Ulanqab Cultivated Land Dynamic And The Spatial-temporal Characteristics Of Dry Warming And The Impact Of Ecological Fragility

This paper based on the National Natural Science Foundation ofChina The impact and the mechanism of cultivated land dynamic andthe spatial-temporal characteristics of dry warming to northernfarming-pastoral ecosystems--a case study in Ulanqab (ID：41161015),summarizes the Inner Ulanqab nearly20years of land use changecharacteristics, dynamic characteristics of arable land, dry warmingclimate change characteristics, effects of cultivated land dynamic anddry warming on ecological environment vulnerability. The main resultsare as follows:(1) According to the land use change data by remotesensing images from1990-2010, The paper study the quantitativedynamic changes of cultivated land in Ulanqab city in thefarming-pastoral zone of North China. Some mathematic models areused to research the spatio temporal change of cultivated land from1990to2010in Ulanqab city, such as land use dynamic degree model,land use type transferring matrix model, and discuss its driving factors.The result indicates that: The change of cultivated land in Ulanqab cityfrom1990-2010, is mainly the cultivated land and grass land changesalternately; The increase of cultivated land from1990-2000,was mainlyfrom grass land, and the cultivated land was decreased in2000-2010,which was changed into grass land and woodland; During1995-2005years, cultivated land change was most significantlyand the average dynamic degree of land use is0.55%; Population grouth,nature conditions, policies and the implementation of ecologicalengineering constitute the major driving factors.(2) Using1990-2009Ulanqab average annual mean temperature and precipitation raster data,analysised the evolution characteristics of Ulanqab’s temperatures andprecipitation, the dry warming climate characteristics in the past20years. The result indicates that: From1990to2009the temperatureshowed a trend of rising and a decrease in precipitation; Ulanqab in1990-2009, dry warming significantly,the phenomenon of2000to2009isobvious higher than the previous10years, especially in2005-2009, isthe dry warming most significant period.(3) With the nearly20years’fractional vegetation cover of Ulanqab analyzed the correlation betweentemperature and vegetation cover,the correlation between precipitationand vegetation cover,got the influence mechanism of dry warmingclimate to the environment vulnerability. The result indicates that:1990-2009, Ulanqab’s fractional vegetation cover showed gradually growingtrend; The correlation of precipitation and fractional vegetation cover issmall, most of the region showed a weak correlation; Temperature andfractional vegetation cover showed a low negative correlation, highertemperatures inhibit the plant growth; Thanks to the humanfactors,although Ulanqab’s dry warming climate increasingly significant, the impact of dry warming climate on environment vulnerability hasbeen alleviated.