基于像元二分模型的艾比湖湿地NDVI指数对微气候的响应

本研究提取了艾比湖湿地不同年份(1998、2007、2011、2014年)的NDVI指数,并进行了实地考察,然后利用像元二分模型对研究区植被覆盖状况进行估算,并分析其在时空分布上的特征及形成原因,建立影响植被覆盖与微气候变化的线性回归模型。结果表明,1)在空间分布上,西南部冲积平原植被覆盖等级最高,东北部覆盖等级略低于西南部,无覆盖和低覆盖等级分布面积最为广泛;在时间分布上,无覆盖面积处于下降趋势,低覆盖和中覆盖面积有所增加,较高覆盖与高覆盖等级面积处于下降趋势;2)不同植被覆盖度对气候变化的响应存在一定的差异;植被覆盖对降水量变化的反应最为强烈,在时间上具有一定的滞后性,对湿度变化的响应不明显,气温与植被覆盖水平之间存在线性函数关系。

Ebinur Lake Wetland vegetation coverage in response to a micro-climate change

The normalized difference vegetation indexes (NDVI) for different years (1998, 2007, 2011, 2014) were extracted through a dimidiate pixel model for The Ebinur Lake Wetland, and combined with high accuracy field investigation data analysis.By using the NDVI index to calculate vegetation cover conditions in the study area, we analyzed temporal and spatial characteristics and the causes of variation, and established a linear regression model between vegetation and climate change.The results showed that: 1) In the spatial analysis, the highest level of vegetation cover was in the southwest of the alluvial plain, the level of vegetation coverage in the northeast was slightly lower than that in the southwest, and no coverage and low coverage grade areas were distributed the most widely.In the temporal analysis, no coverage areas were in a downward trend, low coverage and middle coverage areas increased, and higher coverage and high coverage areas were in a downward trend;2) In response to climate change, there were certain differences in different vegetation coverage levels.The degree of reaction of vegetation coverage to rainfall is the strongest, with hysteresis, at certain times, and showed no obvious response to air temperature.Between humidity and vegetation coverage level there was a completely concat relationship.