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Influences of labor migration on rural household land transfer:A case study of sichuan Province,China

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Journal of Mountain Science 2018年第9期15卷 2055-2067页

作者： XU Ding-de CAO Sha WANG Xu-xi LIU Shao-quan sichuan Center for rural Development Research College of ManagementSichuan Agricultural UniversityChengdu 611130China institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China College of Land and Resource China West Normal UniversityNanchong 637000China

The influence of labor migration on rural household land transfer has been hotly debated in academic circles, which focuses on whether part-time employment leads to land transfer. Using survey data on rural households in the sichuan Province, and applying the theoretical framework of new economics of labor migration, this study explores the influences of labor migration on the direction and scale of land transfer from the perspective of rural household structure. The results indicate that: 1) the quantity of laborers has significant influence on the direction and scale of land transfer. The larger the on-farm labor variable(Labor), the lesser the possibility that land will be rented-out and the amount of land rented out will also be smaller. In addition, there is a greater probability that land will be rented-in and the amount of land rented-in will be greater. 2) The greater the ratio of off-farm laborers to rural household laborers(Off-farm) the greater the possibility that land will be rented-out. In addition the higher the ratio of on-farm laborers to the total household laborers(On-farm), the larger the possibility that land will be rented-in. Meanwhile, if the household has individuals at the age of 64 or older(Old) who are engaged in agriculture, there is a smaller possibility that land will be rentedout. 3) the ratio of part-time laborers to rural household laborers(Pluriactivity) have significant inverse U-shaped influences on the rent-in of land as well as the amount of land rented-in. The inflection points are 33.27% and 14.10%, respectively. Such findings confirm the significance of this study in better understanding the influence of labor migration on rural household land transfer.

关键词： Labor migration Part-time employment Land transfer direction Land transfer scale ruralarea sichuan Province

Total pollution effect of urban surface runoff

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Journal of Environmental Sciences 2009年第9期21卷 1186-1193页

作者： LUO Hongbing LUO Lin HUANG Gu LIU Ping LI Jingxian HU Sheng WANG Fuxiang XU Rui HUANG Xiaoxue State Key Laboratory of Hydraulics and Mountain River Engineering College of Architecture and Environment Sichuan University Chengdu 610065 China College of urban and rural construction Sichuan Agricultural University Du Jiangyan 611830 China. China urban construction Design & Research institute Beijing 100029 China Suzhou University of Science and Technology Suzhou 215011 China

For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD （chemical oxygen demand）, TSS （total suspend solid）, TP （total phosphorus）, TN （total nitrogen） and BOD （biochemical oxygen demand）. The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters： rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 （mass first flush ratio） and FF30 （first 30% of runoff volume） can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs （best management practices） facilities.

关键词： total pollution effect mixed stormwater sampling street community pollution loads split-out flow control

Problem identification and revitalization strategies for the recovery and reconstruction of traditional villages in the Ms 6.8 Luding Earthquake

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Journal of Mountain Science 2024年第2期21卷 361-379页

作者： HUANG Chao QIU Jian LIU Chun JIANG Rui ZHAO Chuanrong ZHANG Yi School of Architecture and Research Center of Space Planning and Engineering Design Southwest Jiaotong UniversityChengdu 611756China sichuan Provincial rural construction and Development Center Chengdu 610041China sichuan institute of urban and rural construction Chengdu 610043China China Association for Promoting Democracy(CAPD)sichuan Provincial Committee Chengdu 610016China sichuan Provincial Architectural Design and Research institute(SADI) Chengdu 610095China

Post-disaster reconstruction is a topic of global concern,and traditional villages have special heritage attributes and need to face more requirements and obstacles in post-disaster *** paper summarizes four concepts based on the research on post-disaster reconstruction both domestically and internationally,as well as the recovery and reconstruction of cultural *** a field survey of traditional villages in the Ms 6.8 Luding earthquake-stricken area,it is found that there are problems such as insufficient awareness of heritage value,misalignment of scientific reconstruction technology,and insufficient protection of reconstruction elements during the reconstruction *** villages face the risk of declining or even loss of heritage *** order to effectively protect traditional villages and inherit the carrier of regional culture,four targeted reconstruction response strategies are proposed,i.e.,to"establish special planning for traditional village preservation","emphasize recovery of the authenticity of village heritage","ensure elements for village heritage recovery"and"promote the activation and utilization of village heritage",based on the problems discovered during the survey and the four concepts summarized in the research on post-disaster reconstruction of traditional *** research results hope to provide useful reference for ancient cultural areas affected by earthquakes on how to protect cultural heritage during the post-disaster reconstruction process.

关键词： Seismic hazard Decision making Traditional village Cultural heritage protection Post-earthquake recovery and reconstruction Revitalization strategy

Waste oyster shell as a kind of active filler to treat the combined wastewater at an estuary

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Journal of Environmental Sciences 2013年第10期25卷 2047-2055页

作者： Hongbing Luo Gu Huang Xiaoying Fu Xiaoling Liu Daocai Zheng Jian Peng Ke Zhang Bo Huang Liangqian Fan Fenghui Chen Xiubo Sun College of urban and rural construction Sichuan Agricultural University China Northwest Municipal Engineering Design Research Institute Co. Ltd. State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Department of Civil and Geological Engineering University of Saskatchewan

Estuaries have been described as one of the most difficult environments on Earth. It is difficult to know how to treat the combined wastewater in tidal rivers at the estuary, where the situation is very different from ordinary fresh water rivers. Waste oyster shell was used as the active filler in this study in a bio-contact oxidation tank to treat the combined wastewater at the Fengtang Tidal River. With a middle-experimental scale of 360 ma/day, the average removal efficiency of COD, BOD, NH3-N, TP and TSS was 80.05%, 85.02%, 86.59%, 50.58% and 85.32%, respectively, in this bio-contact oxidation process. The living microbes in the biofilms on the waste oyster shell in this bio-contact oxidation tank, which were mainly composed of zoogloea, protozoa and micro-metazoa species, revealed that waste oyster shell as the filler was suitable material for combined wastewater degradation. This treatment method using waste oyster shell as active filler was then applied in a mangrove demonstration area for water quality improvement near the experiment area, with a treatment volume of 5 × 10^3 m^3/day. Another project was also successfully applied in a constructed wetland, with a wastewater treatment volume of 1 ×10^3 m^3/day. This technology is therefore feasible and can easily be applied on a larger scale,

关键词： waste oyster shell active filler combined wastewater treatment tidal estuary engineering application

Current Situation and Influencing Factors of Pluriactivity in Mountainous and Hilly rural Areas of sichuan Province,China

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Journal of Mountain Science 2013年第3期10卷 445-454页

作者： LIU Shao-quan ZHANG Hai-qin XIE Fang-ting GUO Shi-li institute of Mountain Hazards and Environment Chinese Academy of Sciences sichuan Research institute of Tourism Planning University of Chinese Academy of Sciences

In this study, the current situation of pluriactivity in mountainous and hilly rural areas of sichuan province was analyzed using representative sample survey data and natural factor data calculated based on 30 m-resolution DEM and GIS. Moreover, using logistic regression model, a quantitative analysis was conducted on factors influencing pluriactivity in terms of individuals, households, communities and natural environmental conditions. The results showed that, （1） only 17.77% of rural laborers in mountainous and hilly areas of sichuan province were engaged in pluriactivity. Geographically, pluriactivity was mainly chosen according to the ＂proximity principle＂, and was concentrated in construction and service industries; （2） the following factors have a significant influence on whether rural laborers in hilly areas engage in pluriactivity： gender, number of years of education, marriage, number of laborers and time to towns. Those with little influence include： age, health, family size, arable land per capita and per capita income, whether there are elderly people over 75 years and children less than 3 years. According to the main factors affecting pluriaetivity, the government should enhance vocational skills training for rural laborers in mountainous and hilly areas, especially for female laborers, further improve transport accessibility and encourage rural laborers, especially female laborers to move into pluriactivity to increase the income of farm households.

关键词： Mountainous and hilly areas rurallaborers Pluriaetivity Influencing factors

Spatial Pattern of rural Settlements in the Upper Reaches of the Minjiang River——a Case Study in Maoxian County, sichuan

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Journal of Mountain Science 2007年第2期4卷 146-154页

作者： FENG Werdan LI Ainong ZHOU Wancun Chengdu institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041SichuanChina Graduate School of Chinese Academy of Sciences Beijing 100039 China Chengdu institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041Sichuan China

A quantitative analysis of the spatial pattern of rural settlements in the upper reaches of the Minjiang River was made with the major data sources being the relevant ETM image and the national geographical database of China （including contour line, fiver and road） at the scale of 1：250000, and using image interpretation and field investigation to obtain spatial information on rural settlements. The results of the spatial analysis technique of GIS and correlation analysis showed that most settlements （78.2 %） were located in the mountain area at 1500-2700 m altitude, and almost half in the arid valley area. More than 80.0 % of settlements had their slopes above 15°. Most settlements had good access to water resources, roads and communications, and tended to cluster close to the road network rather than the fiver. About half of the rural settlements in the study area were relatively concentrated, while the others were decentralized. Those with higher altitude usually had land with steep slope, inconvenient water and road accesses, and were located far apart from each other. In view of such a situation, further research should be done to make reasonable countermeasures on these settlements for better living conditions and ecosystem stability.

关键词： rural settlement spatial pattern GIS Maoxian County China

Nitrification performance evaluation of activated sludge under high potassium ion stress during high-ammonia nitrogen organic wastewater treatment

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Journal of Environmental Sciences 2022年第1期34卷 84-92页

作者： Xiaomei Jiang Heng Wang PeikeWu Hong Wang Liangwei Deng Wenguo Wang Key Laboratory of Development and Application of rural Renewable Energy Biogas Institute of Ministry of Agriculture and Rural AffairsChengdu 610041China sichuan Academy of Environmental Policy and Planning Chengdu 610041China institute of urban Agriculture Chinese Academy of Agricultural SciencesChengdu 610213China

The recycling reverse osmosis(RO)membrane concentrate of some high-ammonia nitrogen(NH_(4)^(+)-N)organic wastewater to the biological unit could cause potassium ion(K^(+))accumulation,thereby affecting the removal of NH_(4)^(+)-N by activated ***,the effects of high K^(+) stress on activated sludge nitrification performance was *** results showed that the high K^(+) stress promoted the floc sludge to produce more extracellular polymers(EPS),which accelerated the sludge sedimentation and enriched the biomass in sequential batch reactors(SBRs).The ammonia oxidation process and nitrite(NO_(2)^(-)-N)oxidation process were further analyzed in the nitrification *** K^(+) stress enriched ammonia oxidizing bacteria(AOB),which ensured the efficient ammonia oxidation process in SBRs,and ensured the removal rate of NH_(4)^(+)-N was maintained above 93%.However,high K^(+) stress(15g/L KCl)inhibited the activity of NO_(2)^(-)-N oxidizing bacteria(NOB)and reduced the abundance of NOB,thus leading to the accumulation of NO_(2)^(-)-N,and finally worsened the nitrification performance of activated *** short,the performance of activated sludge will not be inhibited when the K^(+) in the wastewater does not exceed 5.23 g/*** results could provide a reference for the optimization of the biological performance in treating high-NH_(4)^(+)-N organic wastewater with activated sludge coupled RO membrane treatment process.

关键词： Potassium ion(K^(+)) Activated sludge Nitrification High-ammonia nitrogen organic wastewater Microbial community

Feasibility of condensate water recycle of split air handling unit in Chinese University buildings

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Energy and Built Environment 2024年第2期5卷 309-315页

作者： Xiang Deng Yiyun Shen Senwang Yang Jingyang Feng Si Wang Dongyue Li Yanru Li College of Architecture and urban-rural Planning Sichuan Agricultural UniversityDujiangyan CampusChengdu611130China

Recycling the condensate water of the air conditioner could be explored as an alternative water source to con-tribute to building the green *** paper explored the condensate water production through actual mea-surement based on a split air handling unit(SAHU)in a university ***,the statistical analysis was used to analyze the recycling feasibility and the impact factors of the condensate water production in 31 Chinese provincial capital cities to obtain the recycling potential map of the condensate water generated from a *** showed that:(1)In the measurement,the amount of condensate water produced by a single split air conditioner was 1.6 kg from 12:40 to 13:***,the daily output of condensate water of the air condi-tioner with the university operation schedule could reach 52.99 kg during the main air-conditioning season.(2)Among the 31 provincial capital cities in China,the largest condensate water outputs could be found in the Hot Summer and Warm Winter zone and the Hot Summer and Cold Winter zone,with an average monthly output of 1600 kg and 1100 kg,respectively.(3)Regression analysis showed that the dry-bulb temperature and dew point temperature of outdoor air had the highest positive and significant influence on condensate water *** objective of this study is to provide theoretical guidance for the design and energy conservation evaluation of the feasibility of SAHU condensate water recycling in universities.

关键词： Condensate water Recycling Regression analysis Split air handling unit University buildings

Impacts of long-term ridge culture on aggregate stability in purple paddy soil of sichuan basin

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Journal of Chongqing University 2010年第4期9卷 185-194页

作者：唐晓红 College of urban and rural construction Sichuan Agricultural University Dujiangyan Campus

Ridge culture is a special conservation tillage method, but the long-term influence of this tillage system on soil aggregate-size stability in paddy fields is largely unknown in southwest of China. The paper is to evaluate soil aggregate stability and to determine the relationship between soil organic carbon (SOC) and soil aggregate stability. Soil samples at 0 cm-20 cm layer were adopted from a long-term (16 a) field experiment including conventional tillage: plain culture, summer rice crop and winter upland crop under drained conditions (PUR-r); and conservation tillage: ridge culture without tillage, summer rice and winter fallow with floodwater layer annually (NTR-f), winter upland crop under drained conditions (NTR-r), and wide ridge culture without tillage, summer rice crop and winter upland crop under conditions (NTRw-r), respectively. Different pretreatments, such as slaking in fast wetting, wetting and subsequent slaking, were applied to simulate the breakdown mechanisms of aggregates in paddy soil. The results show that soil particles contents were mainly consisted of silt (0.050 mm to 1.000 mm) in fraction of 42.9% to 51.2%, sand (0.050 mm to 0.001 mm) in fraction of 28.0% to 31.8%, and clay (0.250 mm) in conservation tillage was greatly higher than that in conventional tillage under subsequent fast slaking treatment. Minimal differences of aggregate stability between slaking in fast wetting and wetting were observed, while significant differences were found between ridge culture and plain culture. The aggregate stability under slaking treatment ranked in the order of NTR-r>NTRw-r> NTR-f > PUR-r, while under wetting was NTRw-r > NTR-r > NTR-f >PUR-r. There was a positive correlation between the aggregat

关键词： ridge culture rotation aggregate stability organic carbon paddy soil