Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2022-12-20 Cooperative journals: 《干旱区研究》
Abstract：
With the foundation of global climate change in recent years, droughts in various climatic areas in Inner Mongolia may bring unpredictable disaster risks to local agricultural production. The whole region was divided into five climatic areas, and monthly data was received from 46 meteorological stations from 1981 to 2012. Twenty meteorological stations from 2014 to 2020 were selected to calculate the different time scales of the standardized precipitation evapotranspiration index (SPEI) using precipitation and reference evapotranspiration from the Penman-Monteith method to reveal the drought characteristics and its dominant meteorological factors during the crop growing season (May-September) in Inner Mongolia. A monthly drought during the crop growing season was revealed. The high-incidence month and region of drought in the growing season in various climatic areas were identified by the SPEI of a 1-month scale, and a stepwise linear regression method was selected and verified to extract the dominant meteorological factors driving the drought in each month and the whole growing season in various climatic areas. Results indicated that the following: (1) from the interannual changes, the drought from 1998 to 2008 was more serious, and the drought in other years was less serious. (2) The largest drought area and degree appeared in May during the crop growing season. The probability of moderate drought in the moist and semi- humid area was 37% higher compared to the hyper- arid area, while the extreme drought probably occurred in the moist and semi-humid area and dry and semi-humid area. (3) Dominant meteorological factors driving the drought varied in the crop growth period of various climatic areas in Inner Mongolia. Precipitation and a minimum temperature were the main impact factors for a drought in the crop growing season. (4) Using limited meteorological data, the regression models in each climate region performance well can be used to estimate the monthly SPEI. The results provide a theoretical basis for scientific evaluation of drought characteristics in the spring maize growing season and formulates reasonable measures of response to the drought.
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：针对遥感能量平衡方法估算区域蒸散发(ET)存在的空间歧义性问题，本文以METRIC模型为例，基于地表温度(Ts)与叶面积指数(LAI)相关趋势图，按照“Ts频率直方图占比前5%的最高温度区、LAI频率直方图占比后5%的裸土区为‘干点’，Ts频率直方图占比后5%的最低温度区、LAI频率直方图占比前5%的湿地或农田为‘湿点’”的提取方案，综合确定研究区的干湿限，并通过下垫面涡度相关系统实测数据验证了模型估算精度。经检验，校准期和验证期的区域ET估算控制精度平均为15%，与以往研究成果相比，结果相对合理，提取方案在一定程度上可为METRIC模型主观确定干湿限提供帮助。将ET估算结果按土地利用分类提取，研究区不同土地利用类型表现为ET水体>ET林地>ET耕地>ET未开发利用土地>ET城乡工矿居民用地≈ET草地，成果对区域遥感ET精准估算研究具有一定参考意义。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：利用1971—2015年内蒙古地区52个气象站逐月降水量观测数据，采用降水量距平百分率(Pa)，从干旱频率和干旱变化趋势率分析了研究区近45 a来干旱时空分布特征。结果表明：从时间变化来看，年降水量呈微弱的下降趋势，并于1998年和2012年发生突变；春季、秋季和冬季降水量变化呈上升趋势，夏季降水量变化呈下降趋势；年尺度干旱主要发生在1999—2011年；季节尺度干旱发生频率为冬旱>春旱>秋旱>夏旱。从空间变化来看，多年平均降水量由东向西呈逐级递减趋势，降水分布地域特征明显，大兴安岭以东地区和巴彦淖尔市西部地区降水变化趋势率较高，呼伦贝尔市西北部、通辽市中南部、赤峰市中部、阿拉善盟西部地区降水变化趋势率较低；发生不同等级干旱的几率为轻旱>特旱>中旱>重旱，各级干旱易发生地区集中在呼伦贝尔市西部、赤峰市中北部、通辽市北部、锡林郭勒盟中西部以及阿拉善盟西部地区。Pa变化趋势率表现为，呼伦贝尔市中东部、巴彦淖尔市西部和阿拉善盟东部呈上升趋势，即干旱程度减轻；兴安盟南部至鄂尔多斯市、阿拉善盟中西部呈下降趋势，即干旱程度加重。
Hits
Hits
Downloads
Comment