黑河上游降水同位素特征及其水汽来源分析

为了加深对黑河上游水循环过程的理解, 以研究区5个站点2015年8月至2016年8月的降水同位素实测数据和气象数据为基础, 除对降水同位素特征进行分析外, 主要利用TrajStat软件中的后向轨迹计算模块与潜在源贡献因子分析（PSCF）方法, 对研究区降水的水汽来源进行了分析, 并结合水汽通量等方法进行了补充分析。结果表明： 降水同位素呈夏高冬低趋势, 大气水线斜率（8.02）和截距（11.02）均高于全球大气水线的斜率（8.00）和截距（10.00）, 存在温度效应（δ¹⁸O=0.43x-10.82, r=0.54, P<0.0001）, 不存在降水量效应（δ¹⁸O=-0.05x-7.81, r=0.03, P<0.0001）; 研究区降水受多种水汽影响, 西风水汽影响最大。夏季除受西风水汽影响外, 还受东南季风水汽影响显著且水汽来源复杂; 研究区夏季的潜在蒸发源地集中在一些相对湿度和蒸发量较大的地区, 如祁连山区、 河西地区、 柴达木盆地北部、 青藏高原东南部及酒泉地区西南部等; 当降水量小、 温度高时, 持续性降水的大气水线方程的斜率和截距较小, 暴雨稳定同位素值较贫化, 受东南季风水汽影响最大, 其次是北方和西风水汽, 多种水汽辐合是暴雨事件发生的必要条件。     

Potential impact of climate change on snow cover area in the Tarim River basin

Two data sets, annual temperature and precipitation time series from 19 observation stations in the Tarim River basin covering 1958 through 2002, were investigated by non-parametric tests to detect the trend and features of climate change and variability. Based on these data, the snow cover area (SCA) in situ for the period 1982–2001 was further analyzed to examine the effect of climate change on snow. The results showed that both the temperature and precipitation had a jump in the mid 1980s and significantly increased in winter and summer, respectively. The SCA of the entire basin showed a slowly increasing trend. Responses of the SCA to temperature and precipitation in the northern, western and southern regions showed that the effect of precipitation on SCA is larger than that of temperature. In vertical direction, the SCA in the zone below 2,500 m a.s.l. kept a slow increase, but that in the zone above 2,500 m a.s.l. was inching down. Comparatively, the lower altitude zone was apt to be affected by precipitation, while the higher altitude zone tended to be influenced by temperature. The mid zone from 2,500 to 5,000 m was the area most sensitive to and affected by climate change. Compared with that in the 1980s, both the snowing and melting rates were higher in the 1990s. Correlation analysis implied that the SCA change in the cold season was positively correlated with the contemporary precipitation change, but had no strong correlation with the contemporary temperature change.     

氨氮在弱透水层中的渗透迁移规律研究

通过渗透试验、吸附试验和高压动态土柱试验对氨氮在弱透水层中的渗透、迁移转化规律进行研究。试验结果表明,弱透水层对氨氮具有很强的吸附能力;弱透水层中生物作用微弱,弱透水层对氨氮的去除主要是非生物作用的结果;硬度或其他交换性离子的作用会影响氨氮在弱透水层的穿透时间和吸附稳定性。此研究对揭示深层地下水的氮污染规律及探索地下水污染修复提供理论支持。     

Evolvement characteristics of population and economic gravity centers in tarim river basin, uygur autonomous region of xinjiang, China

Using the data at the county levcl and the regional gravity center model, we calculated six key socio-economic gravity centers, namely population, GDP, output values of primary, secondary and tertiary industries, and arable land area in the Tarim River Basin for each year from 1980 to 2009. We inspected the spatial dynamics of these centers and found that the gravity centers of population and economy evolved simultaneously. The disproportional growth between the population and the economy is also analyzed. The results show that： 1） The gravity centers of the GDR the output values of the main three industries and arable land area show migration trending from southwest to northeast, while the population gravity center shows an excessive growth in the southwest during the same time period. The migration amplitude of the GDP and output values of primary industry, secondary industry, tertiary industry are measurably higher than that of the population. 2） The population gravity center has a negative correlation with the gravity centers of secondary and tertiary industries output values in both longitudinal and latitudinal directions, and a positive correlation with that of primary industry output value in the longitudinal direction. Based on the analysis of correlation coefficient and offset distance, the imbalance between the population and the economy has increased since the 1980s, with regional economic differences now exceeding the international cordon.     

基于系统动力学的新疆焉耆县水资源需求分析

应用系统动力学方法,建立了县域水资源利用SD模型,并对焉耆县主要的水资源利用系统中的农业需水量、工业需水量、生活需水量、牲畜需水量和生态需水量进行了仿真模拟,分析了焉耆县未来20年中各用水系统的动态趋势。通过仿真模拟可以看出,农业用水是该县的主要用水,用水量高达90％以上。农业用水量决定着总需水量的变化趋势,并极大地影响着水资源的供需关系;  其他方面需水量在未来20年中虽有大幅度增长的趋势,但所占比例很小,不能对总供需水关系产生明显的影响。从供水角度讲,提高地表水和地下水联合开发比例,可以较大缓解供水压力。文章旨在运用系统动力学方法,通过建立SD模型,为认识焉耆县水资源供需现状及发展趋势提供一种途径。     

Spatial variability of soil carbon to nitrogen ratio and its driving factors in Ili River valley,Xinjiang, Northwest China

Soil carbon to nitrogen(C/N) ratio is one of the most important variables reflecting soil quality and ecological function,and an indicator for assessing carbon and nitrogen nutrition balance of soils.Its variation reflects the carbon and nitrogen cycling of soils.In order to explore the spatial variability of soil C/N ratio and its controlling factors of the Ili River valley in Xinjiang Uygur Autonomous Region,Northwest China,the traditional statistical methods,including correlation analysis,geostatistic alanalys and multiple regression analysis were used.The statistical results showed that the soil C/N ratio varied from 7.00 to 23.11,with a mean value of 10.92,and the coefficient of variation was 31.3%.Correlation analysis showed that longitude,altitude,precipitation,soil water,organic carbon,and total nitrogen were positively correlated with the soil C/N ratio(P 0.01),whereas negative correlations were found between the soil C/N ratio and latitude,temperature,soil bulk density and soil p H.Ordinary Cokriging interpolation showed that r and ME were 0.73 and 0.57,respectively,indicating that the prediction accuracy was high.The spatial autocorrelation of the soil C/N ratio was 6.4 km,and the nugget effect of the soil C/N ratio was 10% with a patchy distribution,in which the area with high value(12.00–20.41) accounted for 22.6% of the total area.Land uses changed the soil C/N ratio with the order of cultivated land grass land forest land garden.Multiple regression analysis showed that geographical and climatic factors,and soil physical and chemical properties could independently explain 26.8%and 55.4% of the spatial features of soil C/N ratio,while human activities could independently explain 5.4% of the spatial features only.The spatial distribution of soil C/N ratio in the study has important reference value for managing soil carbon and nitrogen,and for improving ecological function to similar regions.     

北京城市建筑密度分布对热岛效应的影响研究

“热岛效应”是现代城市气候的主要特征之一,本文基于高分辨率遥感影像,通过人工目视解译获取了北京市五环内的不同建筑密度区,进而结合遥感反演获得的地表温度数据,分析了城市建筑密度分布与城市热岛效应及其变化之间的关系。结果表明,北京市五环内的建筑以中密度区为主,高密度区次之,各建筑密度区在不同环线之间的分布也有较大差异。高密度区主要分布在二环以内,中密度和低密度建筑区主要分布在二、三环之间,高层建筑区总体分布较少,主要分布在二、三环和三、四环之间。城市建筑区的地表温度与建筑密度呈现显著正相关关系,城市建筑密度越大,其地表平均温度就越高,北京市高密度区的平均温度达到30.5 ℃,而高层建筑对热岛强度具有一定的缓解作用,北京高层建筑区的平均温度为28.32 ℃,比高密度区低2.18 ℃。从热岛强度变化来看,总体上高密度区、中密度区和低密度区的热岛强度均为增强的趋势,其中高密度区热岛强度增加的幅度最大,热岛强度增加了0.56 ℃,只有高层建筑区的热岛强度表现为减弱趋势,热岛强度降低了0.07 ℃。     

天山北坡春季雪洪形成的气候因子分析

春季融雪洪水是天山北坡积雪水文特征之一，有时形成灾害，造成一定财产损失和人员伤亡。本文根据天山北坡乌鲁木齐附近不同海拔四个气象台站冷季降水、蒸发、积雪和气温等资料，分析了春季融雪洪水规模及其产流的时空分布状况。     

塔里木河下游植物群落分布格局及其环境解释

研究表明,塔里木河下游地区共有植物18种,分别隶属于9科、15属。其中藜科 (Chenopodiaceae)、柽柳科 (Tamaricaceae)、豆科 (Leguminosae) 3个科有10种,约占所有种数的56%,反映了干旱区旱生耐盐种类占优势的特点。样地排序结果表明,沿样地CA第一排序轴,所有18个调查样地可划分为3种类型,分别对应3种不同地下水位,即浅地下水位区 (<3 m)、中地下水位区 (3~5 m) 和深地下水位区 (>5 m),不同的植被类型组合亦分别对应不同类型的地下水位。CCA排序表明,影响该地区植物群落分布格局的环境因子主要是地下水位、土壤含水量、土壤pH值。CCA排序分析可将18种植物分为4个组,分别对应于不同的环境因子变化梯度。从管理的角度出发,在塔里木河流域下游地区进行受损生态系统的恢复与重建过程中,要重点考虑到上述提及的主要环境因子,尤其是重视水资源的合理开发与利用,采用适宜的灌溉方式,防止地下水位下降和土壤盐渍化的发生。     

灰色聚类在洪水灾害等级划分中的应用

基于灰色系统理论,阐述了灰色聚类分析的基本原理和步骤,并结合新疆“９６．７”特大暴雨洪水典型地州市灾害等级划分的实例,对其进行了应用分析。最后得出此次暴雨洪水灾害中典型地州市的聚类系数和灾度等级表,取得了良好效果。这表明灰色聚类分析是灾害等级划分问题的一条有效解决途径。