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1. chinaXiv:202201.00081 [pdf]

中亚天山地区关键水文要素变化与水循环研究进展

陈亚宁
Subjects: Geosciences >> Hydrology

天山地处欧亚大陆腹地,是丝绸之路经济带中段的重要水源地。天山地区的水循环系统具有时空差异性大、水源机制复杂、径流构成多元以及水系统脆弱等特点,水循环各环节受陆表格局和气候变化影响显著,水文要素对气候变化响应敏感,难以沿用现有的流域水循环模式阐述其内在机理。结合文献阅读和研究,系统分析了气候变化背景下天山地区关键水文要素的变化,研究了天山山区水汽来源、水汽输送机制以及水汽弱汇作用下的水循环要素变化及其对天山地区降水的影响及贡献率,揭示了气候变化对天山地区产汇流过程和水资源变化的影响机制,分析了气候变化对天山山区降水、冰川积累 消融、积雪变化对水循环的影响,提出了天山地区水循环研究的热点问题,为理解干旱区山区水循环机理、保障国家丝绸之路经济带中段水资源安全提供科学依据。

submitted time 2022-01-21 From cooperative journals:《干旱区地理》 Hits5Downloads3 Comment 0

2. chinaXiv:202201.00020 [pdf]

Estimation of rock Fe content based on hyperspectral indices

WANG Jinlin; WANG Wei; CHENG Yinyi; ZHANG Zhixin; WANG Shanshan; ZHOU Kefa; LI Pingheng
Subjects: Geosciences >> Geography

Information on the Fe content of bare rocks is needed for implementing geochemical processes and identifying mines. However, the influence of Fe content on the spectra of bare rocks has not been thoroughly analyzed in previous studies. The Saur Mountain region within the Hoboksar of the Russell Hill depression was selected as the study area. Specifically, we analyzed six hyperspectral indices related to rock Fe content based on laboratory measurements (Dataset I) and field measurements (Dataset II). In situ field measurements were acquired to verify the laboratory measurements. Fe content of the rock samples collected from different fresh and weathered rock surfaces were divided into six levels to reveal the spatial distributions of Fe content of these samples. In addition, we clearly displayed wavelengths with obvious characteristics by analyzing the spectra of these samples. The results of this work indicated that Fe content estimation models based on the fresh rock surface measurements in the laboratory can be applied to in situ field or satellite-based measurements of Fe content of the weathered rock surfaces. It is not the best way to use only the single wavelengths reflectance at all absorption wavelengths or the depth of these absorption features to estimate Fe content. Based on sample data analysis, the comparison with other indices revealed that the performance of the modified normalized difference index is the best indicator for estimating rock Fe content, with R2 values of 0.45 and 0.40 corresponding to datasets I and II, respectively. Hence, the modified normalized difference index (the wavelengths of 2220, 2290, and 2370 nm) identified in this study could contribute considerably to improve the identification accuracy of rock Fe content in the bare rock areas. The method proposed in this study can obviously provide an efficient solution for large-scale rock Fe content measurements in the field.

submitted time 2021-12-30 From cooperative journals:《Journal of Arid Land》 Hits4622Downloads159 Comment 0

3. chinaXiv:202201.00021 [pdf]

Land use/land cover change responses to ecological water conveyance in the lower reaches of Tarim River, China

WANG Shanshan; ZHOU Kefa; ZUO Qiting; WANG Jinlin; WANG Wei
Subjects: Geosciences >> Geography

The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin. However, excessive exploitation and over-utilization of natural resources, particularly water resources, have triggered a series of ecological and environmental problems, such as the reduction in the volume of water in the main river, deterioration of water quality, drying up of downstream rivers, degradation of vegetation, and land desertification. In this study, the land use/land cover change (LUCC) responses to ecological water conveyance in the lower reaches of the Tarim River were investigated using ENVI (Environment for Visualizing Images) and GIS (Geographic Information System) data analysis software for the period of 1990–2018. Multi-temporal remote sensing images and ecological water conveyance data from 1990 to 2018 were used. The results indicate that LUCC covered an area of 2644.34 km2 during this period, accounting for 15.79% of the total study area. From 1990 to 2018, wetland, farmland, forestland, and artificial surfaces increased by 533.42 km2 (216.77%), 446.68 km2 (123.66%), 284.55 km2 (5.67%), and 57.51 km2 (217.96%), respectively, whereas areas covered by grassland and other land use/land cover types, such as Gobi, bare soil, and deserts, decreased by 103.34 km2 (14.31%) and 1218.83 km2 (11.75%), respectively. Vegetation area decreased first and then increased, with the order of 2010<2000<1990<2018. LUCC in the overflow and stagnant areas in the lower reaches of the Tarim River was mainly characterized by fragmentation, irregularity, and complexity. By analyzing the LUCC responses to 19 rounds of ecological water conveyance in the lower reaches of the Tarim River from 2000 to the end of 2018, we proposed guidelines for the rational development and utilization of water and soil resources and formulation of strategies for the sustainable development of the lower reaches of the Tarim River. This study provides scientific guidance for optimal scheduling of water resources in the region.

submitted time 2021-12-30 From cooperative journals:《Journal of Arid Land》 Hits4570Downloads109 Comment 0

4. chinaXiv:202112.00053 [pdf]

新疆县市“三生”功能时空变化及耦合协调性分析

牛雅萱
Subjects: Geosciences >> Geography

基于“生产-生活-生态”功能视角构建评价体系并引入耦合协调模型,探究新疆县市土地 功能及功能间相互作用程度的时空演变规律,遴选影响区域发展的关键因子,为区域发展提供建议。研究结果表明:(1)新疆县市单元生产功能,生活功能,生态功能及“三生”功能综合评价的时空格局分布差异性显著,均呈现“北高南低”的空间分布特征,以天山北坡城市群为核心高值区。(2)新疆县市“三生”功能耦合协调性总体呈现“北高南低”空间分布态势,县市功能间的耦合协调 关系逐步向好,为区域后续的发展奠定了良好基础。(3)主导产业的选择对于新疆县市功能发展至关重要,同时宏观政策调控有助于功能间的耦合协调性提升,推动县市功能协调有序发展。

submitted time 2021-12-14 From cooperative journals:《干旱区地理》 Hits3287Downloads687 Comment 0

5. chinaXiv:202112.00069 [pdf]

新疆南疆地区太阳能资源时空分布特征及区划研究

顾玮
Subjects: Geosciences >> Geography

研究基于 1980—2015 年中国区域高时空分辨率地面气象要素驱动数据集(ITPCAS)和 30 个气象观测站点逐月日照资料,运用趋势分析、重标极差分析、小波分析及光热资源评价指标评估方法,对 1980—2015 年新疆南疆地区太阳总辐射时空分布变化规律与太阳能资源做出分析评价;并结合风沙天气频次、人口丰富度、陆路交通可达性等因素构建区域太阳能资源区划分级指标体系,探索南疆地区太阳能资源利用区划。结果表明:新疆南疆地区太阳总辐射有明显的年际变化 特征,总体呈现增长趋势,且每 10~15 a 出现一次波动。太阳能资源南多北少,同纬度相比山区多、 平原少;其中,昆仑山系一带太阳能资源最丰富且较稳定。将全区太阳能资源分为 3 个区:阿克苏、 喀什、和田等地区太阳能资源丰富,利用价值较高且沙尘天气相对较少,为Ⅰ级可利用区,是光电与光生物质能综合利用的最佳区域;塔里木盆地及边缘地带,沙尘天气多且陆路交通可达性一般, 为Ⅱ级可利用区,可在该区域推广应用农业温室、太阳能采暖等;若羌地区为Ⅲ级可利用区,该区受沙尘天气影响较大且人口、基础交通设施条件较差,可大力推进分布式光伏电站和独立微网建设。

submitted time 2021-12-14 From cooperative journals:《干旱区地理》 Hits2465Downloads62 Comment 0

6. chinaXiv:202112.00082 [pdf]

博斯腾湖小湖区湿地生态需水量阈值研究

刘英
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

湿地生态需水量阈值是其生态系统发生质变的临界条件,一旦某阈值被超越,系统的某些 物质平衡关系、功能、健康就会受到影响,而月尺度的湿地生态需水量阈值研究有助于水资源优化 配置。针对博斯腾湖小湖区芦苇沼泽镶嵌交错明水塘道的景观结构,结合遥感数据同步获取大范 围数据的优势,利用长时间序列的水面面积频率分析,确定月尺度最小、中等和理想状态的小湖区 湿地明水区面积;采用蒸发皿观测值计算法,核算小湖区湿地的月尺度最小、中等和理想生态耗水量。结果表明:小湖区湿地全年月平均最小、中等和理想的生态水面面积为 14.47 km2、21.56 km2、 26.75 km2;小湖区湿地生长季 3—9 月最小生态需水量为 0.22×108 m3、0.35×108 m3、0.44×108 m3、0.51×108 m3、0.39×108 m3、0.41×108 m3、0.28×108 m3,其中 6 月最大,3 月最小,小湖区湿地年最小生态 需水量约为 3.02×108 m3;如若同时满足小湖区湿地生态目标芦苇生长所需动态水位,3—9 月最小 生态需水量为 0.40×108 m3、0.52×108 m3、0.79×108 m3、0.86×108 m3、2.31×108 m3、0.41×108 m3、0.28×108 m3,其中 7 月最大,9 月最小,小湖区湿地年最小生态需水量约为 5.99×108 m3。本研究计算结果可用于小湖区湿地年、月尺度来水分配及出水调控,有利于提高区域水资源利用效率,确保小湖生态可持续发展。

submitted time 2021-12-14 From cooperative journals:《干旱区地理》 Hits2538Downloads133 Comment 0

7. chinaXiv:202112.00089 [pdf]

蒙古高原交通干线风沙(雪)危害防治技术方案

李生宇
Subjects: Geosciences >> Geography

中蒙俄经济走廊建设是“一带一路”的重要组成部分,将丝绸之路经济带与俄罗斯欧亚大铁路、蒙古国“草原之路”对接联通,对推进区域经济合作发挥着重要作用。区域自然灾害防治是陆路交通干线建设与安全运营的重要关键。中蒙俄经济走廊蒙古高原段在气候变化和人类活动共同作用下,草场退化及风蚀荒漠化问题较为普遍,风沙(雪)害防治则是区域交通干线安全保障的重要课题。结合前人相关的试验理论分析,基于多次大范围实地考察,本文综述了当前蒙古高原交通干线的风沙(雪)害的主要类型及发生机制,预判了路面积沙是未来高等级公路的主要沙害类型;针对现有公路和铁路及未来高等级公路的风沙(雪)危害,结合蒙古高原的生态环境特点,制定了相应防治技术方案和建设性建议,可为蒙古高原段交通干线建设提供科技支撑。

submitted time 2021-12-12 From cooperative journals:《干旱区研究》 Hits62Downloads41 Comment 0

8. chinaXiv:202112.00100 [pdf]

角果碱蓬异型性种子植株生长生理指标的差异研究

姜黎
Subjects: Geosciences >> Geography

采用盆栽试验比较分析在同一栽培条件下,不同居群角果碱蓬(Suaeda corniculata)异型性种子植株的生长、光合色素含量、盐分离子含量和N、P、K含量的差异性,以探讨角果碱蓬适应干旱区盐碱环境的生理生态机制。结果表明:(1)棕色和黑色种子植株在生长、光合色素含量、盐分离子含量和N、P、K含量差异不显著,而新疆和内蒙古角果碱蓬植株在生长发育与生理指标上存在显著性差异。(2)居群类型显著影响植株地上部干重,而不显著影响根部干重;叶绿素a含量、叶绿素b含量、叶绿素a+b含量和类胡萝卜素含量均未显著受到居群类型和植株类型的影响,表明角果碱蓬不同居群的植株光合功能相似。(3)新疆与内蒙古居群的角果碱蓬体内Na+、K+、Ca2+、Cl-、SO42-离子含量和P、K含量均存在显著差异,表明不同居群的角果碱蓬植株维持渗透的能力存在差异。(4)不同居群角果碱蓬地上部的生长差异,与离子含量和对P、K吸收利用的差异有关,与氮素吸收能力和光合作用无关。因此,不同居群的角果碱蓬异型植株盐分离子吸收系统之间存在一定的协同关系,该协同作用与大量的矿质元素P、K含量密切相关,这些是角果碱蓬适应环境变化的重要生理机制之一。

submitted time 2021-12-12 From cooperative journals:《干旱区研究》 Hits88Downloads33 Comment 0

9. chinaXiv:202112.00115 [pdf]

1995—2020 年新疆巴里坤湖面积时序变化及归因

王振
Subjects: Geosciences >> Geography

巴里坤湖是天山东部山间内陆封闭型湖泊,了解巴里坤湖的演变特征对于开展湖泊保护与生态环境治理具有重要意义。利用308景Landsat系列和Sentinel 2遥感影像提取1995—2020年湖泊水面的时间序列,并结合巴里坤气象站资料以及从遥感影像上提取的耕地面积数据,分析湖泊在气候变化与人类活动影响下的变化趋势。结果表明:湖泊变化经历了2个阶段:1995—2006年萎缩,从年均值57.33 km2下降到35.53 km2,下降速率1.98 km2·a-1,萎缩35.79%;2006—2020年扩张,从年均值35.53 km2上升到46.59 km2,上升速率0.79 km2·a-1,扩张31.12%。多年湖泊面积的月变化统计表明:湖泊在5月达到最大值(73.09±21.01)km2,11月达到最小值(43.90±16.97)km2。影响因素:1995—2006年,降水变化幅度较小,农业用水与蒸发量增加是巴里坤湖萎缩的主要原因;2006年后,巴里坤县出台多种湿地保护措施,耕地面积扩张趋势得到控制,降水显著增加与蒸发量减少成为湖泊面积扩张的主要原因。

submitted time 2021-12-12 From cooperative journals:《干旱区研究》 Hits65Downloads45 Comment 0

10. chinaXiv:202112.00046 [pdf]

Geochronology, geochemistry, and Sr–Nd isotopes of Early Carboniferous magmatism in southern West Junggar, northwestern China: Implications for Junggar oceanic plate subduction

LIU Pengde; LIU Xijun; XIAO Wenjiao; ZHANG Zhiguo; SONG Yujia; XIAO Yao; LIU Lei; HU Rongguo; WANG Baohua
Subjects: Geosciences >> Geography

West Junggar is a key area for understanding intra-oceanic plate subduction and the final closure of the Junggar Ocean. Knowledge of the Carboniferous tectonic evolution of the Junggar Ocean region is required for understanding the tectonic framework and accretionary processes in West Junggar, Central Asian Orogenic Belt. A series of Early Carboniferous volcanic and intrusive rocks, namely, basaltic andesite, andesite, dacite, and diorite, occur in the Mayile area of southern West Junggar, northwestern China. Our new LA-ICPMS zircon U–Pb geochronological data reveal that diorite intruded at 334 (±1) Ma, and that basaltic andesite was erupted at 334 (±4) Ma. These intrusive and volcanic rocks are calc-alkaline, display moderate MgO (1.62%–4.18%) contents and Mg# values (40–59), and low Cr (14.5×10–6–47.2×10–6) and Ni (7.5×10–6–34.6×10–6) contents, and are characterized by enrichment in light rare-earth elements and large-ion lithophile elements and depletion in heavy rare-earth elements and high-field-strength elements, meaning that they belong to typical subduction-zone island-arc magma. The samples show low initial 87Sr/86Sr ratios (range of 0.703649–0.705008), positive εNd(t) values (range of 4.8–6.2 and mean of 5.4), and young TDM Nd model ages ranging from 1016 to 616 Ma, indicating a magmatic origin from depleted mantle involving partial melting of 10%–25% garnet and spinel lherzolite. Combining our results with those of previous studies, we suggest that these rocks were formed as a result of northwestward subduction of the Junggar oceanic plate, which caused partial melting of sub-arc mantle. We conclude that intra-oceanic arc magmatism was extensive in West Junggar during the Early Carboniferous.

submitted time 2021-12-06 From cooperative journals:《Journal of Arid Land》 Hits4295Downloads175 Comment 0

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