基于多时相环境减灾卫星数据的冬小麦冻害评估

    Assessing freeze injury to winter wheat with multi-temporal HJ-1 satellite imagery

    • 摘要: 评估冬小麦冻害影响范围和受灾程度对于灾后及时采取田间管理补救措施、恢复农业生产具有重要意义。基于国产多时相环境减灾卫星1号遥感数据(HJ-1),以河北省中南部冬小麦冻害为例,通过分析植被指数对冻害的敏感性,选择了增强型植被指数(enhanced vegetation index,EVI)作为评估冬小麦冻害的最优植被指数。开发了一种基于多时相遥感数据的冬小麦冻害评估方法,以冻害指数作为冬小麦冻害程度的评估指标,利用地面实测样本数据对评估结果进行了验证。结果表明,受灾前后冬小麦EVI的变化与冻害程度呈显著线性相关,该方法能够有效评估冬小麦冻害影响范围和受灾程度。

       

      Abstract: The spatial distribution and severity level of freeze injury on winter wheat is of great importance to timely agriculture recovery. In this paper, taking central and southern Hebei province as study area, a rapid algorithm for assessing freeze injury on winter wheat was developed. Firstly, Enhanced Vegetation Index (EVI) was selected as the optimal vegetation index after sensitivity analysis of vegetation index to freeze injury. Secondly, a freeze injury assessing algorithm was developed based on multi-temporal HJ-1 satellite imagery without ground data. Thirdly, this algorithm was validated through ground survey points. It is shown that the relative change of pre- and post-frozen EVI is linearly related to the damage severity. The new approach is proved to be able to assess winter wheat injury spatial distribution and severity level rapidly and successfully.

       

    /

    返回文章
    返回