环境检测数据审核中的常见问题及质量提升

环境检测工作进行中会产生大量的数据信息,这不仅是环境保护中的重要依据,更承载着环境检测工作成果,基于此,环境检测数据至关重要,数据的真实性及完整性,能够产生对环境检测工作及环境保护的直接影响,需通过审核提高环境检测数据的可靠性。但是在环境检测数据的获取、整合处理及审核阶段,极易因相应不良因素的影响,出现数据问题,降低环境检测工作的质量。本文就通过分析环境检测数据审核中的常见问题,提出质量提升措施,以保证环境检测及环境保护工作顺利进行。

Improvement of Glacial Lakes Detection under Shadow Environment Using ASTER Data in Himalayas, Nepal

The detection of glacial lake change in the Himalayas, Nepal is extremely significant since the glacial lake change is one of the crucial indicators of global climate change in this area, where is the most sensitive area of the global climate changes. In the Hima- layas, some of glacial lakes are covered by the dark mountains＇ shadow because of their location. Therefore, these lakes can not be de- tected by conventional method such as Normalized Difference Water Index （NDWI）, because the reflectance feature of shadowed glacial lake is different comparing to the ones which are located in the open flat area. The shadow causes two major problems： 1） glacial lakes which are covered by shadow completely result in underestimation of the number of glacial lakes; 2） glacial lakes which are partly iden- tified are considered to undervalue the area of glacial lakes. The aim of this study is to develop a new model, named Detection of Shadowed Glacial Lakes （DSGL） model, to identify glacial lakes under the shadow environment by using Advanced Space-borne Ther- mal Emission and Reflection Radiometer （ASTER） data in the Himalayas, Nepal. The DSGL model is based on integration of two dif- ferent modifications of NDWI, namely NDWls model and NDWIshe model. NDWI~ is defined as integration of the NDWI and slope analysis and used for detecting non-shadowed lake in the mountain area. The NDWIshe is proposed as a new methodology to overcome the weakness of NDWI~ on identifying shadowed lakes in highly elevated mountainous area such as the Himalayas. The first step of the NDWIshe is to enhance the data from ASTER 1B using the histogram equalization （HE） method, and its outcome product is named AS- TERho. We used the ASTERhe for calculating the NDWIhc and the NDWIshe. Integrated with terrain analysis using Digital Elevation Model （DEM） data, the NDWIshe can be used to identify the shadowed glacial lakes in the Himalayas. NDWIs value of 0.41 is used to identify the glacier lake （NDWI~ 〉 0.41）, and 0.3 of NDWIshe is used to identify the shadowed glacier lake （NDWIsho 〈 0.3）. The DSGL model was proved to be able to classify the glacial lakes more accurately, while the NDWI model had tendency to underestimate the presence of actual glacial lakes. Correct classification rate regarding the products from NDWI model and DSGL model were 57% and 99%, respectively. The results of this paper demonstrated that the DSGL model is promising to detect glacial lakes in the shadowed en- vironment at high mountains.

Wireless environmental monitoring system for transformer substation based on acoustic sensor

In this paper, an indoor environmental monitoring solution is proposed for the transformer sub- station system by using the ZigBee technology. It mainly analyzes the principle of sulfur hexafluoride sensor based on the acoustic method and puts forward a difference data processing method of single- channel and temperature compensation point at power consumption issues for sensor detection. The method not only reduces the sensor power consumption, but also ensures the accuracy and extends the lifetime of wireless sensor nodes effectively. This paper also analyzes the design of the base sta- tion mode, and demonstrates the running processes of routers and sensors. The feasibility of the pro- posed approach has been testified and proved.

基于红外图像的井下电缆故障检测装置在煤矿井下供电系统中的应用标准

本论文主要讲述了针对目前井下供电系统电缆故障检测手段单一,检测效率低的问题,设计研制了一种基于红外图像的井下电缆故障检测装置,该装置包含电流参数检测模块、环境数据检测模块、主控模块、红外图像采集模块、电机驱动模块和供电模块,能对所选定的供电线路电缆的电流参数、环境数据、温度等数据的实时检测和数据上传,从而实现对井下电缆的故障检测及图像数据的采集,为电缆故障的准确定位和快速排查提供可靠的依据。