic disturbances from soil engineering accelerated the physical weathering and uniformity of purple soil but depressed soil chemical weathering to some extent. The anthropogenic disturbances of agricultural intensification disrupted the homogeneity of soils but did not significantly promoted the physical and chemical weathering of purple soil. This study provides guidelines for rational soil usage in reconstructed farming plots and may aid in soil classification. • Soil engineering accelerates physical weathering but destroys chemical weathering. • Agricultural intensification has positive impacts on soil quality. • Anthropogenic disturbances create a problem for soil classification. [ABSTRACT FROM AUTHOR]

Abstract Zhaotong lignite (ZL), a soft lignite from southwest of China, is an abundant coal resource. However, it has not been utilized on large scale due to its very high moisture content and low calorific value. Drying and depolymerization technologies of ZL for upgrading or producing valuable gases, value-added chemicals, and/or liquid fuels have been widely investigated in laboratories. This paper introduces geological setting and chemical structures of ZL. Drying and depolymerization technologies (including thermal dissolution, pyrolysis, and supercritical water gasification) of ZL are reviewed in detail. Different drying methods have different merits and demerits. Thermal dissolution (especially ethanolysis) of ZL under mild conditions can be used to produce oxygen-containing compounds. Pyrolysis of ZL follows the second-order kinetics and optimal temperatures for preparing tar and valuable gases are distinct. High yields of H 2 and CH 4 are generated from supercritical water gasification of ZL. In addition, future investigations on efficient utilization of ZL are advised. Although the topic of this review mainly focused on a specific lignite, the drying and depolymerization technologies are also applied to other low-rank coals, especially lignites. Highlights • Drying and depolymerization technologies of Zhaotong lignite (ZL) are reviewed. • Advantages and disadvantages of different drying approaches are presented. • High yield of ESP rich in phenols and esters can be obtained from thermal dissolution of ZL. • Optimal temperatures for producing tar and gases from ZL pyrolysis are 600 and 700–800 °C, respectively. • SCWG of ZL without extra dry pretreatment can be used to obtain H 2 and CH 4. [ABSTRACT FROM AUTHOR]

Karst depressions comprise geomorphologically important sources and sinks for sediments and associated pollutants; yet the sedimentology of many depressions is not well understood in the world. In this paper, the Cs technique was employed to estimate recent sedimentation rates in a Chinese polygonal karst depression. The results indicate that the sediment deposition rates ranged from 0.91 to 1.97 mm year from 1963 to 2007, and the average sediment deposition rate and specific deposit yield were estimated to be 1.47 mm year and 20 t km year, respectively. These results are consistent with the local monitoring data of runoff fields, which confirms the validity of the overall approach. This shows that the soil loss rate is very low in some karst areas of Southwest China. Above all, the approach appears to offer valuable potential to study surface erosion by estimating sediment deposition rates of karst depressions, rather than the assessment of complicated soil erosion in stony soils of carbonate rock slopes. In addition, the space distribution of surface soil and Cs inventories are affected remarkably by the inhomogeneous dissolution of limestone under the soil. It may be an important phenomenon, which exists widely in karst areas, and it is significantly different from other places. [ABSTRACT FROM AUTHOR]

Yingjiang is a frontier county in southwest Yunnan, China, with distinctive ethnic and cultural diversity. Bilingual education (BE) has been a prominent feature in Yingjiang since the 1950s due to supportive policies and measures at various levels. BE in Yingjiang developed so well in the 1980s that a bilingual school was awarded the title of 'flower of ethnic minority education'. However, since the late 1990s, BE in Yingjiang has gone dramatically downhill. The old 'followers of bilingual education' are in danger of withering. This can be seen from the shrinkage of the scale of BE and the dramatic reduction of bilingual schools and bilingual students. At the same time, the number and quality of bilingual teachers has been called into question. This paper, based on a document review and a field study, discusses the challenges and prospects for BE in Yingjiang. It is argued here that as the ethnic minority people in Yunnan are trying to make socioeconomic progress like other places in China, it is necessary to promote BE by reviewing the current BE mechanism, social reality and to take more sensible measures to revitalize BE, as was done in the late 1980s. [ABSTRACT FROM AUTHOR]

Rocky desertification is of extensive occurrence in karst mountain areas, particularly in the areas where pure carbonate rocks are underlying in Southwest China. Rocky desertification has great impacts on local social and economic development. This paper puts its focus on the mechanism of rocky desertification and its deterioration due to human activities. Soil creeping and sliding occur intensively in the weathering crust of carbonate rocks and at the interface between the weathering crust and the underlying bedrock. Abrupt soil-rock contact occurs at the interface is attributed to long-term soil creeping and sliding on the bedrock surface, which is usually very smooth. Both surficial and underground soil losses can cause rocky desertification in this area. In the areas where pure carbonate rocks are underlying, underground piping erosion may be the predominant process of rocky desertification because the pedogenic rate is usually lower than the rate of natural soil erosion. In general, rocky desertification is a natural, irreversible geomorphologic process in most of the karst mountain areas where pure carbonate rocks are underlying in Southwest China. Human activities often speed up rocky desertification. Present soil conservation measures, such as forestation and terracing, have little effect on the mitigation of rocky desertification. Therefore, it is a new challenge to mitigate rocky desertification in the karst mountain areas where pure carbonate rocks are underlying. [ABSTRACT FROM AUTHOR]

Abstract: Based on extraction of environmental information from lake (reservoir) sediment, this paper carried out systematic studies on effects of land use/land cover changes on soil erosion in last 40 years in Shibanqiao catchment of Guanling County, located in the southwest of Guizhou Province. Seven sediment cores were retrieved and analysis of activity of 137Cs of sediment samples was undertaken. The information of soil erosion in each phase was deduced, and then integrating it with land use/land cover changes in corresponded phase, the author took a further step to interpret the effects of land use/land cover changes on soil erosion. Such conclusions were drawn: (1) the rate and amount of soil erosion is related not only with land use/land cover regime but also with whether there are abundant erodible sources provided for erosion. (2) During 1960 to 1978, in the beginning of land use change, naturally selective erosion was dominant. Then the percentage of surface soil erosion increased, and became dominant in the subsequent phase. Soil erosion was decreased but rocky desertification expanded in a higher rate. So it can be deduced that there was a lag between the development of rocky desertification and soil erosion;(4) The accelerated soil erosion resulted from the stir of soil during the implementation of ecological engineering was detected between 1990 to 2002, in view of which, a suggestion was put forward in this paper that ecological constructions and engineering towards water and soil maintenance should pay attention to the problem of soil erosion followed, especially should avoid the stir of soil. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of RIUDS [Copyright &y& Elsevier]

In this paper, the spatial-temporal dynamics of soil moisture content was investigated in an evergreen broad-leaved forest and a tea tree plantation in Ailao Mountains, which was dominated by Fagaceae (Castanopsis wattii and Lithocarpus xylocarpus). Soil moisture content was studied between January 2005 and December 2006 at different depths (from 0-150 cm) with a neutron probe. The results showed that mean soil moisture content in the evergreen broad-leaved forest was usually higher than in the tea tree plantation in the dry season, whereas it was lower than the tea tree plantation in the rainy season. In addition, mean soil moisture content was depth dependent, and in the 10-50 cm layer the spatial variability was due to the active root zone within this depth area in two types of land use. From 50-150 cm, the spatial variability was slightly increasing in the evergreen broad-leaved forest or relatively stable in the tea tree plantation. Our study also showed that soil moisture content was higher and more stable under the evergreen broad-leaved forest than the tea tree plantation, hence we stress that evergreen broad-leaved forest plays an important role in holding soil moisture. It is suggested that the protection of evergreen broad-leaved forest should be strengthened. [ABSTRACT FROM AUTHOR]

The existing traditional methods of assessing the rates of soil loss have many limitations and are difficult to apply in the karst areas of Southwest China. Karst depressions comprise geomorphologically important sources and sinks for sediments and associated pollutants, yet the sedimentology of many depressions is not well understood. In this paper, the Cs technique was employed to investigate recent sedimentation rates in a Chinese polygonal karst depression. The results indicated that the sediment deposition rates ranged from 0.91 to 1.97 mm·a in the period from 1963 to 2007, and the average sediment deposition rate and specific deposit yield of the catchment were estimated to be 1.47 mm·a and 20 t·km·a, respectively. The results obtained were consistent with the local monitoring data of runoff plots, confirming the validity of the overall approach. It was shown that soil loss rates were very low in some karst areas of Southwest China. Above all, the approach appears to offer valuable potential to study surface erosion by estimating sediment deposition rates of karst depressions, rather than the assessment of complicated soil erosion in stony soils of carbonate rock slopes. In addition, the spacial distribution of surface soil and Cs inventories was affected remarkably by the inhomogeneous dissolution of limestone under the soil. It may be an important phenomenon which exists widely in the karst areas and is significantly different from other places. [ABSTRACT FROM AUTHOR]

In the present paper, a new species is added to the genus Diomma Motschulsky (Hemiptera: Cicadellidae: Typhlocybinae) from Southwest China, D. pincersa sp. n. At the same time, a key can distinguish all Chinese species of the genus is provided. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Engineering Geology & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)