Developmental Study of Instrumentation for Properties of Snow

为了预防和减轻由强降雪和深积雪引起的雪灾，尽快获得雪量和雪质的信息是非常重要的，人们已经制造了几种类型的降雪探测仪器，但它们的费用和成本对于一般的处理和观测来说还不够有效。本研究的目的是制造一种廉价、紧凑、高成本的雪花测量装置，并建立一种系统的方法，通过现场试验来分析雪的性质。1)利用现有设施对沿海和山区的雪花进行了观测，以比较区域特征。除此之外，还研究了积雪的性质，以比较区域性。2)四种不同的仪器检测雪花新制造如下。（1）红外狭缝降雪传感器（2）多红外狭缝降雪传感器（3）红外狭缝降雪传感器（4）光学传感法红外透射降雪传感器对这些检测系统进行了性能测试，发现新系统工作良好，与现有仪器相比，更有助于检测降雪强度。3)利用摄像机、图象处理器和高速微机建立了另一种分析方法。该系统能够区分不同的雪花尺寸、形状和空气中雪颗粒的密度。4)通过对不同地区日积雪深度的分析，提出了一个有效的雪灾预报指标，并将研究结果发表在参考机构。研究结果可为建立雪灾预报和减灾体系提供科学依据。

For prevention and mitigation against the snow disaster due to heavy snowfall and deep snow cover,it is of great importance to get some information about snow quantities and snow qualities as quick as possible.Several types of instruments for detecting falling snow have been made, however, the expense and cost of them are not yet efficient for general treatment and observations. The objectives of this research are of manufacturing a cheaper and compacted high expense apparatus for snow flakes and to establish a systematic method for analyzing the nature of snow through field testings.The present investigations reported herein are the following items. 1) Observations of snow flakes in both coastal and mountain side regions were performed by the existing facilities to compare regional characteristics. Besides of this work, properties of depositted snow were studied for comparing the regionalities. 2) Four different instruments for detecting snow flakes were newly manufactured as followings. (1)Infrared slit falling snow sensor (2)Multiple infrared slit falling snow sensor (3)Infrared silhoutte falling snow sensor (4)Infrared transmission snow sensor by optical sensing method Performance tests of these detecting systems recognized that new systems worked well and were more useful to detect the intensity of snow falling compare with the existing instrument. 3) An another analytical method was developed by using a video camera, an image processor and a high speed micro computer. This system is enable to distinguish the different snow flake sizes , shapes and a density of snow particles in air. 4) An effective index for snow damage forecasting were proposed by data analyses of daily snow depth depending on the regionalities.The details of this research were published and posted to reference organizations. The results obtained in this research would give the scientific information to build up the forecasting and mitigation systems of snow damages.