60 research outputs found

    Assessment of the resilience of a Tartary Buckwheat (Fagopyrum tataricum) cultivation system in Meigu, Southwest China

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    Recent socioeconomic development, increased transport and new agricultural technology are endangering the survival of traditional agriculture and the Yi people’s traditional knowledge of cultivating Tartary buckwheat. The cultural heritage of Tartary buckwheat cultivation among the Yi communities needs to be investigated and protected before its loss. The main objectives of this study are to document the Tartary buckwheat cultivation system, to analyze the agroecosystem networks that support the current system, and to measure the resilience of the ecological, agricultural and social systems using relevant indicators. The Tartary buckwheat cultivation system in Meigu County uses a rotation system, in which various crops are planted alternatively (e.g., Tartary buckwheat, green manure and potato/corn), utilizing bunch planting and furrow drilling technology. Tartary buckwheat has an important position in the major festival activities among the Yi people’s communities. Network analysis on the current agricultural system, ecosystem and social system indicated that the system was stable. The mean score of ecological, agricultural and social stability were 2.50, 2.85 and 2.53, respectively, indicating moderately stability. In contrast, socio-ecological production landscapes and seascapes (SEPLS) resilience indicators in Meigu performed only moderately, with a score of 2.63. The assessment of the resilience of the Tartary buckwheat cultivation system can provide some guidance for policy makers to strengthen biodiversity conservation, sustainable agricultural production and livelihood development (e.g., land use, responding to extreme environmental stresses and improving education levels)

    Assessment of the resilience in SEPLS (Socio-Ecological Production Landscapes and Seascapes) in Yanuo Village, Xishuangbanna, Southwest China

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    Participatory ‘assessment workshops’ were held in 2018 in Yanuo Village, Xishuangbanna, Southwest China. The ‘Indicators of Resilience in Socio-Ecological Production Landscapes and Seascapes (SEPLS)’ tool was used to provide the community with a framework for discussion and analysis of socio-ecological processes essential for resilience. Workshops were planned and implemented by local people together with researchers from outside the community. Discussion, including a scoring process, was undertaken using a subset of twenty indicators designed to capture the communities’ perceptions of factors affecting the resilience of their landscapes. The indicators were also used to provide the local community with a framework to discuss both current conditions of resilience and potential areas for improvement. A key result was that the existing community management approach did not include loss of traditional knowledge as a factor that would impact on the livelihoods and well-being of the community. A mechanism to encourage young people to inherit and actively use traditional knowledge was agreed to be necessary and included in economic activities. In addition, the socio-economic infrastructure in the community needs further improvement. This community management assessment framework in Yanuo Village can be scaled out to other communities in tropical montane regions with similar socio-economic environments by supporting stakeholders (policymakers, NGOs and development agencies, etc.)

    Comprehensive Evaluation of Self-Healing Polyampholyte Gel Particles for the Severe Leakoff Control of Drilling Fluids

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    Lost circulation has been a serious problem to be solved in many drilling practices during oil, gas and geothermal well drillings. Many materials have been developed and evaluated for the purpose. However, their performance to plug severe leakoff is very limited. Herein, an injectable self-healing hydrogel based on polyampholyte with sulfonated and quaternary ammonium functionalities (P(MPTC-co-NaSS)) was developed and comprehensively evaluated to prevent the severe loss of fluids to formation. By incorporating cation-π (π is for aromatic residues) interaction, the hydrogel shown self-healing property and robustness in severe environment (temperature, salt) by comparison with other hydrogels merely consisting of cation-anion and H-bonding interactions. Aromatic residues enhanced thermal stability above 310 °C. The plugging measurement shown that an addition of 2 wt% dried gel particles can plug high-permeability formation and endure a high pressure of 6 MPa, produce much lower circulation loss and result in a dramatically increased loss volume reduction rate (63.5%) compared with a commercial polymer gel product and an inert material (9.4%) after a self-healing process. Markedly, P(MPTC-co-NaSS) can be used in a wide range of formation temperature (as high as 150 °C) and salt concentrations (NaCl, CaCl2, as high as 15 wt %). In addition to suitable particle size and mechanically robustness, it was also attributed to the soft, swelling, deformable, toughness and self-healable features of P(MPTC-co-NaSS) gel particles as well as the strong adhesion to negatively charged formations in water, even under high thermal and saline condition. These characteristics also contributed to a long-term plugging performance, beneficial to avoid repeated lost circulation in drilling operation. Besides, this self-healing polyampholyte gel particles dispersed well in saline fluid and maintained stable rheological properties after hot rolling, which was favorable to drilling fluid circulation. This study shown the application potential of self-healing materials as plugging material candidate in petroleum drilling industry

    Feasibility and validity of the Health Status Classification System-Preschool (HSCS-PS) in a large community sample: The Generation R study

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    Objectives To evaluate the feasibility, discriminant validity and concurrent validity of the Health Status Classification System-Preschool (HSCS-PS) in children aged 3 years in a large community sample in the Netherlands. Design/setting A prospective population-based cohort in Rotterdam, the Netherlands. Participants A questionnaire was administrated to a sample of parents of 4546 children (36.7±1.5 months). Outcome measures Health-related quality of life (HRQOL) of children was measured by HSCS-PS. The HSCS-PS consists of 10 original domains. Two single-item measures of General health' and Behavior' were added. A disability score was calculated by summing up all 10 original domains to describe the overall health status. Feasibility was assessed by the response rate, percentages of missing answers, score distributions and the presence of floor/ceiling effects. Discriminant validity was analysed between subgroups with predefined conditions: low birth weight, preterm birth, wheezing, Ear-Nose-Throat surgical procedures and behaviour problems. In the absence of another HRQOL measure, this study uses the single-items General health' and Behavior' as a first step to evaluate concurrent validity of the HSCS-PS. Results Feasibility: response rate was 69%. Ceiling effects were observed in all domains. Discriminant validity: the disability score discriminated clearly between subgroups of children born with a very low birth weight', very preterm birth', with four or more than four times wheezing', at least one ear-nose-throat surgical procedures', behaviour problems present' and the reference' group. Concurrent validity: HSCS-PS domains correlated better with hypothesised parallel additional domains than with other non-hypothesised original domains. Conclusions This study supports the feasibility and validity of the HSCS-PS among preschoolers in community settings. We recommend developing a utility-based scoring algorithm for the HSCS-PS. Further empirical studies and repeated evaluations in varied populations are recommended

    Optimization Forest Thinning Measures for Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China: A Case Study

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    Forest thinning is a silviculture treatment for sustainable forest management. It may promote growth of the remaining individuals by decreasing stand density, reducing competition, and increasing light and nutrient availability to increase carbon sequestration in the forest ecosystem. However, the action also increases carbon loss simultaneously by reducing carbon and other nutrient inputs as well as exacerbating soil CO2 efflux. To achieve a maximum forest carbon budget, the central composite design with two independent variables (thinning intensity and thinning residual removal rate) was explored in a natural pine-oak mixed stand in the Qinling Mountains, China. The net primary productivity of living trees was estimated and soil CO2 efflux was stimulated by the Yasso07 model. Based on two years observation, the preliminary results indicated the following. Evidently chemical compounds of the litter of the tree species affected soil CO2 efflux stimulation. The thinning residual removal rate had a larger effect than thinning intensity on the net ecosystem productivity. When the selective thinning intensity and residual removal rate was 12.59% and 66.62% concurrently, the net ecosystem productivity reached its maximum 53.93 t·ha−1·year−1. The lower thinning intensity and higher thinning residual removal rated benefited the net ecosystem productivity

    A Simple Band Ratio Library (BRL) Algorithm for Retrieval of Hourly Aerosol Optical Depth Using FY-4A AGRI Geostationary Satellite Data

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    The Advanced Geostationary Radiation Imager (AGRI) is one of the primary payloads aboard the FY-4A geostationary meteorological satellite, which can provide high-frequency, wide coverage, and multiple spectral channel observations for China and surrounding areas. There are currently few studies on aerosol optical depth (AOD) inversion from FY-4A AGRI data. Based on AGRI data, a new land AOD retrieval algorithm called the band ratio library (BRL) algorithm was proposed in this study. The monthly average surface reflectance band ratio library was established after obtaining the relationship of band surface reflectance ratio from the MODIS combined AOD dataset. In order to calculate the hourly AOD, look-up tables (LUT) for the various aerosol models were constructed using the 6SV model. We quantitatively compared AOD produced from AGRI data with AERONET ground observations to validate the BRL algorithm. AGRI-retrieved AOD is in good agreement with AOD measured by AERONET, which has a correlation coefficient of R is 0.84, the linear regression function is AODAGRI = 0.80 ∗ AODAERONET − 0.004, the root-mean-square error (RMSE) is 0.16, and approximately 60% of the AGRI AOD results fall within the uncertain range of AOD = ±(0.2 × AODAERONET + 0.05). A cross-comparison was made with the MODIS AOD product provided by NASA. The comparison and verification show the proposed algorithm has a good accuracy of land AOD estimation from AGRI data

    A Simple Band Ratio Library (BRL) Algorithm for Retrieval of Hourly Aerosol Optical Depth Using FY-4A AGRI Geostationary Satellite Data

    No full text
    The Advanced Geostationary Radiation Imager (AGRI) is one of the primary payloads aboard the FY-4A geostationary meteorological satellite, which can provide high-frequency, wide coverage, and multiple spectral channel observations for China and surrounding areas. There are currently few studies on aerosol optical depth (AOD) inversion from FY-4A AGRI data. Based on AGRI data, a new land AOD retrieval algorithm called the band ratio library (BRL) algorithm was proposed in this study. The monthly average surface reflectance band ratio library was established after obtaining the relationship of band surface reflectance ratio from the MODIS combined AOD dataset. In order to calculate the hourly AOD, look-up tables (LUT) for the various aerosol models were constructed using the 6SV model. We quantitatively compared AOD produced from AGRI data with AERONET ground observations to validate the BRL algorithm. AGRI-retrieved AOD is in good agreement with AOD measured by AERONET, which has a correlation coefficient of R is 0.84, the linear regression function is AODAGRI = 0.80 ∗ AODAERONET − 0.004, the root-mean-square error (RMSE) is 0.16, and approximately 60% of the AGRI AOD results fall within the uncertain range of AOD = ±(0.2 × AODAERONET + 0.05). A cross-comparison was made with the MODIS AOD product provided by NASA. The comparison and verification show the proposed algorithm has a good accuracy of land AOD estimation from AGRI data

    Determining factors for the diversity of hulless barley agroecosystem in the himalaya region—A case study from Northwest Yunnan, China

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    Traditional barley agroecosystem in the Himalaya region harbour a great diversity of hulless barley landraces. This diversity has been considered largely impacted by agro-ecozone factors as documents by former researches. Five case study sites were selected from Northwest Yunnan to represent five agro-ecozones: Tangman (hot and dry valley), Kena (hot and wet valley), Hongpo (alpine region), Napa (marshy wetland), and Xiangka (mild slopes in high plateau). A participatory rural appraisal was carried out to acquire data for 28 cultural, socio-economic, ecological and agricultural factors in these five sites from 2012 to 2014. Multiple correspondence analysis was conducted to evaluate the weight of the selected factors on the diversity of agroecosystems. Results showed that the diversity and percentage of hulless barley in the area was largely differentiated between the zones, and the differences principally originated from 5 factors, including Religious hulless barley use, Weight of fodder using, Chemical fertilizer, Crop varieties, and Seed exchange consumption. Cultural factors were the most influencing factors, followed by agricultural factors, natural factors and the last social factors. In the cultural factors, religious use hulless barley and seed exchange customs were very important. High elevation and farmers’ distance from cities were the most important factors fostering on-farm hulless barley landrace diversity. The conservation of agricultural biodiversity in traditional Tibetan agriculture ecosystem should be emphasized. Keywords: Hulless barley, NW Yunnan, Agro-ecozone
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