INITIAL RESEARCH INTO CLIMATIC CHANGES AND GRASSLAND DEGENERATION IN INNER MONGOLIA

DuringtheimplementationoftheWestChinaDevelopmentStrategyinthetwenty firstcentury ,thenorthernsteppezoneplaysasignificantroleinsafeguardingtheecologicalsecurityandrealizingsustainabledevelopmentinChina .InnerMongoliaprairieliesinthemiddleofEurasiasteppezoneandisthetransitionzonefromthearidareasinthenorthwesttothehumidareasinthenortheastandthedryfarmingareasinNorthChina .Therigorousnaturalconditions ,thefluctuatingclimateandthecompli catedsocialandeconomicconditionsmakethisareaverysensitiveto…     

基于PLUS-InVEST模型的江西省生态系统碳储量时空演变与预测

土地利用变化是影响陆地生态系统碳储量变化的重要因素,研究土地利用变化与碳储量之间关系对优化区域土地利用结构,维持区域碳平衡可提供可靠的数据支撑.以江西省为例,分析1990~2020年土地利用变化,基于PLUS模型,结合自然发展情景、生态优先情景和经济发展情景设置,对2030年江西省土地利用格局进行模拟分析,运用InVEST模型测算1990~2020年及未来不同情景下江西省碳储量变化,利用空间自相关分析探索江西省不同情景下陆地生态系统碳储量时空变化特征,并提出相应的政策建议.结果表明:①1990~2020年江西省碳储量整体呈下降趋势,共减少4.58×10⁷ t.其中,水域和建设用地的面积增加,耕地、林地、草地及未利用地面积减少是导致碳储量减少的主要原因.②2030年江西省陆地生态系统碳储量在自然发展情景、生态优先情景和经济发展情景下分别为2.20×10⁹、2.24×10⁹和2.19×10⁹ t.③3种情景下的碳储量值在空间分布上具有相似性,碳储量高值区域在江西省北部、西北部及西部区域出现集聚,低值区域则在中部区域聚集.研究结果可为江西省未来国土空间规划,提升陆地生态系统碳储量提供数据支撑.     

洪泛湖泊水位-流量关系的非线性特征分析

湖泊的水位-流量关系是湖泊水文特性的重要表征。该关系与湖盆形态、湖泊与周围水系的水力联系等因素有关。鄱阳湖是长江中游的大型通江湖泊,洪泛特征显著。本文以鄱阳湖为例,研究洪泛湖泊入湖流量-湖泊水位关系及非线性特征。基于1960~2010年实测湖泊日水位和流域日径流数据,采用交叉小波和小波相干方法分析多时间尺度上水位对入湖流量的响应关系。结果表明,鄱阳湖入湖流量-湖泊水位关系存在3个特征阶段:阶段1中,入湖流量与湖泊水位相位差从0°过渡到45°~90°,水位上升初期与流量同步上升,后期水位对流量的响应产生迟滞效应,滞后时间为2~9d;阶段2中,入湖流量与湖泊水位相位差在90°左右波动,入湖流量率先下降,湖泊水位却保持缓慢上升;阶段3中,入湖流量与湖泊水位的相位变化与阶段1相反,从45°~90°过渡到0°,湖泊水位与入湖流量下降逐渐变为同步。本文提出鄱阳湖入湖流量-湖泊水位关系的3个阶段并分析其产生的主要原因,概化其水文特征,对通江洪泛湖泊的水文特征有新的认识,为下一步湖泊水文过程的刻画与模拟提供重要理论基础。     

Lysosomal enlargement and lysosomal membrane destabilisation in mussel digestive cells measured by an integrative index

Lysosomal responses (enlargement and membrane destabilisation) in mussel digestive cells are well-known environmental stress biomarkers in pollution effects monitoring in marine ecosystems. Presently, in laboratory and field studies, both responses were measured separately (in terms of lysosomal volume density - Vv - and labilisation period -LP) and combined (lysosomal response index - LRI) in order to contribute to their understanding and to develop an index useful for decisions makers. LRI integrates Vv and LP, which are not necessarily dependent lysosomal responses. It is unbiased and more sensitive than Vv and LP alone and diminishes background due to confounding factors. LRI provides a simple numerical index (consensus reference = 0; critical threshold = 1) directly related to the pollution impact degree. Moreover, LRI can be represented in a way that allows the interpretation of lysosomal responses, which is useful for environmental scientists.     

我国技术变迁对环境影响的计量分析

为了促进技术变迁因素在我国环境保护中发挥更大的作用,需要分析其以往对环境的影响,为我国的技术政策提供支持。使用动态基期,用统计方法定量计算了 1994~2004年各年度技术变迁因素对我国主要空气和水污染物排放量的影响。按是否以削减污染为直接目标,可将技术变迁分为2类：(1)生产工艺的变化。这种技术变化不以污染削减为直接目标,但会影响到生产投入物的数量和种类、生产过程中污染物的产生量并因此影响到最终的污染强度和排放量。(2)污染削减技术的变化。这种技术变化以污染削减为直接目标。利用环境统计年鉴中的污染削减量数据将技术效应分解为2部分：源自污染削减技术和源自生产工艺,发现从总体上看技术变迁降低了所有污染物的排放量,其中污染削减技术对所有污染排放量的下降都起了积极作用,但伴随较大的年度变化。生产工艺变化对不同污染物的影响方向不同。可见中国目前的污染削减主要依靠“末端”污染削减技术,“过程控制型”生产工艺没有充分发挥应有作用,也反映出目前技术变迁尚未向“环境友好型”演进。因此,要促使我国技术变迁向“环境友好型”演进,特别需要促进清洁生产技术的开发和推广,在生产过程中减少污染物的产生.     

武汉20世纪90年代暴雨异常的物理环境变化背景探讨

根据武汉1951－2000年50年暴雨日数资料，应用Mann-Kendall统计方法对暴雨邓列进行年限突变检验。揭示出武汉暴雨在1979年发生突变，20世纪80年代后暴雨出现频数明显上升，强度增大，90年代达到最大，同时指出武汉20世纪90年代暴雨日数和暴雨量异常的显著特征，着重从西太平洋副热带高压，阻塞高压，太平洋海温等重要物理环境因子的突变出发，探讨造成20世纪90年代武汉暴雨异常的物理变化背景，结果表明，在武汉暴雨异常多的90年代与暴雨异常少的70年代，所对应的大气，海洋环境背景显著不同，90年代北半球500hPa月平均高度场是处于几十年中正异常最大的阶段，西太平洋副热带高压持续偏南，偏强，西伸脊点偏西，东亚中高纬度环流异常，维持稳定的阻塞高压形势，赤道东太平洋海温（SST）出现最大正距平，为近50年来的异常增温时期，厄尔尼诺（ENSO）事件发生频繁。     

东洞庭湖湿地景观变化研究

在遥感和地理信息系统的支持下,对东洞庭湖1989和2001年两个时段的TM（ETM）卫星影像进行了遥感解译。应用景观生态学的理论和方法,对不同景观类型的斑块和面积大小、形状特征进行分析,计算了湿地景观多样性、优势度、均匀度、破碎度及斑块分形维数。定量分析和〖HJ〗研究了1989~2001年东洞庭湖湿地景观的动态变化,结果表明,由于泥沙淤积,东洞庭湖湿地的面积正在日益缩小,湿地景观多样性和均匀度下降,景观优势度和破碎化程度增加,说明东洞庭湖部分湿地景观逐渐从以小斑块、多种景观类型共同控制的景观格局向大斑块、类型较单一的景观格局演变。     

三峡库区非点源氮磷负荷研究

掌握非点源污染形成的机理和变化规律是控制和治理非点源污染的关键。三峡水库非点源污染物来源范围广,每年随上游来水输入库区的非点源污染物成为三峡入库非点源负荷的主要部分。为研究三峡入库非点源污染物负荷变化规律,以SLURP水文模型和输出系数法为基础,建立了长江重庆寸滩断面以上流域的非点源污染负荷模型,模型在模拟计算1996~2002年寸滩断面入库非点源TN年负荷和非点源TP年负荷时,除1998年非点源TP负荷计算误差高于50%外,其它各年非点源TN负荷和TP负荷计算误差基本上小于30%,具有较好的模拟计算效果。该模型的建立和应用将为流域的有关管理部门提供该流域非点源污染控制和治理的决策依据。     

Sludge reduction with Tubificidae and the impact on the performance of the wastewater treatment process

To reduce excess sludge, a Tubificidae reactor was combined with an integrated oxidation ditch with vertical circle (IODVC), and a new integrated system was developed for wastewater treatment. A pilot-scale of this integrated system was tested to investigate the sludge reduction with Tubificidae and the impact on effluent quality and sludge production. The dominant worm was Branchnria Sowerbyi in the Tubificidae reactor after inoculation of Branchnria Sowerbyi and Limnodrilns sp., and the maximal volume density of wet Tubificidae in vessels of the Tubificidae reactor was 17600 g/m3. Two operational modes, treating the excess sludge (first mode) and the returned sludge (second mode) of IODVC by the Tubificidae reactor, were used in this experiment. The results showed that the excess sludge reduction rate was 46.4% in the first mode, and the average sludge yield of the integrated system was 6.19×10-5 kg SS/kg COD in the second mode. Though the sludge returned to IODVC via the Tubificidae reactor, it had little impact on the effluent quality and the sludge characteristics of the IODVC. No new type of recalcitrant substance in the supernatant was discharged into the environment when the sludge was treated by Tubificidae. The experimental results also indicated that no significant changes occurred on the viscosity, specific resistance, and the floc size distribution of the sludge.     

Monitoring morphological and vegetation changes and flow events in dryland river channels

Monitoring of impacts of floods in river valleys of dryland regions has become important with the onset and threats of desertification and is likely to become even more vital with predictions of increased effects of climate and land use change. It is also needed in order to conform to requirements of the EU Water Framework Directive. Monitoring in such regions sets particular challenges. This paper explains a system of low-cost monitoring of changes in morphology, vegetation and sediment cover in channels and valley floors of ephemerally flowing streams. It has been applied in SE Spain for 10 years and has proved very effective. In particular, the use of simple crest-stage recorders for measuring flow height and the use of real-time differential GPS for rapid and accurate survey and for relocating points have proved very valuable. Part of the monitoring is focused on the interaction of plants and channel processes. Small changes in and around vegetation associated with flow events have been detected by a combination of quadrat surveys and cross-profiling of the channel. A range of flow events has been measured over the period of monitoring, demonstrating their differing effects and the varying sensitivity and responsiveness of different sites. The sporadic occurrence of flood events in such an environment means that a strategy of monitoring several sites and of continuation over many years has great benefits.