Spatial differences of Sustainable Development Goals(SDGs)among counties(cities)on the northern slope of the Kunlun Mountains

The county(city)located on the northern slope of the Kunlun Mountains is the primary area to solidify and extend the success of Xinjiang Uygur Autonomous Region,China in poverty alleviation.Its Sustainable Development Goals(SDGs)are intertwined with the concerted economic and social development of Xinjiang and the objective of achieving shared prosperity within the region.This study established a sustainable development evaluation framework by selecting 15 SDGs and 20 secondary indicators from the United Nations’SDGs.The aim of this study is to quantitatively assess the progress of SDGs at the county(city)level on the northern slope of the Kunlun Mountains.The results indicate that there are substantial variations in the scores of SDGs among the nine counties and one city located on the northern slope of the Kunlun Mountains.Notable high scores of SDGs are observed in the central and eastern regions,whereas lower scores are prevalent in the western areas.The scores of SDGs,in descending order,are as follows:62.22 for Minfeng County,54.22 for Hotan City,50.21 for Qiemo County,42.54 for Moyu County,41.56 for Ruoqiang County,41.39 for Qira County,39.86 for Lop County,38.25 for Yutian County,38.10 for Pishan County,and 36.87 for Hotan County.The performances of SDGs reveal that Hotan City,Lop County,Minfeng County,and Ruoqiang County have significant sustainable development capacity because they have three or more SDGs ranked as green color.However,Hotan County,Moyu County,Qira County,and Yutian County show the poorest performance,as they lack SDGs with green color.It is important to establish and enhance mechanisms that can ensure sustained income growth among poverty alleviation beneficiaries,sustained improvement in the capacity of rural governance,and the gradual improvement of social security system.These measures will facilitate the effective implementation of SDGs.Finally,this study offers a valuable support for governmental authorities and relevant departments in their decision-making processes.In addition,these results hold significant reference value for assessing SDGs at the county(city)level,particularly in areas characterized by low levels of economic development.

Spatio-temporal variation of water conservation and its impact factors on the southern slope of Qilian Mountains

The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the perspective of water conservation by classifying different clusters of water conservation functional areas to efficiently use limited human resources to tackle the water conservation protection problem. In this study, we used Integrate Valuation of Ecosystem Services and Tradeoffs(InVEST) model to estimate water conservation and analyzed the factors that influence the function. The results of this study include:(1) from 2000 to 2015, the water conservation of the southern slope of Qilian Mountains generally showed an increasing trend, and the total water conservation in 2015 increased by 42.18% compared with that in 2000.(2) Rainfall, fractional vegetation cover(FVC), and evapotranspiration have the most significant influence on the water conservation of the study area. Among them, water conservation is positively correlated with rainfall and FVC(P<0.05) and negatively correlated with evapotranspiration(P<0.05).(3) The importance level of water conservation functional areas gradually increases from northwest to southeast, and the region surrounding Menyuan Hui Autonomous County in the southeast of the southern slope of Qilian Mountains is the core water conservation functional area. And(4) the study area was divided into five clusters(Cluster Ⅰ–Cluster Ⅴ) of water conservation, with the areas of Clusters Ⅰ through Ⅴ accounting for 0.58%, 13.74%, 41.23%, 32.43%, and 12.01% of the whole study area, respectively.

Temporal and spatial responses of ecological resilience to climate change and human activities in the economic belt on the northern slope of the Tianshan Mountains, China

In the Anthropocene era,human activities have become increasingly complex and diversified.The natural ecosystems need higher ecological resilience to ensure regional sustainable development due to rapid urbanization and industrialization as well as other intensified human activities,especially in arid and semi-arid areas.In the study,we chose the economic belt on the northern slope of the Tianshan Mountains(EBNSTM)in Xinjiang Uygur Autonomous Region of China as a case study.By collecting geographic data and statistical data from 2010 and 2020,we constructed an ecological resilience assessment model based on the ecosystem habitat quality(EHQ),ecosystem landscape stability(ELS),and ecosystem service value(ESV).Further,we analyzed the temporal and spatial variation characteristics of ecological resilience in the EBNSTM from 2010 to 2020 by spatial autocorrelation analysis,and explored its responses to climate change and human activities using the geographically weighted regression(GWR)model.The results showed that the ecological resilience of the EBNSTM was at a low level and increased from 0.2732 to 0.2773 during 2010–2020.The spatial autocorrelation analysis of ecological resilience exhibited a spatial heterogeneity characteristic of"high in the western region and low in the eastern region",and the spatial clustering trend was enhanced during the study period.Desert,Gobi and rapidly urbanized areas showed low level of ecological resilience,and oasis and mountain areas exhibited high level of ecological resilience.Climate factors had an important impact on ecological resilience.Specifically,average annual temperature and annual precipitation were the key climate factors that improved ecological resilience,while average annual evapotranspiration was the main factor that blocked ecological resilience.Among the human activity factors,the distance from the main road showed a negative correlation with ecological resilience.Both night light index and PM2.5 concentration were negatively correlated with ecological resilience in the areas with better ecological conditions,whereas in the areas with poorer ecological conditions,the correlations were positive.The research findings could provide a scientific reference for protecting the ecological environment and promoting the harmony and stability of the human-land relationship in arid and semi-arid areas.

Evolution of economic linkage network of the cities and counties on the northern slope of the Tianshan Mountains,China

The exchanges between cities and counties in the northern slope economic belt of Tianshan Mountains(NSEBTM)are increasingly frequent and the economic linkages are increasingly close,but the spatial distribution of economic development and linkages among the cities and counties within NSEBTM is uneven.Therefore,it is of great significance to study the evolution of spatial-temporal pattern of the economic linkage network of cities and counties on NSEBTM to promote the coordinated and integrated development of the regional economy on NSEBTM.In this study,we used the modified gravity model and social network analysis method to analyze the spatio-temporal evolution characteristics of the economic linkage network structure of cities and counties on NSEBTM in 2000,2010,and 2020.The results showed that the comprehensive development quality level of cities and counties on NSEBTM increased from 2000 to 2020,its growth rate also increased,and its gap between cities and counties continued expanding.Both the spatial distribution patterns of the comprehensive development quality level of cities and counties on NSEBTM in 2000 and 2010 were presented as“high in the middle and low at both ends”,while the spatial distribution pattern of 2020 was exhibited as“high value and low value staggered”.The total amount of external economic linkages of cities and counties on NSEBTM showed an obvious upward trend,and its gap between cities and counties continued expanding,presenting a pattern of“a strong middle section and weak ends”.The direction of economic linkages of NSEBTM existed obvious central orientation and geographical proximity.The density of economic linkage network of NSEBTM increased from 2000 to 2020,and the structure of economic linkage network changed from single-core structure centered with Urumqi City to multicore structure centered with Urumqi City,Karamay City,Shihezi City,and Changji City,shifting from unbalanced development to balanced development.In the future,we should accelerate the construction of urban agglomeration on NSEBTM,cultivate a modern Urumqi metropolitan area,improve comprehensive development quality of the cities and counties at the eastern and western ends,strengthen the intensity of economic linkages between cities and counties,optimize the economic linkage network,and promote the coordinated and integrated development of regional economy.

Temporo-Spatial Distribution and Evolution of Ore Deposits in the West Sector of the Northern Qilian Mountains

The west sector of the northern Qilian Mountains is well-known for the Jingtieshan-type iron deposits. A new breakthrough has been made in prospecting for gold and copper in recent years. In this paper, the distribution characteristics of ore deposits in the study area are discussed from the viewpoint of tectonic evolution. It is suggested that there are 9 stages of mineralization from the Palaeoproterozoic to Indosinian. Four minerogenetic series and two minerogenetic subseries of ore deposits are recognized. Iron mineralization occurred in several stages, while most of the metals were accumulated in large amounts in the Caledonian. The enrichment and mineralization of gold is related to large-scale shear-strike-slip faults and the ascent and unloading of deep-seated fluids.

What are the keys to influence the life satisfaction of eco-migrants in the northern foot of the Qilian Mountains?A test based on the livelihood risk interaction

Eco-migrants'ability to adapt to livelihood risks and their satisfaction with lives directly affect the ecological and economic benefits of ecological migration engineering.To formulate an effective livelihood risk prevention system and welfare guarantee mechanism,we took the ecomigrants in Wuwei City as an example,developed an integrated analytical framework for life satisfaction and employed linear regression models to identify the interactions between livelihood risk and life satisfaction.Our findings indicate that 94.66%of eco-migrants in Wuwei City are threatened by livelihood risks after relocation.High living expenses,poor quality of redistributed production goods,and re-poverty constitute the main risks.The risk multiplicity index is 2.96.Besides cultural types,there are no significant differences in regions and livelihoods.A total of 55.73%of eco-migrants are satisfied with their lives,with the Liangzhou district scoring the highest.Except for satisfaction with development potential and public services,no significant intergroup differences were found among regions and livelihood patterns.Eco-migrant's life satisfaction is significantly affected by livelihood risks.Eco-migrants'satisfaction with living income,social integration,farmer-friendly policies and overall life is negatively affected by the risk of repoverty and inadequate social security.An ecomigrant's satisfaction with development potential and community construction is not influenced by one type of risk alone,but the interaction between risks has a strong influence.The interaction of welfare risks with economic risks and policy risks will balance and weaken the adverse effects of a single risk on those elements in the economic and policy spheres.This study offers novel ideas for rural revitalization,hollow governance,and well-being assurance.

Sustainable land-use patterns for arid lands: A case study in the northern slope areas of the Tianshan Mountains

Sustainable land use patterns are ecological and economic prerequisites of regional sustainable development. This is especially true for arid lands, where the environment is wholly fragile thanks to extremely limited precipitation, and where human activities have greatly transformed natural desert system by clearing natural vegetation, expanding oases and even building dams on inland rivers. However, the current studies on land use patterns are still characterized by field investigations and case studies, with almost no solid scientific basis. This paper holds that land types and their combination patterns are the principal basis for designing sustainable land use patterns, and that GIS and RS-based large-scale land type mapping and the study of their spatial combination structures should be coordinated with the demand of social development. The existing environmental problems induced by irrational land use mostly result from their deviation from the natural properties of land types. Taking the northern slope of the Tianshan Mountains （NSTM） as an example and considering land type patterns as the basis of land use patterns, this paper improves the vertical oa- sis-and-mid-mountain two-belts development model and the sustainable mountain land use model for arid lands put forward in recent years; and in terms of oases patterns, it outlines oasis development models, including intensive land use pattern in alluvial-diluvial fans, moderate agricultural development pattern in alluvial plains, and ecological land use pattern in river-end oases.

An analysis of oasis stability in arid areas:a case study in the northern slope areas of the Tianshan Mountains

This paper discusses oasis stability at regional scale with a case study in the northern slope areas of the Tianshan Mountains (NSTM). The results showed certain significant aspects. (1) As long as water resources in the oasis keep stable and their utilization efficiency can be maintained or gradually increased, the primary productivity could be continuously increased and the natural primary productivity keeped relatively stable. In this case, it is considered that the oasis is stable and its sustainable development can be achieved at regional scale. (2) Considering the availability of water resources in the oases, the oases on the alluvial-diluvial fans are highly stable. In the alluvial plain downstream of the groundwater overflowing zones the oases are moderately stable and in the lacustrine deltas or dry lacustrine deltas the oases are lowly stable. (3) Enlargement of oases and the increase of water resources and vegetation coverage in the oasis will certainly enhance the 'cold-island effect' of the oasis and increase the stability of oases.

Response of ecosystem service value to land use/cover change in the northern slope economic belt of the Tianshan Mountains, Xinjiang, China

Land use/cover change(LUCC)is becoming more and more frequent and extensive as a result of human activities,and is expected to have a major impact on human welfare by altering ecosystem service value(ESV).In this study,we utilized remote sensing images and statistical data to explore the spatial-temporal changes of land use/cover types and ESV in the northern slope economic belt of the Tianshan Mountains in Xinjiang Uygur Autonomous Region,China from 1975 to 2018.During the study period,LUCC in the study region varied significantly.Except grassland and unused land,all the other land use/cover types(cultivated land,forestland,waterbody,and construction land)increased in areas.From 1975 to 2018,the spatial-temporal variations in ESV were also pronounced.The total ESV decreased by 4.00×10^(8) CNY,which was primarily due to the reductions in the areas of grassland and unused land.Waterbody had a much higher ESV than the other land use/cover types.Ultimately,understanding the impact of LUCC on ESV and the interactions among ESV of different land use/cover types will help improve existing land use policies and provide scientific basis for developing new conservation strategies for ecologically fragile areas.

Fluid Activity and Tectonic Evolution in the Northern Qilian High-pressure Metamorphic Belt

The Northern Qilian high-pressure metamorphic belt has experienced multipledeformation-metamorphism, which consists of at least four stages. In 550.8-526 Ma, eclogites wereformed. High temperature and pressure caused the escape of a large quantity of gas-liquid fluidsfrom rocks while silicate melt was generated. In the late stage, small amounts of CO_2 and H_2Oinfiltrating along fractures were introduced. In the formation of glaucophane schist (447-362 Ma),devolatilization reactions were dominated during the subduction-uplift stage of the paleoplate. Inthe uplift-exhumation stage (400-380 Ma) the increase of internal space of fractures in the rocksfavoured fluid infiltration and concentration. These fluids participated in hydration reactions inthe retro-metamorphism. The fluids participating in the mineral reactions have the compositions ofCaCl_2-NaCl-H_2O. In subsequent thrusting (<380 Ma), the metamorphic terrain was uplifted to theshallower crust and ductile-shearing deformation took place, which caused mainly dehydrationreactions of minerals. In a near-surface environment the metamorphic terrain experienced brittledeformation, forming many accompanying fractures. Immiscible CO_2 and low-salinity aqueous fluidsoccurred in these secondary microfractures and were trapped and sealed. The thermodynamic conditionsof different deformation-metamorphic stages of the metamorphic terrain were calculated and thecorresponding P-T-t path was deduced, showing that the metamorphic terrain has experienced aclockwise path indicated by T- and P-rising, and T- and P-falling processes. This reveals that thesubduction zone has undergone multiple tectono-dynamic processes, i.e. initial deep burial,subsequent quick uplift and near-surface tectonism.

Geology,Geochemistry and Minerogenesis of the Shijuligou Zinc-Copper Deposit in Gansu,China

The Shijuligou deposit was separated by an arcuate ductile shear zone cross the center of the deposit region, resulting in the difference between the southern and northern ore bodies. The lead （Pb） isotopic data of ores of the Shijuligou copper deposit have averages of 206Pb/204pb, 207pb/204pb, and 20spb/204pb in 17.634, 15.444, and 37.312, respectively. It has been shown that ore-forming metals originated from intrusive and extrusive rocks in the upper part of ophiolites. The sulfur isotopic data of pyrite and chalcopyrite in the northern part change from ＋7.61‰ to ＋8.09‰ and ＋4.95‰ to ＋8.88‰ in the southern part. Isotopes of δ18O in the Shijuligou copper deposit are between ＋11.1‰ and ＋18.6‰, with the calculated δ18OH2O at ＋0.65‰. It is suggested that the mineralized fluid is a mixture of magma fluid, meteorological water, and seawater through circulating and leaching metals from the volcanic rocks. The zircon uranium-lead （U-Pb） dating of gabbro is 457.9_＋1.2 Ma, and the lower crossing age of the discordant and concordia curves of pyroxene spilite of zircon is 454_＋15 Ma. It is indicated that the Shijuligou deposit formed in a new ocean crust （ophiolite） of the back-arc basin in the late Ordovician. Mineralization should occur in the intermittence period after strong volcanic activity, and the age should be the late Ordovician. Moreover, the mineralization of ophiolite-hosted massive sulfide deposits in the ancient orogenic belt of the late Ordovician in the northern Qilian Mountains was controlled by the primary fault/fracture, with the forming of a metallogenic hydrothermal system by a mixture of volcanic magma fluid and seawater, which circularly leached the metallogenic metals from the volcanic rocks, resulting in their accumulation. The ore bodies were transformed with morphology and metallogenic elements. Jasperoid is an important sign for prospecting such deposits. There were many island arcs in the continent of China. This study provides evidence for understanding and exploration of ophiolite-hosted massive sulfide deposits in western China, especially in the area of northern Qilian Mountains.

祁连山北坡沙尘天气气溶胶特征的飞机观测

了解沙尘天气下气溶胶的垂直分布特征对于进一步认识气溶胶-云相互作用及其天气、气候效应至关重要。基于2023年9月6日沙尘天气下的飞机观测数据,分析祁连山北坡沙尘气溶胶的垂直分布特征。结果表明:此次沙尘天气是在高空锋区及地面冷高压的共同作用下形成。受沙尘天气影响,气溶胶粒径谱宽增宽;气溶胶数浓度较背景可上升约2~3倍,且气溶胶数浓度大值区呈悬垂状态分布,粒子数浓度大值层位于4000~4500 m和3000~4000 m高度;对沙尘气溶胶数浓度贡献最大的细粒子和粗粒子粒径分别为1.2~1.8μm和6.5~16.6μm,且气溶胶数浓度的增大在粗粒子段更为明显。气溶胶来源及输送层、以及气象要素垂直分布演变在气溶胶垂直分布及谱分布中发挥了重要作用。

昆仑山北坡水资源科学考察初报

2021年10月首批启动了第三次新疆科学考察——“昆仑山北坡水资源开发潜力及利用途径科学考察”。结合多源遥感信息和2022—2023年野外科考工作,对昆仑山北坡的水文水资源变化和水资源利用进行了调查研究。结果表明:(1)1990—2020年,昆仑山北坡山区的气温、降水分别以0.14℃·(10a)^(-1)和6.53 mm·(10a)^(-1)幅度增加。(2)冰川变化相对稳定,积雪面积和积雪深度表现为略微增加。(3)永久性水体和季节性水体面积分别显著增加79.89%和144.49%。(4)东昆仑-库木库里盆地的阿牙克库木湖和阿其克库勒湖两大湖泊的水域面积分别增加了68.91%和58.22%,盆地内多条河流具备水资源开发潜力。(5)昆仑山北坡陆地水储量总体呈增加趋势,表现为从西向东增加趋势越加显著。(6)昆仑山北坡的主要河流和田河、克里雅河和车尔臣河年均径流量2010—2023年较1957—2023年分别增加了20.24%、27.85%和45.17%。(7)基于不同气候变化情景模拟预测至21世纪中后叶,主要河流径流量将保持上升态势,区域水资源量总体呈增加趋势。昆仑山北坡的水资源禀赋可为区域绿色高质量发展提供有利的水资源保障条件。

中昆仑山北坡持续性暴雨的水汽输送及其大气三维结构特征

利用基于拉格朗日方法的HYSPLIT_4轨迹模式,结合地基GPS-MET观测资料,对2019年6月24~26日中昆仑山北坡一次持续性暴雨天气大尺度水汽输送特征及水汽源地进行分析,阐明了干旱区强降水期间大尺度环流异常与水汽持续接力输送过程的关系。结果表明:(1)降水前副热带高压(简称副高)位置异常偏西,副高外围偏南气流造成高原增湿明显。强降水期间,副高继续向西北伸展,低纬度水汽沿印度夏季风环流向北输送,经青藏高原接力输送至暴雨区,与塔什干低涡前偏南气流共同构成了中昆仑山北坡持续性强降水的水汽输送通道,水汽持续接力输送造成暴雨区可降水量(PWV)出现两次急剧增湿过程,测站PWV峰值达到气候平均值近2倍。(2)300 hPa温度异常对于本次中昆仑山北坡持续性大暴雨天气水汽输送具有重要的作用。降水前和降水期间,300 hPa暖异常中心激发200 hPa反气旋式环流异常和经向风正异常中心,同时,在暖异常中心南侧(印度半岛北部)和西侧,激发500 hPa反气旋式环流异常中心和气旋式环流异常中心,反气旋式环流后部经向风正异常中心将低纬度地区暖湿气流向北输送,与气旋式环流东部偏南气流在暴雨区汇合,为持续性暴雨的发生提供充沛的水汽供应。

供需平衡视角下昆仑山北坡县域单元地表水资源开发利用潜力初探

定量分析地表水资源开发利用潜力有助于明晰区域水资源禀赋,对区域未来水资源科学规划和可持续开发利用具有重要的指导意义。通过供需水量平衡,从地表径流量、生态需水量、地表水可利用量角度,初步探讨了昆仑山北坡县域单元的地表水资源开发利用潜力,以期为昆仑山北坡科学规划和兵团南进布局提供水资源保障依据。结果表明:(1)昆仑山北坡河流径流2000年后呈显著增加趋势,主要河流2001—2010年年均径流量较2000年以前平均增加了23.36%,2011—2020年较2000年以前平均增加了42.89%,其中车尔臣河增幅最大,和田河增幅最小。(2)车尔臣河流域、克里雅河流域和和田河流域的生态基流量分别为4.67×10^(8)m^(3)、5.38×10^(8)m^(3)和20.26×10^(8)m^(3),天然植被生态需水量分别为4.34×10^(8)m^(3)、4.00×10^(8)m^(3)和2.62×10^(8)m^(3)。(3)昆仑山北坡各县域单元现状地表水已用水量范围为0.1×10^(8)~8.73×10^(8)m^(3),地表水资源潜力范围为-0.07×10^(8)~3.17×10^(8)m^(3),空间差异非常显著,其中水资源潜力大于2.00×10^(8)m^(3)的有墨玉县、铁门关市38团、策勒县、且末县、和田县、民丰县和洛浦县。现状区域的地表水资源调蓄能力不足,水资源利用上限偏低,虽有潜力但有水难用,未来昆仑山北坡各县域单元需制定修编更为适宜的地表水资源规划并加强基础水利工程建设,提升地表水资源利用效率,为区域高质量发展提供水资源支撑保障。

不同牧压对天山北坡中段山地草甸植物群落特征及植物生活型的影响

【目的】研究天山北坡中段山地草甸植物群落特征在不同牧压条件下的变化,为建立合理放牧利用制度提供理论依据。【方法】通过对庙尔沟乡索尔巴斯陶夏、冬牧场的实际放牧强度和草场植被状况进行调查,选择重度(HG)、中度(MG)、轻度(LG)且具代表性地段的放牧场,设置3个不同牧压监测点,每个监测点设置3个重复。【结果】在不同牧压条件下,植物群落优势种略有差异,群落物种数随着放牧强度的增大而减少。随着牧压增大,禾本科、豆科等优良牧草的重要值下降,而杂类草及醉马草的重要值增大;不同牧压对植被生物量的影响最大,其次是植被的盖度和高度,对频度的影响较小,呈现出植被平均高度、总盖度和生物量随放牧强度增大而降低的趋势;不同放牧时期对山地草甸植被优势种和植物生活型有明显影响,在夏季放牧场中植株矮小、重要值很低的金露梅在冬季放牧场中却株型高大,重要值也极高。【结论】在不同牧压条件下,群落物种组成不同,HG、MG、LG物种数分别为26、22和33种,物种间数目相差明显。重度放牧降低了植物群落的高度、盖度和地上生物量,并增大了杂类草和醉马草的优势。随着放牧强度增大,植物的生活型和重要值发生了改变,这也是植物生长过程中适应环境变化的一种策略。

昆仑山北坡区域高质量发展面临的问题、机遇与挑战

昆仑山北坡区域是新时代维护国家安全的重要战略部署区和“丝绸之路经济带”核心区关键通道,战略地位十分突出。但由于历史和自然的原因,该区域经济发展相对滞后。系统分析显示,昆仑山北坡区域目前存在的水资源利用上线偏低、水利工程建设严重滞后、城镇化进程缓慢、产业布局相对单一且缺少重要产业布局,以及区域高质量发展动能不足等问题,结合区域自然环境特点和发展机遇,提出加快构建经济带城市群体系,打造多产业协同发展的昆仑山北坡经济带,大幅提升水资源上线和水利工程管控能力,为昆仑山北坡农业提质增效提供水资源保障,系统打造昆仑山北坡农-林-牧复合基地,构建多元化食物供给体系,以能补水,提升资源综合利用效率,通过兵地优势互补、资源共享,加快推进昆仑山北坡经济带建设和高质量发展等建议。研究成果可为加快昆仑山北坡经济带生态安全和高质量发展提供科技支撑。

昆仑山北坡地表水氢氧稳定同位素空间分布特征

氢氧稳定同位素作为示踪剂被广泛用于水文循环过程研究。地表水是水循环的重要组成部分,是区域水汽来源和现代水文过程分析的有效载体。基于新疆第三次科学考察,于2018年8月至2023年8月在昆仑山北坡采集了地表水样本并测量其氢氧稳定同位素数据,同时汇编了区域以往的地表水同位素数据,分析了昆仑山北坡地表水氢氧稳定同位素的空间分布特征。结果表明:(1)昆仑山北坡地表水同位素值呈现出西低东高的空间变化特征,区域地表水线为δ^(2)H=5.98×δ^(18)O-6.86(R^(2)=0.65,n=141)。(2)对比昆仑山北坡地表水和降水氢氧稳定同位素值发现地表水同位素平均值普遍低于加权降水同位素值。(3)昆仑山北坡地表水同位素空间格局受到西风携带的外来水汽和局地再循环水汽共同影响,此外蒸发也会改变区域地表水同位素值。

天山北坡经济带植被覆盖度动态变化研究

为探明天山北坡经济带植被覆盖度时空变化及其原因,本研究基于MODIS13Q1NDVI数据、气象数据、地形数据、人文数据,基于Google Earth Engine(GEE)平台,利用Theil-Sen Median趋势分析、Mann-Kendall显著性检验和稳定性分析方法,探究2000-2020年天山北坡经济带植被覆盖度(FVC)时空变化特征及其影响因子.结果表明:天山北坡经济带的FVC表现为两条平行的高覆盖度带.其中中部地区具有较高的植被覆盖度,而边缘地区的植被覆盖度相对较低.2000~2020年间,天山北坡经济带的FVC在时空上呈轻度变化,约占总变化的70%.植被改善区域主要呈现带状分布,集中在研究区的中部,而植被减少区域主要分布在研究区的南缘.整体上,天山北坡的植被覆盖度呈现出西北至东南的相间分布趋势,并且有逐渐上升的趋势.与东部地区相比,西部地区的植被改善更为明显.2000~2020年间,天山北坡经济带的FVC整体上表现出较高的稳定性和较小的波动,其变异程度介于弱变异和中等变异之间.但是,在克拉玛依市北部、乌鲁木齐市西南部以及研究区南缘的零星地区,FVC存在较强的变异.通过地理探测器模型对天山北坡经济带FVC影响因素的研究表明,人类活动(人口密度、夜间灯光和土地利用类型)是FVC空间分异的主要解释因素.从驱动因素来看,人口密度P值为0.283,对FVC影响最大,夜间灯光P值为0.125,土地利用类型P值为0.179.

1990—2022年天山北坡地区不同开垦年限耕层土壤盐分变化

近年来,随着频繁的土地利用变化和大量耕地的开垦,土壤盐渍化已成为导致天山北坡耕地质量退化、阻碍绿洲农业发展的环境因素。本研究基于翔实的调查数据资料、土壤实测数据和中国土地覆盖数据集(CLCD),比较传统插值模型和随机森林插值模型对耕层土壤(0~30 cm)含盐量插值的优缺点;选取精度最高的定量预测模型对天山北坡地区耕层土壤含盐量定量预测,得到耕层土壤含盐量分布变化特征;以空间换时间,将近30 a新开垦耕地耕层土壤含盐量进行比较,分析开垦年限对土壤含盐量的影响。结果表明:(1)与传统的插值方法相比,随机森林算法能够更准确地预测盐渍化土地的土壤盐分分布情况。(2)天山北坡地区,耕层土壤含盐量存在较大空间异质性,即高海拔地区土体中的盐分会随着径流的淋溶,在低海拔的河流下游尾闾或低洼区靠近沙漠一侧积聚。(3)随着开垦年限的延长,天山北坡地区耕层土壤含盐量总体呈现下降的趋势,且土壤盐渍化程度倾向于聚集在一个中等的水平上,趋向于平衡或“中心化”。本研究增进了对当前耕地盐渍化状况及从原始荒地开垦到耕地后耕层土壤盐分变化历程的理解。这为干旱区备用土地资源的开发、管理和有效利用提供了理论支撑,并为农业的持续发展提供了科学依据。