Influence of terrain factors on rice yield in hilly area Taking Qijiang county of Chongqing as a case

Based on the technical support of GIS, Sim-DTA and SPSS, this paper took Qijiang, Chongqing asthe research area, the digital elevation model and rice yield of Qijiang as the primary data, extracted the terrainslope position, elevation, slope and topographic wetness index, made superposition with rice yield data and analyzedthe relationships between topographic factors and rice yield. The results showed that the middle slope was the optimal rice planting area, had the largest contribution rate for rice production with the proportion of 57.49%; Within the scope of 250-500 m for elevation, rice planting effect was the best, rice production intensively distributed in 6000-1 0000 kg/hm2. Within the scope of 10-15for slope, rice yield had the most concentrated distribution, and the output values were mainly distributed in 6 000-9 000 kg/hm2. Within the scope of 5.75-6.50 for topographic wetness index, rice production intensively distributed in 6 000-9 000 kg/hm2. Elevation related to the rice yield significantly and negatively at the 0.01 level with the correlation coefficient of -0.317, slope and the rice yield had significantly negative correlation at the 0.05 level with the correlation coefficient of -0.121, topographic wetness index and rice yield were significantly related at the 0.05 level with the correlation coefficient of 0.145.