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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]

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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]

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]

Rainfall erosivity is one important factor that controls soil erosion. The interannual variability of rainfall erosivity in southeast China connected to the ENSO (El Niño-Southern Oscillation). Rainfall erosivity across southeast China was assessed using daily rainfall data from 60 meteorological stations during the period from 1980 to 2013. We determined that models of erosivity based on daily rainfall can accurately predict annual rainfall erosivity. This paper presents a study of the effects of Niño3.4 SST (Sea Surface Temperatures) anomalies, the SOI (Southern Oscillation Index) and the MEI (Multivariate El Niño–Southern Oscillation Index) on rainfall erosivity in the southeast of China. Results indicated that average rainfall erosivity is stronger during El Niño events and weaker during La Niña events. Correlation analyses were applied to rainfall erosivity and Niño3.4 SST anomalies, SOI, and MEI. The effects of Niño3.4 SST and SOI on rainfall erosivity are evident, as demonstrated by a statistically significant correlation (> 95% confidence level). MEI was the best indicator ( P < 0.01) for representing the state of the ENSO. Results further indicated that 45, 31, and 40 of the 60 meteorological stations showed a significant correlation ( P < 0.05) between rainfall erosivity and SST anomalies, SOI, and MEI, respectively. Most of these stations were located in western Fujian Province. The ENSO was determined to exert the strongest influence on rainfall erosivity. This information would be useful in the implementation of new soil conservation strategies. [ABSTRACT FROM AUTHOR]

An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species ( E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index ( m*/ m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species ( L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association ( V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum ( V = 0.28, P < 0.01), which implies that these two mite species can co-exist on the same species of the host, E. miletus. The tendency curve of species abundance showed that the number of chigger mite species gradually decreased with the increase of mite individuals, and this revealed that most chigger mite species were rare with very few individuals, but few dominant species had abundant individuals. The species-sample relationship indicated that the number of chigger mite species increased with the increase of the host samples. The results suggest that a big host sample size over a wide realm of geographical regions is needed in the field investigation in order to obtain a true picture of species diversity and species composition. [ABSTRACT FROM AUTHOR]

The distinctive features of the Lower Devonian rocks of the Longmenshan area in southwestern China are brachiopod shell concentrations, especially in the Bailiuping, Ganxi and Xiejiawan Formations, where brachiopod shell concentrations occur widely throughout. Depending on the dominant skeletal elements, six types of shell concentrations can be distinguished: Protochonete , Acrospirifer , Howellella , Orientospirifer , polyspecific shell and polyspecific fragments concentrations. According to the shell features, taphonomic signature, host sediments and their relationships, four genetic models of the various shell concentrations are described in this paper. The genetic processes and distributions along an onshore–offshore area were clarified on the base of taphonomic analysis. Pavements of opportunistic species of Protochonetes are autochthonous assemblages living in quieter, deeper, more offshore waters near the maximum storm wave base. The pavements are the result of reduced sedimentation; the substrate was silty and water-saturated with variable turbidity soupy-mud. Transport by high-energy processes is interpreted as the final formation process of polyspecific fragments concentrations with most extensive scope from intertidal zone to the maximum storm wave base. The Acrospirifer , Howellella , and Orientospirifer concentrations have been stirred by storm wave action and quickly buried after short transport tempestite model. They are most easily preserved around the average storm wave-base. The polyspecific shell concentrations, which include large bivalves are autochthonous assemblages living in shallow and relatively quieter water near shore environments. Autochthonous assemblages of the opportunist Protochonetes bailiupingensis occurring in the Bailiuping Formation of the Longmenshan area not only record of storm events, but are also important features to identify and correlate the Bailiuping Formation in the field. [ABSTRACT FROM AUTHOR]

The reconstruction of complex political formations in tropical and subtropical environments has long been challenged by the ephemeral nature of archaeological deposits and the detectability of a settlement hierarchy. This paper presents findings from systematic archaeological surveys in the Lake Dian basin in southwest China to evaluate processes of political differentiation during the Bronze Age (ca. BC 900–100) and identified with the protohistoric kingdom of Dian. We discuss the problems of interpreting political consolidation based on mono-centers and ranked site size distributions. Our approach considers the contingent forms that ‘built’ landscapes can take in the humid subtropics in an effort to understand the variable relationship between politics and spatial scale. Combining traditional survey as well as subsurface methods suited for intensively worked paddy landscapes, we discuss the emergence and timing of multiple nucleated settlements as indicative of peer polity dynamics in the basin and examine the formation histories of large shell mound sites to highlight physical modifications that embedded central places during the Bronze Age period. We show that the boundary between on-site and off-site, living and non-living spaces is not solely determined by the availability of prime land but also by spatial conventions with discrete cultural and historical ramifications. By contextualizing macroscale views on complexity with an understanding of local scales of landscape transformation, we provide an alternative to models of pristine state formation based in temperate alluvial environments. [ABSTRACT FROM AUTHOR]

Based on data from the Southwest Basic Education Project, this paper provides an empirical estimation of gender gaps in Chinese and math among primary and lower-secondary school students in poor counties of Southwestern China. Major findings from 2-level HLM analysis by grade (3, 5, 7, and 9) include: (1) small positive gaps favoring girls in Chinese and negative gaps in math were found for all grades. (2) Gaps were larger in higher grades, girls’ advantage in Chinese experienced a small increase over the 2006–2010 period, and gaps varied by province. (3) Being a minority and having a low SES interplayed with gender in some circumstances. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) is a major and growing cause of morbidity and mortality throughout the world. However, there remains a limited understanding of the association between individual socioeconomic status (SES) and COPD diagnosis and treatment worldwide, including in China. This study investigates socioeconomic variations in prevalence, diagnosis, and treatment of COPD in rural China.Methods: The present study employed a cross-sectional survey design. The study population was composed of Han majority as well as Na Xi and Bai ethnic minority individuals 35 years of age and older living in Yunnan Province from 2017 to 2019. In total, 7534 individuals consented to participate in the study and complete a structured interview as well as a post-bronchodilator spirometry test. Multivariate logistic regression was used to analyze the association between individual socioeconomic status variables and the prevalence, diagnosis, and treatment of COPD.Results: The age-standardized prevalence of COPD in the present study was 14.3%. Prevalence differed by gender: prevalence for men was 17.1%, versus 11.4% for women (P = 0.0001). Overall, levels of diagnosis and treatment of COPD for participants with COPD were 24.2 and 23.1%, respectively. Multivariate logistic regression indicated that higher educational levels and good access to medical services was associated with an overall lower risk of COPD (P = 0.032 vs. P = 0.018) as well as a higher probability of COPD diagnosis among those with COPD (P = 0.0001 vs. P = 0.002). Participants with COPD with higher educational levels (P = 0.0001) and higher annual household incomes (P = 0.0001) as well as good access to medical services (P = 0.016) were more likely to receive COPD medications and treatment than their counterparts. While Na Xi and Bai participants had a higher probability of having COPD (P = 0.0001), they had a lower probability of having received a diagnosis or treatment for COPD than Han participants (P = 0.0001 vs. P = 0.0012).Conclusions: Future interventions to further control COPD and improve diagnosis and treatment should focus on ethnic minority communities, and those with low education levels, low annual household incomes, and poor access to medical services. [ABSTRACT FROM AUTHOR]

This study investigated the spatial-temporal patterns and trends of potential evapotranspiration (ET0) and aridity index (AI) over Southwest China during 1960-2013 based on daily temperature, precipitation, wind speed, sunshine duration, total solar radiation, and relative humidity data from 108 meteorological stations. The Penman-Monteith model, Mann-Kendall (M-K) test, moving t test, and Morlet wavelet method were used. The results indicated that ET0 and AI across the region displayed decreasing trends, but the former was significant. After 2000, regionally average trends in ET0 and AI increased rapidly, indicating that droughts increased over Southwest China in recent years. Spatially, the changes of ET0 and AI were dissimilar and not clustered, either. Temporally, both ET0 and AI displayed obvious abrupt change points over different timescales and that of AI was during the winter monsoon period. Significant periodic variations with periods of 27, 13, and 5 years were found in ET0, but only of 13 and 5 years existed in AI. Correlation analysis revealed that the sunshine duration and wind speed were the dominant factors affecting ET0 and that AI showed strong negative correlation with precipitation. The findings of this study enhance the understanding of the relationship between climate change and drought in Southwest China, while the mechanism controlling the variation in drought requires further study. [ABSTRACT FROM AUTHOR]

The unique hydrogeology of karst makes the associated groundwater respond quickly to rainfall events and vulnerable to anthropogenic pollutions. In this study, high-frequency monitoring of spring discharge, temperature, electrical conductivity (EC) and pH, along with monthly hydrochemical and microbial analyses, was undertaken at the outlet of Laolondong karst underground river in Nanshan, southwestern China. The aim was to explore the environmental effects of the catchment’s urban area on the karst groundwater resources. The monitoring data of a tracer test and the response of discharge to rainfall events demonstrate that conduits and narrow fissures coexist in the Laolongdong karst aquifer. The EC, Na+, Cl− and SO42− values (840 μS/cm, 33.7, 38.6 and 137.2 μg/L, respectively), along with high concentrations of fecal coliform bacteria, at the outlet indicate considerable urban pollution in this area. The contaminants sulfate and nitrate showed different relationships with discharge and EC in different stages of a rainfall event. This behavior provided information about aquifer structure and the influence of transport properties. Meanwhile, the hydrological processes of groundwater flow could be modified by urbanization and result in increasing magnitude of urban floods in the underground river. In addition, sulfuric and nitric acids introduced by urbanization not only impact the karst groundwater quality, but also result in a significant perturbation to the carbon cycling system in the karst area. [ABSTRACT FROM AUTHOR]

ABSTRACT: Southwest (SW) China is a drought prone region. Knowledge of the risks and coupling characteristics of drought duration and severity is essential for hazards mitigation and water management. Based on probability distributions, copulas, Mann–Kendall test, overlapping moving windows approach and the self‐calibrated Palmer Drought Severity Index (PDSI) at 69 stations (1959–2013), this study focused on the trends and spatial variability (SV) of (joint) probability drought duration and severity in SW China, and further investigated the potential contributors by analysing the behaviours of precipitation (P), temperature (T), relative humidity (RH), wind speed (WS), atmospheric moisture flux (MF) and divergence (MFD). In particular, the SV was represented by the standard deviation, the drought duration and severity were characterized by the number of months with PDSI < −0.5 in a year [drought months (DM)] and the absolute mean PDSI in drought months (DS), respectively. Results showed that, the DM, DS, DM5, DS5 (5‐year return levels for DM and DS) increased by 0.058 month year−2, 0.012 month−1 year−1, 0.039 month year−2, and 0.009 month−1 year−1, respectively, and the joint return period T(DM > 4,DS > 2) decreased by −0.20 year year−1. Furthermore, due to the decreasing SV in P, T, RH, WS, MF, and MFD, SV of DM5, DS5 and T(DM > 4,DS > 2) significantly decreased in the past decades, by −0.003 month year−2, −0.006 month−1 year−1 and −0.03 year year−1, respectively. These results indicated that drought risks and severity increased significantly in the past decades over SW China. Most importantly, the decreasing SV implied that drought risks and severity might have become more homogeneous in this region. In other words, droughts became more widely spread throughout SW China in the past decades. Therefore, water agencies and governments should be more proactive in seeking measures to improve water resources management and drought mitigation in this region. [ABSTRACT FROM AUTHOR]

Drought over Southwest China occurs frequently and has an obvious seasonal characteristic. Proper management of regional droughts requires knowledge of the expected frequency or probability of specific climate information. This study utilized k-means classification and copulas to demonstrate the regional drought occurrence probability and return period based on trivariate drought properties, i.e., drought duration, severity, and peak. A drought event in this study was defined when 3-month Standardized Precipitation Evapotranspiration Index (SPEI) was less than −0.99 according to the regional climate characteristic. Then, the next step was to classify the region into six clusters by k-means method based on annual and seasonal precipitation and temperature and to establish marginal probabilistic distributions for each drought property in each sub-region. Several copula types were selected to test the best fit distribution, and Student t copula was recognized as the best one to integrate drought duration, severity, and peak. The results indicated that a proper classification was important for a regional drought frequency analysis, and copulas were useful tools in exploring the associations of the correlated drought variables and analyzing drought frequency. Student t copula was a robust and proper function for drought joint probability and return period analysis, which is important for analyzing and predicting the regional drought risks. [ABSTRACT FROM AUTHOR]

Transboundary flows of energy across Yunnan Province in China and to Southeast Asian states provide insight into the changing nature of borders and border areas. Rather than monolithic symbols of state sovereignty, China’s southwest borders in Yunnan can be more accurately characterised as zones of connectivity and exchange, serving a range of local, national and regional objectives. Energy production and distribution in and across Yunnan can be understood as functioning in a set of dynamic transnational processes that serve as economic and political bridges – increasing interaction and deepening regional integration – while also working to mitigate risk to China’s energy demands. In this article, energy projects in Yunnan and Southeast Asia demonstrate the ways border regions can respond to increasing globalisation, simultaneously strengthening national energy security while promoting regional interconnection and diplomacy. Thus, connections to and through a once peripheral region present an apparent contradiction: once rigid territorial borders are increasingly characterised by transboundary infrastructure development and exchanges of energy, capital and diplomacy, while promoting broader, diversified national energy security objectives – essentially strengthening national security through transnational energy projects. This article investigates how energy development works to shape Yunnan’s role as an “energy conduit,” while advancing both transnational and national geopolitical objectives, and thus, suggesting that these projects can be understood as trans-political in nature. [ABSTRACT FROM PUBLISHER]

This study aims to understand the particle size distribution and depositional styles of glacier-associated deposits in the Moxi basin in southwest China. Based on field surveys, 28 samples from glacier-associated deposits (including glacial till, fluvioglacial, debris flow, river and lake deposits) were collected and tested in the laboratory. The results showed that the glacier-associated deposits can be differentiated based on particle gradation, particle size distribution and accumulated percentages. We evaluated the evolution of a former dammed lake in the Moxi basin based on glacier-associated deposits. The results of this study also indicated that the Moxi Platform was not formed by a single depositional process but is composed of both fluvioglacial and debris flow deposits. This research shows that the depositional style analysis is useful in identifying different glacier-associated deposits in high mountain regions. Moreover, the evaluation of the differences in particle sizes of the glacierassociated deposits is useful in reconstructing geohazard events in periglacial regions, and this information can help in identifying and reducing the potential risks associated with geo-hazards. [ABSTRACT FROM AUTHOR]

Context: The National Forest Protection Program (NFPP) and sloping land conversion program (SLCP) were introduced in 1998 and 2000, respectively, with the shared goal of increasing forest cover and decreasing forest loss across China. The NFPP banned commercial logging and funded tree planting efforts while the SLCP subsidized tree planting on steeply sloping and otherwise disused lands. Objective: This study quantifies the patterns of forest loss and gain before and during policy implementation to gauge implementation effectiveness. By measuring patterns associated with spatially explicit processes linking land managers and forest resources, this study improves upon overly simplified assessments of implementation effectiveness that only consider the area of forest cover change. Methods: The shifting patterns of short- and long-term forest cover change in Diqing Prefecture, southwest China, are measured between 1990 and 2009. Eleven pattern metrics quantify the area, topography, and landscape feature proximity of forest loss or gain patches based on Landsat imagery-derived forest cover changes. Results: Trends generally conformed to those expected under successful policy implementation: the proportion and fragmentation of forest loss declined, loss patches were found closer to villages and at lower elevations, and forest gain increased in proportion and median patch area. However, median loss patch area increased, suggesting greater localized harvesting intensity, and loss sites occupied steeper slopes contrary to SLCP goals. Conclusions: Forest cover change patterns did not wholly align with those expected of successful implementation but rather deviated due to the influences of regional tourism development and village- and household-level forest resource scarcity. [ABSTRACT FROM AUTHOR]

Proper methods for estimating reference evapotranspiration (ET0) using limited climatic data are critical, if complete weather data are unavailable. Based on the weather data of 19 stations in Guizhou Province, China, several simple methods for ET0estimation, including the Hargreaves, Priestley–Taylor, Irmak–Allen, McCloud, Turk, and Valiantzas methods, were involved in comparison with the standard FAO-56 Penman–Monteith (PM) method. The Turk equation performs well for estimating ET0in humid locations. Both the Turk method and the Valiantzas method initially performed acceptably with mean root-mean-square difference (RMSD) of 0.1472 and 0.1282 mm d−1, respectively, with only requiring parameters of temperature (T), relative humidity (RH), and sunshine duration (n). The corresponding calibration formulas to Turk and Valiantzas method were suggested as the most appropriate method for ET0estimation with the RMSD of 0.0098 and 0.0250 mm d−1, respectively. The local calibrated Hargreaves–Samani method performed well and can be applied as the substitute of FAO-56 PM method under the condition that only the daily mean, maximum, and minimum temperatures were available, and local calibrated McCloud method was acceptable if only the mean temperature was available. [ABSTRACT FROM AUTHOR]

A case study is presented of ten scenic views of the landscape of the frontier district of Dongchuan, Yunnan Province in Southwest China during the 18th century, including the impact of the Chinese Qing Dynasty's policy of having Han Chinese settle the area's impact on the landscape. An overview of Dongchuan's indigenous people's relations with the Han Chinese is provided.

This study aims to investigate the recent drought in southwestern China and its association with environmental changes in moisture transport (MT) and atmospheric circulation. Climatic Research Unit grid data, in situ observations in China, and ERA-interim reanalysis are used to study the characteristics of the drought and the associated mechanism. Recent precipitation trends show a pattern of “Northern wetting and Southern drying”, similar to the anti-phase of the climate pattern prevailing during 1980–2000 in mainland China; southwestern China incurred a severe drought during 2009–2013. Wavelet analysis reveals that the drought coincides with a warm–dry phase of temperature and precipitation on a period of about 20 years and beyond 100 years, where contributions account for 43% and 57% of the deficiency of the precipitation, averaged for 2003–2012, respectively. A further investigation reveals that the drought results chiefly from the decline of the southwestern monsoon MT toward southwestern China, in addition to mid-latitude circulation changes, which leads to more blockings near the Ural Mountains and the Sea of Okhotsk in the rainy season and negative anomalies around Lake Baikal and northeast China in the dry season. These anomalies are likely to be correlated with global sea surface temperature changes and need to be studied further. [ABSTRACT FROM AUTHOR]