Chongqing Region Research Articles

Engineering Geological Characteristics of one High Cut Slope in Chongqing Wanzhou

Based on the methods of qualitative and quantitative, the engineering geological characteristics of one high cut slope in Wanzhou region of Chongqing is evaluated. The results are obtained: (1) the stratum composed of the high cut slope from top to bottom are artificial accumulation including gravel soils, residual silty clay, silty mudstone; (2) the main weak planes include the interface between soil and rock, two group joints and fissures in the bedrock and bedding plane in the high cut slope; (3) based on the results of stability evaluation, it’s in stable condition at present, but has dropped stone and collapse phenomenon. In the long term effect of weathering and groundwater, the overlying soil creeping deformation along the flare mudstone level would occur.

A palaeoenvironmental study of the Shiniusi archaeological sites in the Wujiang Drainage Area, upper Yangtze River, Chongqing region, China

Environmental archaeology helps researchers understand the correlation between environmental changes and their impacts on human civilization. One such study is taking place along the Wujiang river in Chongqing, China, at and near the Shiniusi site. Moss samples were obtained under natural mountain vegetation, along with soil samples from the QST4 unit at the Shiniusi site and surface soil sites from nearby archeological sites. By combining comprehensive palynology, charcoal, and isotopic chronology analyses with cultural artifacts, and comparing the results with those from adjacent sites, historical insights were obtained. The modern pollen assemblage of the Wujiang comprises mostly monolete spores and tree pollen, with no pollen from the Brassicaceae or rice (Oryza sativa), indicating a lack of human activity. The modern pollen and spore assemblage at nearby sites contains more trilete spores than monolete spores, and increased pollen from the Brassicaceae and Poaceae, indicating increased human activity. From the Shang Dynasty to the Song Dynasty, the pollen and spore assemblage of the QST4 unit was mainly monolete spores and the pollen of trees and herbaceous vegetation, with little pollen of rice and none of the Brassicaceae. Since the Ming Dynasty (1368 to 1644 AD), the pollen and spore assemblage has approached the modern assemblage near the archeological site, with more trilete spores than monolete spores, and increased pollen from the Brassicaceae and Poaceae, indicating greater human activity correlated with cultivation of rice and brassicaceous vegetables. The dominant pollen was from the Brassicaceae, the Poaceae, and the Fabaceae in the CJ unit at the Chenjiazui archeological site from the Zhou Dynasty (1100 to 256 BC) until modern times. High contents of micro-charcoal grains 125 mu m since the Tang Dynasty is probably correlated with local grassland burning to fertilize crops. (c) 2011 Elsevier Ltd and INQUA. All rights reserved.

Effects of topography on status and changes in land-cover patterns, Chongqing City, China

Chongqing Municipality, located on the upper reaches of the Yangtze River, is one of China’s four largest megacities, comparable with Shanghai, Beijing, and Tianjin. In recent years, Chongqing and its surroundings have been experiencing severe environmental problems, such as urbanization, pollution, and deforestation, due to the rapid economic development of China’s inland region. Understanding the current land-cover status over a wide scale, as well as changes in land-cover over time, are necessary for improving the urban environment and implementing conservation measures in the Chongqing region. In this study, remote-sensing data from 1993 and 2001 were used to analyze land-cover changes. Due to the distinctive mountainous topography of Chongqing, digital topography data shuttle radar topography mission (SRTM)-3 were also used. The results of the analysis showed that urban area increased from 109.91 km2 (5.7%) in 1993 to 166.84 km2 (8.7%) in 2001. This increase came at the expense of agricultural and vegetated areas. Although irrigated paddy field and dry farm land decreased due to the development, these two land-cover categories still covered the largest agricultural area. Correlating the land-cover changes with different topography types, the results showed that forest covered a larger area and enjoyed a higher frequency of distribution at higher elevations and on steeper slopes. The increase in urban area, in contrast, was apparently associated with lower elevations and milder slopes. These results indicate that incorporating terrain characteristics into remote-sensing analysis can be a useful tool in developing conservation measures for vegetated and agricultural areas.

Optimal Design of Slip Dog Based on the Elasticoplasticity Contact Analysis

Based on the elasticoplasticity contact analysis theory, a mechanical model for the whole process of the slip holding fast to the drilling pipe is established and a complete method is proposed to assess the performance of slip dog's structural parameters. For drilling pipe systems of different specifications, the coupling effect among tooth anterior corner, posterior corner, tooth height, tooth spacing of slip dog and the effect of the parameter variation on both the drilling pipe and itself after the slips hold fast to the drilling pipe are analyzed, and the slip dog's plastic damage law on the drilling pipe under different parameter combinations is obtained. Using this law to instruct field slip dog design, it is discovered that this slip dog significantly reduces the drilling pipe's plastic damage by both laboratory and field experiments, which has proved the universality and applicability of this method, effectively reduced the drilling operational risk and drilling costs. The technology has been put into use in Sichuan and Chongqing region and acquired good technical assessment.

Molecular Phylogeny of Bactrocera Species (Diptera: Tephritidae: Dacini) Inferred from Mitochondrial Sequences of 16S rDNA and COI Sequences

ABSTRACT Many fruit flies in the genus Bactrocera (Diptera: Tephritidae: Dacini) are economically important insects. However, little attention has been given to the molecular phylogenetic relationship among Bactrocera subgenera. We explored the phylogenetic relationship among the 8 subgenera Afrodacus, Austrodacus, Bactrocera, Daculus, Gymnodacus, Paratridacus, Tetradacus, and Zeugodacus based on the sequences of 2 mitochondrial DNA fragments with a combined length of 1034 base pairs. The 2 mtDNA fragments are a 689-bp segment of the COI gene and a 345-bp segment of the 16S rDNA gene. Thirty-five individuals representing 7 Bactrocera species found in the Chongqing region in China were sequenced for both fragments, and sequences of the same gene regions were acquired from GenBank for another 20 Bactrocera species and 2 other tephritid species, Anastrepha ludens and Ceratitis capitata, which were used as out-groups for the phylogenetic analyses. We reported Bactrocera (Tetradacus) minax and Bactrocera (Zeug...

Mapping the potential distribution of high artemisinin-yielding Artemisia annua L. (Qinghao) in China with a geographic information system

BackgroundArtemisia annua L. is an important source for artemisinin, a potent drug for treating malaria. This study aims to map and predict the potential geographic distribution of A. annua L. in China.MethodsThe Geographic Information System for traditional Chinese medicine (TCM-GIS) was developed and used to map the potential geographic distribution of A. annua L.ResultsClimatic, edaphic and topographic characteristics of A. annua L. microhabitats in Youyang County were mapped to find distribution patterns. The maps identified that certain habitats in the Chongqing region and some potential regions, especially in Guizhou Province, possess similarity indices of ≥98%. In particular, high quality microhabitats A. annua L. were found in the Wuling mountains region.ConclusionThe present study demonstrates a GIS approach to predict potential habitats for A. annua L. TCM-GIS is a powerful tool for assessing bioclimatic suitability for medicinal plants.

Ostracod fauna across the Permian-Triassic boundary at Chongyang, Hubei Province, and its implication for the process of the mass extinction

Thirty species of 10 ostracod genera were identified from 440 fossil specimens isolated through the hot acetolysis of the rock samples collected across the Permian-Triassic boundary at Chongyang section. Twenty species of 6 genera are found to occur in the limestone of Changxing Formation, and 11 species of 7 genera above the main faunal mass extinction horizon. The ostracod assemblages identified at the Chongyang section are obviously different from those previously reported in the contemporaneous microbialites in Guangxi and Chongqing regions, not only in the ostracod components but also in the abundance of filter-feeding ostracods relative to the deposit-feeding ostracods, an indicator of the oxygen level of the seawater. This spatial difference in ostracod assemblages might reflect the diversity of oceanic environmental conditions after the end-Permian mass extinction. Ostracods disappear at 200 cm below and near the main mass extinction horizon, and on the top of the microbialites, respectively, showing an episodic and gradual collapse process at the Chongyang section. The carbon isotope composition is found to appear at 200 cm below the main mass extinction horizon, indicating the initial deterioration of oceanic environment. Fluctuation of the carbon isotope composition is obviously related with the episodic evolution of ostracod species, but not with the abundance of ostracods.

Determination of antibiotics in sewage from hospitals, nursery and slaughter house, wastewater treatment plant and source water in Chongqing region of Three Gorge Reservoir in China

Sewage samples from 4 hospitals, 1 nursery, 1 slaughter house, 1 wastewater treatment plant and 5 source water samples of Chongqing region of Three Gorge Reservoir were analyzed for macrolide, lincosamide, trimethoprim, fluorouinolone, sulfonamide and tetracycline antibiotics by online solid-phase extraction and liquid chromatography-tandem mass spectrometry. Results showed that the concentration of ofloxacin (OFX) in hospital was the highest among all water environments ranged from 1.660 μg/L to 4.240 μg/L and norfloxacin (NOR, 0.136–1.620 μg/L), ciproflaxacin (CIP, ranged from 0.011 μg/L to 0.136 μg/L), trimethoprim (TMP, 0.061–0.174 μg/L) were commonly detected. Removal range of antibiotics in the wastewater treatment plant was 18–100% and the removal ratio of tylosin, oxytetracycline and tetracycline were 100%. Relatively higher removal efficiencies were observed for tylosin (TYL), oxytetracycline (OXY) and tetracycline (TET)(100%), while lower removal efficiencies were observed for Trimethoprim (TMP, 1%), Epi-iso-chlorotetracycline (EICIC, 18%) and Erythromycin-H 2O (ERY-H 2O, 24%). Antibiotics were removed more efficiently in primary treatment compared with those in secondary treatment.

Distributed modeling of the beginning and ending dates and durations of limited temperatures over the rugged terrain of Chongqing

A physically based empirical model was established for the beginning and ending dates (BED) of limited temperatures. Data used were daily mean temperatures from 34 conventional stations in the Chongqing region, measured from 1961 to 2000. Using this model in combination with the distributed modeling results of monthly mean temperatures, we developed a method for creating a distributed simulation of the BED and durations of limited temperatures in the rugged terrain of Chongqing. Spatial distribution maps were generated at a resolution of 100 × 100 m for the BED and durations of the limited temperatures of 0, 10, 15 and 20. Simulations suggest that the distributed model is able to successfully reveal the macroscopic trends and local distributions. For the modeled BED, the mean absolute bias error is 0.6–2.4 d. Cross-validation and case-year tests show mean absolute bias errors of 1.3–2.8 d and 0.7–2.5 d, respectively. Comparison shows that the simulation results are consistent with the field investigations. This implies that the simulations are as good as observations, thus providing a viable technique for simulating mountainous heat resources using conventional meteorological data.

NOVEL MITOCHONDRIAL DNA MUTATIONS ASSOCIATED WITH CHINESE FAMILIAL HYPERTROPHIC CARDIOMYOPATHY

1. Hypertrophic cardiomyopathy (HCM) is a genetic disorder that has a complex set of symptoms and potentially devastating consequences. Increasing evidence indicates that mitochondrial DNA (mtDNA) mutations are responsible for the development of HCM, but the mtDNA mutations appear to differ considerably among different populations and regions. 2. In the present study, three families with HCM were found and investigated: one in Shandong province and two in the Chongqing region of China. The entire mtDNA genome from the 18 affected and 66 unaffected family members was sequenced directly and the mtDNA mutations were determined. 3. The frequency of haplogroup M10 was significantly higher in family members with HCM (HCM group) than in unaffected family members (normal group). Three mtDNA mutations were found with a significantly higher frequency in affected individuals than in unaffected family individuals, namely G7697A in the cytochrome c oxidase subunit II gene (P < 0.0001; odds ratio (OR) 227.5; 95% confidence interval (CI) 23.6–2194.8) and T12477C (P = 0.0037; OR 5.6; 95% CI 1.8–17.6) and G13135A in the NADH dehydrogenase 5 gene (P < 0.0001; OR 26.0; 95% CI 6.9–98.3), suggesting that these mutations are probably associated with susceptibility to HCM. In addition, mitochondrial Complex I activity was markedly decreased in the HCM group, suggesting that these mutations most likely affect mitochondrial respiratory function. 4. In conclusion, the results of the present study imply that mtDNA mutations G7697A, T12477C and G13135A are genetic factors that indicate a susceptibility to HCM and that could be used for the large-scale screening of genetic markers as well as the early diagnosis of HCM.

The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini)

Bumblebees are important pollinators in mountainous regions. The highland region of Sichuan and Chongqing (together, Sichuan in the former broad sense) includes part of the greatest hotspot of bumblebee diversity worldwide, with half of the species of China and more than a fifth of the world's species. In this paper we present the first review of this diverse but particularly poorly known fauna, drawing on 6705 bees from selective samples made by the authors during field work and from museum collections, together with 1123 literature records (an overlapping set). Among this material we recognise 56 species that have 847 names (including infrasubspecific names). One new species, Bombus (Pyrobombus) wangae, is described from Sichuan and Gansu. B. laesus is found to have a colour pattern in this part of its range that was previously undescribed. Six species are recorded from the Sichuan‐Chongqing region for the first time (B. avanus, B. branickii, B. difficillimus B. humilis, B. norvegicus, B. tibetanus), of which B. avanus is only the second published record worldwide. One species, B. braccatus, is endemic to Sichuan and is confirmed as extant in 2005. We provide diagnoses and keys to species for both sexes. Colour variation is described, distributions within the Sichuan‐Chongqing region are mapped, altitudinal and seasonal activity are plotted, and the authors’ records of food plants are listed.

The Women's Movement in the Chongqing Region Duirng China's War of Resistance Against Japan, 1938-1945

Existing Western scholarship on women in the 20th century China mostly focuses on the May Fourth era and the Chinese revolution. Most of the works place the study of Chinese women in the War of Resistance against Japan at the margins of the long history of Chinese revolution and are incomplete in their coverage. They focus mainly on the Chinese Communist Party (CCP)-held border regions in rural areas and pay little attention to women in the more urban, Nationalist-held regions. As Louise Edwards demonstrates in her 2007 study, women's movement in China has continued from the late 19th century to the late 1940s, including during the Second Sino-Japanese War in the GMD-held areas.

Trophic states and nutrient storage of reservoirs in Chongqing

The trophic states of 35 reservoirs were investigated in the region of Chongqing, Southwest China. The results showed that the concentrations of nutrients and chlorophyll a were high and organic pollution and transparence (SD) were low in the water body. The concentrations of total nitrogen (TN) range from 0.52 mg/L to 5.94 mg/L and those of total phosphorus (TP) range from 0.002 mg/L to 0.598 mg/L. Chemical oxygen demand (COD) ranges from 0.75 mg/L to 9.3 mg/L and SD ranges from 0.48 m to 3.2 m. There was a significant positive correlation between COD and chlorophyll a, but a significant negative correlation between SD and chlorophyll a. In terms of the integrated nutrition state index, the eutrophication states of the reservoirs were assessed. Of the investigated reservoirs, about 22 reached the grade of eutrophication. Only one reservoir was in the state of oligotropher, the rest were in the state of mestropher. Integrated nutrition state indices range from 25.4 to 74.5. The storage capacity of nutrients in the reservoirs was calculated. The stored TN, TP and COD were about 4731, 206 and 10259 t, respectively. The main pollution sources are industrial and domestic wastes. With the development of aquaculture, the contamination level increases gradually.

Response of remotely sensed Normalized Difference Water Deviation Index to the 2006 Drought of eastern Sichuan Basin

One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water Index (NDWI) for the summers of 2001-2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water Deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more preferable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

Contour hedgerow intercropping in the mountains of China: a review

Hedgerow intercropping systems were introduced in China in early 1990s. Achievements in research and extension of contour hedgerow intercropping in China during the past 15 years are reviewed here. Results reported in over 70 published papers have shown that hedgerow intercropping contributes to soil and water conservation, soil fertility amelioration, land productivity improvement, bio-terrace formation, and gives more options for income generation based on local resources in mountain areas. Research and demonstration works on contour hedgerow systems have achieved success by integrating local resources and needs into the system, especially in the dry valleys of the upper reaches of the Yangtze River, and the Three Gorges region. Contour hedgerow intercropping has attracted the attention of researchers, policy-makers, and farmers, and has been taken as an alternative to implementation of the Grain for Green policy, and ecological reconstruction and restoration today. To date, hedgerow intercropping has been demonstrated and applied practically on sloping land in more than six provinces of China, particularly Sichuan, Guizhou, Shanxi, Shaanxi, as well as in the Three Gorges region of Chongqing and Hubei Province. The intercropping system has also been practiced as an optimized technology for conserving farming on sloping lands, improving cash income, and reducing agricultural risks in depressed mountainous regions in southwest and northern China over recent years. Some misunderstandings and problems in studies and extension of the system in China are summarized and clarified, and some recommendations for further research and expansion of the system are also presented in this paper.

A new method for spatio-temporal prediction of rainfall-induced landslide

Geological condition and rainfall are two most principal conditions inducing landslides in the Chongqing region. By analyzing the forming conditions of rainfall-induced landslides, a new method for spatio-temporal prediction of rainfall-induced landslide is brought forward on the basis of grading and overlapping geological condition and rainfall factor in this paper. At first, semi-quantitative assessment and grading for the geological condition of a certain area or slope can be carried out with the multi-factor interactive matrix. Then the severity of rainfall in that area is grading according to the maximum daily rainfall and the total rainfall in a rainfall course. Finally, the “landslide probability judgement factor” can be worked out through grading and overlapping “geological condition influencing factor” and “rainfall influencing factor”, by which the landslide can be graded into 4 grades, they are landslide extremely easily happening, landslide easily happening, landslide difficultly happening and landslide hardly ever happening respectively. More accurate spatio-temporal prediction of rain-fall-induced landslides can come true on the ground of detailed geological survey of some dangerous slopes in an area and more precise weather forecast. Finally, the reliability and feasibility of carrying out the spatio-temporal prediction of rainfall-induced landslides with the method of “two factors” grading and overlapping are validated by the example of Jipazi landslide.

Effects of acidic deposition on soil ecosystems under forest in the Chongqing region of China

The effects of acidic deposition on soil ecosystems under temperate coniferous forest in the Chongqing region of China were investigated from 1993 to 1994. Precipitation, throughfall, stemflow, soil solutions, and soil samples were collected to estimate the acidification of soil ecosystems through the changes of their chemical components. The concentrations of ion species in the throughfall and stemflow under masson pine forest in Mt. Zhenwu were higher than those under mixed coniferous forest in Mt. Jinyun and under camphor tree forest in Laojundong, suggesting that Mt. Zhenwu is located in the vicinity of the Chongqing center and that it allowed the canopy of masson pine to intercept air pollutants. However, the level of aluminum dissolution into soil solutions was relatively low under masson pine forest in Mt. Zhenwu in spite of the low pH in the stemflow.

Ozone levels in Chongqing: a potential threat to crop plants commonly grown in the region?

Chongqing, a city with a population of >2.5 million, constitutes the biggest industrial and commercial centre in southwest China. Recent industrialization has led to an increasing air pollutant problem which is exacerbated by the topography and prevailing climate of the region. To date, interest has remained firmly focused on the levels of traditional air pollutants (sulphur dioxide [SO 2], oxides of nitrogen [NO x], smoke and suspended particulate matter [SPM]), with little attention paid to photochemical oxidants such as ozone (O 3). This paper reports the first assessment of ambient O 3 levels in southwest China. Measurements were made in and around Chongqing using a combination of UV-absorption (at a site located in the northern sector of the city) and passive samplers (at 20 sites located in and around the city) between 1993 and 1996. The 7-h daily mean O 3 concentrations ranged between 2 and 16 ppb (×10 9) during the winter months, increasing to 18–41 ppb during the summer (June-August), when peak hourly mean O 3 concentrations of 93 ppb were attained. Ozone exposures across the region commonly approached (or exceeded) UN-ECE and WHO short-term guidelines for the protection of crops. In addition, controlled chamber studies, in which 11 cultivars of Chinese crops commonly grown in the Chongqing region were screened for relative O 3 sensitivity, indicated the potential for subtle effects on the growth of a number of crop plants, if ambient O 3 levels continue to rise in the region. Employing ozone exposures somewhat higher than those experienced in the field, several cultivars of commonly grown Chinese cereal, vegetable and salad crops were found to be sensitive to O 3 in terms of growth, but this was not always associated with the appearance of visible symptoms of injury and, in contrast to what was generally expected, only three species showed significant O 3-induced reductions in root:shoot partitioning. There is a clear and urgent need for a comprehensive study of ambient air quality and its impact on crops and natural vegetation in this, as in other, rapidly developing regions of China.

95/02055 Pattern and cause of acidic deposition in the Chongqing region, Sichuan Province, China

95/02055 Pattern and cause of acidic deposition in the Chongqing region, Sichuan Province, China

Pattern and cause of acidic deposition in the Chongqing region, Sichuan Province, China

The Chongqing region located in Sichuan Province of China, comprises a large city, many small towns and rural areas. The region relies heavily on high-sulfur coal for energy production. Atmospheric pollution by sulfur oxides and other compounds from coal burning has become a major issue. Acid rain is observed throughout the region; volume weighted average pH is about 4.30. Average total S deposition for the region is estimated to be about 8 g S m−2 yr−1. In this paper we report concentrations of major ions in rain, fog, dew and clouds, of SO2 in air and of airborne particles as well as dustfall. The emissions and interactions between important chemical species in air and water droplets are discussed.