Spatiotemporal variability of rain-on-snow events in the arid region of Northwest China

Rain-on-snow(ROS)events involve rainfall on snow surfaces,and the occurrence of ROS events can exacerbate water scarcity and ecosystem vulnerability in the arid region of Northwest China(ARNC).In this study,using daily snow depth data and daily meteorological data from 68 meteorological stations provided by the China Meteorological Administration National Meteorological Information Centre,we investigated the spatiotemporal variability of ROS events in the ARNC from 1978 to 2015 and examined the factors affecting these events and possible changes of future ROS events in the ARNC.The results showed that ROS events in the ARNC mainly occurred from October to May of the following year and were largely distributed in the Qilian Mountains,Tianshan Mountains,Ili River Valley,Tacheng Prefecture,and Altay Prefecture,with the Ili River Valley,Tacheng City,and Altay Mountains exhibiting the most occurrences.Based on the intensity of ROS events,the areas with the highest risk of flooding resulting from ROS events in the ARNC were the Tianshan Mountains,Ili River Valley,Tacheng City,and Altay Mountains.The number and intensity of ROS events in the ARNC largely increased from 1978 to 2015,mainly influenced by air temperature and the number of rainfall days.However,due to the snowpack abundance in areas experiencing frequent ROS events in the ARNC,snowpack changes exerted slight impact on ROS events,which is a temporary phenomenon.Furthermore,elevation imposed lesser impact on ROS events in the ARNC than other factors.In the ARNC,the start time of rainfall and the end time of snowpack gradually advanced from the spring of the current year to the winter of the previous year,while the end time of rainfall and the start time of snowpack gradually delayed from autumn to winter.This may lead to more ROS events in winter in the future.These results could provide a sound basis for managing water resources and mitigating related disasters caused by ROS events in the ARNC.

Analysis of the severe group dust storms in eastern part of Northwest China

Based on the available original dust storm records from 60 meteorological stations, we discussed the identification standard of severe dust storms at a single station and constructed a quite complete time series of severe group dust storms in the eastern part of Northwest China in 1954–2001. The result shows that there were 99 severe group dust storms in this region in recent 48 years. The spatial distribution indicates that the Alax Plateau, most parts of the Ordos Plateau and most parts of the Hexi Corridor are the main areas influenced by severe group dust storms. In addition, the season and the month with the most frequent severe group dust storms are spring and April, accounting for 78.8% and 41.4% of the total events respectively. During the past 48 years the lowest rate of severe group dust storms occurred in the 1990s. Compared with the other 4 decades, on the average, the duration and the affected area of severe group dust storms are relatively short and small during the 1990s. In 2000 and 2001, there were separately 4 severe group dust storms as the higher value after 1983 in the eastern part of Northwest China.

Hydrological and water cycle processes of inland river basins in the arid region of Northwest China

The increasing shortage in water resources is a key factor affecting sustainable socio-economic development in the arid region of Northwest China(ARNC). Water shortages also affect the stability of the region's oasis ecosystem. This paper summarizes the hydrological processes and water cycle of inland river basins in the ARNC, focusing on the following aspects: the spatial-temporal features of water resources(including air water vapor resources, runoff, and glacial meltwater) and their driving forces; the characteristics of streamflow composition in the inland river basins; the characteristics and main controlling factors of baseflow in the inland rivers; and anticipated future changes in hydrological processes and water resources. The results indicate that:(1) although the runoff in most inland rivers in the ARNC showed a significant increasing trend, both the glaciated area and glacial ice reserves have been reduced in the mountains;(2) snow melt and glacier melt are extremely important hydrological processes in the ARNC, especially in the Kunlun and Tianshan mountains;(3) baseflow in the inland rivers of the ARNC is the result of climate change and human activities, with the main driving factors being the reduction in forest area and the over-exploitation and utilization of groundwater in the river basins; and(4) the contradictions among water resources, ecology and economy will further increase in the future. The findings of this study might also help strengthen the ecological, economic and social sustainable development in the study region.

Influence of climate change and human activity on water resources in arid region of Northwest China: An overview

This study reviews the latest progress in research on climate change and water resources in the arid region of Northwest China, analyzes the cause of water resource changes within the region from the perspective of climate change and human activities, and summarizes future likely changes in water resources and associated adaptation strategies. The research shows that the climate in the region has experienced warming and wetting with the most significant warming in winter and the highest increase in summer precipitation since 1961. Areas with the most significant warming trends include the Qaidam Basin, the Yili River Valley, and Tacheng. Spatially, the increasing trend in precipitation becomes increasingly significant from the southeast to the northwest, and northern Xinjiang experienced the highest increase. Studies have shown a decrease in headwater of Shiyang River because runoff is mainly based on precipitation which shows a decrease trend. But an increase in western rivers was observed such as Tarim River and Shule River as well as Heihe River due to rapid glacier shrinkage and snowmelt as well as precipitation increase in mountain area. Meanwhile unreasonable human activities resulted in decrease of runoff in the middle and lower reaches of Haihe River, Shiyang River and Kaidu River. Finally, recommendations for future studies are suggested that include characteristics of changes in extreme weather events and their impacts on water resources, projections of future climate and water resource changes, climate change attribution, the selection of adaptation strategies relating to climate change and social economic activities, and use of scientific methods to quantitatively determine water resource allocation.

Regional Frequency Analysis of Observed Sub-Daily Rainfall Maxima over Eastern China

Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima （AM） sub-daily rainfall series （1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a moving window approach） for eastern China was conducted. Eastern China was divided into 13 homogeneous regions： Northeast （NE1, NE2）, Central （C）, Central North （CN1, CN2）, Central East （CE1, CE2, CE3）, Southeast （SE1, SE2, SE3, SE4）, and Southwest （SW）. The generalized extreme value performed best for the AM series in regions NE, C, CN2, CE1, CE2, SE2, and SW, and the generalized logistic distribution was appropriate in the other regions. Maximum return levels were in the SE4 region, with value ranges of 80-270 mm （1-h to 24-h rainfall） and 108-390 mm （1-h to 24-h rainfall） for 20- and 100 yr, respectively. Minimum return levels were in the CN1 and NE1 regions, with values of 37-104 mm and 53-140 mm for 20 and 100 yr, respectively. Comparing return levels using the optimal and commonly used Pearson-III distribution, the mean return-level differences in eastern China for 1-24-h rainfall varied from -3-4 mm to -23-11 mm （- 10%-10%） for 20-yr events, reaching -6-26 mm （-10%-30%） and -10-133 mm （-10%-90%） for 100-yr events. In view of the large differences in estimated return levels, more attention should be given to frequency analysis of sub-daily rainfall over China, for improved water management and disaster reduction.

Characteristics of highly differentiated granite and metallization of tungsten-tin, rare and rare earth metal in the eastern Nanling region, China

1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate that the Yanshanian highly differentiated-granite formation is closely related to the deposits of tungsten and tin,rare and rare earth metals mineralization in the region(Xiao

The mapping methods and division of tectonic units of the regional tectonic map in the eastern China seas and adjacent regions

The geological-geophysical map series of the eastern China seas and adjacent region （1：1 000 000） will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate （Pacific Plate, Eurasian Plate and Philippine Sea Plate）. The second-order tectonic unit is tectonic domain （East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain）. The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River （Yangtze） Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells.

Correlation and SVD Analysis of Anomalous Spring Precipitation in Northwest China and Sea Surface Temperature in Key Region in Recent 50 Years

[Objective] The aim was to study the relationship between spring precipitation anomaly in Northwest China and sea surface temperature anomaly (SSTA) in Key region in recent 50 years. [Method] Based on monthly average precipitation in Northwest China and global monthly sea surface temperature (SST) grid data, the effects of SSTA in equatorial central and eastern Pacific on spring precipitation in Northwest China were discussed by means of correlation and SVD analysis. [Result] For spring precipitation in Northwest China, the key period of SST was from August to September in the former year, and the equatorial central and eastern Pacific (125°-85° W, 5° S-10° N) was named 'Key region'. Correlation analysis showed that there was obviously positive correlation between spring precipitation in Northwest China and SST (monthly average from August to September in the former year) in equatorial central and eastern Pacific, especially Key region. SVD analysis revealed that spring precipitation anomaly in Northwest China distributed in phase, while SST in equatorial central and eastern Pacific from August to September in the former year had higher positive correlation coefficient, and there was obviously positive couple correlation in Key region. [Conclusion] The study could provide theoretic foundation for the prediction of drought and flood in Northwest China.

Analysis on the Correlated Characteristics between Spring Precipitation in the Arid Region of Northwest China and Global Sea Surface Temperature

[Objective] The research aimed to study the correlated characteristics between spring precipitation in the arid region of Northwest China and global sea surface temperature. [Method] Based on GPCP global monthly precipitation data and NOAA ERSST sea surface temperature data during 1979-2008, the precipitation characteristics in the arid region of Northwest China in 30 years and its correlated distribution characteristics with the global sea surface temperature were analyzed by using the correlation and composite analysis methods. [Result] Spring rainfall presented the fluctuation increasing in the arid region of Northwest China during 1979-2008. The sea surface temperature of Indian Ocean in 15° S-22° N, 45°-105° E had the continuous influence on spring precipitation in the arid region of Northwest China. It could be as a stable factor for forecasting spring precipitation in the arid region zone of Northwest China. When the sea surface temperature was higher in Indian Ocean, Bay of Bengal and Arabian Sea, maybe spring precipitation in the arid region of Northwest China was more. If the sea surface temperature in the equatorial Eastern Pacific Ocean in prior summer, autumn and winter was higher, it was favorable for spring precipitation in the arid region of Northwest China in the next year. The sea surface temperature field in Arabian Sea, Central Indian Ocean and Western Pacific Ocean was the key factor which affected spring precipitation in the arid region of Northwest China. [Conclusion] The research provided the theory basis for the prediction and forecast of precipitation in the arid region.

Responses of phreatophyte transpiration to falling water table in hyper-arid and arid regions,Northwest China

Quantitative assessment of the impact of groundwater depletion on phreatophytes in(hyper-)arid regions is key to sustainable groundwater management.However,a parsimonious model for predicting the response of phreatophytes to a decrease of the water table is lacking.A variable saturated flow model,HYDRUS-1D,was used to numerically assess the influences of depth to the water table(DWT)and mean annual precipitation(MAP)on transpiration of groundwater-dependent vegetation in(hyper-)arid regions of northwest China.An exponential relationship is found for the normalized transpiration(a ratio of transpiration at a certain DWT to transpiration at 1 m depth,T_(a)^(*))with increasing DWT,while a positive linear relationship is identified between T_(a)^(*)and annual precipitation.Sensitivity analysis shows that the model is insensitive to parameters,such as saturated soil hydraulic conductivity and water stress parameters,indicated by an insignificant variation(less than 20%in most cases)under±50%changes of these parameters.Based on these two relationships,a universal model has been developed to predict the response of phreatophyte transpiration to groundwater drawdown for(hyper-)arid regions using MAP only.The estimated T_(a)^(*)from the model is reasonable by comparing with published measured values.

Characteristics of Recent Horizontal Crustal Movement and Tectonic Deformation in the Northwest China Region

Making use of observation data of GPS in the Northwest China region and infrared distancemeasurements crossing the Qilian-Longshoushan fault zone up to 2004, aided by the least square collocation and inversion of negative dislocation model for the boundaries of elastic blocks and the singular force-source, the dynamic evolution features of deformation and strain fields before and after the Ms = 8. 1 earthquake on the west of Kunlun Mountains Pass, especially the recent tectonic deformation and stress field status three years after this earthquake are studied. The possible regions or segments of active blocks and their boundaries reflecting accumulation background of high strain energy of producing earthquakes over middle magnitude, are obtained, as well as the potential epicenter. The results show that after shortterm relaxation and adjustment in the northern margin of Qinghai-Xizang （Tibet） block after the Ms = 8. 1 earthquake, the main control action of background field of northeastward pushing of Indian plate is now recovering. Moreover, the following regions are found to have the background of high strain energy accumulation. They are the middle segment of the northern Tianshan fault zone and its meeting region with the western segment, the middle and western segments of southern Tianshan fault zone and the meeting region with Western Kunlun fault zone, the middle segment of Altun fault, the middle-eastern segment of Qilianshan fault zone and its meeting region with Haiyuan fault, the meeting region of northern margin fault of west Qinling Range and the southeastward expanding line of Zhuanglanghe fault; The Linze and Haiynan areas also see accumulation of strain energy to some degree.

Effects of Tropical Cyclone Activity on the Boundary Moisture Budget over the Eastern China Monsoon Region

In summer, water vapor over the eastern China monsoon region （ECMR） comes mainly from low latitudes and is modu- lated by tropical cyclone （TC） activity in East Asia （EA）. This study examines the variability of water vapor transport over the ECMR, especially of the moisture inflow via the southern and eastern boundaries. The results of composite and correlation analyses, using data from 1979 to 2010, reveal significant differences in moisture budgets along the boundaries between TC days and non-TC days. Almost 80% of the water vapor transport via the eastern boundary occurs during TC days, while at the southern boundary most inflow occurs on non-TC days. The ratio of the total water vapor transport between TC and non-TC days is about 4：6. In addition, the E1 Nifio-Southem Oscillation （ENSO） exhibits a remarkable influence on moisture trans- port over EA and the contributions of moisture inflow on TC days increase （reduce） in E1 Nifio （La Nifia） years. Moreover, different types of TCs, based on their tracks, have different effects on the moisture budgets along the southern and eastern boundaries. When TCs enter EA （but not the ECMR）, they favor the moisture inflow via the eastern boundary and hinder the moisture inflow via the southern boundary. After TCs enter the ECMR, the inhibition of moisture inflow via the southern boundary will be weakened, and more water vapor can be brought into the ECMR. For some recurring TCs with an increase in TC activity in the midlatitudes, the influence is uncertain in different cases. The results herein suggest that TC activity is an important factor that influences the boundary moisture budgets in the ECMR.

Impacts of Future NO_x and CO Emissions on Regional Chemistry and Climate over Eastern China

A coupled chemical/dynamical model （SOCOL-SOlar Climate Ozone Links） is applied to study the impacts of future enhanced CO and NO_x emissions over eastern China on regional chemistry and climate. The result shows that the increase of CO and NOx emissions has significant effects on regional chemistry, including NOx, CO, O_3, and OH concentrations. During winter, the CO concentration is uniformly increased in the northern hemisphere by about 10 ppbv. During summer, the increase of CO has a regional distribution. The change in O_3 concentrations near eastern China has both strong seasonal and spatial variations. During winter, the surface O_3 concentrations decrease by about 2 ppbv, while during summer they increase by about 2 ppbv in eastern China. The changes of CO, NO_x, and O_3 induce important impacts on OH concentrations. The changes in chemistry, especially O_3, induce important effects on regional climate. The analysis suggests that during winter, the surface temperature decreases and air pressure increases in central-eastern China. The changes of temperature and pressure produce decreases in vertical velocity. We should mention that the model resolution is coarse, and the calculated concentrations are generally underestimated when they are compared to measured results. However, because this model is a coupled dynamical/chemical model, it can provide some useful insights regarding the climate impacts due to changes in air pollutant emissions.

Infl uence of environmental regulation intensity on regional technology innovation: An empirical research based on eastern and mid-China region

This paper adopts the comprehensive index method to build environmental regulation intensity index. Based on "Porter Hypothesis", it empirically examines the relationship between environmental regulation intensity and regional technology innovation using the eastern and mid-China region's provincial panel data from 2005 to 2013 and panel data method. The results show that:(1) In the eastern and central regions, the relationship between the intensity of environmental regulation and technological innovation presents a "U" shape, and "Porter Hypothesis" can be verifi ed;(2) The eastern region can break "U" infl ection point earlier than the central region. Therefore, the government should not only strengthen the intensity of environmental regulation, but also pay attention to environmental regulation form, formulate reasonable environmental regulation policy, actively guide the enterprises to seek out technology innovation in order to realize win-win situation of environmental protection and economic development.

Eurasia Continental Bridge——An Important Link of the Coordinated Development between China's Eastern,Central and Western Regions

The new Eurasia Continental Bridgeruns from East China to Central andWest China, crossing 11 provincesand regions, namely Jiangsu, Shandong,Hubei, Anhui, Shaanxi, Gansu, Shanxi,Sichuan, Qinghai, Xinjiang and Ningxia.The total area is 3.6 million sq km and thepopulation is about 300 million, accountingfor a third and a quarter of the whole countryrespectively. The area is very rich in naturalresources, so it is called an "Economic goldbelt" and "Gold corridor". Aerial remote-control survey indicates that along thecontinental bridge from Lianyungang to theAla Mountains within China’s boundary,

Integrity and Size of Green Spaces Are Critical for the Functional Di-versity of Birds:Evidence from the Eastern and Northwestern Regions of China

Urbanization often changes bird species richness and affects the functional diversity.Therefore,understanding these changes helps city planners improve green space design and land use planning.Our study used multiple datasets to explore the effects of land-scape patterns and natural environments on the functional diversity of birds in urban parks and campuses in the eastern and northwest-ern regions of China.Firstly,we used the data to calculate birds of the functional richness(FRic),functional evenness(FEve),and functional divergence(FDiv)of 68 urban spaces in the eastern and northwestern regions of China.Further,we established generalized linear models of natural factors,human factors,and functional diversity.Results showed more bird species with unique traits were in the north-western region.This may be because the earlier urbanization in the eastern region filtered out urban-sensitive species,leaving behind urban adapters.Moreover,we found that the fractal dimension index was the most significant positive factor of FRic in the eastern region but the most significant negative factor of FDiv.Elevation was the most significant negative influence factor of FEve in the eastern region,but it was the most potent positive influence factor of FRic in the northwestern region.Population density had a significant positive effect on FDiv in the northwestern region.However,green space areas significantly negatively impacted FEve in the northwestern region.In addition,birds in parks in both regions had more functional traits than those on campuses,possibly because of the larger green space in parks,which may contain more fragments of native vegetation and reduce human interference.Our study suggests that preserving more original vegetation and reducing human disturbance in cities can increase the functional diversity of urban birds and im-prove urban ecosystem functions.

Simulation and Projection of Monso on Rainfall and Rain Patterns over Eastern China under Global Warming by RegCM3

The authors investigate possible changes of monsoon rainfall and associated seasonal (June-JulyAugust) anomaly patterns over eastern China in the late 21st century under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 emission scenario as simulated by a high-resolution regional climate model (RegCM3) nested in a general circulation model (FvGCM/CCM3).Two sets of multi-decadal simulations are performed at 20-km grid spacing for present day and future climate conditions.Results show that the RegCM3 reproduces the mean rainfall distribution;however the evolution of the monsoon rain belt from South China to North China is not well simulated.Concerning the rain pattern classifications,RegCM3 overestimates the occurrence of Pattern 1 (excessive rainfall in northern China) and underestimates that of Pattern 2 (increased rainfall over the Huai River basin).Under future climate conditions,RegCM3 projects less occurrence of Pattern 1,more of Pattern 2,and little change of Pattern 3 (rainfall increase along the Yangtze River).These results indicate that there might be increased rainfall over the Huai-Yellow River area and reduced rainfall over North China in the future,while rainfall over the lower reaches of the Yangtze River basin is not modified significantly.Uncertainties exist in the present study are also discussed.

Characteristics of Volcanic Rocks in the Shoshonite Province, Eastern China, and Their Metallogenesis

The shoshonite province in eastern China is characterized by extensive distribution (ca. 80000 km2) of Late Jurassic-Early Cretaceous (165-100 Ma) shoshonite series with subordinate high-K calc-alkali series. It was formed in a dominantly tensile stress field. In comparison with their analogues in island arcs and active continental margins in other countries, the volcanic rocks in the shoshonite province have their specific characteristics in petrology, mineralogy and geochemistry as well as related mineralization association, which are the comprehensive reflection of the special composition and structure of the mantle and crust of the province and the special Mesozoic regional tectonic setting.

Systematic Analysis and Optimization of the Agricultural Structure in Ethnic Regions in Northwest Sichuan Province

Based on introducing the basic conditions of the ethnic regions in northwest Sichuan Province,the thesis analyzes its agricultural development status,which can be classified into two aspects--rich natural resources and slow agricultural economic growth.Through the analysis on the agricultural structure of northwest Sichuan Province,it is found that the production efficiency and economic benefits of crop planting in this region are low,animal husbandry,as a major industry in pastoral region,sees high production efficiency,the agricultural production is still at the resource-oriented stage;its agricultural structure is still the farming-pastoral structure relying mainly on animal husbandry,planting is dominated by crop planting and potato planting,animal husbandry mainly produces dairy and beef;the ethnic regions in northwest Sichuan Province is endowed with the advantages to grow crops,beans and fruits as well as to produce beef,mutton and milk,among which,three industries,say fruit,beef and dairy are with increasing location quotient and gradually strengthening industrial comparative advantage,while the location quotient of the other industries is declining and their industrial comparative advantages are more stable.In order to promote the agriculture in northwest Sichuan Province to develop in breadth and depth,the thesis proposes the following measures and suggestions:the first one is to adhere to the development strategy of modern animal husbandry;the second is to appropriately improve the proportion of economic crops;the third is to accelerate the development of green food processing industry.

Analysis of the Comparison of Twice Regional Large Rainstorms in Northwest Yantai City

[Objective] The twice regional rainstorms in northwest Yantai in July in 2009 and July in 2010 were expounded.[Method] The twice regional rainstorm in northwest Yantai in July in 2009 and July in 2010 were selected for comparison analysis by dint of conventional and non-conventional weather data,from the aspects of circulation background,physics quantity,and radar echo,etc.[Result] The twice large rainstorm process were regional convective strong precipitation.The rainstorm fell in the northwest of Yantai and had a strong precipitation center above 200 mm.The twice large rainstorm was affected by subtropical and shear line.The rainstorm area was related to the location of 588 dagpm line,westerly trough,and shear line.It was regional rainstorm of typical subtropical edge warm and wet airstream,combination of low vortex and shear line of westerly.The precipitation occurred around the center of water vapor flux;K index had pretty good indication effects to the generation of rainstorm.Large rainstorm occurred around the place with high K index.The K index of twice large rainstorm was larger than or equal to 34 ℃,and was close to the rainstorm falling area where K index was larger than or equal to 35 ℃.The reflection factor of twice large rainstorms at 0.5° elevation,the largest echo intensity was from 55 to 60 dBz,in strip echo from south to north,through the west peninsula,forming train effect.The data report product also had important reference basis for the report of regional large rainstorm.[Conclusion] The study provided references and basis for the report of large rainstorm in the future.