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 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.

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.

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.

Sinian hydrocarbon accumulation conditions and exploration potential at the northwest margin of the Yangtze region, China

Based on outcrop, drilling, logging and seismic data, the reservoir forming conditions, reservoir forming model and exploration potential of the ultra-deep Sinian Dengying Formation at the northwest margin of Yangtze craton region were examined.(1) This area is in craton rifting stage from Sinian to Early Cambrian, characterized by syn-sedimentary faults and rapid subsidence, significant sedimentary differences, and development of Dengying Formation platform margins on both sides of the rift.(2) The Sinian–Cambrian in this area has two sets of high-quality source rocks, Doushantuo Formation and Maidiping-Qiongzhusi Formation;of which, the latter has a thickness of 150–600 m and hydrocarbon generation intensity of(100-200)×10;m;/km;.(3) The mounds and shoals in the platform margin of Sinian Dengying Formation controlled by faults are thick and distributed in rows and zones;they are reformed by contemporaneous–quasi-contemporaneous and supergene karstification jointly, forming pore-type reservoirs with a thickness of 200-400 m.(4) The two sets of source rocks enter oil generation windows from Permian to Early Triassic, and the oil migrates a short distance to the lithologic traps of mounds and shoals to form a huge scale paleo-oil reservoir group;from Late Triassic to Jurassic, the oil in the paleo-oil reservoirs is cracked into gas, laying the foundation of present natural gas reservoirs.(5) The mound-shoal body at the platform margin of Dengying Formation and the two sets of high-quality source rocks combine into several types of favorable source-reservoir combinations, which, with the advantage of near-source and high-efficiency reservoir formation, and can form large lithologic gas reservoirs. The Mianyang-Jiange area is a potential large gas field with trillion cubic meters of reserves. According to seismic prediction, the Laoguanmiao structure in this area has the Deng-2 Member mound-shoal reservoir of about 1300 km^(2), making it a ultra-deep target worthy of exploration in the near future.

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.

The heterogeneous characteristics of crust-mantle structures and the seismic activities in the northwest Beijing region

In this paper, the abnormal characteristics of the crustal structures in the seismic active region, Yanqing-Huailai and Zhangbei-Shangyi, are obtained by means of comprehensively interpreting and studying the data of deep seis- mic sounding profiles passing through the northwestern part of Zhangjiakou-Bohai seismic zone. The results show that the fluctuation of crystalline basement in the study region is obvious and that there exist considerable differ- ences in depth in different geological units. The locally abrupt variation of crystalline basement depths may be regarded as a mark of existence of crystalline basement faults. These crystalline basement faults and deep crustal faults provide a pass for the magma upwelling, resulting in the strong inhomogeneity of crustal structures. These phenomena of the complex seismic reflected waves and locally discontinuous reflection zones with different en- ergy indicate that the intensive squeeze and deformation of crust took place, which have led to the complex crustal structures and offered the dynamic source for the earthquake occurrence in this region. The low velocity bodies in different depths of crust and the local interface C1 in Zhangbei-Shangyi region may result from repeated magmatic activities. The certain stress accumulation in the brittle upper crust can cause the occurrence of earthquake under the action of local tectonic activity.

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.

Study on the Influence of Informal institution on Rural Legal Construction in Northwest Ethnic Minority Region

The Informal institution in Northwest Ethnic Minority Region has dual effects on rural legal construction. In the process of rural legal construction,it can make up for the defects of formal institution to reduce the cost of legal construction,and increase benefit. It also has negative influence on social function,and can't be conducive to the social stability,development and harmony. Civil law is to be more valued,thus avoiding and hampering the implementation of national laws and even covering the operation of national laws,so it is impossible to achieve rule of law. The coordinated development of Informal institution and socio-economic development in Northwest Ethnic Minority Region will contribute to stable and harmonious social development in Northwest Region.

Malacological Diversity on Some Lamiaceae in the Region of Tlemcen （Northwest Algeria）

The region of Tlemcen is located in the northwestern part of Algeria. Its arid climate leads to the degradation of vegetation in open formation, where can be found the doum, the diss and broom. Other aromatic species such as rosemary, thyme, lavender and horehound are considered as well. The four previous aromatic species belong to the family Labiatae for their morphological and botanical characters. The authors propose to design an approach to identify the diversity of malacofauna found on these different Lamiaceae. These are certainly a nutritional source for this malacological fauna. So, a survey was performed in various stations. The malacological richness is estimated to be 19 for thyme, 18 for rosemary, 16 for lavender, and finally 7 for horehound. It includes four families, namely Milacidae, Sphincterochilidae, Helicidae and Subulinidae. Milacidae are present only in horehound and lavender stations. On the other hand, the Sphincterochilidae, namely Sphincterochila candidissima, is absent on horehound. Rumina decollata is the only species in the family Subulinidae. As for the family Helicidae, it is the richest and includes two specific subfamilies： Helicinae and Helicellinae. The first subfamily consists of 11 species of thyme, 10 species of rosemary and lavender. The second subfamily includes 6 species of thyme and rosemary and 3 of lavender, respectively. In addition, the author tries to look for the malacological species specific to each of these plants and those who are common to them as well. Finally, the vertical distribution of gastropods is given.

Challenges and Policies for Sustainable Development of Northwest Region

After analyzing the social economic situation and the natural conditions of Northwest Region, the paper addresses the major challenges that deserve attention in achieving sustainable development of the region, focusing on the aspects of resources and environment. Pertaining to these challenges, recommendations are made on sustainability oriented policies concerning resources and environment.

西北地区主要锂矿资源分布特征及地球化学找矿远景预测

为圈定锂成矿远景区,采用已有1∶20万地球化学数据,选取西昆仑-阿尔金和阿尔泰两个主要锂矿带,基于锂元素地球化学空间分布及异常特征圈定锂矿远景区,为找矿突破战略行动选区服务。基于重点锂矿带以往1∶20万地球化学数据库,对元素相关性、背景及异常特征等参数进行再分析,结合已有锂矿床或锂矿(化)点,圈定找矿远景区。在昆仑-阿尔金地区圈定锂地球化学异常区15处,在阿尔泰圈定锂地球化学异常区12处。研究圈定27处异常区可为下一步锂矿找矿工作部署提供参考依据。

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.

基于西北地域特色的《水域生态学》实践课程改革探索

《水域生态学》是水产养殖本科专业的核心基础课,具有很强的实践性和应用性。针对当前《水域生态学》实践课程内容设置及现状,提出一系列教学改革策略,重点关注课程学时与内容、师资力量与资源配置以及考核机制等方面的优化,旨在提升实践教学质量,实现更高效、全面、系统化的育人效果。

西北中等职业教育与乡村振兴协调发展:时空特征及其驱动因子

实现中等职业教育与乡村振兴的协调发展是激发乡村内生性力量的关键举措。基于西北地区五省(自治区)2011-2021年的面板数据,构建中等职业教育与乡村振兴综合评价指标体系,综合运用熵值法、综合评价模型、耦合协调模型、趋势分析法以及地理探测器,对两系统协调演进关系定量测定。研究结果发现:西北地区中等职业教育与乡村振兴综合发展水平大致呈现递增趋势且具有“西低东高,南高北低”空间布局特征;耦合协调度逐年提升,协调互促作用愈加显著,且受到经济发展水平、对外开放程度等多因子的综合影响。基于此提出促进西北地区中等职业教育与乡村振兴区域间协调发展建议:改革教育模式,实现供需匹配;促进创新氛围,吸引人才回流;充分发挥区位优势,挖掘乡村价值。

创新价值链视角下西北地区农业技术创新效率研究

提高农业技术创新效率对驱动西北地区农业高质量发展,乃至实现我国农业现代化战略目标意义重大。文章通过构建农业技术创新效率测算模型和Tobit回归模型,对西北地区农业技术创新效率进行评价分析,并探究其主要影响因素。研究表明:西北地区整体农业技术创新效率值较低,且区域差距明显;政府支持力度、涉农企业技术创新水平、农业生产力发展水平均正向影响农业技术创新效率;农村劳动力素质无显著影响;农村经济发展水平对农业技术创新效率具有显著抑制作用。西北地区政府应采取有效措施,提升农业技术创新效率。

2005-2020年亚洲中部干旱区生态站月潜在蒸散量数据集

潜在蒸散表征大气蒸发能力,是衡量区域蒸发能力的重要指标,也是评价气候干旱程度变化、水资源供需平衡、植被耗水量等的关键参数。在收集中亚生态系统监测网络12个生态站和中国生态系统研究网络(CERN)11个位于西北干旱区生态站的气象观测数据基础上,经过数据质量控制与插补,采用Penman-Monteith模型计算潜在蒸散量,生成了2005-2020年亚洲中部干旱区生态站月潜在蒸散量数据集。本数据集时间序列较长、覆盖多种生态系统类型,可作为亚洲中部干旱问题研究的基础数据、模型输入数据、模拟结果验证数据等,也可为该区域水资源的合理开发与利用、生态环境保护等方面研究提供数据支撑。

滇西北地区冰碛层分布特征及工程效应

依托铁路、公路工程建设,在野外勘察、室内和现场原位试验基础上,重点研究滇西北地区冰碛层的分布特征、岩土类型、物质组成及颗粒成分、胶结程度和物理力学性质,对冰碛层的地基强度和边坡稳定性进行综合评价。冰碛层根据分布特征分为洼地型、阶地型、谷肩型;根据物质组成等可分为角砾岩和碎石类混合土,承载力和地基稳定性均较好;角砾岩单轴抗压强度较高;碎石类混合土抗剪强度较高,但水稳定性和地基均匀性较差。冰碛层边坡局部自稳性较好,但底部和层间可能存在软弱夹层。

脚丈乡土--西安建筑科技大学西北乡土建筑研究概述

西安建筑科技大学西北乡土建筑研究团队始终扎根西部、深耕乡土,致力于西部人居环境改善与地域建筑文化的传承。本研究系统梳理了研究团队在黄土高原、河西走廊、西海固、河湟、三江源、藏彝走廊等不同研究片区,以问题意识为导向的核心学术思想和建立在身体力行基础上的研究成果,以期能为区域学科理论建构查漏补缺,为相关研究提供参考与借鉴。

西北干旱区藓类结皮覆盖下土壤多功能性特征及影响因子

生物土壤结皮是由干旱区重要的活性地被物组成,可显著影响地表土壤的物质循环与能量交换,改善表层土壤的物理、化学和生物学性质,从而影响土壤多功能性(Soil Multifunctionality,SMF)。藓类结皮是生物土壤结皮的重要类型之一,本研究旨在探究西北干旱区荒漠藓类结皮覆盖下土壤与裸沙的SMF差异性,探究两者SMF变化的主要驱动因素。通过分析土壤的8个干旱区关键生态系统功能指标,运用平均值法和因子分析法计算SMF,运用最小二乘回归分析和结构方程模型(SEM)等探究SMF变化的主要驱动因素。研究发现:(1)藓类结皮覆盖下土壤的单一和多功能性显著高于裸沙。(2)裸沙和藓类结皮覆盖下SMF变化的驱动要素具有差异性,裸沙SMF的主要驱动因素为干旱(Aridity)和土壤含水量(SWC),而藓类结皮覆盖下SMF驱动要素为土壤砂粒含量。(3)年均温(MAT)对裸沙和藓结皮覆盖土壤SMF的变化均呈现最大的间接效应。因此,藓类结皮发育显著增加了荒漠土壤SMF,同时也调节SMF的相关驱动因素。以上研究结果对深入理解荒漠裸沙和结皮覆盖下SMF的差异性及驱动因素具有重要意义。