Subjects: Geosciences >> Geography submitted time 2024-04-29 Cooperative journals: 《干旱区研究》
Abstract： Winter drought is a main factor hindering winter livestock production in Inner Mongolia. Thus, quanti#2;tative characterization of its spatiotemporal changes and development patterns is of great significance for disaster prevention and reduction and for ensuring the healthy development of agriculture and animal husbandry. Using ERA5-Land reanalysis meteorological data from the winter of 1980 to 2021 (October to March of the following year), the standardized precipitation evapotranspiration index (SPEI) was calculated at monthly and semi-annual scales. Trend analysis, spatiotemporal hotspot analysis, and other methods were used to analyze the winter drought evolution characteristics of the entire Inner Mongolia region and the five main vegetation types. Results show that in the past 40 years, the overall SPEI in Inner Mongolia has shown an increasing trend in winter, andaridification varies among different vegetation and months, with a few vegetation and months tending toward hu#2;midification. The change patterns in Inner Mongolia mainly include three types: oscillating hot spots, oscillating cold spots, and undetected patterns. From a seasonal perspective, hotspots are primarily distributed in most areas of western Inner Mongolia, as well as in Xing’an League and Tongliao City in the east. On a monthly scale, hot#2;spots often appear in the central and western regions of Inner Mongolia. With regard to drought frequency and fre#2;quency statistics, mild drought events have the highest frequency, whereas winter drought events occur more fre#2;quently and seriously in desert grasslands and neighboring desert areas.
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： In recent years, with global warming, the increase of drought events has a more important impact onthe photosynthesis of vegetation, and also seriously affects the balance of terrestrial ecosystems. Based on SPEIbase v.2.7 and GOSIF GPP data set, this paper studies the cumulative and time-delay effects of drought on GPP innorthern grassland. Sen’s slope test, MK trend test and Mann- Kendall mutation test were used to study thetemporal and spatial changes of GPP and SPEI during the study period. Pearson correlation analysis method wasused to explore the cumulative and time- delay effects of drought on GPP in the north grasslands. The resultsshowed that: (1) From 2001 to 2020, the annual average GPP of the northern grasslands showed a spatialdistribution pattern of high in the northeast and low in the southwest, and the annual average SPEI showed aspatial distribution pattern of low in the northeast and high in the southwest, and the annual average of SPEI andGPP showed an upward trend over time. (2) Drought has a cumulative effect on 84.99% of the northerngrassland, and the longest cumulative time scale is mainly concentrated in 3-4 months, covering 39.82% of thenorthern grassland; Drought had a lagging effect on 63.11% of the northern grassland, and mainly occurred in 7months, covering 19.73% of the northern grasslands. (3) By comparing the variation trends of drought anddrought under different water conditions, we found that the cumulative effect of drought on grassland GPP wasstronger than the time-lag effect.
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 >> Geography submitted time 2019-11-15 Cooperative journals: 《干旱区地理》
Abstract：近半个世纪，有关全球气候的话题一直是科学界争论的焦点，拥有世界最大温带草原的蒙古高原降水变化是属于全球变化问题，又是其脆弱环境变化的最主要驱动因子之一。通过利用蒙古高原1961—2014年136个气象站点的月降水量数据，采用Sen’ s斜率法、Mann-Kendall趋势检验法和空间地统计方法，研究了该地区近54 a降水要素基本气候特征及其时空变化规律。结果表明：（1）近54 a蒙古高原年降水量呈减少趋势，趋势为-2.30 mm·（10 a）-1（P＞0.05），整体上年降水量东南及西北显著减少，东北及中南明显增加（2）夏季和秋季降水量呈减少趋势，趋势分别为-5.75 mm·（10 a）-1和-0.42 mm·（10 a）-1（P＞0.05）；春季和冬季降水量呈显著增加趋势，趋势分别为1.95 mm·（10 a）-1和0.50 mm·（10 a）-1（P<0.05）；季节降水量出现正负距平的年份和周期有所不同。（3）春季和冬季降水量呈增加趋势的站点居多，占全部站点的89.0%和84.6%，主要分布于高原东北部和中南部地区；夏季和秋季降水量呈减少趋势的站点居多，占全部站点的80.1%和57.4%，主要分布于高原东南部和西北部地区。为准确评估蒙古高原气候变化以及合理提出生态环境决策提供科学参考。
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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