Abstract: Grain is the fundamental material basis for human survival and development, as well as for the national economy. Further analysis of the spatio-temporal characteristics of grain production in grain production bases can provide a basis for improving grain production area and output. The MODIS data set was employed to obtain NDVI values from 2000 to 2022. The spatial-temporal evolution pattern of NDVI along the Yangtze-to-Huaihe Water Diversion Project (YHWDP) area was analysed qualitatively and quantitatively using a maximum synthesis method, mean value method, S-G filtering and various spatial analysis methods. The results are presented below. There were significant differences in the monthly NDVI values of high-quality rice-wheat along the YHWDP area. The growth period for rice was rapid from June to August, while that for wheat was rapid from February to April and from June to August. The annual NDVI average of high-quality rice and wheat along the YHWDP exhibited a fluctuating upward trend. The high-quality rice areas along the YHWDP area are mainly distributed in the southeast of the counties along the YHWDP area. In contrast, the high-quality wheat area is concentrated in the northwest of the counties along the YHWDP area, with scattered distribution in the southeast, forming a cluster area. The NDVI in the high-quality rice and wheat area along the YHWDP demonstrated a discernible tendency towards spatial aggregation, with this tendency becoming increasingly pronounced over time. The area of high-quality rice with the highest NDVI values along the YHWDP gradually shifted from the southeastern part of the counties along the YHWDP to the central part. Initially, the high NDVI cluster of high-quality rice was dispersed, but over time, it became concentrated in districts and counties adjacent to the YHWDP.

Key words: grain production, NDVI, Yangtze-to-Huaihe Water Diversion Project (YHWDP), spatial analysis, S-G filter