地下水污染修复技术研究进展——零价铁PRB技术的应用与实践

对零价铁可渗透反应墙（Fe^0-PRB）技术在地下水污染修复中的应用进行了研究和总结。研究表明该技术具有能持续原位处理、处理组分多、价格相对便宜等优势，且近年来发展迅速，在反应机理研究、PRB的结构及安装、活性材料的改进以及实践方面都取得了突破和成果。同时也分析了当前该技术的缺陷和技术难关，如某些反应机理的不明晰、实际应用中的不良表现、实际应用范围仍比较有限等。基于进展研究和问题分析，提出了该技术的研究方向和发展前景，为在中国开展该方法的研究和应用打下基础。     

Possible influence of Arctic oscillation on precipitation along the East Asian rain belt during boreal spring

Theoretical and Applied Climatology - The sandy land in the southern region of the Tengger Desert is adjacent to cities and towns, and land desertification poses a threat to the livelihood and...     

极端降水事件变化的观测研究

利用湖北1961—2014年站点逐日降水资料及人口和人口城乡构成数据,通过平均值分离、最小二乘法拟合、趋势系数和气候倾向率分析、M-K检验和累积距平检验等方法,从时空分布、趋势变化、局地特征等方面,分析了近54 a湖北极端降水的变化特征及其与城市化的关系,结果表明：(1)对于第95百分位的极端降水事件,湖北极端降水阈值的范围为43.5~85.1 mm,大部分站的阈值在暴雨雨量范围,高阈值区位于江汉平原和鄂东,低阈值区位于鄂西北,最高阈值出现在武汉站,最低阈值出现在竹山站和房县站。(2)近54 a来湖北多年平均的极端降水日(D_ep)、极端降水量(P_ep)、极端降水强度(I_ep)、最大5 d降水(R_{5 d})和雨量比均存在明显的区域特征,但I_ep、R_{5 d}的地域差异不如D_ep、P_ep明显。鄂西南南部以及鄂东南东部和南部是极端降水事件的高发区,鄂西北北部是极端降水事件的低发区。(3)极端降水指数(R)能反映极端降水的强弱,其大尺度存在明显的年际差异,而长期变化趋势不显著,P_ep、I_ep和雨量比呈弱增加趋势,R_{5 d}和极端降水频数呈弱减少趋势。(4)城市化发展速度会改变R及其局地距平百分比DR_ij、趋势系数和气候倾向率的空间分布。随着城市化发展速度加快,湖北城市“雨岛效应”的格局发生了变化,D_ep、P_ep、I_ep、R_{5 d}及其DR_ij从南北差异明显变为东西差异明显,江汉平原和鄂东的D_ep、P_ep、I_ep、R_{5 d}增加,而鄂西南的减少,且四者趋势系数通过显著性水平检验的站点数更多,气候倾向率绝对值也普遍增大,但大部分站点的变化趋势为负值。(5)湖北极端降水具有明显的城市效应,城市化发展速度较快的大城市代表站的极端降水阈值大于配对的小城市代表站,两种代表站平均的D_ep、P_ep、I_ep、R_{5 d}的年际变化较一致,但大城市代表站的I_ep、R_{5 d}普遍较大,极端降水的变化趋势更明显。

     

IMPACTS OF TWO TROPICAL CYCLONES EXPERIENCING EXTRATROPICAL TRANSITION DURING NORTHWARD PROGRESSION ON THE RAINFALL OF LIAODONG PENINSULA

Both of Typhoon Winnie (9711) and Matsa (0509) underwent an extratropical transition (ET) process when they moved northward after landfall and affected Liaodong Peninsula. However, Matsa produced half as much rainfall as Winnie, although it struck Liaodong Peninsula directly while Winnie passed through the Bohai Sea. The relations between the ET processes and the precipitation over Liaodong Peninsula are examined. The result shows that the precipitation difference between Winnie and Matsa was closely related to the interactions between the westerly systems and typhoons during their ET processes. Winnie was captured by the upper westerly trough and then coupled with it when moving to the mid-latitudes, and the positive anomaly of moist potential vorticity (MPV) was transported downward from the upper troposphere over the remnant circulation of the tropical cyclone (TC). It was favorable to the interaction between tropical warm and wet air and westerly cold air, causing convective cloud clusters to form and develop. The rain belt composed of several meso-β cloud clusters over the Liaodong Peninsula, resulting in heavy rainfall. On the other hand, Matsa did not couple with any upper trough during its ET process and the positive anomaly of MPV in the upper troposphere and its downward transfer were weak. Only one meso-β cloud cluster occurred in Matsa’s rain belt during its ET process that tended to lessen rainfall over Liaodong Peninsula.     

暴雨模拟中积云对流参数化方案的对比试验

利用WRF中尺度数值预报模式,选用七种微物理方案及网格嵌套技术分别与Kain-Fritsch(new Eta)、Betts-Miller-Janjic、Grell-Devenyi（简称KF、BMJ、GD方案）三种积云对流参数方案匹配,对2007年6月1—2日湖南南部的暴雨过程进行了模拟试验。模拟结果表明：选用Lin等微物理方案和三种积云方案,采用20 km的格点分辨率,基本上可以模拟这场暴雨的范围,且采用网格嵌套技术的模拟结果优于未采用嵌套的模拟结果;其中KF方案模拟的强降水位置、强度与实况比较接近;BMJ方案模拟的强降水范围偏大、强度偏强,位置偏南,上述两种方案都不同程度地存在着虚假的暴雨中心;GD方案模拟的强降水范围、强度均偏小。     

Grassland productivity in an alpine environment in response to climate change

Situated in a climatically stressful environment, alpine grassland is sensitive to subtle climate changes in its productivity. We remedy the current deficiency in studying grassland productivity by taking the integrated effect of all relevant factors into consideration. The relative importance of temperature, rainfall and evaporation to the alpine grassland productivity in western China was determined through analysis of their relationship with the normalized difference vegetation index (NDVI) between 1981 and 2000. Climate warming stimulated grassland productivity in the 1980s, but hampered it in the 1990s. Temperature is more important than rainfall to grassland productivity early in the growing season. However, their relative importance is reversed late in the growing season. Monthly summer month rainfall modified by maximum monthly temperature is a good predictor of alpine grassland productivity at 62.0 per cent. However, the best predictor is water deficiency, which is able to improve the estimation accuracy to 78.3 per cent. Hence, the impact of temperature on grassland productivity is better studied indirectly through evaporation.     

区域产业布局优化及理论依据分析

目前关于产业布局的理论多强调其经济效益,在一定程度上忽视了环境效益和社会效益。从经济、社会与环境协调发展的角度对产业布局优化的内涵进行阐释,并论述实现区域产业布局优化的经济学、环境学及生态学理论依据。     

黄河中下游沿线城市水资源利用效率的时空演变及影响因素

采用超效率DEA模型、GIS空间分析方法、动态面板的系统GMM估计方法对2010—2017年黄河中下游沿线城市水资源利用效率时空格局及影响因素进行分析,结果表明:①黄河中下游沿线城市水资源利用效率整体由2010年的0.70波动下降为2017年的0.67,且区域内70%以上的城市水资源利用效率变动趋势与其一致;②黄河中下游沿线城市水资源利用效率呈"U"型区域两侧相对较高,中间区域相对较低的空间分布态势,且空间分布重心始终位于地理重心的北方;③环境规制、经济发展水平、产业结构优化、技术水平对水资源利用效率呈显著正向影响,农田水利设施建设、城镇化对水资源利用效率呈显著负向影响。研究结论可为黄河流域生态保护与高质量发展的推进提供决策支持。     

Effects of current climate,paleo-climate,and habitat heterogeneity in determining biogeographical patterns of evergreen broad-leaved woody plants in China

Journal of Geographical Sciences - Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for...     

Integration of InVEST-habitat quality model with landscape pattern indexes to assess mountain plant biodiversity change: A case study of Bailongjiang watershed in Gansu Province

Journal of Geographical Sciences - Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious...