关键词: 生产能力指数, 黄河三角洲, 熵权, 遥感, 耕地年龄

Abstract:

Yellow River Delta is the mainly distribution region of land reserve resources in China. The reclamation at the estuary of the Yellow River beach is becoming the key point of maintaining cultivated land dynamic balance in Shandong Province, even the whole nation. Taking Dongying City, Kenli County, Hekou District and Lijin County as a study area, this paper monitored the dynamic change and retrieved the cultivation age of cultivated land in Yellow River Delta, using TM images of 6 different periods ( 1984, 1995, 2000, 2004, 2008 and 2010 ). Based on cultivation age data, an assessment model of cultivated land productivity was built up by entropy weight method. This model used vegetation index (EVI and MSAVI), vegetation coverage (Fv) and temperature- vegetation dryness index (TVDI) as factors indicating land productivity. Results show that: significant dynamic changes of cultivated land had been occurred from 1984 to 2010 in the study area. During 26 years, 77362.33 ha newly-reclaimed cultivated land, most of which came from grassland, had been reclaimed. In the newly-reclaimed cultivated land, the land at cultivation age during 8 to 12 years had most area, which accounted for 34.47%. The newly-reclaimed cultivated land productivity in the study area presented that productivity increased with the cultivation time increased. Average productivity of newly-reclaimed cultivated land at age during 2 to 4 years had lowest productivity, which was only 67.66% of traditional cultivated land. The traditional cultivated land productivity in the study area also presented that productivity increased with the cultivation time increased. Average productivity of traditional cultivated land in 2010 had increased 76.51% than in 1984.

Key words: cultivation age, land productivity index, entropy weight method, remote sensing, Yellow River Delta