Adapting capitalism: Household plots, forest resources, and moonlighting in post-Soviet Siberia1

Economic reform in post-Soviet Russia has proceeded unevenly, resulting in broad variation between rural and urban areas. In the case study presented here, I examine how Communism's `economy of favors' has been transformed into a localized quasi-capitalist economy, which predominantly operates outside the national market economy. Using data from two villages in Tunkinskij Raion of the Buriat Republic in Russia, I look at how people at a micro-sociological level have adapted to current economic conditions. In particular I examine the relationships between informal networks and the ability to intensify agricultural production on household plots, to gain access to a variety of forest resources, and to find seasonal, part-time, or one-time work outside the household and the formal labor market. This revised version was published online in July 2006 with corrections to the Cover Date.     

兰州市郊人工林群落结构及稳定性初探

植物群落稳定性是生物本身与其生存环境的一种和谐,通过对南北两山人工植物群落主要树种、结构、天然植被的现状研究,以近自然林业理论为指导,从群落稳定性角度出发,提出了南北两山人工林群落总体布局和现有林地优化改造的思路。兰州南北两山人工林群落的稳定性,应建立于南北两山环境条件和与之相适应的树种之间一种相互适应的基础上,南北两山近城区及兰州至中川机场绿色通道面山灌溉较好的地段,宜发展乔、灌、草复合群落结构;局部条件优越的台、坪地宜发展以经济林为主的单层乔木林;灌溉条件较差或无灌溉区域宜为灌、草两层群落结构,形成稳定的近自然群落。对适宜区采取科学合理的调控技术,充分利用天然降水,维持群落的稳定性,降低运行成本。     

Effects of afforestation on carbon storage in Boyang Lake Basin, China

By using field survey data from the sixth forest inventory of Jiangxi Province in 2003, the biomass and carbon storage for three studied species （Pinus massoniana, Cunninghamia lanceolata, and Pinus elliottii） were estimated in Taihe and Xingguo counties of Boyang Lake Basin, Jiangxi Province, China. The relationship between carbon density and forest age was analyzed by logistic equations. Spatio-temporal dynamics of forest biomass and carbon storage in 1985-2003 were also described. The results show that total stand area of the three forest species was 3.10 × 10^5 ha, total biomass 22.20 Tg, vegetation carbon storage 13.07 Tg C, and average carbon density 42.36 Mg C/ha in the study area in 2003. Carbon storage by forest type in descending order was： P. massoniana, C. lanceolata and P. elliottii. Carbon storage by forest age group in descending order was： middle stand, young stand, near-mature stand and mature stand. Carbon storage by plantation forests was 1.89 times higher than that by natural forests. Carbon density of the three species increased 8.58 Mg C/ha during the study period. The carbon density of Taihe County was higher in the east and west, and lower in the middle. The carbon density of Xingguo County was higher in the northeast and lower in the middle. In general, the carbon density increased with altitude and gradient. Afforestation projects contribute significantly to increasing stand area and carbon storage. Appropriate forest management may improve the carbon sequestration capacity of forest ecosystems.     

Roving revisited,towards an optimum throughfall sampling design

Additional aspects regarding the optimum fixed and roving sampling techniques, to those already explored in a previous authors’ throughfall study, are further investigated here. The roving technique consists in the random repositioning, with a frequency f_r, of N throughfall gauges among M positions (M > N), oppositely to the fixed or stationary arrangement where N = M. Both fixed and roving optimum sampling techniques of 100 monitored throughfall events sampled with 200 fixed gauges under a semideciduous tropical rain forest in Panama were investigated by means of Monte‐Carlo numerical experiments. Mean dispersion was shown to be always smaller in the roving versus the fixed gauge arrangement, independently of the relocation frequency studied (f_r = 0.1, 0.2, 0.5, 1), such that all roving schemes with N ≥ 50 gauges lay within ±5% of the mean cumulative throughfall. Results indicated that a low variability, high precision, and accuracy are obtained with a modest relocation frequency f_r = 0.2 (i.e. a relocation every five episodes of the original 100 measured events) and N = 30 roving gauges, with no significant improvement worth the extra field work beyond f_r > 0.2 and N >30. Only by increasing the number of roving positions from M < < 200 to M = 200, the precision and accuracy of the mean estimate were improved without comprising additional labour. Hence, a roving sampling scheme which relocates gauges over completely new fresh sites each roving cycle is recommended for future throughfall studies. Finally, we designed an a priori sampling strategy which permitted us to conclude that using only the first 20 out of the total 100 measuring events, for the remaining 80 throughfall field measurements, N = 40 roving gauges (i.e. five time less than the originally 200 gauges displayed) would have been sufficient for ensuring ≤5% error, expressed as percentage of the mean cumulative throughfall. Copyright © 2012 John Wiley & Sons, Ltd.     

Financing REDD in developing countries: a supply and demand analysis

Reducing emissions from deforestation and forest degradation (REDD) in developing countries has been at the centre of negotiations on a renewed international climate regime. Developing countries have made it clear that their ability to engage in REDD activities would depend on obtaining sufficient and stable funding. Two alternative REDD financing options are examined to find possible ways forward: financing through a future compliance market and financing through a non-offset fund. First, global demand for hypothetical REDD credits is estimated. The demand for REDD credits would be highest with a base year of 1990, using gross—net accounting. The key factors determining demand in this scenario are the emission reduction targets and the allowable cap. A proportion of emission reduction targets available for offsets lower than 15% would fail to generate a sufficient demand for REDD. Also examined is the option of financing REDD through a fund. Indirectly linking the replenishment of a REDD fund to the market is a promising mechanism, but its feasibility depends on political will. The example of overseas development assistance for global health indicates the conditions for possible REDD financing. The best financial approach for REDD would be a flexible REDD mechanism with two tracks: a market track serving as a mitigation option for developed countries, and a fund track serving as a mitigation option for developing countries.     

长时间序列多源遥感数据的森林干扰监测算法研究进展

时空意义明确的森林干扰和恢复信息是评价森林生态系统碳动态的关键因素之一。然而由于诸多的现实困难,多尺度的森林干扰定量化时空信息相对缺乏。Landsat数据具备光谱、时间和空间分辨率上的优势,以及可以免费获取的特点,使其成为主要的长时间序列动态监测的遥感数据源之一,为长时间周期内提供具有合适的空间细节和时间频率的森林干扰信息成为可能。特别是基于Landsat时间序列堆栈(LTSS)的森林干扰自动分析算法的出现,更为森林生态系统的近实时监测提供强有力的工具。本文全面评述了长时间序列遥感数据准备和预处理技术以及国内外基于遥感数据源的多时相森林干扰监测方法,重点分析了基于Landsat的多种指数监测和自动化方法的优缺点,并总结了其与多源数据结合的扩展应用,最后就现有方法与国内外新的数据、技术手段的关联进行了展望,以期为推广中国本土卫星影像应用于森林干扰监测提供理论借鉴。     

基于气象因子及机器学习回归算法的夏季空调负荷预测

气温、气压、相对湿度等气象因子对夏季用电负荷的影响非常显著。为了定量研究气象因子导致用电负荷的变化,本文将夏季用电负荷与当年4月及9月用电平均值之差定义为夏季空调负荷,并利用2014年1月到2016年12月南京市逐时气温、气压、相对湿度、水汽压、降雨量、风速、露点温度等气象资料,以及逐日逐时用电负荷数据资料,采用多元线性、K近邻法,决策树,bagging回归、随机森林等5种机器学习回归算法进行建模,并对其分别进行参数调优工作,进而得到空调负荷预测结果。结果表明:多元线性回归方法是5种回归算法里效果最差的一种,但通过增加特征量的种类和样本数,可以提高预测精度;随机森林回归算法是5种回归算法里效果最好的一种,较多元线性回归算法减小误差达44%,并且较好描述了空调负荷高值区的极端情况并减少了对于训练数据的过拟合现象。     

1979—2019年武汉市重点水体多要素协同的时空演变特征

城市发展对水体多方面要素产生了巨大影响,尤其是对水资源丰富的城市,迫切需要开展相关监测研究。研究以武汉市为例,通过梳理国内外相关研究以及武汉水体保护政策,提出融合水体面积、水质、水体景观、滨水区生态环境4个方面要素的分析技术路线以更为全面的反映城市尺度的水体时空演变特征,具体的,利用随机森林模型基于1979—2019年遥感影像获取武汉67个重点水体信息,并以此获取水体面积和水体景观的变化特征;同时,通过梳理多年水质监测数据分析水质变化特征;另外,基于遥感生态指数（Remote Sensing Ecological Index, RSEI）分析滨水区生态环境变化;最后,采用多尺度地理加权回归模型（Multi-scale Geographically Weighted Regression, MGWR）对重点水体面积变化的影响因素研究,希冀为政府制定差异化的水体保护政策提供科学支撑,并为其他地区水体的多要素分析提供有益借鉴。结果表明：① 武汉市水体面积呈下降趋势,水体总面积、重点水体面积分别减少10.75%及13.12%,中心城区及郊区水体变化存在显著差异;② 水体景观呈退化趋势,周长面积分维数、平均斑块面积、聚合指数及结合指数分别减少了6.43%,79.35%,1.55%及10.94%;③ 重点水体水质总体呈恶化趋势,其中江河及水库多数常年为III类及以上水体,中心城区湖泊多为V类及以下水体,郊区湖泊多为IV类及V类水体;④ 中心城区及郊区滨水区遥感生态指数（RSEI）分析表明滨水区生态环境呈恢复态势,其中中心城区滨水区平均RSEI增长了14.29%;⑤ MGWR分析表明,自然气象因素中,相对湿度的增加对江夏区湖泊恢复影响更为显著,降水对水面较小的水体恢复影响更为显著;社会经济因素中,各行政区GDP的增加有助于水体恢复,对中心城区、黄陂及新洲的水体保护影响更为显著;滨水缓冲区内不透水面占比（IS）的增加导致大多数水体面积的减少,然而,对于少数重点修复水体,IS增加是受相关保护政策影响,IS增加有助于这些水体恢复。     

基于CNN和RF算法的ECMWF降水分级订正预报方法

利用卷积神经网络(CNN)和随机森林回归模型,提出了一种新的欧洲中期天气预报中心(ECMWF)降水订正预报方法.该方法首先根据ECMWF模式对站点雨量预报值所属的等级进行划分,再计算出不同等级相对应的高相关因子矩阵.进一步利用CNN模型对高相关矩阵进行综合特征提取的学习和训练.最后对CNN模型最终输出的特征因子中,选取...     

Nature rehabilitation by floodplain excavation: The hydraulic effect of 16 years of sedimentation and vegetation succession along the Waal River, NL

The “Ewijkse Plaat” is a floodplain along the Waal River, NL. In 1988, the floodplain was excavated as part of a program for enlargement of the discharge capacity and was assigned as a nature rehabilitation area. This paper describes the combined geomorphological and vegetation evolution of the floodplain until 16 years after the initial excavation using elevation data and data on vegetation structure derived from detailed aerial stereographic imagery. The impact of these processes on flow velocity and water surface elevation was evaluated by using a hydraulic model. Within 16 years, the excavated amount of sediment was redeposited in the area. The dominant geomorphological process after excavation was vertical accretion of the floodplain which resulted in the formation of natural levees. The amount of sedimentation was correlated to the across-floodplain flow (R² = 0.89). In the research period, 41% of the sedimentation took place during two single major flood events. The creation of pioneer stages by excavation promoted softwood forest establishment, which influenced the sedimentation pattern significantly. The landscape evolved toward structure-rich vegetation. Nine years after excavation the initial hydraulic gain was lost by the combined effect of sedimentation and vegetation succession. Implications for river and nature management are discussed.