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新疆典型冰川特征变化及其对关键气象因子的响应
No full textGlaciers are formed under the influence of climate change and are responsive to climate change. The glacier itself changes can also indirectly reflect the climate change. Glacier is the solid form of water body,storing rich fresh water resources. In the arid and semi-arid areas where water resources are scarce,glaciers are important sources of water resources. Glacier changes have an important impact on the ecological environment and people's production and living in arid areas. The study of glacier change is of great significance to the realization of sustainable development of arid and semi arid areas. With the development of remote sensing technology,it is one of the important means to study glaciers in the glacier areas where the climate is bad, the terrain is steep and the snowstorm is difficult to reach. Xinjiang glaciers are widely distributed,mainly concentrated in the Tianshan Mountains. Tianshan Mountains is one of the most mountainous mountains in the world,and the main distribution types of Tianshan glaciers are radially distributed with high mountain peaks. The Altai Mountains are the highest glaciers in China,and the glaciers in the region are small in size. Karakorum mountain mountains magnificent numerous peaks with large scale glaciers,. Snow line elevation is up to 5000m. The region is the world's low latitude mountain glacier development of the region.In order to be more comprehensive understanding,the response of Xinjiang glaciers to climate change is explored.In this paper,four typical glaciers are selected,which are the glaciers in the Friendship Peak area of the Altai Mountains,the glaciers in the Bogda peak area of the Tianshan Mountains and the glaciers in the Kelikinshan area.Based on Landsat TM,ETM + \ OLI remote sensing image data from 1990 to 2015,the glacier boundary was modified by snow cover index method (NDSI) and threshold method. The glacier catalog data were combined with visual interpretation method. The area of glacier in the area of the Bogda area, the area of glacier of the Kelikelku area,the Friendship Peak area,the sound Sugari area, the glacier slope to the ice and the glacier area center of gravity change was analysed. The climatic responses of typical glaciers in the eastern Tianshan Mountains over the past 20 years were studied by combining the temperature of long time series and the key meteorological factors of precipitation. And the characteristics of glacier changes in four study areas were combined with the changes of the key meteorological factors and the characteristics of the terrain and the glaciers themselves.Through the preliminary study, we get some conclusions: （1）The glaciers in the four study areas have experienced the phenomenon of accelerated retreat and the recent fluctuation in the 1990s. From the area of retreat rate,the friendship rate of the largest area of the retreat rate,followed by the Bogda peak area,and then for the sound Sugar area,and finally for the region of the Kelikelku area. （2）The glacier area in the four study areas shows the phenomenon of migration to the origin,which shows that the study area in each quadrant are showing a trend of retreat,in addition to Friendship peak area,the other three study area 4 quadrant area The center of gravity changes are relatively large. （3）From the perspective of the slope map,the glacier area on the southern slope of the Kelikelku mountain area is larger than the northern slope,and the glacier area on the north slope is larger than the glacier area in the southern slope. Glacier area retreat rate northwest slope up slightly increased,the other areas in all directions are showing a retreat trend in addition to the friendship peak area in the. Both the Bogda peak area and the Kelikelku mountain area have the fastest retraction rate in the northwest slope and the sound Sugari area and the Friendship peak area are the fastest in the east slope. （4）According to the analysis of raster meteorological data,the response sensitivity of the key meteorological factors in the Friendship peak area is greater than that in the Bogda area,which is larger than that of the area of the Kelikelku mountain area and the friendship area.The increase in precipitation in the Bogda peak area has little effect on the retreat of the glaciers,and the precipitation in the Kelikelku mountain area has a certain inhibitory effect on the retreat of the glacier area. （5）On the scale of the year,the main reason for the Bogda peak area,the Kelikelku mountain area,the sound Sugari area and the Friendship peak area are due to the increase of the temperature in the wet and dry season and the precipitation in the wet and dry season are not making the overall retreat of the glaciers slowed down
冷荒漠降水增加对囊果苔草生活史及繁殖对策的影响
No full textEphemeral plant is a unique existence in cold desert around the world and playsimportant role in maintaining ecological stability in Gurbantunggut desert of Xinjiang,Northwest China. In order to understand the reproductive strategy adjustment ofephemeral plant under continuously precipitation increase in cold desert, we chooseCarex physodes, an endemic ephemeroid rhizomatous clonal plant from Cyperaceaefamily, as study object. The characteristics of seed germination and seedlingestablishment were studied both in indoor control and field survey under snowenhancement in winter and water enhancement in spring-summer seasons. The clonalreproductive strategies and sexual reproduction allocation were also monitored duringthe treatments. The main results and conclusions are as follows:(1) Under different snowfall conditions, the seed vigor and germination rate of C.physodes were different. The seed vigor and germination rate were higher under snowenhancement, indicating that increased snowfall is beneficial to the vigor of seeds,and also subsequent seed germination.(2) Increased rainfall affect the vegetative growth of C. physodes compared withthe natural state. The crown length and width, and the leaf number decreased underwater enhancement, while the plant height increased, with up to 14.41% increaseunder 50% water enhancement. The underground biomass and diameter of rhizomaticroot increased its the waterfall enhancement. This showed that C. physodes maybereduce surface face by reducing leaf number and crown length and width, andincrease the biomass input in underground parts, to adapt to water enhancement inarid desert environment.(3) Compared with the natural waterfall amount, Carex physodes reproductivestrains and vegetative strains numbers increased, and the effect was significant forreproductive strains. Reproductive strains increased by 176% under 30% waterenhancement, and by 281% under 50% water enhancement, and the ratio of reproductive and vegetative stain number was also raised. Thus, the results indicatethat the increase of spring and summer precipitation promotes C. physodesreproductive and vegetative strains growth, which benefit for the populationdevelopment of the species in desert.(4) Compared with the natural state, water enhancement made Carex physodesfruit's length increase, while fruit width decrease. And made seed width increase, andseed length decrease, with 6.52% decrease under 30% water enhancement and 2.55%decrease under 50% water enhancement. The thousand seed weight decreased and thethousand fruit weight increased. These results showed that the increase of spring andsummer precipitation may affect the reproductive organ plasticity of C. physodes, andthe following seed dispersal and inhibition in the desert
克拉玛依市中部区域荒漠生态功能区划研究
No full textOn the basis of field investigation and data collection, ecological function principles, together with qualitative and quantitative methods are applied in this paper to analyze eco-environment situation and reveal space differentiation rules of eco-environment sensitivity and ecosystem services importance of Karamay City middle area. Consequently, combined with the developing characteristics of its own society and economy, according to the division principle, basis and methods, Karamay City middle area can be divided into 3 ecological function regions and 39 ecological function small regions. Meanwhile, according to the eco-environment characteristics, main eco-environment problems and ecological functions of each ecological function regions, key tasks and specific measures on ecological nursing and construction are put forward to provide a scientific basis for ecological construction planning in the middle area of Karamay. The main conclusions of this paper are listed as follows:(1) The eco-environment is fragile, and regional eco-environment question is outstanding in the middle area of Karamay. Lack of precipitation, water resources are deficient. The type of vegetation and ecosystem are single, the forest resources are increased, but the coverage is still low, and the vegetation is destroyed seriously. The soil erosion in the mountain area is significant, the trend of land desertification in the plain is obvious, and the soil salinization is serious. (2) From the spatial distribution characteristics of eco-environment sensitivity of Karamay middle area, highly sensitive and extremely sensitive are mainly distributed. Spatial differentiation is obvious, we should adjust measures to local conditionsa and make reasonable moderate development in development process. Eco-environment extremely sensitive regions are mainly distributed in the northern of Shixi Road, the southern of Industrial Park, Wu Ming Hu wetland, the middle area of West mountain. (3) From the spatial distribution characteristics of ecosystem service function of Karamay middle area, important and extremely important are mainly distributed. Space differentiation is obvious, we should focus on management development and construction in view of the dominant ecological function. Extremely important regions are mainly distributed in the north of Kuibei Railway, part of the region between Shixi road - Kuibei Railway, Wu Ming Hu wetland, Mahe old river of Xiaoguai-Zhongguai, southern part area of Industrial Park. (4) GIS technology through the spatial overlay is applied in this paper to divide Karamay middle area into 3 ecological function regions and 39 ecological function small regions. Eco-environment sensitivity, ecosystem services and the already existing problems and causes in each ecological function region are analyzed. The ecological construction measures and development directions of 39 ecological function regions are put forward at last
吉尔吉斯南天山阿特巴西增生杂岩结构-构造解析及其意义
No full text古增生杂岩的解剖对理解增生造山带的构造过程具有重要意义。然而，由于古增生杂岩具有复杂的物质成分且经历了强烈变形，因此对古老造山带中增生杂岩的识别与解剖具有挑战性，其难点在于野外岩块-基质形成的时限及相互关系、构造背景厘定等诸多方面。本文通过对吉尔吉斯南天山阿特巴西增生杂岩系统的构造、年代学和地球化学研究，分析了中亚造山带西部的构造演化、大洋板块地层形成和增生时序。吉尔吉斯南天山阿特巴西增生杂岩位于中亚造山带南部关键的大地构造位置，分别以北部的阿特巴西-伊内尔切克-南那拉提断裂和南部的穆兹杜克-北塔里木断裂分隔伊犁-中天山岛弧和塔里木克拉通，记录了塔里木克拉通与伊犁-中天山岛弧的拼贴历史。具有高压/超高压变质岩和蛇绿岩混杂带出露的阿特巴西增生杂岩是解剖南天山增生杂岩最好的天然实验室之一，对解决国际学术界关于中亚造山带南部最终拼贴时空格局具有重要的理论意义。通过详细的大比例尺地质填图与构造解析、室内综合研究，取得以下主要创新成果与认识：（1）阿特巴西增生杂岩可分为 4 个构造单元，即北部蛇绿混杂岩单元、高压/超高压变质岩组合单元、层序-混杂岩组合单元和南部蛇绿混杂岩单元。构造单元中大量发育岩块-基质的混杂特征，主体构造样式表现为逆冲-褶皱推覆体、双重构造和叠瓦扇构造。（2）高压/超高压变质岩组合夹于一个由北部右行转换挤压体系和南部左行转换伸展体系形成的复杂双重构造中，表明高压/超高压变质岩的折返具有平行于岛弧、朝西南斜向挤出的复杂三维（3D）形态。（3）榴辉岩和基性岩具有 N-MORB 和 OIB 性质，其中西部以具有 OIB 性质的海山/洋底高原/洋底高原环境为主，东部以具有 N-MORB 的正常洋壳为主。（4）榴辉岩等高压变质岩最小变质年龄为 217Ma-221Ma，基性岩的最小锆石年龄为 214Ma-248Ma。（5）变质沉积物的碎屑锆石年龄范围集中于 470-500Ma 之间，主体记录伊犁-中天山岛弧活动特征，表明沉积物源自位于俯冲上盘的伊犁-中天山岛弧。（6）获得4个构造单元中沉积物碎屑锆石的最小年龄分别为264Ma，223Ma，350Ma 和 303Ma，表明构造变形至少发生于这些时代之后。（7）确定古生代-早中生代增生楔大洋板块地层学特征，提出南天山洋整体向北俯冲，俯冲板片结构沿走向上存在西部海山/洋底高原较多、东部正常洋壳的差异性；南天山洋俯冲可能持续至晚二叠至晚三叠世，期间高压/超高压变质杂岩于晚三叠世哈萨克斯坦山弯构造南翼（伊犁-中天山岛弧）向东运动期间，朝西南斜向挤出。（8）讨论了信息技术在高寒山区岛弧增生楔构造填图中的辅助作用。这些成果具有重要理论意义，有助于解决长期针对南天山洋俯冲极性和最终闭合时间的重大争议问题，并示范了通过野外大比例尺构造填图、使用大洋板块地层学来解决古老造山带增生楔构造解析难点的关键作用
基于贝叶斯网络的绿洲水资源综合管理研究
No full text绿洲作为干旱区独特的自然与人文景观，是动植物生存、人类定居的重要场所。其中，水资源一直是制约其存在、稳定以及发展的首要自然因素，并与特定的人文、经济以及水管理政策等社会因素共同决定着绿洲水资源利用的可持续性。忽略任一因素都不能通过水资源管理研究有效地解决绿洲生态环境与人类活动系统间的用水短缺与冲突，更不能为干旱区绿洲用水安全与可持续发展提供科学支撑。将水文、生物物理、生态环境等自然因素与人文、经济、用水政策等社会因素进行耦合的跨学科研究，已经成为国际水资源综合管理研究的前沿问题。在干旱绿洲区，如何以水为主线，开展绿洲“水资源-生态环境-社会经济”耦合系统的跨学科水资源综合管理研究，不仅是干旱区绿洲可持续发展面临的现实问题，也是水资源管理科学基础研究的热点问题。本论文选取西北干旱区塔里木盆地南缘的策勒绿洲为典型研究区，以“绿洲水资源来源分析—绿洲生态需水量估算—权衡与协调绿洲农业灌溉与生态需水间用水冲突—各需水部门利益相关者参与下的绿洲水资源综合管理”为研究思路，针对解决各个环节中出现的不确定性因素而开展相应的绿洲水资源综合管理研究。首先，重建策勒河流域的气象数据，通过建立水文模型模拟径流并分析其不确定性，探讨气候变化背景下的绿洲区地表水来源变化与不确定性特征；其次，拓展支持绿洲生态系统服务功能的生态需水量概念，利用最大值与兼容性原理估算其绿洲生态需水量；再次，提出权衡与协调系统，通过建立离散与混合贝叶斯网络模型，解决农业灌溉与生态需水间的用水冲突；最后，征求不同用水部门利益相关者与水管理专家的观点，构建绿洲生态系统服务功能综合于水资源管理的参与式贝叶斯网络模型，提出不同管理情景下的策勒绿洲水资源管理方案和建议。通过研究得到以下主要结论：（1）改进的 Delta 统计降尺度方法在多数据源下提高了气象数据的重建精度。利用多数据集合理论有效地减小了径流模拟的不确定性。根据气候相似性原理，利用改进的 Delta 方法和昆仑山北坡的 12 个参考气象站数据对策勒河流域高山区喀尔塔什站和策勒国家站的气温、降水以及蒸发数据的重建表明，相比重建的月降水量数据，重建的月平均气温和月蒸发量数据精度相对较高，这说明了连续时空场相对于离散时空场更容易重建。利用重建的气象数据作为 TL-FNN-BP (9, 1, 1) 水文模型输入数据获得较为理想的径流模拟结果（NSCE > 0.80）。尽管利用多气象数据集合理论能有效减小径流模拟的不确定性，但由于重建数据不确定性与模型结构不确定性二者的叠加，径流的模拟仍然具有一定的不确定性。 （2）量化的绿洲生态需水量占径流量的 40.29%-58.75% 之间。在各要素生态需水中，荒漠地下水恢复量占最大比例。根据绿洲生态系统特征与功能，拓展了支持干旱区绿洲生态系统服务功能生态需水量的概念，包括保障河流生态系统健康的最小流量、天然绿洲生态系统各要素需水量，以及荒漠地下水位恢复量。计算表明，策勒绿洲所需的生态需水量在最大、中等、最小三等级中分别估算为 0.752×108，0.619×108 和 0.516×108m3，占河流径流量的 58.75%，48.36% 和 40.29%。在各要素生态需水中，荒漠地下水恢复量占最大比例，在最大、中等、最小三等级中分别占绿洲生态需水量的 48.27%, 42.32% 和 37.03%。（3）提出的离散贝叶斯网络权衡系统耦合了绿洲水文和生态需水等自然因素与节水措施和灌溉方式等社会因素，有效地决策了最适绿洲生态需水量。根据离散贝叶斯网络决策系统分析，策勒绿洲最适生态需水量分别在丰水年、平水年和枯水年应为策勒河径流量的 50.24%，49.71% 和 48.73%。其中，在滴灌和节水工程管理下，分别在丰水年、平水年以及枯水年能够节省策勒河径流量的 1.93%，0.66% 和 0.43% 用于绿洲生态需水。（4）建立的混合贝叶斯网络协调系统利用动态离散化算法模拟了主要农作物经济补偿标准，更有效地协调了绿洲生态需水与农业灌溉间用水冲突。通过混合贝叶斯网络模拟结果分析，农作物经济补偿取决于可利用的供水和满足不同程度的生态需水量。在枯水年，保障“中等”程度的绿洲生态需水量对小麦、玉米、棉花以及大枣的经济补偿标准应该分别为 1995.90, 1675.42, 3239.76以及 3513.12 RMB/ha。同时，采用先进的节水工程设备与滴灌技术能分别节省冬小麦、夏玉米、棉花以及大枣 247，271，246 以及 237 RMB/ha 的经济补偿标准。（5）构建的参与式贝叶斯网络将生态系统服务功能综合于水资源管理系统中，成功地模拟了水资源管理情景下的结果与效应。通过参与式贝叶斯网络的构建与模拟，目前任何管理模式都不能很好地保持策勒绿洲的可持续水发展。建立水库是缓解春季灌溉不足最有效的措施，但建立水库导致下游绿洲区生态需水严重缺乏，这就需要科学地在策勒河上游按照下游绿洲区不同季节需水量排放一部分河水支持生态需水。强烈建议利益相关者之间通过互相合作共同处理用水之间的冲突，特别是建立水权机制，提高农业灌溉节水效率，将农业节水的一部分水用于绿洲生态需水
毛里塔尼亚努瓦克肖特地区土地沙漠化过程及其驱动环境研究
No full text毛里塔尼亚伊斯兰共和国位于非洲西撒哈拉地区，素有“沙漠共和国”之称。毛里塔尼亚首都努瓦克肖特是全国最大的城市，同时受到海洋与沙漠的双重威胁。在气候和人类活动因素的共同作用下，该地区环境出现了一系列严重问题，沙漠化的危害尤其严重。所以研究努瓦克肖特地区土地沙漠化现状及其时空分布格局，探讨沙漠化发展的驱动环境，预测沙漠化发展趋势，对于将来更好的开展荒漠化防治工作，以及该地区的可持续发展有着重要而深远的意义。本研究选取努瓦克肖特首都地区，通过对研究区 5 个时期（1985 年、1988年、2000 年、2006 年和 2010 年）沙漠化土地和不同土地利用类型的遥感解译与分类处理，研究了该地区 1985 年-2010 年五期沙漠化土地时空变化特征，并在整理分析长时间序列气象、人口与牲畜数据基础上，进一步分析了影响土地沙漠化时空变化的驱动力，通过 Geo-SOS 模型模拟，对该地区未来 10 年的土地沙漠化状况进行了预测研究。结果表明：研究区从 1985 至 2010 年间，沙漠化土地发展趋势以 2000 年为分界点，呈现二段式分布。1985-2000 年间，沙漠化过程处于正向发展阶段，2000-2010 年间，沙漠化过程处于逆向减少阶段。沙漠化土地转化较为频繁的类型是极重度沙漠化土地与重度沙漠化土地。非沙漠化土地中，城镇用地与人工绿地一直处于增长趋势。从空间分布来看，沙漠化土地发生逆转的区域主要分布于城镇用地的周边和东南部区域，而发生沙漠化正向进程的地区则主要分布与城市的东北部及东南部区域。从自然驱动力来看，通过对该地区最高温、最低温、降雨的趋势及周期变化分析，气温的升高，降雨的减少，使该地区气候向暖干的方向发展，在这种气候环境下，极有可能促进土地沙漠化的发展；但是由于该地区有雨季和旱季之分，所以气候变化对土地沙漠化的影响存在着季节差异。该地区平均风速具有明显的阶段性，可分为偏强期和偏弱期。1980 年为转折年份，在 1960 年至 1980 年，该地区风速偏弱；1981 年到 2011 年为偏强期。流动沙丘的动态变化作为沙漠化进程的主要表征之一，其景观的斑块数量与形态的破碎度与沙漠化程度有这一定关系，流动沙丘的景观斑块数量破碎化的增大，会促使沙漠化程度的加剧。通过对该地区沙丘粒度的研究，发现该地区纵向沙丘物质组成主要以细沙和极细沙为主，该地区沉积环境则以风成和沿岸盐沼沉积为主。结合自然驱动力，在降雨量多的年份，降雨会成为该时期植被恢复的主要因素；但在降雨少或者无降雨的时期，人类活动作为沙漠化的驱动因素之一则成为了沙漠化正逆发展的主要影响因素。人口的增长，GDP 的增长，城市土地的扩张，畜牧业的发展，无一不对土地利用产生巨大的压力，特别是本身就很脆弱的沙漠化土地，这都为土地沙漠化进程ᨀ供了潜在的有利条件。综上，通过 Geo-SOS 模拟得到 2021 年模拟预测结果，结果表明在气候条件与 2000-2010 年相似等情况下，2021 年努瓦克肖特地区沙漠化土地面积总体上将呈减少趋势
三工河流域土地开发利用中的无机碳汇强度模拟
No full textThe role of terrestrial ecosystems as sources and sinks of C has played a crucial function on the global climate. Changes in land use are among the main human activities affecting the ecosystem carbon cycle. Obviously, it is essential to understand human activities affecting the carbon source and sink to release the increasing of temperature in relation to the global climate change. Accurately quantitative estimation of regional inorganic carbon sink is one of main topic in studies of global carbon cycle. Soil inorganic carbon is increasingly significant contribution to global carbon cycle. Now and next long time, it seeks carbon accumulation in the process of water cycle as one part of ―missing sink‖. But, inorganic carbon sink as dissolved part is a long-been-neglected phenomenon of the transfer and sequestration of dissolved inorganic carbon in the process of oasis development because of specific water resource consumption of inland river in arid zone.This study was conducted to quantify the contribution of land use in arid areas to regional carbon cycle in a typical inland river watershed, named Sangong River watershed in arid of the northwest of China, based on the data of simulated irrigation of soil columns and collected leaching solutions at irrigated landscapes in the process of land reclamation and utilization in the study area. Furthermore, land use change and amount of water consumed in irrigated landscape types were analyzed based on data from remote sensing image, land use, and water resources combined with field investigation. The results showed the following: (1). Oasis agricultural landscape, especially farmland dominates the region of Sangong River watershed, exploitation of land resources in area of becoming irrigated farmland expanded was from upper to lower of the watershed, and from middle to around of it. Land-use change was mainly characterized by the increasing multiplicity and fragmentation from 1958 to 2015. There have been persistent changes both spatially and temporally, resulting in 55% of the total area experiencing transitional changes among the land cover types. The general trend observed in the study area implied a loss of grassland and shrub land cover and an increase in cultivated areas. Land exploitation as socioeconomic processes are the major divers for land-use change.(2) The values of leaching inorganic carbon content and sink intensity were significantly difference under various cropland types in changes of irrigated condition. In flood irrigated condition, dissolved inorganic carbon content: planted forest corn land (19 g C m-2yr-1) , orchard land (18 g C m-2yr-1),forest nurseries land (17 g C m-2yr-1), winter wheat land (17 g C m-2yr-1), > melon land (13g C m-2yr-1) > planted forest belt land (10 g C m-2yr-1) , rice land 10 g C m-2yr-1) > oil plant land (5 g C m-2yr-1). In drip irrigated condition, dissolved inorganic carbon content:vegetable land < corn land< melon land< planted forest < sunflower land< cotton land<wheat land< rice land < oil plant land. Values of leaching inorganic carbon sink intensity in orchard land and forest nurseries land were highest in all crop land types, but were lowest in corn land and melon land.(3) In the spatial of watershed, the sink intensity and amount of annual leaching inorganic carbon were 20.1 g C m-2yr-1and 4722 T C yr-1in the process of land irrigation during 1958-2015. In Fubei farmland, the mean value of leaching inorganic carbon sink intensity was 17.5 g C m-2yr-1, with a range of 13 to 24 g C m-2yr-1(about 2 times for maximum value than minimum value) during 1961-2015, and there is a clear firstly increased then decreased trend of leaching inorganic carbon sink intensity in the process of long-term agricultural land use. The amount of annual leaching inorganic carbon in the watershed and Fubei catchment were increased by about 4 and 3 times respectively from 1961 to 2015. (4) Leaching inorganic carbon sink intensity was influenced by different factors interaction such as meteorological factors, irrigation plan, crop types, and land use history. Leaching inorganic carbon sink intensity was lower in drip irrigated condition than that in flood irrigated condition. In limited volume of water resource condition, crop types by adjusted plant structure would significantly increase leaching inorganic carbon sink intensity and amount. When area of water-saving irrigated land is 92% in irrigated land, leaching inorganic carbon sink intensity and amount would be 21.2 g C m-2yr-1and 7160 TC in the Sangong River watershed separately. In general, the amount of leaching inorganic carbon was still ‗notable amount‘ in the process of arid land development and utilization
准噶尔盆地典型生态系统大气颗粒物特征及氮沉降研究
No full textRecently, the continual worsening of environment due to natural factors and human activities, Air pollution has become one of the most serious environmental problems in China. Airborne inhalable particles (PM10), fine particulate matter (PM2.5) and atmospheric reactive nitrogen species such as NH3 and NOx will cause harm to human-bodies and the environment. While northwest China’s pollution is certainly less severe problem than the east and coastal cities, but it shows rapidly increased air pollution because of high population density and economic development. Due to the unique natural environment and more serious aridification in Xinjiang region, Nitrogen deposition can cause a series of ecological problems. This thesis selects Junggar basin as a research region, choosing eight sites from grassland, urban, desert, desert and oasis ecotone ecosystems, quantifying atmospheric reactive nitrogen concentration and deposition fluxes, through rain gauges and passive samplers; Meanwhile an urban site was chosen to monitor particulate matter concentrations and chemical compositions using a four-channel partical sampler .The objective of thesis is to provide a basis for a comprehensive understanding of atmospheric particulate matter dynamics and atmospheric reactive nitrogen (Nr) deposition in the Junggar basin. The main results of the research are as follows:1. The annual average concentration of PM2.5, PM5, PM10, TSP were 69.34, 118.57, 132. 87 and 215.86 μg m-3 in urban site, respectively. There is no significant difference in particulate matter concentration trends, but they were all highest in February and lowest in July. The annual average concentration of PM10 in desert oasis ecotone was 56.55 μg m-3. It found an obvious difference in seasonal variation, concentration of maximum and minimum value appeared in the winter and summer respectively. The annual average concentration of PM10 was 45.81 μg m-3 and there was no significant difference in seasonal variation of Oasis-desert transitional zone in Mosuowan.2. Through multi-sampling observations, it has an obvious spatial and temporal variation in concentrations of primary Nr (NH3 and NO2) in Junggar basin. The maximum value of concentration of NH3 was 9.38 μg N m-3 in desertification grassland, the minimum value was 2.2 μg N m-3 in Alpine grassland. The maximum value of concentration of NO2 was 25.58 μg N m-3 in urban, the minimum value was 0.74 μg N m-3in Alpine grassland. The concentration of particulate NH4+, NO3- were higher than in winter than other seasons.3. The concentrations of particulate NH4+ and NO3- were closely related to NH3 and NO2 concertrations. The pNH4+ concentration showed significantly positive correlations with the pNO3- concentration. 4. The total nitrogen deposition were 28.66, 26.77, 6.4 kg N ha-1yr-1 in Urumqi, Fu Kang, Jing He sampling sites, the atmospheric dry nitrogen deposition were 21.41, 17.75, 2.94 kg N ha-1yr-1, respectively. For NH4+-N, highest deposition flux occurred in winter, lowest deposition flux in summer. The wet nitrogen deposition was 7.23, 6.69, 11.13, 3.46, 6.82, 1.47 kg N ha-1yr-1 at various sampling sites. The wet nitrogen deposition was influenced by N concentration and precipitation amount
基于随机森林算法的成像高光谱蚀变信息识别技术研究
No full textRemote sensing technology has been applied to the field of geology since itappeared, and the alteration mineral information extraction is one of the mostimportant applications. How to extract the alteration mineral information quickly andaccurately is a difficult problem. With the development of science and technology, theresolution of the sensor is improved. Therefore it is possible to obtain the continuousspectrum of ground objects, which makes it possible for people to distinguishdifferent alteration minerals.According to the characteristics of the alteration information extraction, scholarshave proposed a variety of methods, such as spectral angle mapper, spectralabsorption index and spectral feature fitting. With the development of machinelearning, decision tree, artificial neural network, support vector machine, randomforest and other algorithms have been introduced into the application of remotesensing classification. The random forest is a new algorithm. Compared to thedecision tree and artificial neural network, which is more stable. The accuracy ofrandom forest is higher than that of the support vector machine, and the computationspeed is faster. It has great application potential in the extraction of hyperspectralinformation. In the process of general classification, most of the training samples areobtained from the image by a priori knowledge and visual discrimination. But theextraction of alteration mineral information is different from the general remotesensing image classification, and the conventional sample extraction methods are notapplicable to this application. Therefore, it is a problem how to extract trainingsamples accurately. In order to successfully achieve the application of random forestalgorithm in the alteration information extraction, we need to solve the problem. Inview of the above problems, a systematic study was carried out. The main researchcontents and results are as follows:（1）In this study, The performance of random forest is investigated and theclassification results are compared with the support vector machine under differentconditions. The results shows random forest has obvious advantages in operation speed and better performance, when the number of training samples used to establishclassification model by the two classifiers is similar. Therefore, random forest cansave a lot of time under the condition of ensuring the classification accuracy, and hashigh application value in the remote sensing classification.（2）A novel method is proposed by combining random forest algorithm withspectral angle mapper. In the experiment, we select training samples by spectral anglematching, then construct a random forest classification model, and carry out theexperiment using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) dataat Cuprite, Nevada. The results of the study showed that this method is valuable foridentification of alteration information.（3）HySpex hyper-spectral data were applied in practice. In the key areas, theexperiment was carried out to identify and extract the alteration information. Afterfield verification, the method is proved to be effective and has strong practicalsignificance
基于高密度 SNP 芯片的绵羊肉用性状全基因组关联分析
No full text随着羊肉需求数量的增加，绵羊肉用性状的选育工作越来越受到重视。利用标记或基因辅助选择（MAS）是快速提高绵羊肉用性能、培育优良肉羊品种的最佳途径，而标记或基因辅助选择的前提条件是肉用性状功能基因的准确定位。全基因组关联分析（GWAS）是目前畜禽功能基因快速、准确定位的主要策略和手段。本研究以特克塞尔羊（Texel）为父本、阿勒泰羊（Altay Sheep）为母本，组建了由 303 只个体组成的 F2 代资源群体。对所有个体的生长发育性状（出生重、断奶重、宰前活重、断奶前日增重和断奶后日增重）、胴体体尺（胴体长、后腿长、臀宽、胸宽、肩宽、胸深和踝骨宽）、胴体分块重（胴体重、屠宰率、脖子重、前腱重、胸腹肉重、方切肩重、脊排重、腰椎肉重、带臀腿重）、胴体脂肪（背部脂肪厚、GR 值、肠系膜脂肪重、肾周脂肪重和尾脂重）和胴体肌肉（眼肌面积、背最长肌重、大里脊重、小里脊重、针扒重、膝圆重、烩扒重、尾龙扒重和后腱重）等肉用性能共计36个性状进行测定，利用Illumina绵羊高密度（600K）SNP 芯片对分布于基因组范围内的 606006 个 SNP 位点进行基因分型。通过TASSEL 软件构建的混合线性模型，利用质控后分布于常染色体上的 530354 个SNPs 对上述 36 个肉用性状进行全基因组关联分析，筛选与目的性状显著相关的SNPs。依据绵羊基因组（Ovis_aries_v3.1）对 GWAS 中发现的显著相关 SNPs 进行基因注释，并结合功能基因组学确定候选基因。结果如下：（1）与断奶重、宰前活重（8 月龄）和胴体重在基因组水平上显著相关的 SNPs 有 3 个，初步确定KCNC2 基因是断奶重的候选基因，RAB3C 基因和 PLK2 基因是影响宰前活重和胴体重的候选基因，没有发现与出生重和日增重显著相关的 SNP。（2）与胴体长、胸深和后腿长显著相关的 SNPs 有 12 个，初步确定 MC4R 基因是影响绵羊胴体长的候选基因，NPNT 基因和 Smad5 基因是影响胸深的候选基因，TMED2 基因和 CALCRL 是影响后腿长的候选基因。没有发现与肩宽、胸宽、臀宽和踝骨宽显著相关的 SNP。（3）与背部脂肪厚、GR 值、肠系膜脂肪重、肾周脂肪重和尾脂重显著相关的 SNPs 共有 21 个，初步确定 FFAR2 基因和 SERPINA6 是影响背部脂肪厚的候选基因，CENPF 基因是影响绵羊 GR 值的候选基因，SLC6A15 基因是影响肠系膜脂肪重量和尾脂重的候选基因，PPARα和 CELSR1 基因为影响肾周脂肪重的候选基因。（4）与带臀腿重显著相关的 SNP 有 24 个，其中有 19个 SNPs 集中分布在 2 号染色体上 10 Mb（120.72Mb-130.64 Mb）的区域内，初步确定 DNAJC10、TMED2、CALCRL 和 EGF 影响带臀腿重的候选基因。没有发现与脖子重、前腱重等其它胴体切块重显著相关的 SNP。（5）与带臀腿肌肉总重及其肌肉块重显著相关的 SNPs 有 61 个，主要集中分布在 2 号染色体 13.8Mb（110.8Mb-122.2Mb）的区域内，MSTN、BIN1 和 TMED2 是影响带臀腿肌肉总重的主要候选基因。与眼肌面积显著相关的 SNP 有 5 个，MSTN 基因和 IGFBP3基因是影响眼肌面积的候选基因，没有发现与小里脊重和背最长肌重显著相关SNP。为了筛选和确定影响背部脂肪厚的数量性状核苷酸（QTN），本研究选择FFAR2 基因为研究对象，采用 PCR 扩增、Sanger 测序方法进行突变碱基的检测，利用单标记回归方法筛选与背部脂肪厚显著相关的 SNPs，并采用荧光定量 PCR方法分析 SNP 与 FFAR2 基因表达量之间的关系。结果显示，在 FFAR2 基因上共发现 23 个 SNPs，其中位于 FFAR2 基因 3’UTR 的 SNP2709（A->G）位点与背部脂肪厚显著相关。荧光定量 PCR 分析发现，SNP2709 基因型与 FFAR2 基因在背部脂肪中的相对表达水平呈正相关关系。由此推测，SNP2709 可能是影响背部脂肪厚的候选 QTN。本项研究从全基因组水平分析了与 36 个绵羊肉用性状相关的 SNP 位点和候选基因，共检测到 129 个与带臀腿肌肉总重、眼肌面积、背部脂肪厚、尾脂重等性状显著相关的 SNPs，定位到 2 号染色体的 MSTN、BIN1、CALCRL 和 TMED2基因，3 号染色体上 SLC6A15、PPARα、CELSR1、PEX5 和 GFBP3 基因及 14号染色体上 FFAR2 基因，其中与重要影响胴体品质的背部脂肪厚性状相关的基因被确定为 14 染色体的 FFAR2 基因，通过 QTN 分析、群体验证和表达水平分析初步确定了该基因的功能