Subjects: Geosciences >> Geography submitted time 2024-01-28 Cooperative journals: 《干旱区地理》
Abstract：基于19812020年塔里木河流域四源5个水文站的日径流数据及格网温度、降水和雪深等数据，采用最大值及POT采样法，分析洪水发生量级、频率和峰现时间等特征，同时采用相关性分析揭示不同洪水指标与影响因素之间的关系并识别关键影响因子。结果表明：（1） 19812020年塔里木河四源各站点洪峰流量大小依次为：卡群>协和拉>同古孜洛克>沙里桂兰克>大山口，年及季节尺度洪峰流量普遍呈增加趋势，冬季洪峰发生时间均呈提前状态，其中沙里桂兰克年均提前最多为2.61 d，卡群站提前仅0.67 d。（2） 研究时段内塔里木河流域共有2个洪水高发期，为19942002年和20062011年，流域内大量级洪水集中发生在1990年之后。（3） 洪水发生前不同时间内最小温度、降水和雪深以增加趋势为主；而最大温度以减少趋势为主。春季洪水指标与最大3 d降水的相关性最高，而秋季洪水指标与最大7 d降水的相关性最高。相比于单日降水，多日降水与洪水指标的相关性更高。在雪深相关因子中，最大15 d雪深与各站点的春季洪水指标相关性最高。研究结果对区域水资源管理以及洪水灾害预测提供理论依据。
Subjects: Geosciences >> Geography submitted time 2024-01-07 Cooperative journals: 《干旱区地理》
Abstract：基于Web of Science（WoS）核心合集和中国知网（CNKI）数据库，借助可视化软件，采用文献计量学方法，对19802021年蒙古高原土地沙漠化研究领域的文献进行了分析。结果表明：（1）发文数量由1980年的2篇增长至2021年的96篇，其变化经历了缓慢增长-波动式增长-快速增长过程；2000年后英文文献占主导，作者单位以中国科学院为主，与美国的合作最多。（2）2000年之前对土地沙漠化过程的关注度最高，之后土地沙漠化成因成为研究热点，近10 a沙漠化土地的生态修复成为主题。2000年之前研究主要集中在内蒙古沙地地区，21世纪后扩展到以农牧交错带为主的中国北方地区，20112021年聚焦在中国北方草原地区。（3）19802000年关注土地沙漠化概念、土地沙漠化成因及防治对策，进入21世纪后转变为土地沙漠化环境效应研究，20172021年则聚焦于沙漠化土地生态系统服务、生态修复研究，也是主要的研究趋势之一。今后的研究力求辐射蒙古高原整体，实现多源数据的高度融合，提高所获信息的精确度，以促进蒙古高原沙漠化土地生态功能的提升及中国北方生态屏障建设进程。
Subjects: Geosciences >> Geology submitted time 2023-09-19 Cooperative journals: 《干旱区地理》
Abstract： In recent years, China has made great progress in the construction and management of national naturereserves such as the Daqingshan National Nature Reserve in Inner Mongolia. However, the associated ecologicalbenefits have not been effectively assessed. The purpose of this study is to assess whether the establishment ofthe Daqingshan National Nature Reserve has contributed to the ecological recovery and improvement of the area.Examining changes in vegetation dynamics can be an effective tool for regional ecological engineering assessment, and this study analyzes such changes using the normalized difference vegetation index (NDVI). Based onthe Google Earth Engine (GEE) cloud platform, the study uses Landsat remote sensing imagery to extract NDVIdata for the nature reserve for the years 1995 to 2020. Spatial and temporal variation in NDVI and variation drivers before and after the establishment of the reserve were analyzed using Pearson correlation, residual analysisand the Lindeman-Merenda-Gold (LMG) model. A decreasing NDVI trend was identified during the 1995—2008period in 69.04% of the studied area, while an increasing NDVI trend was identified during the 2008—2020 period in 94.98% of the studied area. These results indicate that the quality of vegetation in the study area has improved significantly since it became a national nature reserve. Negative impacts from human activities and climatic warming during the 1995—2008 period led to decreases in NDVI in the studied area, with climate warming being the dominant factor. An increase in precipitation and positive impacts from human activities drove increasesin NDVI in the studied area during the 2008—2020 period, with positive human impacts arising from ecologicalenvironmental protection engineering implementation being the main reasons for vegetation recovery during thisperiod. The selection of Landsat remote sensing images and the use of the GEE integrated computing environment enabled the study to obtain vegetation monitoring data over a long time span and at a high spatial resolution. Spatiotemporal variation in vegetation was also more accurately portrayed using the NDVI measure, therebyenriching the technical means for long time-sequence and small region-scale vegetation monitoring. The resultsof this study provide clear evidence of the ecological benefits brought by the establishment of the Daqingshan National Nature Reserve. At the same time, the study provides basic information and technical support for futureecological-environmental management decisions concerning the protected area.
Subjects: Geosciences >> Geography submitted time 2023-09-19 Cooperative journals: 《干旱区地理》
Abstract：摘 要： 基于20012020年NDVI和EVI两种遥感植被指数及蒙古国60个气象站点的气温和降水数据，利用累积植被指数的Logistic曲线曲率极值法和动态阈值法提取蒙古国植被返青期，并结合偏相关分析方法探讨二者与冬春季昼夜气温非对称变化之间的关系。结果表明：（1） 近20 a来，最高气温在冬春季的变暖速率分别为0.07 ℃a-1、0.15 ℃a-1（PR2=0.33），最低气温在冬春季的变化速率分别为-0.01 ℃a-1、0.04 ℃a-1，冬春季气温日较差的变化速率分别为0.08 ℃a-1、0.11 ℃a-1（PR2=0.52），存在明显的季节性差异。（2） 蒙古国植被返青期对冬春季气候变暖的季节性响应是非对称的，冬季最高气温和气温日较差的影响大，而春季则是最低气温影响大，且均表现为负相关。（3） 蒙古国气候变暖对植被NDVI产生的非对称影响主要表现在春季，即春季最高气温和气温日较差对植被NDVI主要表现为负相关，而春季最低气温对植被NDVI主要表现为正相关。研究结果可为进一步了解全球气候变暖背景下植被春季物候及植被后期生长的季节性影响提供重要参考价值。
Subjects: Geosciences >> Hydrology submitted time 2023-03-14 Cooperative journals: 《干旱区地理》
Abstract： The Mongolian Plateau is a sensitive area for coping with global changes. It is also the only place for three of the nine routes of migratory birds. Lakes play the role of“indicator”and“life posthouse”in the plateau ecological environment. Relatively few research results have been presented on the changes of lakes in the Mongolian Plateau at home and abroad. Most of them focused on the analysis of typical and large lakes. Research on their causes has focused on meteorological and human factors, while that on small lakes and the relationship between the lake area and the soil environmental factors are relatively weak. Based on the Landsat remote sensing imagery, the information of the lake area above 1 km2 per year on the Mongolian Plateau from 2000 to 2020 was extracted by the MNDWI water body index. The results of the temporal and spatial change characteristic analysis of the lake area showed that: (1) The area and the number of lakes have decreasing and increasing trends before and after 2009, respectively. Overall, the area and the number of lakes depicted a decreasing trend from 2000 to 2020. (2) The changes of lakes of different grades were quite different. The changes of the super large- and medium-sized lakes were relatively stable. Furthermore, the large-sized lakes showed the largest reduction. (3) The changes of the lakes in different regions also differed. These changes in the northwest were relatively stable, while those in the central and eastern regions were more dramatic. (4) Before 2009, the number of lakes in the dense areas in the central and eastern regions decreased, resulting in the weakening of the spatial distribution agglomeration of lakes in the study area. After 2009, the newly added lakes in the sparse area in the central region were scattered, weakening their spatial distribution agglomeration. (5) The correlation between the lake area and the annual average temperature, annual precipitation, annual evaporation, vegetation index, and four layers of soil moisture was relatively significant. The degree of influence exhibited in the two time periods significantly differed. Mastering the temporal and spatial changes of the lake in the Mongolian Plateau and their causes can provide a reference for the climate regulation, biodiversity protection, and climate disaster reduction research in the Mongolian Plateau and the whole world.
Subjects: Geosciences >> Geography submitted time 2023-03-13 Cooperative journals: 《干旱区研究》
Abstract： The ecological civilization construction in Inner Mongolia, an important ecological barrier in northern China, is important for national ecological security, the stability of the border areas, and the sustainable economic and societal development of the minority areas. In this study, we extracted four key indices based on long-term satellite observations to describe the quality of the ecosystem. We constructed the remote sensing ecological index (RSEI) through principal component analysis. Furthermore, we adopted the Mann-Kendall (M-K) trend test for analyzing the changes in ecological quality in the Hulunbuir grassland of Inner Mongolia from 1990 to 2021. The RSEI can comprehensively reflect the quality of the ecological environment, and results revealed that the quality of grassland in Inner Mongolia has improved in the past 30 years, with an increasing trend of 0.0037 every year (P < 0.01; R2 = 0.39). The significant increasing trend of RSEI and the improved ecological quality from 2012 to 2021 was further verified through the M-K trend significance test. A single factor cannot fully characterize regional ecological quality so, four factors i.e., greenness, dryness, humidity, and heat were included in RSEI. The space quality showed a gradual improvement from west to east, with lower RSEI for grassland in the west compared with that for forest and farming areas in the east. A similar trend for quality was observed with the variation of the vegetation coverage. This study enriched the assessment methods of grassland ecological quality in Inner Mongolia, which can provide an important reference for the ecological protection, restoration, utilization, and sustainable development of meadow steppe in Inner Mongolia.
Subjects: Geosciences >> Geology submitted time 2022-12-20 Cooperative journals: 《干旱区研究》
Abstract：
Land expansion is facing problems, such as extensive utilization of resources, destruction of ecological environments, and imbalanced regional development. Clarifying the adaptation of the land’s functions is conducive to regional coordinated development. The main contents include evaluating the adaptation of the land’s functions in the Hohhot- Baotou- Erdos region in 1990, 2000, 2010, and 2018, and analyzing its temporal and spatial adaptation characteristics. This paper evaluates the synergy/trade-off relationship of the adaptation of the land’s functions based on the coupled coordination model and the bivariate spatial autocorrelation model. The main conclusions are as follows: first, the land functions in the region of Hohhot-Baotou-Erdos have significant temporal and spatial differentiation characteristics, the production/living functions rise locally, and the spatial distribution takes each municipal district as the high- value center circle/semi- circle distribution pattern with a decreasing outward gradient; second, the overall trend of the ecological function is continuously downward and its spatial agglomeration has the scale-dependent effect of a natural landscape; third, the synergy trade- off relationship of the spatial-temporal differentiation characteristics of the land’s functions are obvious. The coupling coordination degree of land and spatial functions of each flag county has been on the rise from the time sequence adaptation characteristics, and the number of flag counties increases; however, the overall level is low; fourth, the synergy/trade-off relationship of various functions in land space has obvious spatial differentiation characteristics, and this relationship alternately changes with time. The spatial distribution and agglomeration effect of the synergy/trade-off relationship of production and living functions is significant, and the spatial distribution of the this relationship between production/living ecological functions tends to be discrete. Ultimately, the spatial coupling effect of the synergy/trade-off relationship between various functions is at a low level as a whole.
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：基于内蒙古100个气象站点1960—2014年日降水数据，选取气候变化监测与指数专家组(ETCCDI)推荐的9个极端降水指数，采用Sen’s斜率法和Mann-Kendall非参数统计检验方法以及空间地统计方法，研究了极端降水指数时空演变特征。结果表明：研究区区域平均的全部极端降水指数均呈不同程度的下降趋势，且年际波动显著；分区的年际趋势有所差异，即东部地区潮湿日数（NW）呈增加趋势，其余极端降水指数均呈减少趋势，其中持续干燥指数（CDD）呈显著下降趋势（P<0.05）；中部地区所有极端降水指数均呈减少趋势，其中年总降水量（PRCPTOT）减少趋势较明显；西部地区持续湿润指数（CWD）、强降水量（R95）、单日最大降水量（Rx1day）、5日最大降水量（Rx5day）呈减少趋势，其余指数均呈增加趋势。从极端降水指数变化趋势的空间分布特征来看，区域差异显著，总体上呈下降趋势的站点主要分布于内蒙古东部和中部地区，而呈上升趋势的站点主要分布于内蒙古东北部和西部地区。
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