基于MODIS16的新疆干湿气候时空变化及影响因素

为研究新疆地区的蒸散发及湿润指数分布与变化情况，采用新疆52个气象站点2000—2013年逐日地面观测资料和MOD16产品数据，从蒸散发、湿润指数两个方面利用一元线性回归、倾斜率、变异系数、Hurst指数、湿润指数等方法，综合分析了新疆地区近14年干湿状况的变化特征。结果表明:（1）全疆年均蒸散发值空间分布大多处于40～830 mm，ET高值区大多分布在伊犁河谷及额尔齐斯河谷附近，全疆各站点ET平均值变化范围为178.29～214.87 mm，年均ET为197.49 mm，PET平均值变化范围为1 297.12～1 447.48 mm，年均PET为1 374.39 mm；（2）全疆ET倾斜率分布主要呈轻微减少趋势；（3）整体来看近14年新疆气候趋于湿润的变化趋势，各气象因子中，降水和相对湿度与湿润指数呈显著正相关，气温与湿润指数呈显著负相关。

Temporal and Spatial Variation Characteristics of Evapotranspiration and Dry-Wet Climate in Xinjiang Based on MODIS16

In order to study the distribution and change of evapotranspiration and wetting index in Xinjiang, we use daily ground observation data of 52 meteorological stations and MOD16 product data in Xinjiang during the period 2000-2013. The characteristics of dry and wet conditions in Xinjiang were comprehensively analyzed by means of linear regression, tilt rate, coefficient of variation, Hurst index and wetting index from the aspects of evapotranspiration and wetting index. The results show that:(1) the spatial distribution of annual average evapotranspiration in Xinjiang is mainly between 40 mm and 830 mm; most of the ET high-value areas are located near the Ili Valley and the Irtysh Valley, and the average value of ET in the stations varies from 178.29 to 214.87 mm; the average annual ET is 197.49 mm, and the average value of PET varies from 1 297.12 to 1 447.48 mm, and the average annual PET is 1 374.39 mm; (2) the distribution of ET slope rate in Xinjiang has a slightly reducing trend; (3) overall, the climate in Xinjiang has tended to be wet in recent 14 years; among the meteorological factors, precipitation and relative humidity are significantly positively correlated with the wetting index, and the temperature is significantly negatively correlated with the wetting index.