当前位置： SCI文献检索 > ENVIRONMENTAL MONITORING AND ASSESSMENT期刊下所有文献 > Rice cropping density and intensity lessened in southeast China during the twenty-first century.

Rice cropping density and intensity lessened in southeast China during the twenty-first century.

Abstract：

:Accurate and updated time series maps of paddy rice distribution and planting intensity will greatly improve our knowledge. Unfortunately, spatiotemporal explicit information on rice fields is relatively limited, and considerable uncertainties still exist as regards to its inter-annual variations in China. In this study, an improved rice mapping methodology was proposed through combined consideration of vegetation phenology and surface moisture variations from different seasonal rice. This method was applied to southeast China based on 500 m 8 day composite Moderate Resolution Imaging Spectroradiometer (MODIS) Enhance Vegetation Indices with two bands (EVI2) during the period 2001-2013. Its efficiency was validated with 763 ground survey sites, with an overall accuracy of 95.02 % and the kappa index of 0.9217. Spatiotemporal analysis indicated that rice cropping density and intensity lessened in southeast China during the period 2001-2013. Particularly, the paddy rice-planted areas reduced by 30.09 %, changing from 231,005 to 161,484 km(2). Among them, the planted areas of double rice decreased by 49.34 %, changing from 34,215 to 17,335 km(2). Therefore, averaged rice cropping intensity in southeast China decreased from 1.148 to 1.107. The primary dynamic patterns were from single rice or a rotation of rice plus other crops to non-rice (93,386 km(2)) and double rice to non-double rice (24,132 km(2)). When analyzed at provincial and altitudinal gradient levels, it was obvious that areas with greater rice cropping density or intensity were associated with more remarkable reductions. Graphical abstract The left graph shows that the rice cropping density lessened in Hubei, Hunan, Guangdong, Jiangxi, Anhui, Jiangsu, Henan provinces and other three provincial-level administrative units (Zhejiang, Fujian and Shanghai) from 2001 to 2013. The middle graph indicates the movement of gravity center as well as the variations in the total planted areas of single rice, rice plus others and double rice. The right graph denotes that the rice cropping intensity decreased in each provincial-level administrative unit from 2001 to 2013.

journal_name

Environ Monit Assess

journal_title

Environmental monitoring and assessment

authors

Qiu B,Qi W,Tang Z,Chen C,Wang X

doi

10.1007/s10661-015-5004-6

subject

Has Abstract

pub_date

2016-01-01 00:00:00

pages

issue

eissn

0167-6369

issn

1573-2959

pii

10.1007/s10661-015-5004-6

journal_volume

188

pub_type

杂志文章

在线工具

Rice cropping density and intensity lessened in southeast China during the twenty-first century.