Study On The Extraction And The Change Of Crop Planting In HeiLongJiang Province

This paper use 23 pictures of MODIS remote sensing images,250 meters of the spatial resolution,and Landsat TM images with 30 meters ofthe spatial resolution(Landsat 5)in 2000 and 2016,combined with crops in cities and counties from 1981 to 2015 to compare and analyze temporal and spatial variation pattern of the study area the characteristics of crop planting area statistics data.And then explore factors influencing crop planting structure changes and puts forward relevant adjustment direction.The main contents and methods used in this paper are as follows:(1)Smoothing the reconstructed time series curve of NDVI(Normalized Difference Vegetation Index)use S-G filtering method,and extract 11 key parameters of phenology and processing them by normalization and principal component analysis.(2)In HeiLongJiang Province,a large area in different regions of the same crop may have different spectral features,or in the same area of different crops appear the same spectral features.This phenomenon is called "synonyms spectrum" or "objects with the same spectrum".It will lead to the whole image to extract the crops the structure and difficult to ensure the accuracy of the results.this paper uses the concept of "phenology homogeneous region",the area in HeiLongJiang is divided into several small regions,and each region of the multi-scale segmentation,this approach can greatly improve the extraction accuracy of crop planting structure,and proved the optimal scale is 5.(3)Finally,the object oriented nearest neighbor classification method is used to extract the planting structure in HeiLongJiang province.The accuracy of the extraction results is verified,and the accuracy is good.From the point of view of HeiLongJiang Province,corn planting area is the most,followed by rice.Between the 2000 and 2016 in HeiLongJiang province crop planting structure,crop planting structure in 2000 than in 2016 is more complex,there are a variety of mixed mode.In 2016,Songnen Plain maize area increased significantly compared with 2000,and for corn or maize soybean hybrid single way.In 2016,the area of Maize in Sanjiang plain was less than 2000,and the region of rice was increased.The rice planting area is still concentrated in the Sanjiang plain and the South and south of HeiLongJiang along the river.Soybean planting in 2016 than in 2000 increased significantly,but single soybean planting area is less,and the two hybrid soybean-corn,soybean and soybean into rice and soybean-rice-cornmixed cropping area.(4)The planting structure of HeiLongJiang province was divided by the method of fast cluster analysis.It can be seen that the crop planting structure in HeiLongJiang Province in 1981 is mainly a single corn planting area.In 2015,the main planting structure types in HeiLongJiang province is mainly rice and corn-soybean hybrid zone,corn planting area and corn soybean hybrid zone.In 1981,the single planting area of Maize in HeiLongJiang province was mainly distributed in the Songnen Plain,and in 2015 it was mainly distributed in the South and middle of the Songnen Plain.In 2000,the single planting area of rice was mainly distributed in the Sanjiang plain.In 2015,the soybean planting areas were mainly distributed in the Sanjiang plain and Greater Khingan Range area.(5)The influence factors of crop planting structure change are analyzed briefly,and some reasonable suggestions on the optimization and adjustment of crop planting structure in HeiLongJiang province are put forward.The research results show that: by using MODIS-NDVI time series data extraction and segmentation and classification of phenological information of crop processing can be large scale regional effective recognition,statistical data comparison between 1981 and 2015 can accurately.extract the crop planting structure and analysis of influence factors of crop planting structure changes.Timely and accurately get the structure of crop planting and analyze the reasons for its change,so as to provide necessary conditions for the development of agriculture and ensure the orderly development of agriculture.