Growth behavior and resource potential evaluation of gas hydrate in core fractures in Qilian Mountain permafrost area, Qinghai-Tibet Plateau

The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.

The simulation of LUCC based on Logistic-CA-Markov model in Qilian Mountain area, China

The Qilian mountain area was examined for using the Logistic-CA-Markov coupling model combined with GIS spatial analyst technology to research the transformation of LUCC, driving force system and simulate future tendency of variation. Results show that： （1） Woodland area decreased by 12.55%, while grassland, cultivated land, and settlement areas increased by 0.22%, 7.92%, and 0.03%, respectively, from 1986 to 2014. During the period of 1986 to 2000, forest degradation in the middle section of the mountain area decreased by 1,501.69 km2. Vegetation cover area improved, with a net increase of grassland area of 38.12 km2 from 2000 to 2014. （2） For constructing the system driving force, the best simulation scale was 210m×210m. Based on logistic regression analysis, the contribution （weight） of composite driving forces to land use and cover change was obtained, and the weight value was more objectively compared with AHP and MCE method. （3） In the natural scenarios, it is predicted that land use and cover distribution maps of Qilian mountain area in 2028 and 2042, and the Lee-Sallee index test was adopted. Over the next 27 years （2015-2042）, farmland, woodland, grassland, settlement areas show an increasing trend, especially settlements with an obvious change of 0.56%. The area of bare land will decrease by 0.89%. Without environmental degradation, tremendous structural change of LUCC will not occur, and typical characteristic of the vertical zone of the mountain would remain. Farmland and settlement areas will increase, but only in the vicinity of Qilian and Sunan counties.

The relationship between ENSO cycle and temperature,precipitation and runoff in the Qilian mountain area

El Nino and La Nina are the events concerned internationally. The corresponding relationship between El Nino events, temperature, precipitation and runoff in the Qilian mountain area are analyzed according to the date from the weather and the hydrometric stations in the area, the results show that effects of El Nino events to temperature, precipitation and runoff are different in the different time and zones. When El Nino occurs, temperature rises, but precipitation and runoff decrease in the whole Qilian mountain area, especially in the east and middle parts of the area. Temperature rises, precipitation and runoff still decrease in the eastern Qilian mountain area in the next year El Nino occurring, but decrease extent is fewer. There are not obvious relationship between temperature, precipitation and runoff with El Nino events in the western Qilian mountain area.

Gas Sources for Natural Gas Hydrates in the Permafrost Region of the Qilian Mountains

Objective As a new type of gas hydrates,the natural gas hydrates in the perfost region of the Qilian Mountains are characterized by their shallow burial depth,welldeveloped coal seam,high content of heavy hydrocarbons and multiple sets of mature and over-mature source rocks.Gas sources of these gas hydrates in the study area include coal-type gas and oil-type gas.

Study of temperature and precipitation change in upstream mountain area of the Hexi inland river basin since 1960s

All rivers in the Hexi inland region of Gansu Province, China, originate from the northern slope of the Qilian Mountains. They are located in the southern portion of the region and respectively belong to the three large river systems from east to west, the Shiyang, Heihe and Shule river basins. These rivers are supplied by precipitation, snowmelt and ice-melt runoff from the Qilian Mountain area. Therefore, changes of precipitation and temperature in the upstream watersheds of these rivers have an important effect on changes of mountainous runoff and reasonable utilization of water resources in this region. For this reason, the Qilian Mountain area, upstream watersheds and runoff forming areas of these rivers are chosen as the study area. The change characteristics and variation trend of temperature and precipitation in this area under the backdrop of global warming axe analyzed based on observa- tional data of relational weather and hydrologic stations in the area. Results show that temperatures in the upriver mountain areas of these three large river basins have been increasing, although the increasing degree is differentially affected by global warming. The rising extent of annual and seasonal temperatures in the upstream mountain area of the Shule river basin located in the west- em Qilian Mountains, were all largest over the past 50 years. Precipitation in the upstream mountain areas of Hexi region＇ three river basins located respectively in the western, middle and eastern Qilian Mountains have been presenting an increasing trend to varying degrees as a whole for more than 50 years. This means that climate in the upstream mountain areas of Hexi region＇ three river basins are becoming increasingly warmer and moister over the past 50 years, which will be very good for the ecological en- vironment and agricultural production in the region.

天然热释光测量技术在多年冻土区天然气水合物勘查中的应用

冻土区天然气水合物形成机理复杂,成因多源,发展多种捕捉微渗漏信息技术,提高勘查成功率是亟需解决的难题。本文首次把天然热释光测量技术应用于冻土区天然气水合物勘查中,利用RGD-6型热释光剂量仪测试了祁连山冻土区土壤样品热释光强度,总结出适用于木里冻土区天然气水合物勘查的加热程序,以及样品取样粒级。试验结果表明,祁连山冻土区土壤样品最佳取样粒级为-60~100目,最佳升温速率应设置为5℃/s,最佳升温区间为50~400℃。根据祁连山冻土区土壤天然热释光强度异常特征,圈定了天然气水合物在地表的异常边界,天然热释光强度异常模式为顶部异常,与烃类异常模式存在良好的对应关系。土壤天然热释光不受微生物的影响,灵敏度高,是一种很有前景的寻找天然气水合物的方法,在今后的冻土区天然气水合物资源勘查过程中可以将这种技术加以推广。

祁连山国家公园肃南片区生态敏感性评价

生态敏感性评价是反映国家公园生态问题与保护利用关系的重要手段,对国家公园规划建设具有一定的理论和实践指导意义。文章以祁连山国家公园肃南片区为例,基于现存主要生态问题,采用层次分析法(AHP)确定评价因子权重,并运用ArcGIS空间分析方法完成了肃南片区的生态敏感性综合评价。结果表明,祁连山国家公园肃南片区的综合生态敏感性总体处于中等偏高的水平,中等敏感性以上地区占总面积的78.90%;空间分布呈现由东北至西南逐渐增加的趋势。根据祁连山国家公园肃南片区综合生态敏感性评价结果,针对不同敏感性级别的区域提出了差异化的保护管理模式。

祁连山国家公园煤矿修复对地表节肢动物多样性的影响

高寒山区煤矿覆土回填和种植草本植物能够快速改善环境,强烈影响地表节肢动物多样性及其生态功能,地表节肢动物对煤矿修复的响应还会因海拔及放牧扰动强度的变化而异。选择祁连山国家公园甘肃片区中部西营河和东大河保护站煤矿修复区和毗邻草地(对照区)为研究对象,利用陷阱法调查煤矿修复区及对照区地表节肢动物的种类组成和数量变化,解析地表节肢动物群落及关键类群对煤矿修复的响应模式,确定影响地表节肢动物多样性变化的关键要素。结果表明,煤矿修复缩小了修复区和对照区地表节肢动物群落差异,但煤矿修复区和对照区地表节肢动物群落组成明显不同并存在地域差异。西营河煤矿修复显著提高了地表节肢动物活动密度,而东大河保护站煤矿修复导致地表节肢动物活动密度略有降低,地表节肢动物类群丰富度、多样性和均匀度指数变化与活动密度相反。主要地表节肢动物科对煤矿矿区修复的响应模式不同并存在区域差异,西营河保护站煤矿修复显著提高了平腹蛛科、微蛛亚科和隐翅虫科的活动密度,但显著降低了硬体盲蛛科和象甲科的活动密度;东大河保护站煤矿修复显著提高了步甲科活动密度,但降低了蚁科和狼蛛科的活动密度。pRDA排序结果表明,海拔高度和全氮含量解释了西营河保护站煤矿修复区和对照区20.8%的地表节肢动物群落变异;草本地上生物量和海拔高度解释了东大河保护站煤矿修复区和对照区24.3%的地表节肢动物群落变异。总之,高寒山区人工覆土和植被建设引起的植被和土壤环境变化强烈影响地表节肢动物多样性,地表节肢动物对煤矿修复的响应存在明显的区域差异,地表节肢动物多样性可以指示和评估煤矿修复效果。

祁连山地区复合生态系统韧性时空演化及障碍因子识别

祁连山地区是我国重要的生态功能区,也是我国生态环境脆弱区之一,研究祁连山地区自然-经济-社会复合生态系统韧性,以期有效治理祁连山地区生态环境问题。构建三维空间矢量模型、耦合协调模型和障碍度模型,测度2007—2021年祁连山地区复合生态系统韧性和子系统耦合协调性,揭示影响复合生态系统韧性提升的障碍因子,并借助地理信息系统技术分析复合生态系统韧性的空间演化过程。结果表明:(1)祁连山地区复合生态系统韧性呈上升趋势,空间上呈现从东部逐渐向西部降低的趋势;自然子系统韧性呈下降趋势,空间上呈现中东部向西北部逐渐降低的趋势;经济子系统韧性呈上升趋势,且增速较快,高经济韧性集中分布于东部和北部;社会子系统韧性上升幅度不大,高社会韧性集中分布于东部。(2)祁连山地区复合生态系统韧性耦合度提升明显,已达到高水平耦合;耦合协调度呈波动上升,已达到中级协调等级。(3)自然子系统对复合生态系统韧性提升影响较大,来自经济子系统的指标障碍度提升明显。

祁连山周边内流区人类活动对表层沉积物的影响

【目的】表层沉积物代用指标可以指示现代环境要素进而推断古环境演化过程,但是在人类活动较强的地区,人类对沉积物产生作用的时间和作用方式以及这种作用是否影响表层沉积物代用指标对该地区气候进行反演的评估较少。【方法】选取祁连山及周边地区所采集的456个表层沉积物,通过总有机氮(TN)、总有机碳(TOC)、碳氮比(C/N)、有机碳同位素(δ^(13)C_(org))、碳酸盐碳同位素(δ^(13)C_(carb))和氧同位素(δ^(18)O)等代用指标分析,建立了代用指标与海拔、经纬度、温度、降水等要素之间的关系,探究了现代人类活动对表层沉积物古环境代用指标的影响。【结果与结论】研究发现人类活动影响区表层沉积物古环境代用指标在该区域波动明显,相较其他地区,相关性大幅降低,表明人类活动影响可以改变古环境代用指标的指示意义。通过系统分析和计算表层沉积物与环境要素之间的关系,探讨了人类活动对表层沉积物的影响,进一步明确代用指标的现代环境指示意义,从而为后续利用沉积地层中古环境代用指标反演过去气候变化和分析人类活动提供理论依据。

基于SHAW模型的祁连山浅山区荒漠草地土壤水热动态模拟研究

祁连山是我国重要的生态安全屏障,其浅山区是连接高寒山区与绿洲平原的过渡地带,土壤水热变化显著影响该区生态系统与水文过程的相互作用。本文利用祁连山浅山区荒漠草地的观测资料,基于SHAW模型对土壤水热动态进行了模拟和分析,利用控制变量法量化了不同冻融阶段气温和降水变化对土壤温度和水分的影响。结果表明:模型模拟的各层土壤温度纳什效率系数(NSE)均大于0.95,且土层越深模拟效果越好,模型模拟的土壤水分总体上能反映土壤水分的动态变化和浅层土壤中降水的入渗过程。不同冻融阶段土壤水热分布的剖面特征差异明显,总体而言,土壤温度波动随深度逐渐变小,而土壤水分随深度逐渐升高,浅层土壤水热过程对气象要素变化更敏感。情景分析表明,气温每升高1.0℃,土壤冻结发展期、完全冻结期和融化发展期分别缩短1.4 d、0.8 d和2.2 d,表层和深层土壤温度分别升高0.6℃和0.1℃,土壤温度升高的幅度随深度减小。降水的变化对完全融化期0.20~1.20 m的土壤水分影响最显著,对融化发展期和冻结发展期的影响体现在0.20~0.60 m的浅层土壤,而对完全冻结期的土壤未冻水含量基本没有影响。研究结果可为气候变化背景下祁连山浅山区脆弱生态系统的稳定性维持提供参考。

祁连山高寒地区零碳农宅技术研究

我国西北祁连山高寒区地区因海拔高、气候寒冷,导致采暖期长、采暖能耗高、碳排放量大。该地区农宅主要消耗能源为煤炭、生物质、电力,户均碳排放量约11.8 tCO_(2)。在该地区建设低碳或零碳农宅主要有两种措施:一是通过改善围护结构等节能技术实现低能耗建筑,二是结合当地丰富太阳能资源的低碳能源供给系统。研究表明,在对门窗和墙体的建筑本体节能的基础上,采取分布式光伏+光热+空气源热泵能源供给系统,可以实现农宅的零碳排放;单位投资年减排量为5480 kgCO_(2)/万元,系统寿命期单位投资减排量为137.2 tCO_(2)/万元。在我国西北祁连山高寒区构建零碳农宅具有可行性,可改善居民居住环境。

祁连山祁丰矿区废弃矿山植被恢复调查分析

为了解祁连山祁丰矿区植被恢复情况,以期为该地区的废弃矿山植被恢复和重建提供理论依据,在该矿区选择包括石灰石矿、煤矿、铜矿、多金属矿、石英岩矿的5处典型废弃矿山为研究对象,通过设置植被样方并进行植被群落结构调查。结果表明:废弃矿山的主要恢复措施为建筑物及废弃设施拆除、垃圾清理、渣堆整平、废弃探采坑洞的回填及刷坡整平、覆土、人工平土、植草绿化、纤丝石笼挡墙、道路翻耕、封育围栏等。从植被恢复效果看,土壤层较厚(蓄水能力强)的矿点及有灌溉条件的矿点,其植被恢复效果好;而土壤层较薄或无灌溉条件的矿点,其植被恢复效果差一些。因此,建议继续坚持人工修复和自然修复相结合,同时加强植被生态恢复后的后期管理,使矿山植被生态系统恢复进入良性循环。

基于InVEST模型的祁连山地区土壤保持功能时空演变及驱动因素分析

[目的]探讨祁连山地区土壤保持服务时空变化特征及空间异质性影响因素,为该区生态保护与可持续发展提供科学参考。[方法]基于2005—2020年4期土地利用数据,结合地形、土壤和气象数据,运用InVEST模型及地理探测器方法,模拟土壤保持服务、探究土壤保持量时空变化特征及其价值,对其空间异质性进行归因分析。[结果]①祁连山地区2005—2020年土壤保持量变化区间为5.02×10^(9)~7.89×10^(9)t,呈下降趋势;土壤保持量在空间分布上表现为东南高西北低,高值区均集中在研究区青海湖东侧和祁连山脉区域。②不同土地利用类型中,草地土壤保持总量最大,林地土壤保持强度最大;土壤保持强度随海拔增加呈先增后减的单峰曲线,随坡度增加呈线性增大。③研究区年均土壤保持服务价值为3.912×10^(13)元,以保持土壤肥力的价值E 1为主。④地理探测结果显示:坡度和土壤类型对土壤保持空间异质性的解释力最高,整体上以植被覆盖度和土壤类型交互作用解释力最高。[结论]坡度和土壤类型共同作用于植被覆盖度。植被覆盖度为影响土壤保持服务空间异质性的主导因子,应将部分耕地转为草地或林地,加大生态保护力度,提高植被覆盖度,减少水土流失,增加土壤保持能力,从而改善生态环境。

中祁连湖滩地区菜子沟一带锰矿成矿条件分析

菜子沟位处中祁连东段拉脊山-雾宿山褶皱带内,其中奥陶系雾宿山群是变质热液型铜、铁、铅、锰矿床的有利含矿层,铜矿赋存于该层安山岩中,锰矿主要赋存于该层硅质岩中。在该区域共发现的11个锰矿体分布于下圈、大台子脑、年家湾、张家沟、陈家沟等地,主要赋存于中上奥陶统雾宿山群的中-基性火山岩与正常沉积岩互层中,岩性为硅质(板)岩,次为安山岩,呈近东西向带状展布。矿床成因属火山喷发-沉积变质型,含矿地层、矿化蚀变信息可作为直接找矿标志。

祁连山东端林区森林和草原火灾发生规律调查及防范对策

为提高祁连山东端林区森林和草原火灾防范能力,调阅研究其2017-2021年不同地点、时间、植被类型、火源和受灾面积火灾发生次数。通过分析调阅资料,总结祁连山东端林区森林和草原火灾发生规律,并根据火灾发生规律,提出防范对策,对祁连山东端林区乃至整个祁连山地区森林和草原火灾防范具有一定指导作用。

国有林场自然资源确权登记操作规程研究

以祁连山国家公园肃南片区、榆中县贡井林场、洮河生态建设局作为国有林场自然资源确权操作规程研究区域,进行国有林场确权登记操作流程研究,划分了不同类型国有林场自然资源登记单元,确定了登记范围和边界,明确登记范围内自然资源的数量、质量、面积、公共管制等基本信息,查清单元内各类自然资源的所有权、用益物权等权属信息,通过确权登记操作规程的研究,形成了验证区各登记单元内自然资源分布成果。祁连山国家公园肃南片区登记单元内草原资源分布最多,贡井林场登记单元内森林资源分布最多,洮河生态建设局登记单元内森林资源分布最多。

祁连山国家公园青海片区生态系统水文调节价值评估及分析

生态系统水文调节服务对人类福祉有重要的影响,运用InVEST产水量模型和支持向量回归模型对祁连山国家公园青海片区生态系统水文调节价值进行了评估和预测。结果表明:(1)草地在祁连山国家公园青海片区生态系统水文调节中发挥了重要作用,2020年草地水文调节价值量为31.29亿元,占水文调节总价值的60.06%。(2)林地面积虽然不大,但其生态安全的保障作用明显,2020年的水文调节价值为7.25亿元,占水文调节总价值的13.92%。(3)2010—2020年,祁连山国家公园青海片区不同类型的生态系统水文调节实物量是增加的,年均增长2.24%,价值量年均增加约0.97%,价值量年均增长幅度小于实物量,主要是由部分生态系统水文调节价值下降引起的。(4)预测可知,2030年祁连山国家公园青海片区生态系统水文调节实物量、价值量较2020年均有所增加,实物量增加4.90亿t,价值量增加3.86%。

生态修复前后祁连山地区植被覆盖变化

祁连山是我国重要的生态屏障,定量评估气候变化和人类活动对植被变化的影响对祁连山生态保护和修复具有重要意义。以祁连山地区为研究区,分析1986—2020年植被覆盖时空动态变化,计算气候变化及人类活动对植被覆盖变化的贡献率,进而评估生态修复工程对于植被覆盖变化的影响程度。结果表明:(1)1986—2020年间祁连山地区植被覆盖度呈现显著增加趋势,变化趋势为0.022/10a;中高覆盖度主要分布在东南地区,西北地区仍然是以低覆盖度为主,且1999年的退耕还林还草工程施行后,中低覆盖度向中高覆盖度方向转化。(2)祁连山地区植被覆盖变化是气候因素和人类活动共同作用的结果。气候因素对植被覆盖的贡献率为93.40%,人类活动贡献率为6.60%,气候因素是祁连山区植被变化的主导因素,但人类活动在植被变化中的影响程度逐年增加。祁连山地区植被覆盖呈转好趋势,这主要是因为退耕还林还草等生态工程极大地改善了祁连山地区的植被覆盖状况,为后续植被的恢复和生态系统的稳定奠定了良好的基础。

基于InVEST模型的甘肃省祁连山林区乔木林碳储量时空变化研究

以祁连山林区乔木林为研究对象,基于甘肃省林地更新数据和中国土地覆盖及地形数据,运用InVEST模型估算和分析祁连山林区乔木林的碳储量时空变化特征。结果表明,1)研究区乔木林碳储量的分布呈现北部片状—中部点状片状—南部线状的分布特征。2)2016-2019年研究区乔木林碳储量增长了258.91万t,年均碳汇量86.30万t。3)2016、2019年云杉的碳储量占比最大,平均占比88.82%,且以最具未来碳汇潜力的中龄林和近熟林增长为主,主要分布在海拔2500~3500 m、坡度10°~40°的阴坡和半阴坡及半阳坡。4)2016-2019年,牧草地、耕地、未利用地、建设用地向林地转移1219.22 hm^(2),呈现牧草、耕地、未利用地、建设用地向林地回转的趋势。研究结果一定程度上反映了研究区森林碳汇功能向良性转变,表明了退耕还林、人工造林等生态治理工程的有效性。