基于成本收益理论的宅基地自愿有偿退出有效阈值——以改革试点区宜城市为例

宅基地退出是有效缓解城乡建设用地之间的矛盾、促进乡村振兴的重要手段。在梳理宅基地有偿退出路径的基础上构建宅基地价值补偿体系,按照政府能承受、农户能接受、工作可持续的原则,基于成本收益理论科学测定在不同模式下宅基地自愿有偿退出的有效阈值。结果表明：（1）宅基地退出补偿阈值是农户能接受的最小值和政府能承受的最大值所组成的补偿范围。（2）农户退出宅基地损失的机会成本和退出总成本之和小于最小阈值时农户愿意有偿退出,最大阈值低于宅基地、地上附属设施权利价值和退出总成本之和。（3）“异地改造”模式下,政府处于主导地位,资金来源较少,实际补偿金额接近最小阈值。“一户多宅”模式下,政府和农户诉求相当,补偿金额偏向中位数。“整体搬迁”和“社区化”模式下,农户处于主导地位,政府补偿资金来源较多,实际补偿金额趋向最大阈值。     

强化林火扑救力度实施林场有偿扑火

分析了新形势下单纯依赖专业森林消防队伍扑救森林火灾的不足与问题，提出了有偿扑火构想与保证措施。     

Characterizing ionic species in PM2:5 and PM10 in four Pearl River Delta cities, South China

PM_(2.5)and PM_(10)samples were collected at four major cities in the Pearl River Delta(PRD),South China,during winter and summer in 2002.Six water-soluble ions,Na~ ,NH_4~ ,K~ ,Cl~-,NO_3~- and SO_4~(2-)were measured using ion chromatography.On average,ionic species accounted for 53.3% and 40.5% for PM_(2.5)and PM_(10),respectively in winter and 39.4% and 35.2%,respectively in summer. Secondary ions such as sulfate,nitrate and ammonium accounted for the major part of the total ionic species.Sulfate was the most abundant species followed by nitrate.Overall,a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities.Significant seasonal variations were also observed with higher levels of species in winter but lower in summer.The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well.NO_3~-/SO_4~(2-) ratio indicated that mobile sources have considerably contribution to the urban aerosol,and stationary sources should not be neglected. Besides the primary emissions,complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.     

Assessing field vulnerability to phosphorus loss in Beijing agricultural area using Revised Field Phosphorus Ranking Scheme

Guanting Reservoir,one of the drinking water supply sources of Beijing,suffers from water eutrophication.It is mainly supplied by Guishui River.Thus,to investigate the reasons of phosphorus(P)loss and improve the P management strategies in Guishui River watershed are important for the safety of drinking water in this region.In this study,a Revised Field P Ranking Scheme(PRS)was developed to reflect the field vulnerability of P loss at the field scale based on the Field PRS.In this new scheme,six factors are included, and each one was assigned a relative weight and a determination method.The affecting factors were classified into transport factors and source factors,and,the standards of environmental quality on surface water and soil erosion classification and degradation of the China were used in this scheme.By the new scheme,thirty-four fields in the Guishui River were categorized as"low","medium"or"high"potential for P loss into the runoff.The results showed that the P loss risks of orchard and vegetable fields were higher than that of corn and soybean fields.The source factors were the main factors to affect P loss from the study area.In the study area,controlling P input and improving P usage efficiency are critical to decrease P loss.Based on the results,it was suggested that more attention should be paid on the fields of vegetable and orchard since they have extremely high usage rate of P and high soil test of E Compared with P surplus by field measurements,the Revised Field PRS was more suitable for reflecting the characteristics of fields,and had higher potential capacity to identify critical source areas of P loss than PRS.     

农村居民点用地问题研究--以安徽宣城市为例

引入距离指数、分散度等定量指标,采用定性与定量相结合的方法,从用地数量、布局等方面对宣城市农村居民点用地现状进行了阐述,在此基础上对农村居民点用地存在的主要问题进行了深入分析与探讨,并针对存在的问题提出相应的对策及建议.其研究结果不但为农村居民点用地整理的开展、农村社区生态环境的改善等提供了理论参考,而且对土地利用总体规划的修编提供了重要参考价值.     

Carbonaceous aerosols in PM10 and pollution gases in winter in Beijing

An intensive observation of organic carbon (OC) and element carbon (EC) in PM10 and gaseous materials (SO2, CO, and O3,) was conducted continuously to assess the characteristics of wintertime carbonaceous aerosols in an urban area of Beijing, China. Results showed that the averaged total carbon (TC) and PM10 concentrations in observation period are 30.2±120.4 and 172.6±198.3 μ/m3, respectively. Average OC concentration in nighttime (24.9±19.6 μ/m3) was 40% higher than that in daytime (17.7±10.9 μ/m3). Average EC concentrations in daytime (8.8±15.2 μ/m3) was close to that in nighttime (8.9±15.1 μ/m3). The OC/EC ratios in nighttime ranging from 2.4 to 2.7 are higher than that in daytime ranging from 1.9 to 2.0. The concentrations of OC, EC, PM10 were low with strong winds and high with weak winds. The OC and EC were well correlated with PM10, CO and SO2, which implies they have similar sources. OC and EC were not well correlated with O3. By considering variation of OC/EC ratios in daytime and night time, correlations between OC and O3, and meteorological condition, we speculated that OC and EC in Beijing PM10 were emitted as the primary particulate form. Emission of motor vehicle with low OC/EC ratio and coal combustion sources with high OC/EC ratio are probably the dominant sources for carbonaceous aerosols in Beijing in winter. A simple method was used to estimate the relative contribution of sources to carbonaceous aerosols in Beijing PM10. Motor vehicle source accounts for 80% and 68%, while coal combustion accounts for 20% and 32% in daytime and nighttime, respectively in Beijing. Averagely, the motor vehicle and coal combustion accounted for 74% and 26%, respectively, for carbonaceous aerosols during the observation period. It points to the motor vehicle is dominant emission for carbonaceous aerosols in Beijing PM10 in winter period, which should be paid attention to control high level of PM10 in Beijing effectively.     

纸载环境监测数据的电子化处理、安全管理和有偿利用的探讨

在当今各部门、各系统办公自动化管理,各种信息网络化共享的情况下,大量的环境监测数据的电子化保存与网络化共享是一个趋势和不争的事实。在电脑普及以前的纯纸载环境监测数据,由于其使用烦琐,利用率偏低,不利于这些数据的再利用和网络化资源共享。鉴于实习学生需要了解历史监测情况,有步骤地安排数据录入,将纸载文档转化为电子文档,放于网上,实行分级授权开放,部分有偿使用尝试,取得不错的效果。     

试点碳市场配额有偿分配经验及对全国碳市场的借鉴意义分析

我国7省市碳排放权交易试点经过多年实践,积累了宝贵经验。在配额分配方面,多数试点在免费分配的基础上进行了配额有偿分配的探索,形成了各具特色的有偿分配实践。研究表明,试点碳市场配额有偿分配的经验对全国碳市场配额分配具有重要的参考借鉴意义。建议结合全国碳市场建设和发展实际以及配额分配实施方案的制定,科学合理设计有偿分配相关规则,并建立相应的监管机制。     

有偿分配下排污权基准价定价模型研究

排污权的合理定价可以为环境保护提供正确的经济激励,引导排污企业将污染排放量设定在社会的最优水平。从理论上分析了排污权定价时应综合考虑的影响因素,构建了排污权定价模型的指标体系;运用主成分分析法和客观赋值法,从地区因素、污染物因素和行业因素3方面附加权重计算排污权基准价定价模型的价格系数,为排污权合理定价提供参考。     

流域水质资源有偿使用机制的思考——以东江为例

阐述了水质资源的基本概念和水质资源计价原则及定价方法,介绍了恢复成本法作为水质资本定价方法和确定水质资本核算函数和曲线的步骤.然后从有偿使用与生态补偿的概念、使用权和所有权以及支付方式3个方面对二者进行比较,指出有偿使用体制可实现水质资源使用权与国家所有权分离,从而可构成市场主体的财产权.基于以上概念和方法,从分析东江水源区的优质水保护与东江供水的关系入手,指出实行水质资源有偿使用的迫切性和重要性,从实现社会公平和完善市场机制两方面分析有偿使用的必要性,并提出了有偿使用机制的若干建议.