锡林郭勒草原干旱灾害监测与风险评估研究

发布时间：2018-01-15 09:58

  本文关键词：锡林郭勒草原干旱灾害监测与风险评估研究　出处：《中国农业科学院》2016年博士论文　论文类型：学位论文

  更多相关文章： 气候变化 蒸散发 干旱监测 群落变化 风险评估

【摘要】：为进一步提高锡林郭勒草原的干旱灾害监测和防灾减灾能力,论文利用3S技术结合野外实地调查、数学建模、社会经济数据统计分析和自然灾害风险评估等方法,对锡林郭勒草原进行干旱灾害监测和风险评估等内容的研究。研究结果表明:(1)近54年(1961~2014年)锡林郭勒草原年降水量呈下降趋势,气候变化率为-1.46mm/10a;夏季和7~8月降水量均呈下降趋势;夏季降水量占全年的66.4%,7、8月降水量占全年的50.0%,年度和夏季降水量的下降主要是由7~8月降水量的下降引起的;空间上各年代200mm等降水量线呈东西波动变化状态。年、季、月尺度的气温均呈上升趋势,气候变化率为0.41°C/10a,年平均气温在2℃以上区域所占面积逐步增加,2℃等温线向东北方向小幅度推进。(2)近15年(2000~2014年)蒸散发的年动态表明,草甸草原的蒸散发在250mm上下波动,典型草原、沙地植被和总体在200mm上下波动,荒漠草原在150mm上下波动;季节动态表明,草甸草原、典型草原、沙地植被和总体的蒸散发均为夏秋季冬春季,荒漠草原为秋冬季春夏季;月动态表明,草甸草原、典型草原、沙地植被和总体的蒸散发均为7月和8月最高,而荒漠草原为11月和2月最高,各类草原的最低蒸散发均出现在5月。(3)基于实际蒸散发(ET)和潜在蒸散发(PET)的蒸散发亏缺指数(ETDI)与实测土壤含水量的相关性最高,建立的土壤含水量反演模型SVM=-48.851×ETDI+54.669(R2=0.62,RMSE=2.75%)的验证精度为RMSE=3.27%,该模型达到了区域土壤含水量快速反演的应用水平。(4)近15年(2000~2014年)锡林郭勒草原的干旱年动态表明,草甸草原基本无旱,典型草原、沙地植被和总体基本为轻旱,荒漠草原基本为重旱;近15年总体的无旱和重旱面积呈增加趋势。月尺度上,各类草原返青期4~5月尤其5月的干旱程度较重,基本为中旱或重旱;草甸草原、典型草原和沙地植被6月的干旱程度均缓减,到盛草期7~8月基本为无旱或轻旱,到枯草期9~10月干旱进一步缓减;而荒漠草原各月干旱均较重,基本为中旱或重旱。近15年锡林郭勒草原4~5月的重旱面积呈上升趋势,需要注意和加强预防返青期干旱。(5)主要群落变化分析表明,草甸草原和典型草原的禾本科植物优势度均明显上升,菊科植物的优势度均明显下降,豆科植物的相对重量均呈下降趋势,群落内以禾本科植物为主的物种聚集程度增加,植物的个体数量向不均匀方向发展;荒漠草原的禾本科和菊科植物的优势度均下降,而其它科植物的优势度上升;典型草原和荒漠草原的物种丰富度下降,植物科、属、种的数目均为下降趋势;各类草原的植物种类变化均较大、相似性较低。(6)锡林郭勒各旗县市之间的干旱灾害风险差异较大,其中二连浩特市是干旱灾害风险极高区域;苏尼特右旗、苏尼特左旗和镶黄旗是干旱灾害风险高的区域,风险仅次于二连浩特市;阿巴嘎旗、锡林浩特市和正镶白旗是发生干旱灾害风险中等的区域;东西乌珠穆沁旗和正蓝旗发生干旱灾害风险较低;多伦县和太仆寺旗是发生干旱灾害风险极低的区域。近11年(2003~2013年)东西乌珠穆沁旗、阿巴嘎旗和锡林浩特市的干旱灾害风险均呈下降趋势,其它旗县市的干旱灾害风险均呈上升趋势。
[Abstract]:In order to further improve the drought disaster monitoring and disaster prevention and mitigation capacity of Xilinguole grassland, the use of 3S technology combined with field investigation, mathematical modeling, social economic data and statistical analysis of natural disaster risk assessment methods of drought disaster monitoring and risk assessment of Xilingol Grassland. The results show: (1) 54 years (1961~2014 years) the annual precipitation of Xilinguole grassland decreased, climate change rate of -1.46mm/10a and 7~8; summer precipitation decreased; summer precipitation accounted for 66.4%, 7,8 accounted for 50% of the annual precipitation decreased, annual and summer precipitation is mainly caused by the decline of 7~8 monthly precipitation the space in the 200mm; isohyet is fluctuation. Year, season, month scale temperature showed an upward trend, climate change rate is 0.41 ~ C /10a, the annual average temperature A gradual increase in the area occupied area of more than 2 DEG C, 2 C isotherm to the Northeast small forward. (2) in recent 15 years (2000~2014 years) the annual dynamic evapotranspiration showed that meadow evapotranspiration fluctuation in 250mm under typical steppe, vegetation and the overall in the 200mm wave, desert the fluctuation in 150mm grassland; seasonal dynamics showed that the meadow steppe, typical steppe, vegetation and the total evapotranspiration was in summer and autumn winter spring sandy desert grassland for spring summer autumn and winter months; dynamic show, meadow steppe, typical steppe, vegetation evapotranspiration and total body fat were highest in July and August, and the desert the grassland in November and highest in February and lowest of all kinds of sporadic steamed grassland appeared in May. (3) based on actual evapotranspiration (ET) and potential evapotranspiration (PET) evapotranspiration deficit index (ETDI) and the measured soil moisture is the highest, the establishment of soil moisture inversion Model SVM=-48.851 * ETDI+54.669 (R2=0.62, RMSE=2.75%) to verify the accuracy of RMSE=3.27%, the model achieves the application level of regional soil water content inversion. (4) in recent 15 years (2000~2014 years) in Xilingol Grassland drought year development indicates that the basic meadow grassland drought, typical steppe, sandy vegetation and general mild drought the basic, severe drought in desert steppe; nearly 15 years overall drought and severe drought area showed an increasing trend. The month scale, various types of grassland green period 4~5 months especially drought in May is heavy, basic for drought or heavy drought; meadow steppe, typical steppe and sandy vegetation in June were drought mitigation to 7~8, Sheng grass is mostly drought and light drought, 9~10 drought withered period further reduced; and each month in arid desert steppe were heavier, basic for drought or heavy drought. Nearly 15 years 4~5 months of heavy drought in Xilinguole grassland area increased to To pay attention to and strengthen the prevention of reviving period drought. (5) the main community change analysis shows that the typical steppe and meadow steppe grasses dominance increased obviously, Compositae dominance decreased and the relative weight of leguminous plants decreased in the community dominated by Poaceae species increase the aggregation degree the number of individual plants, unevendevelopment direction; desert steppe Gramineae and Compositae dominance decreased, while the other species dominance increased; species richness in typical steppe and desert steppe decreased, plant families, genera, species number was decreased; the change of all kinds of grassland plant species a large, low similarity. (6) the difference between the risk of drought disaster in Xilinguole flag counties of Erenhot city is larger, the high risk of drought disaster area; Sunite Right Banner, and Xianghuangqi is regional drought disaster risk high risk, second only to Erenhot city and Xilinhaote city; Abagaqi, Zhengxiangbaiqi region drought disaster risk is moderate; and something Ujimqin Zhenglanqi drought disaster risk is relatively low; Duolun County and Taipusiqi are regional drought disaster risk is extremely low. Nearly 11 years (2003~2013 years east Ujimqin), drought disaster risk in Xilinhaote city and the decreased drought disaster risk of other counties, is on the rise.

【学位授予单位】：中国农业科学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S812.6
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本文编号：1427836