西畴县近48年来降水及气温小波分析

利用连续小波分析1962～2009年西畴县年降水量和年平均气温序列的小波变化特征,揭示了西畴县降水量与平均气温存在多时间尺度的周期变化特征。其中降水有2个明显的特征时间尺度,分别是4年和8年,平均气温存在以准2～4年为周期的周期振荡。此外,也可以看出近48年来,平均气温存在明显升高的趋势,降水也有减少的趋势,为掌握西畴县的气候变化规律及今后的气象预报服务工作提供了一定的参考价值。     

湿地的防洪功能分析评价——以东洞庭湖为例

湿地作为生产力最高的土地类型,具有水文、水质、食物链和栖息地等方面的功能以及社会经济价值。其中水文功能主要表现在防洪功能方面,包括调蓄洪水、削减洪峰、滞流和减少侵蚀等。文中通过利用地理信息系统、遥感数据、模拟、统计分析和空间计算等方法,定量分析评价东洞庭湖湿地的防洪功能,提出了湿地防洪功能评价方法。     

Study on characteristics and regeneration rules of Salix gordejevii in Hunshandak Sandland, China

Salix gordejevii, a species of dune-fixing pioneer shrub in the Hunshandak Sandland in China, plays a vital role in maintenance and improvement of the local ecological environment. Salix gordejevii has an r-type reproductive countermeasure, which means it produces large quantities of seeds that have a high germination rate but relatively low seedling viability. Our research on the seed regeneration and sprouting regeneration characteristics of Salix gordejevii shows that its sprouting regeneration process is more productive and efficient than its seed regeneration process. At the same time, growth of Salix gordejevii would decline when the drifting sand dune was fixed. To assess its sprouting regeneration process, we analyzed the number, length, and diameter of new shoots under different cutting treatments, and found significant differences based on various cutting heights and different cutting times (April vs. October). We conclude that cutting measures which take advantage of this species’ robust sprout tillering can increase the biomass of this shrub and also can improve its canopy density and its forage properties for livestock grazing, with the added benefits of improved sand-fixing and prevention of wind erosion.     

珠江三角洲三水盆地早全新世以来 孢粉分析与古环境重建

为了深入探讨珠江三角洲的沉积古环境和古气候历史,在三水市区获取了2个高取芯率的钻孔岩芯,进行了12个AMS 14C测年,并结合孢粉、硅藻等分析结果探讨三水地区全新世的海平面与河流水动力变化,以及古植被演替过程。结果表明：钻孔所在区域全新世沉积总体从9 000 cal. a B.P.左右开始,呈现河流相―河湾相―河口湾相―潮坪相―河口湾相―河漫滩相的演变过程。三水区的早全新世沉积阶段年代最早为9 000 cal. a B.P.左右,表现为河口湾相的淤泥质粉砂沉积,硅藻以淡水种类为主,最高沉积速率为1.6 cm/a。海侵初始时间为8 700 cal. a B.P.左右,最高海平面时间为7 600 cal. a B.P.左右,此时海岸带发育红树林,丘陵山地发育较茂盛的亚常绿热带常绿阔叶林;中―晚全新世阶段（6 500―2 200 cal. a B.P.）,以泥炭粉砂沉积为主,沉积速率为0.2~0.5 cm/a,河口区高潮线附近及河流弯道低洼滩地在5 000 cal. a B.P.前后形成淡水沼泽、河口三角洲边缘区洼地水松林发育。在晚全新世（2 200 cal. a B.P.左右）以来,陆相黏土质沉积指示河口泥沙快速堆积,三角洲平原迅速扩大,沉积速率高达1.7 cm/a。孢粉结果显示次生的芒箕孢子剧增,陆地植被稀疏,人类活动显著增强。     

北京西部山地景观生态整治与景观规划--以北京房山区史家营乡的典型研究为例

北京市西部山区是因矿区开发使山地景观生态环境破坏的重点地区,在北京市生态环境整治与建设中具有十分重要的典型意义。不合理的煤炭资源开采导致了矿点密度大,采空塌陷区分布广,水资源急剧减少,水质污染严重,植被大规模遭破坏,水土流失严重,泥石流等灾害加重以及煤尘污染问题突出等一系列环境问题,呈现出山地生态系统遭受严重破坏的景观生态特征。本文以史家营为例,在典型调查的基础上,规划了景观生态环境恢复与重建区、种植养殖和观光生态农业示范区、果粮养殖生态农业区、林草放牧生态畜牧业示范区、生态旅游区的五个景观规划区域,探讨了生态型矿业、中低山特色生态农业和生态旅游发展的产业发展模式,并初步提出了景观生态整治的措施。     

硫多金属矿床开采对水环境的影响——以福建大田地区矿产开发为例

闽西大田地区矿床采选冶活动对水土生态环境系统造成了严重的破坏,矿区采选矿废水pH值、SO4^2-浓度远远超过水环境标准,选矿废水和接纳采选矿废水的河流水体中Fe、Mn、Cu、Pb、Zn、Cd的含量大部分超过地面5类水标准,少部分超过4类水标准,矿区采选矿业废水是地表水金属污染的重要源头。矿业废水pH值与金属Fe、Mn、Cu、Pb、Zn、Cd的含量具有明显的负相关关系,SO4^2-浓度与金属离子Fe、Mn、Cu、Pb、Zn、Cd浓度具有较一致的变化规律。提出整治硫多金属矿山环境污染,应坚持因地制宜、矿业资源开发与环境保护并重的方针,用石灰石碱性中和酸性废水,隔离覆盖尾矿矿堆,对废弃矿山植树种草进行生态修复,对效益低下的开采矿山退矿还林,对严重环境污染的矿山实行关闭,对新开矿山要进行科学规划开发。     

玉龙雪山景区游客分布特征分析

基于2001~2009年玉龙雪山景区索道接待人次数据,从客流量的年度变化、季度变化、黄金周变化等方面分析了景区客流时空分布特征。主要结果如下:(1)景区客流量随着时间变化呈逐年上升的趋势且增幅明显;(2)夏季为玉龙雪山景区的旺季,冬季为淡季,景区内部各景点季节性差异大小为:牦牛坪冰川公园云杉坪。(3)黄金周客流量变化呈"单峰"型,中期人数最多;最大日客流量为年内日平均客流量的2.43倍。各景点"五一"、"十一"客流分布集中程度相似,牦牛坪的变化程度最大,冰川公园最小。(4)景区客流量空间分布集中程度高,主要集中于云杉坪和冰川公园。     

Migration and enrichment of trace elements of Lower Palaeozoic carbonate rock strata in Beijing

Analyses of trace elements of the Lower Palaeozoic carbonate rock strata in Beijing show that the contents of As, Hg, F increase from primary carbonate rocks to weathered carbonate rocks and from primary carbonate rocks to the soil coexisting with carbonate rocks, but the distribution regularity of S is not obvious. In the whole weathered stages, the sorption of As is mainly affected by Fe2O3. In soil Fe2O3 is also the main affecting factor of Hg enrichment. The main existing forms of Hg in primary carbonate rocks should simply be physical adsorption, coprecipitation and false isomorphous form between surface of carbonate rock and Hg. In soil the enrichment of F has little relationship with sul-fides and Fe2O3. In primary carbonate rocks, F is mainly absorbed by sulfides and clay minerals, etc. Weathered samples have closer genetic relationships with primary carbonate rocks. This also implies that weathered carbonate rocks have the close existing forms to that of primary carbonate rocks. In primary carbonate rocks FeS2 and FeS are the main forms of S, and sulfides have fixation effect on some heavy metals, whereas in weathered carbonate rocks and soil the fixation effect is weakened.     

大气颗粒物遥感研究进展

大气污染已成为全球性的环境污染问题之一,PM2.5和PM10已成为当前大气遥感研究的热点,以京沪穗为代表的特大城市更成为相关研究的重要焦点。通过对国内外相关文献的分析,以广州为例描述了地面站点监测的现状和不足,指出PM2.5遥感的关键问题为区域尺度气溶胶光学厚度垂直订正和区域尺度近地面消光系数湿度效应校正研究;通过空气质量模式系统进行相关研究,是包括PM2.5在内的大气颗粒物遥感的重要途径之一。     

Field determination for roughness length above the different non-erodible surfaces

Non-erodible elements, for its disturbance to the near-surface airflow, have been widely used in arid and semi-arid regions to protect the surface from wind erosion. Roughness length was usually used to evaluate the protection effect of non-erodible elements from wind erosion. In this study, the wind profiles above five types of non-erodible surfaces including gravel, wheat straw checkerboard barriers, cotton stem checkerboard barriers, shrubs, and herbs were measured and analyzed. The wind velocities above these surfaces increased with height approximately in logarithmic functions. The roughness length of different non-erodible surfaces was calculated by the functions of wind profiles. The results reveal that:(1) Roughness length increased with wind velocity in given wind velocity ranges. (2) On vegetative surfaces, wind did not effectively bend the stems. The threshold wind velocity for bending the stems of Achnatherum splendens was 4 m/s, 10 m/s for Agropyron cristatum, and for Artemisia ordosica, no obvious bending of stems even for wind velocity reaching 12 m/s. (3) Correlation analysis results show that the vegetation''s coverage and frontal area affect the roughness length more significantly than the other parameters. (4) The protective results of these non-erodible elements were evaluated. The checkerboard sand barriers made of cotton stem could provide more effective protection than that made of wheat straw. In the same coverage conditions, vegetation could provide more effective protection from wind erosion than gravel, and the blending of different non-erodible elements especially the combination of blending of vegeation and checkerboard sand barriers could provide more effective protection to the surface.