The Change Detection Of Global Cropping Index Based On Satellite Remote Sensing

Cropping index is an important indicator in agricultural production,which directly reflects the situation and degree of cultivated land resources.The existing studies have shown that improving the cropping index can significantly increase grain yield and promote the development of agricultural economy.Therefore,monitoring and analyzing the changes of the cropping index in time and space can provide indirect reference for food security assessment,and also is of great significance for the agricultural plan and policy.The cropping index change that is for a long time and large regional scale has very important significance,such as to study the response of global environmental change and the big country agricultural policy.The purpose of this study is to extract global crop index by using the remote sensing.Data is provided by LTDR(long time land data record),it is from 1982 to 2013.Show the global cropping index changes in the past more than 30 years in time and space,analyze the changes and provide scientific basis for rational utilization of cultivated land resources.The main contents of this study are as follows:(1)Method of noise removal for long time series NDVI data;(2)Extraction algorithm of cropping index;(3)Cropping index extraction results and verification method;(4)The cropping index calculation and variation analysis of the typical countries in different regions.The main results of this study are as follows:(1)The global multiple cropping index has latitudinal zonality,and the multiple cropping index decreases with the increase of latitude in other natural conditions;(2)The multiple cropping index is lower in developed countries than in developing countries;(3)The multiple cropping index in China is on the rise;(4)The impact of climate change on crop cultivation,the occurrence of extremeclimate events El Nino phenomenon will reduce the multiple cropping index.