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利用NASA提供的MOD16遥感产品,在ENVI遥感图像处理系统和ARCGIS地理信息系统支持下,统计分析了安徽省2000~2014年蒸散量时空分布特征,结果表明:(1)安徽省2000~2014年,年平均ET为694.9 mm,不足PET的一半,表明安徽省整体上处于干旱缺水状态,尤其以2011~2014年期间特别显著,其中最大值出现在2003年(为730.6 mm),最小值出现在2011年(为647.6 mm)。各月平均ET和PET均呈现单峰分布形态,ET峰值出现在8月,而PET峰值出现在5月。(2)对各月ET与PET进行线性回归分析发现,10月份至次年3月,安徽省ET呈现显著的减少趋势,除此之外,夏季的6~7月份也表现出减少趋势,而PET全年主要表现为增多趋势。两者变化趋势说明安徽省旱情越来越严重。(3)从ET与PET空间分布上看,安徽省表现出明显的南高北低的特征,并且北部年度、月度变化大,南部较稳定。(4)不同土地利用类型的蒸散量表现出不同的年、月变化特征,年蒸散强度整体表现为森林>草地>农田,月份变化上,月蒸散分布表现为,冬季草地大于森林,之后森林蒸散逐渐超越草地,并且三者蒸散差距不断扩大,直至7月或8月的峰值出现。农作物种植的季节性和温度、降水等敏感因子共同作用下,森林与草地各月蒸散表现为单峰型分布,最大值出现在7月,农田表现为双峰型分布,分别出现在5月和8月,前者强度弱于后者。
Using the MOD16 remote sensing products provided by NASA, the temporal and spatial distribution characteristics of evapotranspiration in Anhui Province from 2000 to 2014 were statistically analyzed with the support of ENVI remote sensing image processing system and ARCGIS geographic information system. The results show that: (1) From 2000 to 2014, The annual average ET is 694.9 mm, less than half of that in PET, indicating that the province is in arid and dry conditions as a whole, especially during the period 2011-2014. The maximum value of this index appeared in 2003 (730.6 mm) and the minimum value appeared in 2011 (647.6 mm). The monthly average ET and PET showed a unimodal distribution morphology, ET peak appeared in August, and PET peak appeared in May. (2) The linear regression analysis of ET and PET in each month showed that from October to next March, the ET in Anhui Province showed a significant decreasing trend. In addition, the summer from June to July also showed a decreasing trend, and PET throughout the year mainly for the increasing trend. The trend of the two shows that the drought in Anhui Province is getting worse and worse. (3) From the perspective of spatial distribution of ET and PET, Anhui Province showed obvious characteristics of high south and low north, and its annual and monthly changes in the north were large, while those in the south were relatively stable. (4) The evapotranspiration of different types of land use showed different characteristics of annual and monthly variations. The annual evapotranspiration showed the following characteristics: the forest> grassland> farmland. The distribution of monthly evapotranspiration showed that the distribution of monthly evapotranspiration was greater in winter than in forest, Gradually over the grass, and evaporative gap between the three expanding, until the peak in July or August. Under the combined action of seasonal and temperature and precipitation and other sensitive factors, the evapotranspiration of each stage of forest and grassland showed a unimodal distribution, with the maximum appeared in July and the farmland showed bimodal distribution, which appeared in May and In August, the former is weaker than the latter.