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.

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.

Analysis on Variations of the Temperature and Precipitation in North Slope Area of the Western Tianshan in Recent 50 Years

[Objective] The research aimed to analyze variation characteristics of the temperature and precipitation in north slope area of the Western Tianshan in recent 50 years.[Method] According to temperature and rainfall data from 1961 to 2010 at three meteorological stations in north slope area of the Western Tianshan,climate change in the zone in recent 50 years was analyzed by using linear trend analysis method and 5-year sliding average method.[Result] The temperature in north slope area of the Western Tianshan showed significant warming trend.The annual average temperature significantly increased at 0.3 ℃/10 a in recent 50 years.But rise rates of the temperature in different seasons were different:autumn> winter> spring> summer.The annual rainfall in north slope area of the Western Tianshan in recent 50 years overall presented relative increase trend.Seen from annual rainfall,it significantly increased at 16.9 mm/10 a.Seen from seasonal rainfall,except in autumn,rainfalls in other three seasons in the past 50 years all showed significant increase trends,with amplitude of 3.2-11.2 mm/10 a.The largest increase amplitude was in summer.After a small precipitation peak in the 1980s,autumn rainfall slightly declined in the past 20 years.[Conclusion] The climate in north slope area of the Western Tianshan become warm and wet.

Sensitivity of mountain runoff to climate change for Urumqi and Kaidu rivers originating from the Tianshan Mountains

The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends on variation of temperature, precipitation and runoff, and the correlativity between temperature, precipitation, and runoffwere analyzed based on the past 40 years of observational data from the correlative hydrological and weather stations in the study areas. Various weather scene combinations are assumed and the response models of runoff to climate change are established in order to evaluate the sensitivity of runoff to climate change in the study areas based on the foregoing analysis, Results show that all variations of temperature, precipitation, and runoff overall present an oscillating and increasing trend since the 1960s and this increase are quite evident after 1990. There is a markedly positive correlation between mountain runoff, temperature, and precipitation while there are obvious regional differences of responding degree to precipitation and temperature between mountain runoff of Ummqi River and Kaidu River Basins Also, mountain runoff of Urumqi River Basin is more sensitive to precipitation change than that of Kaidu River Basin, and mountain runoff of Kaidu River Basin is more sensitive to temperature change than that of Ummqi River Basin.

Ecological response to the climate change on the northern slope of the Tianshan Mountains in Xinjiang

The Tianshan Mountains is a high and huge mountain body lying across the central part of Xinjiang, China, and is also the main area where the runoff forms in Xinjiang. In this paper, a set of RS-based study methods is put forward for deriving the information about the natural change of the ecology in arid areas, and the relationship between the climate change trend and the corresponding ecological response on the northern slope of the Tianshan Mountains since recent 40 years is analyzed from the scales of the land cover ecosystems and landscapes based on the observed data of climate, hydrology, modern glaciers and lakes on the northern slopes of the Tianshan Mountains since recent 40 years and the satellite RS data since recent 10 years by using the RS and GIS technologies. The results are as follows: (1) The overall trend of climate change on the northern slope of the Tianshan Mountains since recent 40 years is that both air temperature and precipitation are increased, especially the increase amplitudes of air tempera-ture, precipitation and annual runoff volume are high since the decade of the 1990s; (2) the in-tegrated indexes of the vegetation in all the geographical divisions on the northern slope of the Tianshan Mountains are obviously increased since recent 10 years, especially in the artificial oases and the foothill belts, such a change trend is advantageous for improving the vegetation ecology; and (3) the vegetation ecology in the arid areas is extremely sensitive to the climate change, the vegetation coverage and the biomass on the northern slope of the Tianshan Moun-tains are continuously increased because of the climate change since recent 10 years, their in-crease amplitudes in the plains and during the late stage are obviously higher than that in the mountainous regions and during the early stage.

348-YEAR PRECIPITATION RECONSTRUCTION FROM TREE-RINGS FOR THE NORTH SLOPE OF THE MIDDLE TIANSHAN MOUNTAINS

Correlation census shows that the correlation between the tree-ring chronologies in the Urumqi River Basin and precipitation during July in the last year to February in the concurrent year is significant,and the best single correlation coefficient is 0.74,with significance level of 0.0001. Using two residual chronologies collected from west Baiyanggou and Boerqingou,precipitation for 348 years can be reconstructed in the North Slope of middle Tianshan Mountains,its explained variance is 62%.According to much verification from independent precipitation data,historical climate records,glacier and other data.it shows that the reconstructed precipitation series of 348 years is reliable.Analysis of precipitation features indicates that there were three wet periods occurring during 1671(?)—1692,1716—1794 and 1825—1866 and three dry periods during 1693 —1715,1795—1824 and 1867—1969.Two wet periods,during 1716—1794 and 1825—1866, correspond to the times of the second and the third glacial terminal moraine formation,which is in front of No.1 glacier in Urumqi River source.According to computation,corresponding annual precipitation amounts are 59mm and 30mm more than now.The reconstructed precipitation series has a significant drying trend from 1716 to 1969.and has better representativeness to the precipitation of Urumqi and Changji Prefecture on the North Slope of Tianshan Mountains.

天山北坡经济带城乡聚落格局变化与影响因素分析

以天山北坡经济带城乡聚落为研究对象,采用景观格局指数、地理信息系统(GIS)空间分析、位序-规模法等分析1980-2020年间城乡聚落格局的变化,结合地理探测器从自然、区位及社会经济因素探究城乡聚落格局的影响因素。结果表明:1980-2020年间,城乡聚落数量、规模持续扩张且趋于集聚,前20 a扩张以耕地、草地为主,后20 a以未利用地为主;城乡聚落密度变化显著,高密度区主要集中在各绿洲呈现“多核集中分布”特征,中密度区沿高密度区周围扩张,低密度区沿绿洲边缘分布并在非绿洲区有扩张;首位聚落规模发展较好,趋于位序-规模曲线,中型聚落略微发育,小型聚落数量持续减少;交通等区位因素是天山北坡城乡聚落格局的首位影响因素,社会经济因素次之,自然地理因素影响较小,各影响因素差异显著。

新疆中天山北坡断裂带不同海拔高度土壤温度分布特征

研究中天山断裂带从高山带到准噶尔盆地边缘整个过渡带的土壤温度分布特征有助于理解干旱区土壤环境特征,从而为土地利用、农业生产提供依据。本文选取新疆中天山断裂带海拔高度呈梯度分布的6个气象站2005年至2020年各层土壤温度的日观测数据,利用统计方法分析了不同地形、不同深度土壤温度随海拔高度的变化特征以及不同海拔高度土壤温度随深度的变化特征。分析表明:中天山北坡土壤温度变幅随海拔高度的降低而升高。不同地形的土壤最高温和最低温的年温差浅层大于深层,由浅至深年最高温度和年最低温度出现的时间逐渐推迟;年内中天山北坡不同海拔高度0~20 cm的土壤日平均温度曲线大致呈余弦函数曲线,320 cm深度的土壤温度基本呈正弦函数分布,较0~20 cm地温的最高和最低晚3个月左右。研究区土壤温度随海拔高度降低呈现先升高后降低的趋势。在海拔为3539~600 m高度范围,土壤温度随着海拔的升高而降低。在600~441 m高度范围,土壤温度随着海拔的下降而下降;0~20 cm为土壤温度变化的活跃层,40 cm深度的土壤温度可称之为过渡层,320 cm深度称为土壤温度的稳定层,80~160 cm称为土壤温度的次稳定层。

天山北坡城市群国土空间格局识别与时空变化分析

气候变化和人类活动大环境下,探索国土空间格局演化特征及其规律对进一步缓和绿洲地区人地矛盾有着重要的意义。以天山北坡城市群为例,选取2000、2010年和2020年3期土地利用数据及DEM数据,基于“三生”空间理论对天山北坡城市群国土空间结构数量与空间分布进行分析。结果表明:(1)20 a间天山北坡城市群“三生”空间类型面积呈不同程度的增减,其中水域和林地生态空间的转出量最多,牧草和其他生态空间两者间相互的转换数量最大;(2)研究区除阜康市、木垒哈萨克自治县、奇台县、石河子市及乌鲁木齐市的国土空间利用程度综合指数呈小幅度增加和递减外,其他县域呈逐年提高趋势;(3)生产空间的核密度高值区呈东南-西北条带状,连片分布于研究区的中部,而生态空间的核密度高值区则分布于研究区外围;生活空间的核密度高值区以乌鲁木齐市为中心呈点状分布,周围衍生出许多零碎的中值点,总体分布较为破碎,空间连接性较低。

地形因子对天山北坡天山云杉林土壤有机碳的影响

【目的】研究地形因子对天山北坡天山云杉林土壤有机碳的影响。【方法】在新疆农业大学实习林场选取不同海拔、不同坡度和不同坡向的样地采集土壤样品,测定土壤有机碳含量并计算其碳密度。【结果】不同海拔梯度下,天山云杉林土壤有机碳含量介于41.65~77.67 g/kg,土壤有机碳密度介于9.47~14.27 kg/m^(2),土壤有机碳含量及密度均随着海拔的升高呈减少的趋势。0~20 cm土层坡度小于15°时,土壤有机碳含量表现为最高(105.08 g/kg),而当坡度达到30°~35°时,土壤有机碳含量最低;不同坡向上土壤有机碳含量从高到低依次为阴坡>半阴坡>半阳坡>阳坡,其中0~20 cm土层阴坡上土壤有机碳含量显著高于阳坡(P<0.05),20~60 cm土层土壤有机碳含量在各坡向之间差异不显著。【结论】天山北坡天山云杉林在高海拔区域内整个剖面土壤有机碳含量分布较低海拔区域相对均匀。坡向对土壤有机碳的再分配作用在20~60cm土层土壤中难以发挥作用。

数字经济与实体经济耦合协调研究——基于天山北坡经济带的实证研究

数字经济与实体经济之间有着紧密的联系。通过对天山北坡经济带2016-2020年9个县市的面板数据进行统计分析,构建了数字经济和实体经济评价的基本框架,并通过耦合模型评价了二者的耦合协调程度。结果表明:2016-2020年,天山北坡经济带数字经济与实体经济发展耦合协调度总体呈上升趋势,除奎屯市以外,其他各县市都达到了失调以上;乌鲁木齐市发展一直很稳定,并且耦合协调度在一直上升。但由于各个县市之间仍存在着较大差距,所以总体的耦合协调度水平还不够高。因此,需要积极促进居民消费,大力发展工业;继续加强薄弱部门的基础设施建设;推动中小企业数字化转型。通过这些措施促进区域经济社会协调发展。

中天山北坡冬季降雪变化及其影响因子分析

利用中天山北坡17个国家级气象站1978—2020年冬季逐日降水、气温要素等观测资料,采用多种统计方法,分析冬季降雪时空变化特征及其与气象因子的关系,结果表明:降雪日数和降雪量区域分布相似,均呈“城区多,山区少”分布特征;小雪日减少是导致总雪日减小的直接原因,中雪和暴雪显著增多是造成总降雪量增多的主要原因;持续1 d降水过程是冬季主要降雪过程,随着持续时间的增长,降水过程显著减少,≥5 d降水过程仅占2.8%;近43 a中天山北坡气候呈现较明显的暖湿化趋势,1987年、1994年分别发生降雪量由少变多和平均气温由低变高的突变;降雪量与年降水量、冬季平均最低气温、降雪日数呈显著正相关,年降水量越大、冬季最低气温越低、出现降雪日数越多,冬季降雪量就越大,反之越小。

干旱区绿洲城市群地表温度时空变化及其影响因素——以天山北坡城市群为例

基于2005—2019年的MYD11A2时间序列LST遥感数据,首先采用均值标准差法对LST进行分级,分析了天山北坡城市群的LST空间分布格局;其次利用Sen′s斜率分析法、Mann-Kendal趋势检验法和Hurst指数揭示了天山北坡城市群LST在2005—2019年和未来的变化趋势;最后借助地理探测器模型并综合考虑地表覆盖、气候、社会经济和地形因素分析了多空间尺度下LST的主要影响因素。结果表明:(1)天山北坡城市群的吐鲁番市是高温(HT)和极高温(EHT)的主要集聚地;白天和夜间的LST格局差异大,在绿洲区域表现为典型的“昼冷岛,夜热岛”特征。(2)LST在白天和夜间的变化率分别为0.04℃/a和0.03℃/a,白天的升温幅度强于夜间;在乌鲁木齐市、昌吉回族自治州、石河子市和五家渠市LST表现出显著的升高趋势,且在未来也具有相同的趋势。(3)在不同的空间尺度上,LST的主要影响因素不同;从整个天山北坡城市群来看气候因素和地形因素是LST的主要影响因素,而在在石河子市、五家渠市和奎屯市LST的主要影响因素是社会经济因素。

东天山北坡荒漠区15种植物热值特征研究

灌木和半灌木是维持干旱和半干旱地区生态系统稳定性的重要植被类型。采集东天山北坡荒漠区的15种优势灌木和半灌木植物茎、枝、叶等器官样品,测定其热值、灰分、碳含量,研究灌木种类、器官、灰分含量和碳含量对灌木热值的影响及其相关性,以期为深入了解干旱地区典型沙漠环境下的物质和能量循环研究提供理论依据。结果表明:1)15种植物全株(地上)热值范围为14.21KJ/g(短叶假木贼)~19.87KJ/g(小檗),平均热值为18.38KJ/g,该值高于全球陆生植物平均热值;2)灌木物种科间热值和碳含量存在差异,豆科和菊科植物相对于蔾属和蓼科植物有更高的热值和碳含量;3)灌木植物茎、枝、叶的热值,灰分含量和碳含量也存在差异,植物各器官热值平均值大小顺序为茎>枝>叶,灰分含量平均值大小顺序为叶>枝>茎,碳含量平均值大小顺序为枝>茎>叶;4)热值与灰分之间呈现极显著负相关(P<0.01),与碳含量呈现极显著正相关(P<0.01)。

天山北坡经济带城市NO_(2)污染的时空分布特征

基于2015-2020年近地面NO2质量浓度数据和2019年哨兵-5P TROPOMI卫星探测的对流层NO2柱浓度数据,采用相关性分析、趋势分析等方法探究新疆天山北坡经济带6个城市NO2污染的时空分布特征。结果表明:(1)从年均值来看,天山北坡经济带NO2质量浓度总体呈下降趋势,尤其2018-2020年下降明显。其中乌鲁木齐NO2质量浓度值最高、博乐最低。(2)从季度均值和月均值来看,各城市NO_(2)质量浓度季节变化明显,其中夏季最低、冬季最高;月均值呈“中间低、两头高”的变化特征。(3)从日均值来看,各城市NO2质量浓度大多呈现双峰型分布,分别出现在早上10:00和晚上23:00。(4)从空间分布来看,NO2柱浓度高值区多分布在人口密集和工业发达的城市地区,尤其是乌鲁木齐、昌吉、五家渠、石河子污染最为严重。

天山南坡山前荒漠草地植物群落分布对环境因子的响应——以拜城县为例

为探明天山南坡拜城县山前荒漠草地植物群落分布对地形与土壤因子的响应,本研究选取了拜城山前荒漠草地典型区域进行调查,采用优势度法和典范对应分析(Canonical correspondence analysis,CCA)法,研究山地荒漠草地植物群落分布与地形和土壤因子之间的关系。结果表明:(1)不同调查样点灌木层和草本层物种多样性存在差异,东坡调查样点Shannon-Wiener指数、Pielou指数和Simpson指数均表现为灌木大于草本,西坡和北坡调查样点Shannon-Wiener指数、Pielou指数和Simpson指数均表现为草本大于灌木;(2)典范对应分析法分析结果表明,地形因子对植物群落的影响大小顺序为:坡向(SA)>坡度(SG)>坡位(SP),土壤因子对植物群落的影响大小为:30~100 cm土层土壤水分(SMC-2)>土壤总孔隙度(STP)>0~30 cm土层土壤水分(SMC-1)。地形和土壤因子对不同植物群落的形成具有一定的筛选作用,30~100 cm土层土壤水分和坡向是影响天山南坡拜城县山前荒漠草地植物群落分布的关键因子。

近60 a天山北坡冰川变化研究

从流域尺度揭示天山北坡冰川变化状况,对下游绿洲地区水资源的合理开发利用具有重要意义。基于多源遥感影像提取天山北坡诸河流域近期冰川边界,结合前期发布的冰川编目及AS⁃TER DEM数据,对该区域冰川面积和物质平衡变化特征进行了分析。结果表明:(1)2015年前后天山北坡共计分布冰川10061条,总面积约4855.85±245.86 km^(2)。1960s—2015年天山北坡国内段冰川面积萎缩速率为0.52%·a^(-1)±0.06%·a^(-1),且近年来呈加速萎缩趋势(0.96%·a^(-1)±0.88%·a^(-1));1999—2015年天山北坡国外段冰川面积萎缩速率约为0.56%·a^(-1)±0.31%·a^(-1)。(2)2000—2020年天山北坡冰川表面高程变化速率约为-0.57±0.01 m·a^(-1),冰川物质呈持续亏损态,物质平衡为-0.39±0.04 m w.e.·a^(-1)。(3)天山北坡东、西段冰川面积和物质平衡变化均存在一定的空间差异性,近十几年间,东段各子流域冰川面积萎缩速率和物质亏损速率均相对较大。

乌昌石都市圈城市空间发展对NO_(2)浓度时空变化的影响

为探究城市空间发展对天山北坡经济带重心乌昌石都市圈NO_(2)污染的影响,利用多源遥感数据对乌昌石都市圈NO_(2)排放量时空变化进行研究。结果表明:基于2006—2020年OMI遥感数据,按全疆NO_(2)平均排放量大小进行划分后发现,新疆地区NO_(2)低污染区为和田等小城市,较低污染区为喀什及哈密等地区,中污染区在其中西部地区,次高污染区出现在天山南坡中等城市巴音郭楞蒙古自治州中部,高污染区在乌昌石都市圈。在空间格局上,城镇用地与建设用地以乌鲁木齐市五大城区为中心,以昌吉回族自治州昌吉市、阜康市及石河子市城区为副中心不断增长。乌昌石都市圈城市化进程加快,距离城区越近NO_(2)浓度越高,对其周围环境的污染程度越高。乌昌石都市圈2次疫情防控时,NO_(2)浓度下降幅度最大。对新型冠状病毒感染疫情防控前后(2019—2021年)乌昌石都市圈潜在源贡献因子(PSCF)及浓度权重轨迹(CWT)进行分析,结果表明主要潜在源区为乌鲁木齐本地区域以及昌吉回族自治州西南部邻近城市。