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 >> 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.
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