Southern Shaanxi Research Articles

The spatiotemporal evolution of non-grain conversion of cultivated land in southern Shaanxi Province and its driving factors

The spatiotemporal evolution of non-grain conversion of cultivated land in southern Shaanxi Province and its driving factors

How Does Poverty Alleviation Relocation Affect the Non-Agricultural Employment of Women’s Labor Forces? Evidence from Southern Shaanxi Province

With the completion of the relocation task, fully promoting the non-agricultural employment of relocated women is of great significance for improving the livelihood sustainability of relocated peasant households’ and consolidating the results of poverty alleviation. Based on the sample data of 1616 rural households in southern Shaanxi Province, China, using the IV-Probit model, IV-Tobit model, and mediation effect model, this study empirically analyzes the impact and mechanism of participation in relocation on women’s non-agricultural employment. The results show that by introducing an instrumental variable to solve endogeneity, participation in relocation has a significant positive impact on the behavior and intensity of women’s non-agricultural employment. A mechanism analysis shows that training, public services, and land abandonment play a mediation role in the relationship between participation in relocation and women’s non-agricultural employment. In terms of women’s non-agricultural employment behavior, the mediation effects are 56.9%, 15.0%, and 11.0%, respectively. In terms of women’s non-agricultural employment intensity, the mediation effects are 58.5%, 15.7%, and 11.6%, respectively. Based on the above findings, this study puts forward policy implications for follow-up relocation support, to further release the surplus women’s labor forces and promote women’s non-agricultural employment.

Livelihood adaptive capacities and adaptation strategies of relocated households in rural China

Adaptation to environmental change is the focus of sustainability research. Rural households face multiple environmental and social pressures due to global environmental change, so effective livelihood changes must be made to reduce capability losses and adapt to current or future livelihood challenges. Livelihood adaptive capacity and its evaluation provide a new framework for research into the livelihoods of relocated households, we attempt to evaluate the livelihood adaptive capacity of rural households in disaster resettlement areas and to explore how disaster resettlement affects the choice of adaptation strategies. Taking the case of southern Shaanxi as an example, this paper selects indicators from the dimensions of awareness, ability, and action. An index system is constructed for evaluation of farmers' livelihood adaptive capacity, and factors influencing the adaptation strategy are identified by using the multinominal probit regression model. The analysis shows: (1) the most adaptation strategies adopted after disaster resettlement are “expansion strategy,” “expansion and adjustment strategy,” “expansion and assistance strategy,” and “expansion and adjustment and assistance strategy”; (2) disaster avoidance relocation has a significant impact on expansion strategies, and whether centralized resettlement has a significant effect on the choice of “expansion strategy” and “expansion and adjustment strategy”; and (3) household size, physical assets, and skills training also have a significant impact on the choice of adaptation strategies. Local governments should increase the assistance to the relocated households, improve the households' livelihood adaptive capacity, and encourage adoption of the most favorable adaptation strategies.

Study on Thermal Storage Wall Heating System of Traditional Houses in Cold Climate Zone of China: A Case Study in Southern Shaanxi

Solar energy has the advantages of being green, renewable, and energy-efficient. The use of solar energy in buildings can result in significant energy savings, and a great deal of practical and theoretical research has been conducted on solar buildings around the world. Southern Shaanxi belongs to a climate zone with hot summers and cold winters (HSCW). The mean room temperature is 4 °C, and it is lower than 2 °C at night, which greatly exceeds the thermal comfort range that the human body can bear. Aiming at a range of challenges including backward heating methods and low heating efficiency in southern Shaanxi, a fully passive thermal storage wall heating system (TSWHS) is proposed for traditional houses in the area. The specific method is to set up a thermal storage wall (TSW) outside the outer walls on the east, west, and south sides of the residential buildings. The wall is provided with an air exchange port, and there is no glass in the outer area of the doors and windows, which does not affect the normal application. The principle is that after the TSW receives solar radiation, the temperature of the internal HDPE (high-density polyethylene) and the air inside the cavity rises, which raises the interior temperature via the heat transfer and the air exchange port inside the TSW. The hot air inside the thermal wall achieves the purpose of heating. Lastly, through a comparison with the original heating system (OHS), it is confirmed that the TSWHS has certain practicability. According to an experimental simulation, the system can increase the indoor temperature by an average of 5.1 °C in winter and save about 1726.43 kWh of energy, accounting for 27.24% of the energy saving.

Analysis of the Pile-Soil Combined Effect of Micropiles in Strengthening Expansive Soil Landslide in Southern Shaanxi Based on the Dynamic Soil Arch Model

Southern Shaanxi region is mountainous and landslide disasters are frequent. Micropile reinforcement technology is widely used in landslide management, especially in landslide emergency rescue projects, due to easy construction, small soil disturbance, and strong site adaptability. Soil arch effect is an important prerequisite for safe and economic performance of the support function of micropile. For the swelling soil landslide of the accumulation layer in southern Shaanxi, firstly, a numerical model is established by means of thermal-mechanical coupling of FLAC3D to explore the variation of the soil arch form with different swelling forces. Then, two theoretical models are proposed under normal working condition and rainfall working condition. The evolution and failure mode of soil arch are analyzed. The results show that the soil expansion after rainfall causes the change of the soil arch mode, the range of pile-soil interaction is obviously reduced, and the soil arch effect is weakened. It should be considered in the design of micropiles in strengthening expansive soil landslide.

The putative earliest Cambrian trilobite–brachiopod association in southern Sichuan Basin of South China

ABSTRACT Parabadiella is considered the earliest trilobite representative in South China and was originally recovered from the mid-upper part of the Guojiaba Formation, in Liangshan section. Previous studies suggested that the earliest brachiopod co-occurred with the oldest trilobite, and the Parabadiella–Eoobolus association from the Xihaoping Member (Cambrian Series 2, Stage 3), in southern Shaanxi was considered the first trilobite–brachiopod assemblage zone in South China. Therein, brachiopods occur together with trilobites recovered in Well JS103 seemingly extending the First Appearance Datum deeply in the lower Cambrian at the central Yangtze Platform. Well JS103 is a shale gas exploration well that targets the lower Cambrian Jiulaodong Formation in southern Sichuan Basin. The uppermost fossiliferous layers are siliciclastic rocks nearly 10 metres thick. Here, two distinct trilobite zones are found, including the lower Parabadiella Zone and the upper Wutingaspis–Eoredlichia Zone. Additionally, the lowermost part of the Guojiaba Formation is poorly fossiliferous, and ranges from 200 to 250 metres in thickness. Thus, the discovery of the brachiopod–trilobite assemblage provides new insights into the biostratigraphy in Sichuan and is of great potentials for biostratigraphic correlation of the siliciclastic rocks in the western margin of the Yangtze Platform.

Study on the Measures for Optimizing China’s Provincial Territorial Space Based on the Perspective of Resource and Environmental Carrying Capacity in the New Situation

The comprehensive resource and environment carrying capacity (RECC) evaluation is an important method for measuring the rationality of the population, resource, and environment allocation, which is an important scientific guidance for scientific research and the judgment of regional economic and social development potential and the optimization of the national land spatial pattern. This paper constructs a comprehensive evaluation index system of the RECC under the new situation of climate policy and high-quality economic development; it analyzes the factors influencing the RECC, the overall level, the spatial difference, and the carrying status by using the TOPSIS model based on the entropy weight method, and it identifies the shortcomings; then, it analyzes the characteristics of regional dynamic change and sustainable development trend, and finally, it simulates the optimal spatial pattern under the scenario simulated by the FLUS model. The conclusions are as follows: ① the resource factors have the greatest influence on the carrying capacity of the resources and the environment, followed by economic factors. Among them, per capita water resources, forest coverage rate, and health institutions have the highest impact on RECC. ② The overall level of comprehensive RECC from 2015 to 2020 shows an upward trend, and although the positive impact of resource-led provinces on the level of economic development power and RECC is greater than the negative one, the environmental support is the shortcoming of the future development of the regional economy. ③ The overall spatial performance of RECC is characterized as being high in Guanzhong, second in northern Shaanxi, and low in southern Shaanxi. The northern area of Yulin in the Guanzhong Plain City Cluster, which is an important national energy chemical base, is the core of the national-level urbanization development areas, and the northern area of the Guanzhong Plain City Cluster is the key choice of the provincial-level urbanization development areas. The area along the west bank of the Yellow River in the Qinba Mountain area in southern Shaanxi and the Baiyu Mountain area in northern Shaanxi can be positioned as national key ecological function areas.

The Chromosome-level genome of Aesculus wilsonii provides new insights into terpenoid biosynthesis and Aesculus evolution.

Aesculus L. (buckeye and horse chestnut) are woody plant species with important horticultural and medicinal values. Aesculus seeds are widely used as biomedicine and cosmetic ingredients due to their saponins. We report a chromosomal-scale genome of Aesculus wilsonii. Sequences amounting to a total of 579.01 Mb were assembled into 20 chromosomes. More than half of the genome (54.46%) were annotated as repetitive sequences, and 46,914 protein-coding genes were predicted. In addition to the widespread gamma event with core eudicots, a unique whole-genome duplication (WGD) event (17.69 Mya) occurred in Aesculus after buckeye differentiated from longan. Due to WGD events and tandem duplications, the related synthetic genes of triterpene saponins unique to Aesculus increased significantly. Combined with transcriptome characterization, the study preliminarily resolved the biosynthetic pathway of triterpenoid saponins like aescin in A. wilsonii genome. Analyses of the resequencing of 104 buckeye accessions revealed clear relationship between the geographic distribution and genetic differentiation of buckeye trees in China. We found that the buckeye species found in southern Shaanxi is A. wilsonii rather than A. chinensis. Population dynamics analysis further suggests that the population size and evolution of existing buckeye species have been influenced by climate fluctuations during the Pleistocene and recent domestication events. The genome of A. wilsonii and population genomics of Aesculus provide a resource for future research on Hippocastanaceae. These findings will contribute to the utilization and diversity protection of Aesculus.

Assessment of diverse energy consumption structure and social capital: A case of southern Shaanxi province China

This study aims to analyze the current situation of farmers' social capital and energy consumption structure in the Qinba mountainous area of southern Shaanxi China. Based on 746 survey data of farmers' social capital and energy consumption it further explores the impact of social capital on farmers' energy consumption structure by using Tobit model and Logit models. Findings of this study reveal that: (1) The energy consumption of farmers in the Qinba mountainous area of southern Shaanxi is diverse and structurally stable. Farmers' energy consumption is mainly based on the electricity, coal, and firewood and farmers' utilization rate of coal, gasoline, and diesel, liquid gas, and solar energy is more than 30%. (2) Findings also reveal that farmers' energy consumption gradually turned to commercialization; cleaning farmers' energy consumption had an obvious tendency, and the power utilization rate was 94.3%. (3) Social capital was significantly positively correlated with commercial energy consumption and new energy consumption, and significantly negatively correlated with non-commercial energy consumption. Improving farmers' social capital, improving energy infrastructure and optimizing energy consumption structure can not only improve farmers' quality of life in rural areas, but also provide reference for reducing carbon dioxide emissions and alleviating global environmental degradation.

Evaluation and analysis of ecological security based on the improved three-dimensional ecological footprint in Shaanxi Province, China

The increase in human activities has led to a series of ecological issues such as ecological imbalance, environmental pollution and resource depletion. Developing a comprehensive, applicable and simple ecological security assessment system is critical for determining the current state of the regional ecological environment and formulating sustainable development strategies. Therefore, an integrated ecological security index was established in this study based on entropy method by incorporating the ecological pressure index (EPI), ecological utilization efficiency (EUE), ecological and economic coordination index (EECI) and utilization ratio of capital stocks to flows (Rflowstock). The ecological security of Shaanxi Province from 2000 to 2019 was analyzed from single and comprehensive perspectives. The results showed that (1) during 2000–2019, the per capita ecological deficit of Shaanxi first increased at an average annual rate of 105.75 %, and then decreased at an average annual rate of 3.26 %, reaching a peak of −1.815 nha/cap in 2016. And the sequence of ecological deficit of three regions in Shaanxi was Guanzhong > Northern Shaanxi > Southern Shaanxi. Only Hanzhong, Shangluo and Ankang had an ecological surplus in 2019, whereas the remaining cities were in deficit. (2) Shaanxi’s ecological footprint depth increased from 1.52 to 2.86 in 20 years, indicating that capital flow is insufficient to meet the ever-increasing consumer demand, and the capital stock has been continuously consumed. In 2019, the ecological footprint depth of the cities in Shaanxi ranked from high to low as Weinan (12.69) > Xianyang (9.98) > Tongchuan (7.39) = Yulin (7.39) > Xi'an (4.50) > Baoji (3.01) > Yan'an (2.08) > Hanzhong (1.34) > Shangluo (1.21) > Ankang (1.11). (3) Although Shaanxi’s EUE continued to improve, the EPI, EECI and Rflowstock indicated that the ecological situation of Shaanxi was gradually deteriorating. (4) From 2000 to 2019, Shaanxi’s IESI increased by 54.55 %, exhibiting the spatial distribution of Guanzhong > Northern Shaanxi > Southern Shaanxi. Only the IESI of Hanzhong, Ankang and Shangluo showed a downward trend, indicating that the level of ecological security was strengthening in these regions. The findings will help local governments develop and implement regional character-based policies in support of regional sustainable development. Moreover, this study provides a framework for evaluating ecological security with broad coverage, simple operation and comparable results.

Assessment of Synergistic Development Potential between Tourism and Rural Restructuring Using a Coupling Analysis: A Case Study of Southern Shaanxi, China

Tourism plays an important role in rural restructuring, especially in mountainous areas. Mismatches between tourism and rural in terms of the development level and efficiency have given rise to a variety of challenges. In order to achieve the orderly growth of tourism and sustainable rural restructuring, there is an urgent need to explore the interaction between the two. Thus, we introduce the concept of synergistic development potential (SDP) and construct an assessment framework using coupling analysis. Southern Shaanxi, in the Qin-Ba mountainous area, a Chinese region rich in ecological tourism resources, was selected as a case study to evaluate the SDP during the period 2013 to 2018. In our framework, a comprehensive index system with 21 indicators was developed to evaluate the tourism development levels (TDL) and rural development levels (RDL) in 2013 and 2018, and the tourism development efficiency (TDE) and rural restructuring efficiency (RRE) during this period. Secondly, correlations between TDL and RDL, as well as correlations between TDE and RDE, were quantified using the coupling coordination degree model (CCDM). Finally, the SDP evaluation model was constructed through combing the coupling coordination degrees of current development levels and development efficiencies. The case study results indicate that the primary-level coordination counties are both dominated in this region in terms of the relationship of development levels as well as the development efficiencies. Additionally, the SDP results show a significant difference in 25 counties, with 36% of them having low potential, 48% having medium potential, and 16% having high potential. This study could intuitively show the development differences among various units and provide theoretical and methodological support for the rural tourism zoning strategies.

Spatial Pattern and Influencing Factors of Rural Settlements in Qinba Mountains, Shaanxi Province, China

Spatial patterns and the influencing determinants of rural settlements are the most important indicators for understanding the constituent structure of rural regional systems. However, there is little knowledge addressing the characteristics from the settlement perspective by realizing the spatial reconstruction and sustainable development of rural settlements. Therefore, in this study, we analyzed the geographical, size, and morphological properties of rural settlement patterns in the Qinba Mountains in southern Shaanxi Province, China, using rural settlement and remote sensing data through spatial measurement index, gradient transects, demographic-economic index, and geodetector analysis. The results show the following: (1) Overall, rural settlements have spatial characteristics of “high-density multi-core clusters (0.8–1.6/km2) and low-density broadly scattered (<0.08/km2)”. There is a significant positive correlation between the scale of rural settlement density and the characteristics of high-value agglomeration. (2) The spatial disparities of morphological traits of settlement shapes are significant. Furthermore, 1840 NP/piece of plain basin landform types provide high-value areas for each settlement feature value, and locations with moderate slopes are best for settlement dispersal. Moreover, rivers, roads, and distance from township centers are all examples of beneficial directivity. There is consistency between the spatial differentiation of rural settlement areas per capita and the distribution of settlement scale. Conversely, the settlement density is inconsistent with the agricultural production value density’s spatial distribution features. (3) The impact of geographical factors on the diversification of settlement characteristics has significant spatial differences. Moreover, natural ecological characteristics such as elevation and landform and the distribution of cultivated land strongly influence the spatial pattern of the study region. Finally, the study findings can be beneficial for land and space planning and rural governments to develop sustainable rural settlements.

Optimized Neural Network for Research Evaluation of Mineral Resources Carrying Capacity in Southern Shaanxi

Evaluation of the carrying capacity of mineral resources is one of the important research content in the implementation of sustainable development. Based on analyzing the metallogenic geological characteristics, distribution, and resource status of mineral resources in southern Shaanxi, this paper establishes an analysis model of mineral resources and mineral advantages based on the analytic hierarchy process and applies them to evaluate the advantages of mineral resources. To provide optimal and efficient results, an improved model of an artificial neural network based on the bat optimization algorithm has been utilized. Through model analysis, the potential value and carrying capacity of mineral resources in three major prefecture-level cities in southern Shaanxi are comprehensively evaluated and analyzed. The results show that the main dominant minerals in southern Shaanxi are gold, lead zinc, and molybdenum ore. There are three grades of mineral resources carrying capacity: Shangluo City is an excellent grade, Hanzhong City is a good grade, and Ankang City is a general grade.

Biostratigraphy of the Small Shelly Fossils From the Upper Maidiping Formation (Terreneuvian) at the Fandian Section, Sichuan Province, South China

Small shelly fossils (SSFs) are a useful and critical tool for subdivision and correlation of the Cambrian Terreneuvian stratigraphy. The Maidiping Formation in southern Sichuan is a well-known Terreneuvian lithologic unit with rich SSFs. Here, the upper Maidiping Formation at the Fandian section, an important supplementary section of the classic Maidiping section, is studied for understanding its SSF assemblages and stratigraphic implication. There are 26 genera, 24 species, and 3 undetermined species recovered from the Fandian section, andWatsonella crosbyiwas discovered from this section for the first time. Two SSF biozones of the Yangtze Platform,i.e., the possibleParagloborilus subglobosus–Purella squamulosaAssemblage Zone (? Zone II) and theW. crosbyiAssemblage Zone (Zone III), can be recognized. Comparing with the Maidiping section, the Fandian section has a relatively successive SSF biostratigraphy and carbon isotope stratigraphy in the upper Maidiping Formation. The SSF Zone II (?) and Zone III from the Fandian section can be, respectively, correlated to the same zones from the upper Maidiping Formation of the nearby Maidiping section (only Zone III), the upper Zhongyicun and Dahai members of the Zhujiaqing Formation in eastern Yunnan, the top Kuanchuanpu Formation in southern Shaanxi and northern Sichuan, and the beds 4 and 5 (or units 3 and 4) of the Yanjiahe Formation in western Hubei. The almost cosmopolitan distribution and nearly synchronous earliest appearance ofW. crosbyistrengthen the applicability of its first appearance data (FAD) to define the base of Cambrian Stage 2 in South China (Xiaotanian) as well as in other continents. The FAD ofW. crosbyijust around the onset of the ZHUCE carbon isotope excursion at the Fandian section also further reinforces the utility of the onset of ZHUCE as an auxiliary maker for defining the base of the Xiaotanian in South China.

Deep Learning-Based Artificial Neural Network-Cellular Automata Model in Constructing Landscape Gene in Shaanxi Ancient Towns under Rural Revitalization.

With the development of modern industrialization, the rational planning of land resources, especially rural settlements (RSs), has become an important part of rural revitalization. Optimizing the RS spatial layout and enhancing its evolution simulation can encourage effective land resource allocation. It helps improve rural residents' production and living standards, alleviates the pressure of urban and rural land conflicts, and promotes the common development of urban and rural economies. This work mainly uses the ANN-CN (artificial neural network-cellular automata) model to study the cultural landscape gene construction of ancient towns in Shaanxi. First, RSs' spatial layout and landscape pattern index (LPI) in Shaanxi are analyzed. Second, the ANN-CA model is designed using the artificial neural network (ANN). Finally, Hua Yang Ancient Town in southern Shaanxi, Feng Huo Town in Guan Zhong, and Zhong Jiao Town in Northern Shaanxi are selected as the research objects. The influencing factors of spatial layout are extracted, and the evolution extracted of spatial layout is simulated based on the ANN-CA model. The simulation experiment finds that the area change of Hua Yang Ancient Town is more obvious than that of the other two ancient towns, with a change rate of 6.98%. Although the area change rate of Feng Huo Town is 19.79%, the actual change area is less than that of Hua Yang Ancient Town. Second, comparing the simulation accuracy of the model under different parameters, we can obtain the most suitable parameter for predicting the ancient towns' land-use type and construing landscape gene land. Specifically, for Hua Yang Ancient Town, T = 0.9 and the random disturbance parameter α = 1.0. For Zhong Jiao Town, T = 0.8 and α = 1.0. For Feng Huo Town, T = 0.9 and α = 1.0. It is hoped that this work can further carry forward Shaanxi's traditional culture and carry out the protective development of traditional rural buildings.

Assessment of Soil-Heavy Metal Pollution and the Health Risks in a Mining Area from Southern Shaanxi Province, China.

Soil-heavy metal pollution in mining areas is one of the problems in the comprehensive treatment of soil environmental pollution. To explore the degree of soil-heavy metal pollution and the human health risk in mining areas, the contents of soil As, Cd, Cu, Cr, Hg, Ni, Pb, and Cr(VI) in an abandoned gold mining area were determined. The geoaccumulation index (Igeo), single-factor pollution index (SPI), Nemerow comprehensive pollution index (NCPI), potential ecological risk index (PERI), and the human health risk assessment model were used to assess the pollution degree and the risk of soil-heavy metal pollution. Finally, the assessment results were used to provide remediation guidance. The results showed that (1) the average contents of As, Cd, Cr, Cu, Hg, and Ni in the mining area exceeded the background values of the soil elements. (2) The mining area was polluted by heavy metals to different degrees and had strong potential ecological hazards. (3) The total carcinogenic risk of heavy metals exceeded the health risk standard. The main components of pollution in the mining area were As, Cd, Cr, and Hg. Results from this study are expected to play a positive role in pollution treatment and the balance between humans and ecology.

Analysis of PM2.5 Transmission Characteristics in Main Cities of Jinzhong Basin in Winter

In this study, we analyzed the hourly concentration data of PM10 and PM2.5 in major cities in Jinzhong basin from 2017 to 2019. The main distribution characteristics of aerosols in Jinzhong and Taiyuan were determined, and PM2.5 hourly concentration data and HYSPLIT in Jinzhong basin in winter were discussed. The results showed that the overall level of particulate matter concentration in Taiyuan was higher than that in Jinzhong, and the monthly and seasonal variation characteristics were similar. All showed high concentrations in winter and low concentrations in summer, and the highest concentration value appeared in January. The aerosol pollution caused by the static and stable weather in Jinzhong was more common than that caused by the sand and dust weather in Taiyuan. The distribution of particulate matter showed the characteristics of more intermediate values in Jinzhong and more high and fewer low values in Taiyuan, and winter was the highest incidence season of PM2.5 pollution in Jinzhong basin. PM2.5 transmission passageways in the main cities of Jinzhong basin in winter could be divided into four categories:class 1 was transmitted along the transverse valley of Taihang Mountain, and class 2 was the southeast transmission channel. Class 1 and class 2 were the short-range transmission passageways; air masses carried more moisture, and PM2.5 transmitted along such passageways allowed moisture to be absorbed more easily, increasing levels and aggravating local pollution. Class 3 was the northwest passageway, corresponding to the most serious pollution period of PM2.5 in Jinzhong basin before the arrival of cold air, which also corresponded to the dust transmission passageway. Class 4 was the Fenwei Plain passageway, corresponding to high-concentration PM2.5 pollution. Areas with dense pollution tracks (more than 100 pollution tracks) and areas with slow air flow movement (RTA pollution track end points greater than 50) easily became potential source areas of target cities (PSCF contribution greater than 0.7). The main potential source areas of PM2.5 in winter in Jinzhong (PSCF contributing more than 0.7) were mainly distributed in Linfen, Jincheng, and other places in Shanxi province, as well as in the north of Henan province, the south of Hebei province, and central and south Shaanxi province. The distribution range of main potential source areas of PM2.5 in Taiyuan in winter was wider than that in Jinzhong, including the south of Lvliang, Yangquan, Linfen, and Yuncheng and the south of Jinzhong in Shanxi, as well as most areas in southern Shaanxi, northern Henan province, and southern Hebei province. In addition, the PSCF distribution of high-value centers above 0.9 was wider than that of Jinzhong. When pollution occurs in cities that PSCF contributed more than 0.9, special attention should be paid to the influence of mutual transmission between them and cities in Jinzhong basin. Jinzhong and Taiyuan showed different distribution characteristics corresponding to the surface wind direction when light and higher pollution occur, when the wind direction near the ground in Jinzhong was E, the frequency of light and higher pollution was 8.1%; it was the highest in all wind directions. When the wind direction near the ground in Taiyuan was SSW, the frequency of light to higher polluted weather was the highest in all wind directions (5.1%). In the case of calm wind, the frequency of light to higher pollution in Taiyuan (3.4%) was higher than that in Jinzhong (0.5%).

Evaluation and analysis of water conservation function of ecosystem in Shaanxi Province in China based on "Grain for Green" Projects.

The evaluation of water conservation function of the ecosystem and the analysis of influencing factors are conducive to the implementation of "Grain for Green" Projects, scientific management of land use types, and the optimization of ecosystem service functions. In this paper, we selected the data of precipitation, soil, evapotranspiration, land use/cover change, and other data to quantitatively evaluate the water conservation function of the ecosystem in Shaanxi Province from 1980 to 2015 and explored the key factors which lead to the spatial differences in water conservation functions. The results showed that (1) from 1980 to 2015, the water production and water conservation of Shaanxi Province's ecosystem based on grid units decreased by 12.81 × 108 m3 and 7.74 × 108 m3, respectively. (2) The use types of cultivated land, forest land, and grassland had a prominent contribution to the water production and water conservation of the ecosystem, while the contribution rate of water area, construction land, and unused land was small. During the research period, "Grain for Green" Projects consumed a lot of water production in a short period of time, which was not conducive to the improvement of water production capacity in Shaanxi Province. However, the conversion of cultivated land to grassland would help improve the water conservation capacity of the ecosystem, increasing the water conservation capacity by 0.77 × 108 m3. (3) The water conservation function of Shaanxi Province was "hot in the south and cold in the north," with obvious regional and spatial heterogeneity from 1980 to 2015. (4) The factors of precipitation, evapotranspiration, slope, common cultivated land area, afforestation area, and water conservation function showed a positive correlation, and the impact was significant, while the overall vegetation coverage index showed a negative correlation with it. Therefore, it is necessary to comprehensively consider the local climatic and environmental conditions to implement ecological protection and restoration policies in terms of enhancing water conservation function of the ecosystem. (5) Targeted measures are proposed for different areas in Shaanxi Province: The Northern Shaanxi area should be regarded as an ecological restoration and management area, focusing on returning farmland to grassland; Central Shaanxi Plain should be considered as an ecological protection zone, and the key task is to effectively protect the ecological land; the Southern Shaanxi area should be regarded as a key water conservation area, and the main function of the forest and grass ecosystem to conserve water is to be exerted.

Allium tsinlingense (Amaryllidaceae, Allioideae), a new species from Shaanxi, China

A new species, Allium tsinlingense, from southern Shaanxi Province, China, is described and illustrated here. This species is similar to A. maowenense in Allium sect. Daghestanica, but it can be distinguished by its leaves solid, its spathe persistent after flowering, its flowers changing color from green, greenish to white in different stage, but never purplish, with the midvein of tepal greenish and never pale red, and its pedicels with bracteoles at base. Molecular phylogenetic analyses also suggested that this new species is a member of Allium sect. Daghestanica and a sister taxon to A. maowenense.

Investigation Into Environmental Selenium and Arsenic Levels and Arseniasis Prevalence in an Arsenic-Affected Coal-Burning Area.

This study aims to explore whether selenium (Se) concentration correlates with arseniasis in a high-arsenic coal area in the southern Shaanxi Province, China. Herein, an epidemiological investigation was conducted among 100 arsenic (As)-poisoned patients in Ziyang County, an area with high soil As and Se levels. Fifty healthy subjects were selected from areas without endemic As poisoning. The subjects in the high-As coal area were diagnosed with either normal, suspicious, mild, moderate, or severe As poisoning. Local coal, water, soil, corn, and pepper samples, as well as hair, blood, and urine samples of subjects and patients were collected and analyzed for their As and Se contents. The contents of As and Se in coal, soil, corn, pepper, and hair samples from Ziyang County were significantly higher than those in the control area. The As content of hair in Ziyang County positively correlated with As poisoning, whereas the Se content of hair and urine negatively correlated with As poisoning. The Se content in the body was negatively correlated with the degree of As poisoning, indicating that Se may accelerate the metabolism and decumulation of As and antagonize As toxicity.