南宁市空气质量状况分析

总结分析2002—2009年南宁市逐日及月平均、季平均、年平均空气质量状况。2002—2009年,南宁市空气质量优良率为96．8％,首要空气污染物主要为可吸入颗粒物和二氧化硫,而又以可吸入颗粒物居多。在2002年至2009年,西乡塘区是南宁市空气质量最好的城区,江南区是南宁市空气质量最差的城区。2005年以后,南宁市全...     

激光雷达在大气混合层探测中的应用

利用香港的激光雷达资料,结合当地的探空资料和天气资料,分析激光雷达在观测大气混合层厚度及其特征。     

藤县暴雨的统计特征分析

利用藤县1981～2010年30a的降水资料,对藤县的暴雨分布特征及影响天气系统进行统计分析,以了解藤县暴雨的时空分布特征和发生发展规律,最近30a,藤县各年代的累计暴雨日数是逐渐减少的,最近10a的暴雨日数比上世纪八十年代少了19％。在前汛期（4～6月）,藤县暴雨主要是以西风带系统为主,而在后汛期（7～9月）,热带系...     

贺州自动站替换人工观测对资料连续性影响分析

对贺州站2004～2005年自动站与人工站平行观测的气温资料进行资料差异性分析,对气温月、日平均值及其平均差值进行了显著性检验,结果表明自动站气温和人工站气温数据差异性不显著,资料的连续性很好,但仍存在一定的系统误差.如能采用适当的方法进行订正,将极大地提高资料的可用性.     

承压井水位对含水层潮汐应力响应是否满足不排水条件的检验

以Hsieh模型为基础,提出了利用地震前后承压井水位潮汐分波的振幅及初始相位变化与否作为判断依据,检验井水位对含水层潮汐应力响应是否满足不排水条件的简便方法.将该判别方法用于分析会理川-06井和川-18片水位观测数据,利用Baytap-G潮汐分析方法分别计算出3次选定地震前后两井水位各分波(M2和O1)振幅和相位值.结...     

Logistic regression model for predicting the failure probability of a landslide dam

Landslides may obstruct river flow and result in landslide dams; they occur in many regions of the world. The formation and disappearance of natural lakes involve a complex earth–surface process. According to the lessons learned from many historical cases, landslide dams usually break down rapidly soon after the formation of the lake. Regarding hazard mitigation, prompt evaluation of the stability of the landslide dam is crucial. Based on a Japanese dataset, this study utilized the logistic regression method and the jack-knife technique to identify the important geomorphic variables, including peak flow (or catchment area), dam height, width and length in sequence, affecting the stability of landslide dams. The resulting high overall prediction power demonstrates the robustness of the proposed logistic regression models. Accordingly, the failure probability of a landslide dam can also be evaluated based on this approach. Ten landslide dams (formed after the 1999 Chi-Chi Earthquake, the 2008 Wenchuan Earthquake and 2009 Typhoon Morakot) with complete dam geometry records were adopted as examples of evaluating the failure probability. The stable Tsao-Ling landslide dam, which was induced by the Chi-Chi earthquake, has a failure probability of 27.68% using a model incorporating the catchment area and dam geometry. On the contrary, the Tangjiashan landslide dam, which was artificially breached soon after its formation during the Wenchuan earthquake, has a failure probability as high as 99.54%. Typhoon Morakot induced the Siaolin landslide dam, which was breached within one hour after its formation and has a failure probability of 71.09%. Notably, the failure probability of the earthquake induced cases is reduced if the catchment area in the prediction model is replaced by the peak flow of the dammed stream for these cases. In contrast, the predicted failure probability of the heavy rainfall-induced case increases if the high flow rate of the dammed stream is incorporated into the prediction model. Consequently, it is suggested that the prediction model using the peak flow as causative factor should be used to evaluate the stability of a landslide dam if the peak flow is available. Together with an estimation of the impact of an outburst flood from a landslide-dammed lake, the failure probability of the landslide dam predicted by the proposed logistic regression model could be useful for evaluating the related risk.     

环境与灾害监测预报小卫星CCD数据质量评价

中国环境与灾害监测预报小卫星星座双星4部CCD传感器具备大范围、全天时环境与灾害监测等方面的能力,在空间覆盖与重复观测频率方面有很大的优势。结合美国陆地卫星TM数据,从几何精度、辐射质量2个方面定量分析了该卫星CCD传感器的数据质量。结果表明：①环境减灾卫星CCD数据无波段错位现象,有极小的畸变与扭曲（0.05%）,然...     

A wind tunnel study of aeolian sand transport on a wetted sand surface using sands from tropical humid coastal southern China

This article reported a wind tunnel test of sediment transport related to surface moisture content and wind velocity using sands from tropical humid coastal area. A 1 mm-thick portion of surface sand was scraped using a self-made sediment sampler, and the gravimetric moisture content was determined. Sand transport was measured via a standard vertical sand trap with a 60 cm height. The result shows that the sand transport profile above the wet surface can be expressed with an exponential equation. In general, the influence of moisture content on sand transport profile mainly focuses on the bottom of the blowing sand cloud. Meanwhile, with moisture content increased, total sand transport dropped, and a relatively larger proportion is transported at greater heights. The vertical movement of particles on higher moisture surface (0.587% < M < 1.448%) is more sensitive to moisture content variation as compared to those on low wet surface (M < 0.587%), total sand transport rate tends to be rather low (0.99 g cm⁻¹ s⁻¹) when M > 1.448%. The total sand transport rate varying with moisture content is divided into three regions of differing gradient at the moisture contents of 0.587 and 1.448%. The gradient of the curve reflected the different influences of the various water forms in surface sediments. The higher moisture surface (M > 1.448%) merely functions as a transport plain for the saltation material. Surface moisture content was the dominant control factor for saltation activity between the moisture contents of 0.587 and 1.448%, wind velocity could resume control saltation after the surface dried to the extent (M < 0.587%).     

江苏省煤炭资源保障程度及勘查研究

通过对江苏省煤炭需求和资源保障程度的分析,对省内资源潜力进行了预测评价,提出了煤炭资源勘查近期和中长期勘查部署方案。建议将赋有优等资源的徐沛区作为下一步工作重点区域,尤其是资源量较多的区域,更应优先考虑;苏南区预测储量有限,且分布零散,含煤性差,近期可不考虑投入工作,已有的工作成果可作为中长期远景规划的依据。     

新型PTH-Ⅵ型气象参数测量仪的研制

介绍一种新型气象参数测量仪的主要技术指标和功能特点.该仪器使用了高准确度的HD9008TR温湿度传感器、MS5534C气压传感器,采用先进的电子线路设计,具有准确度高、稳定性好、可扩展性强、性能价格比高等特点,满足常规气象监测.