Joint study on snow damages in northeastern part of China

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A joint project was carried out on snow damages in northeastern part of China during a period of three years from 1992 to 1994. This project dealt with snow and snow-related problems such as snow deposit, snow flow, snowmelt runoff, water quality, acid precipitation, frost damages, extruded ice (ice hill), weather conditions and so on.In this district, precipitation is high in summer and very few in winter. Snow depth measured along the survey route was between 10cm and 25cm in February of 1993. Snow layrs in snow cover were divided into three types from the snow surface to the bottom. It is characterized that the depth hoar extremely devel oped at the bottom of snow cover.The pH values of snow cover were between 5 and 7. Concentrations of Ca^<2+> and Mg^<2+> in snow were very high. It can be consi dered that these high pH-values were influenced by high alkaline soil, manure or coal ashes.Water from a spring or river freezes up in a moutainous area by a chill of winter season and devel … More ops furthermore into a ice hill. This phenomenon is called to be slaver-flow-ice (extruded ice) in China. This develops to the road top and brings a traffic obstacle. These ice was able to be classified into some kinds by a place and development requirements. Prevention of this disaster is possible by carrying out large scale improvement construction of ground conditions. But we proposed that the cheap prevention way must be selected in China.A drift by a snowstorm causes two problems ; a traffic obstacle and a delay of cultivation of field in spring. Relations among the forms of road, row of trees and drift were investigated. Wind velocity distribution and a quantity of drift were measured in the windbreak forest. We need to seek for the reasonable constitution and arrangement of windbreak forest by increasing observation example.Many knowledges were acquired on characteristics of forest damages on concrete structures and buildings, methane emissions from soils, horest feave amount of soil in seasonally frozen ground, the influence of precipitation on the quality of phreatic water, the relation among acid precipitation meteorological elements and weather conditions and so on. A symposium about this project was held in Japan, and the result report was published. Less