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南京城市湖泊湿地的水质动态及其评价   总被引:4,自引:1,他引:3  
选取南京市玄武湖、莫愁湖、内秦淮河湿地为对象,通过定点、定时采样和水质分析等方法,对城市湖泊湿地水质的季节动态、水质影响因素及其富营养化评价等进行了研究。结果表明,TN、TP、BOD和COD是反映城市湖泊水体污染度的重要指标,TP含量过高是造成城市河湖湿地水体富营养化的主要原因。水体污染程度随季节动态表现为:夏季>春季>秋季>冬季。相对封闭的莫愁湖湿地水质的季节变化较小,但水质较差,各个季节均表现出重富营养化—严重富营养化状态;受工业或生活污水影响较大的内秦淮河湿地,水体受污染严重,全年均属严重富营养—异常富营养化;玄武湖湿地的水体,在春季和秋季均已达到富营养化水平,夏季相对较好,TN、TP为富营养化水平,其余指标为中—富营养水平。  相似文献   
2.
孙婵  徐国强 《大气科学》2019,43(1):131-141
本文针对2016年6月山西、山东地区一次强对流活动,通过GRAPES(Global/Regional Assimilation andPrediction Enhanced System)云分析系统融合了多普勒雷达反射率三维组网拼图资料和ADTD(Active DirectoryTopology Diagrammer)闪电定位资料,对模式初始场的云水、云冰等云微物理变量进行了调整和分析,并对这次强对流过程设计了3组数值试验。结果表明:(1)云分析系统在加入雷达反射率资料以后,能在模式初始场中较准确的计算模式的初始水物质;(2)闪电定位资料转换成的替代雷达反射率对原有的雷达反射率有一定的补充作用,使模式的初始场与真实状况更接近;(3)从模式降水的角度看,在加入雷达资料以后,GRAPES云分析可以显著提高6小时以内降水的模拟效果,而闪电定位资料的加入,对中雨以上量级的降水模拟有进一步的改进作用。  相似文献   
3.
The impact of warming and wetting on the ecological environment of the Qinghai-Tibet Plateau (TP) under the background of climate change has been a concern of the global scientific community. In this paper, the optimized interpolation variational correction approach is adopted for the analysis of monthly high-resolution satellite precipitation products and observations from meteorological stations during the past 20 years. As a result, the corrected precipitation products can not only supplement the “blank area” of precipitation observation stations on the TP, but also improve the accuracy of the original satellite precipitation products. The precipitation over the TP shows different spatial changes in the vegetation growing season, known as the time from May to September. The precipitation in the vegetation growing season and leaf area index (LAI) in the following month show a similar change pattern, indicating a “one-month lag” response of LAI to precipitation on the TP. Further analysis illustrates the influence of water vapor transport driven by the Asian summer monsoon. Water vapor derived from trans-equatorial air flows across the Indian Ocean and Arabian Sea is strengthened, leading to the increase of precipitation in the central and northern TP, where the trend of warming and wetting and the increase of vegetation tend to be more obvious. By contrast, as a result of the weakening trend of water vapor transport in the middle and low levels in southern TP, the precipitation decreases, and the LAI shows a downtrend, which inhibits the warming and wetting ecological environment in this area.  相似文献   
4.
孙婵  徐国强 《气象科技》2017,45(4):658-668
使用GRAPES中尺度模式对中国新疆南部的塔里木盆地2013年1、4、7、10月逐日的天气过程进行数值模拟,并与站点的实况资料对比分析,结果表明,GRAPES模式对沙漠地区的温度、风场、降水都有一定的预报能力,但也存在较明显的预报误差。GRAPES模式可以大致的预报出塔里木盆地地区2 m温度的日变化趋势,但GRAPES模拟的温度极值还存在较明显的误差;GRAPES模式对10m风场的预报,在风速较大的1月、4月和10月预报效果较好,基本可以预测出沙漠地区的风速和风向,但在风速很小的7月,模式的预报效果不理想;GRAPES模式对沙漠地区的降水预报与实况相比还存在明显的偏差,主要表现为降水空报率较高,降水中心也存在一定的偏差;GRAPES模式在沙漠地区对高空温度的预报呈现出低层温度预报误差较大,高空相对较小的特征。  相似文献   
5.
With the extreme drought (flood) event in southern China from July to August in 2022 (1999) as the research object, based on the comprehensive diagnosis and composite analysis on the anomalous drought and flood years from July to August in 1961-2022, it is found that there are significant differences in the characteristics of the vertically integrated moisture flux (VIMF) anomaly circulation pattern and the VIMF convergence (VIMFC) anomaly in southern China in drought and flood years, and the VIMFC, a physical quantity, can be regarded as an indicative physical factor for the "strong signal" of drought and flood in southern China. Specifically, in drought years, the VIMF anomaly in southern China is an anticyclonic circulation pattern and the divergence characteristics of the VIMFC are prominent, while those are opposite in flood years. Based on the SST anomaly in the typical draught year of 2022 in southern China and the SST deviation distribution characteristics of abnormal draught and flood years from 1961 to 2022, five SST high impact areas (i.e., the North Pacific Ocean, Northwest Pacific Ocean, Southwest Pacific Ocean, Indian Ocean, and East Pacific Ocean) are selected via the correlation analysis of VIMFC and the global SST in the preceding months (May and June) and in the study period (July and August) in 1961-2022, and their contributions to drought and flood in southern China are quantified. Our study reveals not only the persistent anomalous variation of SST in the Pacific and the Indian Ocean but also its impact on the pattern of moisture transport. Furthermore, it can be discovered from the positive and negative phase fitting of SST that the SST composite flow field in high impact areas can exhibit two types of anomalous moisture transport structures that are opposite to each other, namely an anticyclonic (cyclonic) circulation pattern anomaly in southern China and the coastal areas of east China. These two types of opposite anomalous moisture transport structures can not only drive the formation of drought (flood) in southern China but also exert its influence on the persistent development of the extreme weather.  相似文献   
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