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1. 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 Cooperative journals:《Journal of Arid Land》 Hits6702Downloads376 Comment 0

2. 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 Cooperative journals:《Journal of Arid Land》 Hits6597Downloads331 Comment 0

3. chinaXiv:202201.00022 [pdf]

Mass balance of saline lakes considering inflow loads of rivers and groundwater: the case of Lake Issyk- Kul, Central Asia

Kei SAITOH; Rysbek SATYLKANOV; Kenji OKUBO
Subjects: Geosciences >> Geography

This study aimed to elucidate the influence of inflow water on the salinity concentration process of a saline lake and the mass balance of Lake Issyk-Kul, a tectonic saltwater lake in Kyrgyzstan. Based on the survey results and meteorological data from 2012 to 2015, we analyzed the dissolved chemical composition loads due to water inflow. Then, we discussed the relationship between the increase in salinity and water inflow into the lake. Through the water quality analysis data, we used the tank model to estimate the river inflow and analyze the loads by the L-Q curve. The groundwater loads were then estimated from the average annual increase in salinity of the lake over a period of 30 a. The results suggest that Lake Issyk-Kul was temporarily freshened between about AD 1500 and 1800 when an outflowing river existed, and thereafter, it became a closed lake in AD 1800 and continued to remain a saline lake until present. The chemical components that cause salinization are supplied from the rivers and groundwater in the catchment area, and when they flow into the lake, Ca2+, HCO3? and Mg2+ precipitate as CaCO3 and MgCO3. These compounds were confirmed to have been left on the lakeshore as evaporite. The model analysis showed that 1.67 mg/L of Ca2+ and Mg2+ supplied from rivers and groundwater are precipitated as evaporite and in other forms per year. On the other hand, salinity continues to remain in the lake water at a rate of 27.5 mg/L per year. These are the main causes of increased salinity in Lake Issyk-Kul. Since Na+ and Cl– are considered to be derived from geothermal water, they will continue to flow in regardless of the effects of human activities. Therefore, as long as these components are accumulated in Lake Issyk-Kul as a closed lake, the salinity will continue to increase in the future.

submitted time 2021-12-30 Cooperative journals:《Journal of Arid Land》 Hits6766Downloads240 Comment 0

4. chinaXiv:202201.00023 [pdf]

Drought and flood characteristics in the farming- pastoral ecotone of northern China based on the Standardized Precipitation Index

CAO Huicong; YAN Dandan; JU Yuelin
Subjects: Geosciences >> Geography

The farming-pastoral ecotone of northern China (FPENC) provides an important ecological barrier which restrains the invasion of desert into Northwest China. Studying drought and flood characteristics in the FPENC can provide scientific support and practical basis for the protection of the FPENC. Based on monthly precipitation data from 115 meteorological stations, we determined the changes in climate and the temporal and spatial variations of drought and flood occurrence in the FPENC during 1960–2020 using the Standardized Precipitation Index (SPI), Morlet wavelet transform, and inverse distance weighted interpolation method. Annual precipitation in the FPENC showed a slightly increasing trend from 1960 to 2020, with an increasing rate of about 1.15 mm/a. The interannual SPI exhibited obvious fluctuations, showing an overall non-significant upward trend (increasing rate of 0.02/a). Therefore, the study area showed a wetting trend in recent years. Drought and flood disasters mainly occurred on an interannual change cycle of 2–6 and 9–17 a, respectively. In the future, a tendency towards drought can be expected in the FPENC. The temporal and spatial distribution of drought and flood differed in the northwestern, northern, and northeastern segments of the FPENC, and most of the drought and flood disasters occurred in local areas. Severe and extreme drought disasters were concentrated in the northwestern and northeastern segments, and severe and extreme flood disasters were mainly in the northeastern segment. Drought was most frequent in the northwestern segment, the central part of the northeastern segment, and the northern part of the northern segment. Flood was most frequent in the western part of the northwestern segment, the eastern part of the northeastern segment, and the eastern and western parts of the northern segment. The accurate evaluation of the degrees of drought and flood disasters in the FPENC will provide scientific basis for the regional climate study and critical information on which to base decisions regarding environmental protection and socio-economic development in this region.

submitted time 2021-12-30 Cooperative journals:《Journal of Arid Land》 Hits6159Downloads232 Comment 0

5. chinaXiv:202201.00024 [pdf]

Characterizing the spatiotemporal variations of evapotranspiration and aridity index in mid-western China from 2001 to 2016

MU Le; LU Yixiao; LIU Minguo; YANG Huimin; FENG Qisheng
Subjects: Geosciences >> Geography

Mid-western China is one of the most sensitive and fragile areas on the Earth. Evapotranspiration (ET) is a key part of hydrological cycle in these areas and is affected by both global climate change and human activities. The dynamic changes in ET and potential evapotranspiration (PET), which can reflect water consumption and demand, are still unclear, and there is a lack of predictive capacity on drought severity. In this study, we used global MODIS (moderate-resolution imaging spectroradiometer) terrestrial ET (MOD16) products, Morlet wavelet analysis, and simple linear regression to investigate the spatiotemporal variations of ET, PET, reference ET (ET0), and aridity index (AI) in mid-western pastoral regions of China (including Gansu Province, Qinghai Province, Ningxia Hui Autonomous Region, and part of Inner Mongolia Autonomous Region) from 2001 to 2016. The results showed that the overall ET gradually increased from east to southwest in the study area. Actual ET showed an increasing trend, whereas PET tended to decrease from 2001 to 2016. The change in ET was affected by vegetation types. During the study period, the average annual ET0 and AI tended to decrease. At the monthly scale within a year, AI value decreased from January to July and then increased. The interannual variations of ET0 and AI showed periodicity with a main period of 14 a, and two other periodicities of 11 and 5 a. This study showed that in recent years, drought in these pastoral regions of mid-western China has been alleviated. Therefore, it is foreseeable that the demand for irrigation water for agricultural production in these regions will decrease.

submitted time 2021-12-30 Cooperative journals:《Journal of Arid Land》 Hits6587Downloads242 Comment 0

6. chinaXiv:202201.00025 [pdf]

Contribution of underlying terrain to sand dunes: evidence from the Qaidam Basin, Northwest China

LI Jiyan; QU Xin; DONG Zhibao; CAI Yingying; LIU Min; REN Xiaozong; CUI Xujia
Subjects: Geosciences >> Geography

Underlying terrain strongly influences dune formation. However, the impacts of underlying terrain on the dune formation are poorly studied. In the present research, we focused on dunes that formed in the alluvial fans and dry salt flats in the Qaidam Basin, Northwest China. We quantified the dunes' sediment characteristics on different types of underlying terrain and the terrain' effects on the surface quartz grains by analyzing grain-size distribution, soluble salt contents and grain surface micro-textures. Results showed that barchan dunes were dominated by medium sands with a unimodal frequency distribution, whose peak corresponded to the saltation load. Linear dunes were mainly composed of fine sands with a bimodal frequency distribution, whose main peak represented the saltation load, and whose secondary peak represented the modified saltation or suspension load. Sand was transported from source area by running water (inland rivers) over short distances and by wind over relatively longer distances. Thus, quartz grains had poor roundness and were dominated by sub-angular and angular shapes. Surface micro-textures indicated that dune sands were successively transported by exogenic agents (glaciation, fluviation and wind). Soluble salt contents were low in dunes that developed in the alluvial fans, which represented a low-energy chemical environment, so the grain surface micro-textures mainly resulted from mechanical erosion, with weak micro-textures formed by SiO2 solution and precipitation. However, soluble salt contents were much higher in dunes that developed in the dry salt flats, which indicated a high-energy chemical environment. Therefore, in addition to micro-structures caused by mechanical erosion, micro-textures formed by SiO2 solution and precipitation also well developed. Our results improve understanding of the sediment characteristics of dune sands and the effects of underlying terrain on dune development in the Qaidam Basin, China.

submitted time 2021-12-30 Cooperative journals:《Journal of Arid Land》 Hits3076Downloads237 Comment 0

7. chinaXiv:202201.00026 [pdf]

Effects of restoration modes on the spatial distribu?tion of soil physical properties after land consolida?tion: a multifractal analysis

KE Zengming; LIU Xiaoli; MA Lihui; TU Wen; FENG Zhe; JIAO Feng; WANG Zhanli
Subjects: Geosciences >> Geography

soil physical properties (SPP) are considered to be important indices that reflect soil structure, hydrological conditions and soil quality. It is of substantial interest to study the spatial distribution of SPP owing to the high spatial variability caused by land consolidation under various land restoration modes in excavated farmland in the loess hilly area of China. In our study, three land restoration modes were selected including natural restoration land (NR), alfalfa land (AL) and maize land (ML). Soil texture composition, including the contents of clay, silt and sand, field capacity (FC), saturated conductivity (Ks) and bulk density (BD) were determined using a multifractal analysis. SPP were found to possess variable characteristics, although land consolidation destroyed the soil structure and decreased the spatial autocorrelation. Furthermore, SPP varied with land restoration and could be illustrated by the multifractal parameters of D1, ?D, ?α and ?f in different modes of land restoration. Owing to multiple compaction from large machinery in the surface soil, soil particles were fine-grained and increased the spatial variability in soil texture composition under all the land restoration modes. Plough numbers and vegetative root characteristics had the most significant impacts on the improvement in SPP, which resulted in the best spatial distribution characteristics of SPP found in ML compared with those in AL and NR. In addition, compared with ML, ?α values of NR and AL were 4.9- and 3.0-fold that of FC, respectively, and ?α values of NR and AL were 2.3- and 1.5-fold higher than those of Ks, respectively. These results indicate that SPP can be rapidly improved by increasing plough numbers and planting vegetation types after land consolidation. Thus, we conclude that ML is an optimal land restoration mode that results in favorable conditions to rapidly improve SPP.

submitted time 2021-12-30 Cooperative journals:《Journal of Arid Land》 Hits3078Downloads178 Comment 0

8. chinaXiv:202201.00002 [pdf]

节律在听觉言语理解中的作用

陈梁杰; 刘雷; 葛钟书; 杨晓东; 李量
Subjects: Psychology >> Cognitive Psychology

言语理解是听者接受外部语音输入并且获得意义的心理过程。日常交流中,听觉言语理解受多尺度节律信息的影响,常见有韵律结构节律、语境节律、和说话者身体语言节律三方面外部节律。它们改变听者在言语理解中的音素判别、词汇感知以及言语可懂度等过程。内部节律表现为大脑内神经振荡,其能够表征外部言语输入在不同时间尺度下的层级特征。外部节律性刺激与内部神经活动的神经夹带能够优化大脑对言语刺激的处理,并受到听者自上而下的认知过程的调节进一步增强目标言语的内在表征。我们认为它可能是实现内外节律相互联系并共同影响言语理解的关键机制。对内外节律及其联系机制的揭示能够为理解言语这种在多层级时间尺度上具有结构规律的复杂序列提供了一个研究窗口。

submitted time 2021-12-29 Hits449Downloads233 Comment 0

9. chinaXiv:202112.00162 [pdf]

补偿他人还是保护自己?内疚与羞耻情绪对合作行为的影响差异

郝娜; 崔丽莹
Subjects: Psychology >> Developmental Psychology

作为两种常见且易混淆的自我意识情绪, 内疚和羞耻对合作行为的影响及其机制存在差异, 内疚的影响更为稳定及具有普适性, 羞耻的影响更为复杂。两种情绪的影响可从动机机制和调节机制方面进行解释, 包括内疚对他人的补偿、修复动机, 羞耻对自我的保护、修复动机, 以及个体因素和情境因素对情绪影响的调节作用。未来研究可进一步关注内疚和羞耻诱发与测量方法的有效性, 情绪作用发生的内在过程和生理机制, 情绪影响的个体和文化差异。

submitted time 2021-12-28 Hits752Downloads318 Comment 0

10. chinaXiv:202112.00135 [pdf]

智力运动专家领域内知觉与记忆的加工特点及其机制

赵冰洁; 张琪涵; 陈怡馨; 章鹏; 白学军
Subjects: Psychology >> Cognitive Psychology

智力运动是以开发智力为目的且涉及到较多认知活动的竞技运动。研究表明,长期的智力运动经验会影响专家在领域内任务中知觉及记忆的行为表现及其大脑活动。智力运动经验使专家知觉广度增大的同时,促进专家对棋子关系进行整体性知觉加工,且这一过程与颞顶联合区、缘上回、压后皮质、侧副沟、梭状回等区域有关;在长时记忆中存储的具体(空间位置)及抽象信息(知识、策略、棋子关系等)是专家记忆优势发生的基础,该过程与内侧颞叶、额叶和顶叶有关。未来研究可以从智力运动类型、创新实验范式,结合测量设备及认知特点,深入探讨智力运动专家整体知觉优势及记忆优势的神经机制,为人工智能和技能训练等提供理论依据。

submitted time 2021-12-26 Hits549Downloads284 Comment 0

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