Characteristics of Coalbed Methane Resources of China

The paper deals with the coalbed methane gas-bearing characteristics such as the gas content, theoretical gas saturation, gas concentration and abundance, as well as coal reservoir characteristics such as the adsorption, desorption and permeability of China's coal reservoirs. The paper also introduces the resources of coalbed methane with a gas content ≥ 4 m3/t and their distribution in China.

Climate change has more adverse impacts on the higher mountain communities than the lower ones: people’s perception from the northern Himalayas

The Himalayas are assumed to experience rapid climate change,with serious environmental,social and economic consequences for people living in and around the mountain area.However,the extent of climate change and its impact on the region are underexplored,especially on northern slope of the mountains.Based on local knowledge,we report perceived changes in climate and consequences of such changes for natural andsocial systems.The respondents in this study were distributed at a continuous elevation gradient of 3570-4646 m above sea level in the northern Himalayas.Therefore,it is possible to analyze the process of the shift of bioclimate zones under climate change and the differences in climate change effects cross altitudes.Among those in the pastoral area(Zhegu town)with an altitude of 4600 m,91.2%(n=114)of the respondents believe that the climate is obviously changing;the ratio of reporting rainfall decreasing is 77.2%(n=114);those who perceive delayed rainy season,and increased climate change-related natural disasters account for 38.9%(n=113),72.8%(n=103),respectively;more than two thirds(70.3%)(n=111)view drought as the biggest challenge to address climate change,and more than half(59.3%)(n=113)of the respondents believe that the impact of climate change is mainly negative.All these data rank first among the four survey areas(Zhegu town/pastoral region,Nedong County/crop growing regions,Zhanang County/crop growing region and Nagarze County/farming-pastoral region).Due to climate warming,Labidura riparia spreads to a higher altitude in the basins in Nedong County(Shannan City,Tibet)and Zhanang County(Shannan City,Tibet)at the rate of 31.1±6.4 m/a and 46.7±8.8 m/a,respectively in elevation.Most of the respondents view the natural variability as the main cause of climate changes,only 10.7%-29.0%among them view human activities as the main reason.Key challenges for local people to address climate change include droughts and economic hardship.Most local perceptions conform to scientific data.Comparative analysis of people’s perception of climate change impacts in different regions of the Himalayas will enhance the understanding of climate change effects on the whole region.

Preliminary Study on Water Demand Law of 1-0 Rooted Cuttings of Populus szechuanica

In order to provide theoretical basis and technical support for the afforestation and artificial water supply of P.szechuanica in arid areas,the characteristics of water consumption of P.szechuanica were explored,and the law of water demand of P.szechuanica was grasped.In this paper,potted seedlings of 1-0 rooted cuttings of P.szechuanica were taken as research objects,and change situation of water consumption under different water control gradients was measured regularly by using weighing method,further analyzing dynamic change of water consumption of P.szechuanica and revealing water demand law of 1-0 rooted cuttings of P.szechuanica.The results showed that total change of water consumption of 1-0 rooted cuttings of P.szechuanica had"slow-fast-slow-fast"double-peak trend in the growth period of the current year,and corresponded with univariate linear relation(R^(2)=0.7137),with significant difference.In whole growth period,water consumption in August was the highest,which was 2.7 times of that in June and July and 1.5 times of that after September.In different water control treatments,the dynamic changes of daily and monthly water consumption were significantly different.In seven water control treatments,monthly water consumption was between(6315.95±1690.70)and(10105.28±3065.30)g/month,and mean was(8211.07±2308.23)g/month.With intensification of water control treatment,water consumption increased,but there was no seedling death due to water shortage.P.szechuanica has great plasticity in water demand,and can survive in both arid and humid environments.Meanwhile,it is revealed that P.szechuanica is the most widely distributed tree species in the region.

Comparative Analysis of Automatic Observation Data of DSG3 Precipitation Phenomenon Instrument and Manual Observation Data

The observation data collected by DSG3 precipitation phenomenon observation instrument and the manual parallel observation data in 5 stations of Gansu Province from January 2018 to December 2019 were compared and analyzed.The results show that the missing observation rate of the observation instrument was 0%,and the performance of the equipment was good;the empty forecast rate of drizzle was the highest;the false forecast rate of hail was the highest,and the accuracy of automatic observation records was relatively poor;the capture rate and empty forecast rate of rain and snow were higher,while their false forecast rate and missing forecast rate were lower.The capture rate and missing forecast rate of sleet were higher,and its missing forecast rate was low;the accuracy of automatic observation was better.It shows that the empty forecast and false forecast of DSG3 precipitation phenomenon observation instrument mainly occurred in weak precipitation phenomena,and the recognition of drizzle and hail was poor.