湖北省农地利用方式变化的碳效应特征与空间差异

农地利用方式变化是引起碳排放的一个重要因素,优化农地利用结构成为推动农业绿色发展的重要手段。本文运用LMDI分解法和聚类分析,分析湖北省农地利用方式变化的碳效应特征与空间差异,进一步基于Kernel密度估计法研究其时空动态演进趋势。研究发现:(1)1993—2015年湖北省农地利用碳排放年均递增2.77%,总体呈现四阶段变化特征。其中,农业经济发展因素累积引发276.33%的碳增量,结构、效率、农业劳动力因素则分别累计实现8.05%、79.14%、89.14%的碳减排。(2)对碳排放总量和强度进行聚类分析表明,武汉等7个区域属于"低-低"型,荆州、黄冈属于"高-低"型,宜昌、襄阳属于"高-高"型,随州、仙桃属于"低-高"型。(3)2005—2015年林地和草地碳汇量均呈现一定幅度的递减态势,因生态退耕产生的碳汇波动比较大,因建设占用产生的碳排放虽有波动但大体呈现"先升后降"的趋势。(4)运用Kernel密度估计湖北省农地利用净碳排放演进特征发现,总体上湖北省各地市州的农地利用净碳排放的差距呈现缩减态势。分区域来看,鄂东地区各地市州农地利用净碳排放差距有微弱的扩大后又出现明显的缩小,但净碳排放整体上无明显变化;鄂中地区各地市州差距扩大,净碳排放整体有减少态势;鄂西地区各地市州差距有所扩大但不明显,净碳排放整体有增长态势。基于研究结论,提出加强农地碳库建设,建设以绿色为导向的农地补偿制度等推进湖北省农地利用低碳化和可持续化的对策建议。     

民族地区能源开发与经济增长效率研究——基于“资源诅咒”假说

"资源诅咒"现象是伴随着能源资源开发带来的新问题。本文基于2000-2012年间的面板数据,运用固定效应变截距模型,探讨民族地区"资源诅咒"效应,讨论"资源诅咒"效应的差异性,分析"资源诅咒"效应的影响因素,并运用层次分析法计算权重,构建经济增长效率模型,探讨"资源诅咒"对经济增长效率的影响。结果表明,民族地区存在"资源诅咒"现象,从单个变量看,能源产业依赖度抑制了云南、广西、贵州、青海、新疆的"资源诅咒"效应,但却加剧了内蒙古和宁夏的"资源诅咒"效应,而能源产业丰裕度和能源开发强度能够缓解青海、宁夏、新疆的"资源诅咒"效应,但加剧了内蒙古、云南、广西、贵州的"资源诅咒"效应;从省际层面看,内蒙古"资源诅咒"效应明显,其他省区表现相对较弱。由面板模型的结果可知,对经济增长起促进作用的变量是技术创新投入、能源开发强度、物质资本投资,对经济增长起阻碍作用的变量是能源产业依赖度和能源产业丰裕度。从各省区煤炭、天然气、石油产量变化情况看,"资源诅咒"现象的来源主要是煤炭,除了煤炭之外,青海对石油、宁夏对天然气、新疆对石油和天然气的依赖度也很大。从2000-2012年间经济增长效率值的动态变化来看,内蒙古、云南、广西、青海、宁夏"资源诅咒"现象明显,时间拐点分别出现在2004年、2006年、2003年、2001年、2003年;新疆的经济增长效率值离散情况虽然比较严重,但总体来看呈现下降趋势;贵州的"资源诅咒"现象前期表现明显,但在2006年以后"资源诅咒"效应得以消除。民族地区要摆脱"资源诅咒"效应应当优化产业结构,降低对煤炭资源的依赖度,由资源依赖型产业向非资源型经济转移,扩大就业及经济增长空间;从技术创新投入入手,加强科技和教育投入,提高技术创新能力,加快能源开发效率。     

中国农业碳排放拐点变动及时空分异研究

与基于总量或人均指标衡量经济增长与环境质量相比,以播种面积作为测算指标揭示农业经济增长与农业环境质量之间的关系,既便于年度间纵向对比,又消除了复种指数影响,使得研究更具操作性和公平性。以农业碳排放强度作为碳排放指标、以农业经济强度作为经济增长指标,对中国农业碳排放进行EKC检验,在此基础上对农业碳排放拐点变动及时空分异进行实证分析。结果表明:1从长期来看,中国农业碳排放强度与农业经济强度之间存在"倒N型"EKC关系且存在双拐点,其临界值分别为15 167元/hm2和27 647元/hm2。2012年,我国农业经济强度为28 725元/hm2,已超出高拐点临界值(27 647元/hm2),这意味着伴随我国农业经济的进一步发展,农业碳排放强度将呈现下降趋势。2从空间分布来看,有18个省(区、市)农业经济强度超过高拐点值,包括北京、福建、海南、浙江、广东、上海、天津、江苏、辽宁、山东、陕西、河北、新疆、湖南、湖北、四川、广西、河南等,主要为东部沿海省份以及中西部部分农业较为发达的省份。这18个省(区、市)农业碳排放量将随其农业经济的发展而逐渐下降。其余13个省(区、市)则低于拐点值,均分布于我国中西部地区。3从时间路径来看,对于未抵达拐点的13个省(区、市)而言,各自农业碳排放EKC拐点存在明显差异,甘肃、重庆、吉林、青海在未来5年内可达到EKC拐点;宁夏、安徽、黑龙江、陕西在未来6-10年内可达到EKC拐点;西藏、内蒙古、江西、云南、贵州则分别需要12年、14年、21年、23年、32年才有可能抵达EKC拐点。     

西南地区农业碳排放趋势及影响因素研究

对2000—2014年西南地区农业碳排放趋势、驱动因素及主要贡献因子进行研究,结果表明:西南地区农业碳排放呈增长趋势,各省碳排放占比分别为重庆10.70%、四川40.78%、贵州15.51%、云南23.35%和西藏9.66%;农业效率、结构及劳动力规模等因素在一定程度上缓解了农业碳排放压力,而农业经济发展水平是该区农业碳增排的最主要因素;到2020年该区农业碳排放将达16 949.51万t CO2-eq。建议通过提高农资利用效率,改进农业生产措施,优化农业结构,发展非农经济等措施来减少西南农业碳排放。     

中国西部地区环境承载力多情景模拟分析

随着西部大开发战略的实施,受气候变化和人类活动影响,西部地区生态环境急剧恶化,生态环境承载能力不断降低,制约了经济社会的可持续发展。对中国西部地区环境承载力进行研究有利于西部地区可持续发展,可为西部地区今后发展提供一定的科学依据。本文以全国各省(市、自治区)2010年的GDP数据和污染物排放数据,以及国家"十二五"污染物排放总量控制数据为基础,选取了大气环境中的二氧化硫排放量和氮氧化物排放量,水环境中的化学需氧量排放量和氨氮排放量为指标,对西部地区不同省市的环境承载力进行评价,并设定了四种不同的排放水平情景,在不同情景下核定了西部各省市的GDP潜在增长率。通过分析,西部地区的环境承载力在经济社会可持续发展基础上可分为三类:一类省市包括重庆、陕西、四川三省市,该区环境承载力接近超载,需按2010年东部较为发达地区的污染物排放水平排放才可支持其经济高速发展,达到其规划的GDP增长率;二类省市包括西藏、贵州、云南、内蒙古、广西等五省市,环境承载力有一定空间,能够支持该区到"十二五"、"十三五"的经济发展目标;三类省市包括新疆、青海、甘肃、宁夏等四省市,环境承载力空间较大,能够支持该区较高的GDP发展速率。针对不同省市,在今后的发展过程中,四川、重庆、陕西三省市应以东部先进省市污染物排放水平或发达国家污染物排放水平为目标调整产业结构,提高节能减排技术,降低污染物排放量,提高污染物处理水平,在今后承接各类产业时,提高环境污染物排放要求。广西、云南、西藏、贵州、内蒙古五省市在今后发展中,应以全国平均或东部平均污染物排放水平为目标,适当降低污染物排放水平,在满足国家对各省份环境要求下,稳步进行经济发展。新疆、青海、甘肃和宁夏四省市由于目前环境容量较大,可以在现有水平下,稳步进行经济发展。     

农业部划出乡镇企业三个经济梯度区

农业部乡镇企业司对全国30个省、市、自治区乡镇企业发展水平进行新的评价,较为科学地划分出了3个梯度经济区,并描述出了3个区域内乡镇企业的现状。新划出的结果是:北京、天津、上海、辽宁、河北、山东、汀苏、浙江、福建、广东10省、市为东部地区;黑龙江、吉林、山西、陕西、四川、河南、安徽、江西、湖北、湖南10省为中部地区;内蒙古、宁夏、甘肃、青海、新疆、云南、贵州、广西、西藏、海南10省、区为西部地区。     

中国水土流失经济损失的货币化评价

绿色国民核算体系弥补了现有核算体系不足成为学者们研究的重点,而如何对生态环境进行经济核算是实现绿色国民核算体系的难点.本文通过对我国31个省(市、区)水±流失损失进行经济计量核算,得出以下结论:(1)我国水土流失空间差异显著,呈西强东弱,南强北弱的空间分布格局.(2)水土流失损失最多的五个省份是贵州、四川、云南、陕西、湖北.损失最少的五个省份是新疆、北京、海南、西藏、江苏.(3)我国水土流失损失约占全国GDP的1.45%,东部、中部、西部分别为0.35%、1.5%、4.6%,西部地区水土流失损失大于东部地区.(4)贵州的真实储蓄为负值,处于不可持续发展状态;西藏、云南、青海、甘肃、宁夏等省份真实储蓄虽大于0,但真实储蓄率较低,可持续发展能力低.(5)我国东部和西部的人均真实储蓄比值大于人均GDP,比值,东、西部间的可持续发展能力差距比现实的经济发展差距更大.     

湖北省农地利用碳排放时空特征与脱钩弹性研究

基于化肥、农药、农膜、农用柴油、翻耕、稻田6个主要方面的碳源，测算了湖北省1995~2009年及其地、市、州2008年的农地利用碳排放量。结果表明：（1）自1995年以来，湖北农地利用碳排量总体呈现“上升-下降-上升”的三阶段特征，其碳排放强度变化轨迹与此基本一致。（2）区域差异明显：农地碳排放总量，江汉平原、鄂东北地区高，鄂西、鄂东南地区较低；农地碳排放强度，总体呈现东高西低的特征，即鄂东>鄂中>鄂西。进一步运用Tapio脱钩模型对湖北省农地利用碳排放与农业经济发展间的脱钩关系进行了研究，发现以弱脱钩和强脱钩为主，可见近些年来农地利用碳减排取得了一定成效     

基于STIRPAT和GM(1,1)模型的湖南省农地投入碳排放增长机理及趋势预测

探索农地投入的碳排放特征、增长机理及趋势预测,并提出减排对策对农业发展向低碳绿色转型具有重要意义。研究采用回归分析法、STIRPAT和GM(1,1)模型解析湖南省农地投入碳排放增长机理并做出趋势预测。结果表明:2000~2014年湖南省农地投入碳排放量呈上升趋势,年均增长率为3.25%,各类碳源中化肥累计的碳排放量最大,其次是农药;此外翻耕、农药、农膜、柴油、灌溉、化肥累计碳排放年均增长量分别为0.68%、3.22%、7.47%、6.42%、2.57%、3.25%。农业人口、人均农业GDP、机械化水平、农业生产效率、农业产业结构显著影响农地碳排放,各因素每发生1%的变动会相应带来农地碳排放量约0.20%、0.95%、0.12%、0.98%和0.93%的变化。通过GM(1,1)模型对2016~2020年湖南省农地投入碳排放量进行预测,碳排放量呈持续上升趋势,2020年预计达到430.43万t。最后根据研究结果提出促进农地投入碳减排的政策建议。     

贵州省人口对耕地、粮食的压力分析

本文先进行国内横向比较,即比较贵州省与其它省份的人口对耕地、粮食的压力。我们规定:全国人均耕地面积为1个标准压力,用全国人均耕地面积除以各省的人均耕地面积,商值即为各省的人口对耕地的压力。据统计,1988年我国各省人口对耕地的压力,由大到小顺次排列是:上海3.37、北京2.27、浙江2.11、广东2.05、福建2.02、天津1.70、湖南1.54、贵州1.47、四川1.46、广西1.39、江西1.34、湖北1.29、海南1.27、江苏1.23、云南1.12、安徽1.07、山东1.02、河南1.01、辽宁0.96、西藏0.83、陕西0.77、河北0.77、青海0.67、山西0.65、甘肃0.54、吉林0.52、宁夏0.49、新疆0.40、内蒙古0.38、黑龙江0.34。在全国30个省、直辖市、自     

Present status of Rn in groundwater in Extremadura

Radon-222 was measured in groundwater sources of Extremadura (Spain), analyzing 350 samples from private and public springs, wells, and spas by liquid scintillation counting (LSC) and gamma spectrometry. The ²²²Rn activity concentrations ranged from 0.24 to 1168 Bq L⁻¹. The statistical analysis showed a log-normal distribution with a mean of (111 ± 7) Bq L⁻¹ and a median of (36 ± 3) Bq L⁻¹. A hydrogeological study revealed correlations between the activity concentration and the aquifer material's characteristics. A map of ²²²Rn in groundwater was elaborated and compared with the natural gamma radiation map for this region. About 35% of the samples showed ²²²Rn activity concentrations above the Euratom recommended limit of 100 Bq L⁻¹. Three uranium series radionuclides (²³⁸U, ²³⁴U, and ²²⁶Ra) were also assayed by alpha-particle spectrometry, estimating the annual effective dose due to the presence of these natural radionuclides in drinking water.     

我国南方地区50 a冬季降水和相对湿度特征分析

根据中国地面气候日值数据集资料，利用气候趋势系数、气候倾向率等方法，研究了我国南方地区冬季50 a降水和湿度的时空变化特征，并运用基尼系数对降水均匀性的空间分布进行了分析。结果表明：降水和相对湿度分布皆自西北向东南递增，最大中心位于长江以南附近内陆区域，最小值基本位于高原。降水强度整体呈现增加趋势，在沿长江附近区域以及云南部分地区增强明显，最大气候倾向率为1.0 mm/d/10 a左右，有明显的突变时间，为1979年；降水量呈微弱的增加趋势，其中云贵和川渝局部区域降水量呈减少趋势，为-3 mm/10 a左右，没有明显的突变时间；降水日数在长江以南局部区域及云贵区域显著减少，其中云南的西南地区为最小气候倾向率-10 d/10 a，明显突变时间为1980年；相对湿度表现出一定的局地增减趋势，长江以北（南）主要呈微弱增加（减少）趋势，云南南部减小趋势显著；相对湿度和降水呈明显的正相关，其中与降水量和降水日数相关系数高达0.784、0.753。降水量基尼系数的空间分布与降水分布相似，只是降水分布的大（小）值中心为基尼系数小（大）值中心，不同年代及冬季不同月份的降水量基尼系数大（小）值区域范围有所增减。总的来看，我国南方冬季中部和东部大部分区域为降水均匀区，西南高原区域为不均匀区。 关键词： 南方地区；冬季；降水；相对湿度     

Kinetics of dissolution of Chernobyl fuel particles in soil in natural conditions

Kinetic of fuel particles dissolution under natural environmental conditions has been investigated using the data on (90)Sr speciation in soils collected from 1995 to 1997 within the Chernobyl nuclear power plant 50 km zone. The dependency of fuel particles dissolution constants on the soil acidity (pH = 4-7) has been obtained on the basis of large and statistically reliable experimental data. Results show that between 2 and 21% of (90)Sr activity is associated with weathering resistant fuel particles. Therefore, these particles would not influence the radiological situation in the near future. The map of the main agrochemical characteristics and the map of the fuel particles dissolution constants have been created for the 30-km zone territory. According to the prognosis of dynamics of fuel particles dissolution in the investigated zone, a radiological situation along the fuel paths of radioactive fallout in present time reached a stable state. An increasing in absolute contents of (90)Sr mobile forms in neutral soils will be observed in the next 10-20 yr. However, the difference between the maximum level of mobile forms contents and their existing contents will not exceed 20%.     

Predictions of in situ solid/liquid distribution of radiocaesium in soils

Previous work has demonstrated that plant uptake of radiocaesium (RCs) is related to the activity concentration of RCs in soil solution, which is linked to the soil/soil solution distribution coefficient, K(D). The solid-liquid distribution of RCs is generally studied in soil suspensions in the laboratory and there are few reported measurements for in situ soil solutions. From a data set of 53 different soils (contaminated with either 134CsCl or 137CsCl) used in pot trials to investigate grass uptake of RCs, we analysed the variation of in situ K(D) with measured soil properties. The soils differed widely in % clay (0.5-58%), organic matter content (1.9-96%) and pH (2.4-7.0, CaCl2). The K(D) varied between 29 and 375,000 L kg-' (median 1460 L kg(-1)). Stepwise multiple regression analysis showed a significant correlation between the log K(D) and pH (p < 0.001), log %clay (p < 0.01) and log exchangeable K (p < 0.001) (overall R2 = 0.70). The in situ K(D) values were further compared to K(D)S predicted using an existing model, which assumes that RCs sorption occurs on specific sites and regular ion-exchange sites on the soil solid phase. Sorption of RCs on specific sites was quantified from the radiocaesium interception potential (RIP) measured for each soil and the soil solution concentrations of K+ and NH4+. The in situ log K(D) correlated well with the predicted K(D) (R2 = 0.85 before plant growth, R2 = 0.83 after plant growth). However, the observations were fivefold to eightfold higher than the predictions, particularly for the mineral soils. We attribute the under-prediction to the long contact times (minimum 4 weeks) between the RCs tracers and our experimental soils relative to the short (24 h) contact times used in RIP measurements. We conclude that our data confirmed the model but that ageing of RCs in soil is a factor that needs to be considered to better predict in situ KD values.     

Seasonal changes in radon concentrations in buildings in the region of northeastern Poland

In this study, seasonal observations of radon concentration changes inside buildings carried out in the northeastern region of Poland is presented. One-year measurements of radon concentrations were performed in chosen buildings. The integral method of Cr-39 trace detectors in diffusive chambers was used. Mean values of radon concentrations were determined in monthly, 2-, 3-, 6-month, and annual observations. The fraction of a mean annual concentration of the value obtained in a shorter observation was calculated. Monthly concentration values were from about 0.2 to 14.9 of the annual mean. All buildings revealed seasonal fluctuation of radon concentration. Negative correlation of indoor radon concentration in the buildings and the mean temperature outside was observed in most examined buildings. The lowest coefficient range, determining which part of the annual mean value would be obtained in the 6-month observation, was gained for exposure begun in April or October.     

Diffusion of Lead-free Soldering in Electronics Industry in China

The EU directives on e-waste management (WEEE and RoHS) have drawn the attention of electronics producers around the world to the environmental benign technologies in recent years. One of the technological challenges to the electronics manufacturers is the adoption of the lead-free soldering system. This article studies the diffusion of lead-free soldering technology among the electronics producers in China, and finds out the relevance of clusters for the diffusion of environmental benign technological innovation among firms. Four agents, as key promoters, were identified within the production network –leading global brand-name companies, the OEM companies who provide integrated manufacturing service, the suppliers of lead-free components, and specialized consultant companies. The conclusion is that industrial cluster facilitates communications among all agents for the diffusion of innovation, whereas, the incentives for firms within the cluster, to collaborate for innovation, comes from outside.     

Concentration and characterization of plutonium in soils of Hubei in central China

To study the Pu concentration and isotope ratio distributions present in China, the ^239+240Pu total activities and ²⁴⁰Pu/²³⁹Pu atom ratios in core soil samples from Hubei Province in central China were investigated using Accelerator Mass Spectrometry (AMS). The activities ranged from 0.019 to 0.502 mBq g⁻¹ and the ^239+240Pu inventories of 45 and ∼55 Bq m⁻² agree well with that expected from global fallout. The ²⁴⁰Pu/²³⁹Pu atom ratios in the soil ranged from 0.172 to 0.220. The ratios are similar to typical global fallout values. Hence, any close-in fallout contribution from the Chinese nuclear weapons tests, mainly conducted in the 1970s, must have either been negligible or had a similar ²⁴⁰Pu/²³⁹Pu ratio to that of global fallout. The top 10 cm layer of the soil contributes ∼90% of the total inventory and the maximum concentrations appeared in the 2-4 cm or 4-6 cm layers. It is suggested that climatic conditions and organic content are the two main factors that affect the vertical migration of plutonium in soil.     

Reuse of mining wastewater in agricultural activities in Jordan

A pilot study was completed in the Al-Abyad area near phosphate mining activity in Jordan. Six plots of 50 m² each were planted with two types of plant species (Zea mays spp. and Medicago lupulina spp.) and irrigated using three types of water (fresh groundwater, mine wastewater, and hydride water consisting of 50% fresh and 50% mine wastewater) to investigate the suitability of utilizing mine wastewater for food production in the area. Water, soil and plant sampling was completed for each plot over different time intervals and analyzed for heavy metal (Cr⁺⁶, Ni⁺², Zn⁺² and Pb⁺²) in addition to major ionic composition of the water used for irrigation. Crop yield was estimated at the end of the experiment. Plots irrigated with mine wastewater showed slightly higher heavy metals concentrations and soil salinity during the experiment period was higher for plots irrigated with mine wastewater compared to plots irrigated with fresh water, and it was uniform through the upper 45 cm of the soil profile due to the high amount of irrigation water used during the experiment. Crop yield was inversely proportional to salinity as an increase of salinity by 2-folds resulted in reducing yield by almost 50%. However, no risk of heavy metals contamination was found in plants and soil. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Evaluation of Urban Sustainability in Specific Sectors in Latvia

In Latvia, the concept of sustainability is only slowly gaining recognition. An analysis of Development Plans prepared by the four largest cities of Latvia indicates that sustainability is presented as one of the guiding principles. However, a comparison of Development Plan policies against the urban sustainability issues reveals a great deal of ambiguity and contradiction.At the municipal level, planners and politicians lack indicators to gauge whether the long-term goals of Development Plans and the principles of sustainable development are being achieved. As a consequence, the broad public is deprived of the opportunity to assess for itself the process of development in relation to Development Plan policies, thus limiting accountability in development decision-making. Relevant statistical data collected on a regular basis are required to create sustainability indicators reflecting sustainability issues, to supplement and replace existing statistical compilations pertaining almost exclusively to economic growth and consumption. Development and utilisation of sustainability indicators can be an effective instrument for promoting the values of sustainable development amongst politicians, planners and the broad public and for enhancing accountability in decision-making.