Debris flows along the Sino-Pakistan Highway have developed with various types and seriously affected the tourism and trade through the China-Pakistan Economic Corridor. Based on morphological features of debris flow gully profiles along the highway, in this paper, the morphological characteristics and activity level of debris flows has been revealed, the causes and hazards of debris flows have been discussed from regional geology, topography, meteorological factors and so on. It is found that the major types of debris flow along Aoyitake-Bulunkou Section of the Sino-Pakistan Highway can be divided into rainfall type (26 gullies) and glacial type (27 gullies). Glacial type debris flow has powerful activity, i.e., the ratio of glacial debris flow shape index N ≥ 1 accounting for 81% of the total glacier gullies, and most of them being concave parabolas; rainfall type debris flow has less activity, i.e., the ratio of rainfall debris flow shape index N ≥ 1 accounting for 50% of the total glacier gullies, and most gullies shapes being convex parabolas. A large fall, rich material supply and plenty of water supply have significant influence on the development and activity of debris flows and they are also controlling factors for the difference in activity among various types of debris flows. The research results would be useful for debris flow forecast and control along the highway in the China-Pakistan Economic Corridor and be helpful for traffic engineering route selection and debris flow control.

Glacier lake outburst floods (GLOF) is one of the major disasters in the Tibetan Plateau, which results in a serious threat to people's life and property. The size of the surge caused by glacier collapse is the most important factor of GLOF. However, due to its remote location, long interval time and strong randomness, there is no in-situ observation till now. So far, the research about the size of the surge caused by ice collapse is fruitless till now. By using the finite volume method and CFD software Fluent, the surge process of Jialong Co when the feeding glacier collapsed has been simulated. Process of the initial surge has been analyzed, as well as, the surge wave propagation along the path and the height of the surge at the opposite bank. The results have been compared with the calculation given by PAN Jiazheng's method. Finally, it was found that the numerical simulation could well reproduce the surge wave formation, scale, propagation and slope climbing, so it is believed that the simulation would provide new ideas for the risk assessment and the study of GLOF.

Based on daily data from 96 meteorological stations from 1961 through 2015, the meteorological element variations in relation to freezing rain occurred in southwest China were analyzed by using fuzzy information distribution method, in order to establish freezing rain weather assessment indexes. The results show that a comprehensive meteorological threshold condition can be used to assess freezing rain weather, i.e., the daily average temperature less than or equal to 2℃, daily maximum temperature less than or equal to 8℃, daily minimum temperature less than or equal to 0℃, relative humidity more than or equal to 80% and sunshine hours less than or equal to 2 hours. The number of days with freezing rain has a unimodal variation from November through March. In the southern margin of Sichuan Basin, the vast majority of Yunnan-Guizhou Plateau and the eastern Hunan Province, there is a high freezing rain index, indicating that there is a serious area suffering from freezing rain. Temperature in the Tibet Plateau and the Western Sichuan Plateau is low, but the relative humidity is small, and the sunshine time is long, which does not meet the conditions of freezing rain. Therefore, the risk of freezing rain is small. In recent years, the intensity of freezing rain in Southwest China has been decreasing. The indexes can be used to reconstruct the freezing rain intensity index sequence in various sites, and thus to evaluate the spatial distribution of freezing rain disaster in Southwest China.

Based on the statistical datasets of Hail disaster area, total disaster area, crop planting area, GDP and the hail frequency of Hail for each city in Xinjiang, the hail disaster economic loss index and risk index were constructed, while the hail disaster in Xinjiang were also accessed. The former index could be used in reviewing the changing tendency of hail disaster economic loss, while the latter could indicate the hail disaster risk zone with the virtue of GIS special information processing technology. It is showed that, the hail disaster economic loss generally ascends with great impact from environmental instability, while keeping fine positive correlation with each other. The overall risk of hail disaster in Xinjiang is mainly medium and low risk, followed by high risk. High risk areas are mainly concentrated in the horned valley area Yili and those region that around the vally, that is Akesus and Bozhou. It is suggested to reduce hail damage in these areas by adjusting the structure of agricultural industry and improving the capacity of artificial hail suppression.

In recent years, there is a warm and wet tendency over the Tibetan Plateau, as a result, the lake levels extensively rise up and dike burst happens occasionally. In this study, the TM(ETM+)history document data and environmental mitigation satellite(HJ-1A/B)CCD data in the Zonag Lakes(including Kusai Lake, Hedin Noel Lake and Yanhu Lake), combined with the air temperature, precipitation data from Wudaoliang Meteorological Station, were used to analyze the variation of lake surface area. The results showed that from 1961 to 2012, precipitation had increased in Hoh Xil, which was the basis of the Zonag Lake outburst. Two strong precipitation processes occurred before August 22, 2011 and then followed by a continuous precipitation, which led to a substantial leakage of the lakes, and finally led to outburst. There were two earthquake events before the dike burst, which may have a certain influence on the basin structure of the lakes, accelerating the dike burst process. Outburst of the lake led to shoreline retreat and land desertification, which deteriorated the Tibetan antelope farrowing environment and resulted in adverse impact on the surrounding grassland ecology environment and major engineering projects.

According to the economic loss caused by snow disaster and the frequency of snow disaster from 1951 to 2014 in Liaoning Province, the average loss and meteorological disaster index, the meteorological disaster loss of the prefectures and counties of the province were calculated as a snow disaster index for zoning. Based on the data from 58 national weather stations (daily snowfall ≥5 mm) in Liaoning Province and Liaoning Province snow disaster information from 1951 to 2014, snow disaster was zoned, the thresholds for various zones were determined and snowfall impact pre-assessment was done by using statistical analysis and other methods. The results show: (1) Severe disaster areas and moderate disaster areas are mainly located in urban clusters or economically developed regions in the center of the province, with annual average loss of 2.8 million yuan or more, which should belong to severe loss area. Mild disaster and micro disaster areas are mainly located in eastern mountainous and northwestern mountainous of the province, with annual average loss of 0.68 million yuan or lesser, which should belong to milder loss area. Highways is most damaged by snow disaster, followed by agricultural facilities. (2) Using snow disaster hazard threshold and the snow damage rank in the disaster zones to pre-assess the snowfall impact, together with the quantitative precipitation forecast pre-assessment results generated automatically, will improve the decision-making meteorological service.

Secondary geohazards, such as thaw settlement, frost heave, frost mound and icing, have occurred in permafrost regions along the China-Russia Crude Oil Pipeline (CRCOP) since January, 2011, when the pipeline began to operate. The construction and operation of the pipeline with a seasonally fluctuating warm oil temperature have broken the hydrothermal balance of the ground, resulting in differential frost heave and thaw settlement of the foundation soils around and under the pipeline. The accumulation of the differential displacement may cause damage to the pipeline. A frost mound in the Site MDX364 near Jagdaqi city, Heilongjiang Province, Northeast China, was sounded by using the EKKO 100 ground-penetrating radar. The mechanisms of the frost mound were discussed and then three relative mitigative measures were proposed in detail. This study is useful for construction, design, operation and maintenance of the CRCOP and other similar oil and gas pipelines in permafrost regions.

As China's ongoing electric transmission lines constructed in permafrost regions, the issues related to permafrost are concerned increasingly. The general disasters of thawing and freezing in the transmission lines constructed in permafrost regions and the solutions are analyzed in this paper. It is found that since the moment when the tower foundation of transmission line was buried, the permafrost around the foundation has been disturbed more strongly and the heat transfer has been more prominent as compared with those in highway and railway foundations. Therefore, controlling of diseases resulted from frost heaving and thaw settlement should be conducted in every stages of the construction of transmission lines. Transmission line belongs to dotted line project, so the frost heaving and thaw settlement would be avoided or eliminated by wise selection of line and tower type. Frost heaving should be paid more attention in choosing tower type. The choice of the construction period and time and the controlling of the construction process will be effective in controlling thermal disturbances if there is an open excavation foundation. A simultaneous permafrost monitoring following the construction going on will play an important role in analyzing project stability, switching engineering construction sequence, and operating and maintaining the project. It turns out that the performance of the permafrost issues are varying in different stages, it could only be tackled scientifically by a comprehensive research.

Glacial lake outburst flood (GLOF), together with debris flow, is one of main natural hazards in Tibet Autonomous Region (TAR). On July 5, 2013, a glacial lake outburst flood happened in Zhongyu Town of Jiali County, TAR. As a result, some persons were missing, numerous buildings were destroyed, and some infrastructures such as bridge and road were damaged. The economic loss was estimated as 270 million RMB Yuan. Based on topographic maps and remote sensing images in different periods, Ranzeria Co Lake was believed to be responsible for this GLOF event by using RS and GIS technology. According to the detailed meteorological data including precipitation and temperature in day, month and annual scale, avalanche and glacier calving possibly induced the outburst of Ranzeria Co Lake, and the indirectly cause was the continued heavy precipitation and quick temperature increase before the GLOF. Meanwhile, the steady expansion of Ranzeria Co Lake during 1970-2013 provided abundant mass of the GLOF. Because all villages are located in the low banks of the narrow Niduzangbu valley, and the high altitude gap is between Ranzeria Co Lake and Zhongyu Town, the GLOF caused severe damage to this area. After the break, Ranzeria Co Lake was abruptly diminished and was separated into two parts with area of 0.25 km² and 0.01 km², respectively. The re-occurrence probability of the GLOF from Ranzeria Co Lake is infinitesimal. However, after this GLOF, two dammed lakes form in the Luoqiong valley and Yibu valley of the Niduzangbu River. So far, the area of these two dammed lakes is 0.33 km² and 0.13 km², respectively. Due to the large area of the watershed or the dammed lake being completed blocked, these two dammed lakes are considered to be in a high risk. So monitoring work and engineering measures on these dammed lakes should be strengthened in the future.

Glacier and snow cover distributed widely in Xinjiang, when its melt water supply to the rivers often accompanied by glacial floods, snowmelt floods, glacial lake outburst floods, glacial debris, ice and snow avalanches, snowdrift and other snow disasters. There are greater threats on the local urban residence and the important defense lines because of these disasters. The extent and range of the ice and snow disasters impact subjected to the changes of glacier and snow cover. The glacier flood and glacial lake outburst floods occurred mainly in the Karakoram Mountains, Kunlun Mountains and the western of the southern slope of the Tianshan Mountains in the Tarim River Basin. The snowmelt floods occurred mainly in Altay area, Tacheng area and the northern slope of the Tianshan Mountains in North Xinjiang. The glacier debris and the ice and snow avalanches disasters occurred mainly in the Pamirs Plateau, the western of the Tianshan Mountains, the Karakorum and the West Kunlun Mountains. The snowdrift occurred mainly in the middle and western of the Tianshan Mountains regions. With global warming, especially the beginning of the climate change from warm-dry to warm-wet in 1987 in Xinjiang, the glacier retreat intensified, the melt water increases, the glacier floods and debris flows increased with the increased of glacier melt water, and the snowmelt floods, ice and snow avalanches and snowdrift enhanced with the snow cover increased in winter and the air temperature rise, the alpine ice disintegration caused by ice avalanches with climate warming showed an increasing trend. The ice and snow disasters dominated by the glacier and snow floods in Xinjiang. The increasing trend of the frequency and intensity of glacier and snow floods under the influence of climate change have been observed in the last decade in the Xinjiang region. The water safety and disasters and other problems caused by glacial lake outburst floods and glacial floods in the Tarim Basin and the ice and snowmelt floods in spring in North Xinjiang have become increasingly prominent, and have great harm on the local lives, property and socio-economic development. With the glacier melt water increasing, some new disaster may be formed in the future. For the numerous glaciers, snow disaster induced by the climate change, there is a lack of adaptation on disaster monitoring, forecasting and early warning. So it should be keep an eye on the ice and snow disasters with the global climate change accelerating consistently, and to strengthen the study of the impact assessment and adaptation strategies of the disasters, and make the science and technology play a leading role in disaster reduction.