水保所知识产出(1956---)知识库

以关中地区为研究区，基于 Google Earth Engine(GEE)平台，根据冬小麦生育期内归一化植被指数
(NDVI)时序曲线和物候特征，采用 NDVI 重构增幅算法和光谱突变斜率，构建了关中地区冬小麦提取模型并实现了
冬小麦种植面积的提取。用农业统计面积验证提取结果表明:在市级和县级尺度上，决定系数 Ｒ 2 分别为 0．82 和0．62，
一致性指标 d 分别为 0．95 和 0．84，提取结果与实地调查数据的空间一致性精度为 93．4%。结果显示:关中地区冬小麦
主要分布在中部关中平原，冬小麦种植面积在 2011—2017 年呈下降趋势，减少了 83．22×10 3 hm 2 (8．47%)。综合考虑冬
小麦 NDVI 时序曲线的“峰”“谷”特征，具有一定的普适性，可为大面积连续年份冬小麦种植面积时空监测提供参考。

 A method based on Google Earth Engine (GEE) was developed and tested in this study for mapping
winter wheat planting area over Guanzhong Ｒegion． After analyzing the winter wheat MODIS NDVI time series curve
and its phenology calendar in Guanzhong Ｒegion，the extraction model was established based on NDVI remodel ampli-
fication and NDVI increase/decrease slope threshold． The result showed that area of winter wheat extracted by remote
sensing agreed well with statistics，with the determination coefficient Ｒ 2 of 0．82 and 0．62，and the index of agreement
d of 0．95 and 0．84 at city level and county level，respectively． Further，the spatial consistency accuracy of extraction
results and field survey data was 93．4%． Winter wheat was mainly distributed on Guanzhong Plain，whose terrain is
relatively flat． In 2011－2017，winter wheat planting area in Guanzhong Ｒegion was showing a downward trend． There
was a series decline by 8．47% (83．22×10 3 hm 2 ) in planting area of winter wheat in 7 years． In this study，the peak
and valley of NDVI curve were considered as never before． This study can serve as a reference for large-scale and
long-time monitoring of spatial and temporal information of winter wheat planting area with remote sensing data．