黄河下游窄河道挖河疏浚是维持黄河健康生命的重要措施之一

黄河水利委员会提出了“维持黄河健康生命”的治河新理念,把维持黄河健康生命作为黄河开发与管理的终极目标。“堤防不决口,河道不断流,污染不超标,河床不抬高”是实现其终极目标的4个主要标志。河床不抬高就要通过综合措施解决泥沙问题,包括上中游拦减人黄泥沙,中下游采取人工调控水沙“关系”,在黄河下游挖河疏浚。在黄河下游窄河道特别是在河口地区挖河疏浚,减少其对下游河道的反馈影响,是维持黄河健康生命的重要措施之     

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Thinning and shrinkage of Laohugou No. 12 glacier in the Western Qilian Mountains, China, from 1957 to 2007

Landsat images, real-time kinematic GPS measurements, and topographic maps were used to determine changes in ice elevation, volume, and areal extent of the Laohugou No. 12 glacier (Qilian Mountains, China) between 1957 and 2007. The glacier experienced significant thinning and areal shrinkage in the ablation zone, but slight thickening in part of the accumulation zone. Elevation decreased by 18.6±5.4 m between 1957 and 2007 in the regions covered by the GPS measurements. The total volume loss for the entire glacier was estimated to be 0.218 km3 using a third-order polynomial fit method. The area diminished by 0.28 km2 between 1957 and 1994, 0.26 km2 between 1994 and 2000, and 0.28 km2 between 2000 and 2007, suggesting that the rate of loss in glacial coverage has increased since the mid-1990s. Significant increases in annual mean air temperature may have contributed to shrinkage and thinning of the glacier.     

Effects of sea surface temperature, radiation, cloud microphysics, and diurnal variations on vertical structures of tropical tropospheric temperature: a two-dimensional equilibrium cloud-resolving modeling study

The effects of sea surface temperature (SST), radiation, cloud microphysics, and diurnal variations on the vertical structure of tropical tropospheric temperature are investigated by analyzing 10 two-dimensional equilibrium cloud-resolving model simulation data. The increase of SST, exclusion of diurnal variation of SST, and inclusion of diurnal variation of solar zenith angle, radiative effects of ice clouds, and ice microphysics could lead to tropical tropospheric warming and increase of tropopause height. The increase of SST and the suppression of its diurnal variation enhance the warming in the lower and upper troposphere, respectively, through increasing latent heat and decreasing IR cooling. The inclusion of diurnal variation of solar zenith angle increases the tropospheric warming through increasing solar heating. The inclusion of cloud radiative effects increases tropospheric warming through suppressing IR cooling in the mid and lower troposphere and enhancing solar heating in the upper troposphere. The inclusion of ice microphysics barely increases warming in the mid and lower troposphere because the warming from ice radiative effects is nearly offset by the cooling from ice microphysical effects, whereas it causes the large warming enhancement in the upper troposphere due to the dominance of ice radiative effects. The tropopause height is increased mainly through the large enhancement of IR cooling.     

Community structure changes of macrobenthos in the South Yellow Sea

The ecological environment in the Yellow Sea has changed greatly from the 1950s to 1990s and this has had significant impact on marine organisms. In this study, data on soft-sediment macrobenthos occurring in depths from 25 m to 81 m in the South Yellow Sea were used to compare changes in community structure. The agglomerative classification (CLUSTER) and multidimensional scaling (MDS) methods were applied. Five communities were recognized by cluster analysis: 1. The Yellow Sea Cold Water Mass community dominated by cold water species, which changed slightly in species composition since the 1950s; 2. The mixed community with the coexistence of cold water species and warm water species, as had been reported previously; 3. The polychaete-dominated eurythermal community in which the composition changed considerably as some dominant species disappeared or decreased; 4. The Changjiang (Yangtze) River Estuarine community, with some typical estuarine species; 5. The community affected by the Yellow Sea Warm Current. The greatest change occurred in the coastal area, which indicated that the change may be caused by human activities. Macrobenthos in the central region remained almost unchanged, particularly the cold water species shielded by the Yellow Sea Cold Water Mass. The depth, temperature and median grain size of sediments were important factors affecting the distributions of macrobenthos in the South Yellow Sea.     

生物地球化学方法与金矿找矿--以新疆西准噶尔安齐成矿断裂带为例

以新疆西准噶尔安齐成矿断裂带的生物地球化学测量工作为例,详细研究了生物地球化学找金法的样品选取,采集和分析过程及其影响因素,并对生物地球化学方法的实际找金效果进行了分析。实验表明,在干旱,半干旱地区,野薤、等是金的敏感载体植物,它们可以带来地下７０ｍ深处的地球化学信息,利用这些信息生物,可以有效地指导找矿。     

太原市城市复合生态系统调节服务时空格局演化及驱动机制研究

以太原市主城区为例,根据生态系统服务理论对太原不同土地利用类型所提供的正负生态系统调节服务价值分别进行测度计算,并综合分析城市复合生态系统调节服务的时空演化特征,最后,从直接原因(土地利用变化)和根本原因(空间城镇化、人口城镇化、产业空间组织与空间规划、政府相关政策与规划)2个方面,对太原市生态系统调节服务能力变化进行...     

基于无人机遥感的黄河下游河南段河滩地植物群落多样性研究

周期性的农业活动和水沙变化已经显著改变了黄河下游河滩地的植物群落结构,快速、准确地获取河滩地的植物群落多样性信息,可以为黄河流域生态保护和恢复提供参考依据.以位于河南省新乡市原阳县朱贵村南部的黄河下游河滩地的植物群落为研究对象,采用最大似然、人工神经网络、面向对象和随机森林分类方法,利用无人机多光谱遥感影像数据,对河滩...     

宁夏沙地主要灌木饲料林树种经济性状分析

经过对大量的野外调查数据的分析和研究，建立了宁夏沙地主要灌木饲料林树种毛条、柠条、沙柳、花棒丛生物量（鲜重）（地上部分）的多元线性回归方程，用半定位观测方法测定了这四个灌木树种丛生物量（鲜重）可食部分与不可食部分之比以及生物量的干鲜比，并给出了它们的营养成分。可为灌木饲料林的经营和管理提供理论依据。     

环胶州湾公路海上段汽车尾气的环境影响

对类比路段进行连续模拟试验,进行现场调查,给出汽车尾气主要污染物的排污强度,预测了汽车尾气中CO、C_nH_m和NO_x的扩散范围。