华北平原主要作物遥感提取及时空变化研究

发布时间：2018-06-08 18:26

本文选题：遥感监测 + 农业土地利用变化　；参考：《青海师范大学》2015年硕士论文

【摘要】：农业土地利用是影响地表水平衡的重要因素,华北平原作为我国棉粮果重要生产基地,在过去的几十年中由于抽取地下水灌溉造成严重的水资源短缺。因此准确地提取华北平原不同作物的空间分布信息可为作物耗水估算、水资源可持续化利用和农业资源配置提供基础数据。为了解决多年份、不同作物遥感监测种植面积变化过程中,不同的训练样本或分类规则不能较好地反映作物种植面积时空格局变化的问题。本文首先根据研究区(华北平原)农业气象观测站提供的主要农作物物候观测资料获得主要农作物典型物候期特征,利用Savitzky-Golay对MODIS NDVI时间序列数据进行重建,进而提取不同作物的NDVI时序曲线,结合二次差分法获取的复种指数,探讨了基于不同作物生育期的差异,采用CART(Classification and Regression Tree)算法对华北平原多年份、不同作物的遥感分类方法进行可行性分析,进而提取了2000—2013年华北平原主要作物冬小麦、玉米、棉花和果树的种植面积,并参考县级的农业统计数据和实地样本数据进行精度评价,最后分析了华北平原近14年间主要作物空间格局变化及其动因。得出以下结论:(1)经检验,近13年的冬小麦、玉米和棉花的遥感监测种植面积与农业统计面积相关系数分别为0.78、0.71和0.83(置信水平都为95%),具有较高的相关性。在参考实地样本数据与分类结果建立的混淆矩阵显示,14年间的分类结果Kappa系数在0.72~0.96之间;总体精度在79%~97%之间,85%以下年份仅出现2年,从整体上来看,近14年的分类精度可行。(2)从作物的空间分布特征上看,华北平原的冬小麦-夏玉米主要分布于山东省和河南省的黄灌区及太行山山前平原区;林果主要分布于晋州-赵县-深州一带、泊头-沧县一带、乐亭-昌黎一带和信阳-惠民-滨州一带以及环北京周边地区;棉花集中分布于华北平原中部。在时间变化上,华北平原冬小麦、玉米面积均呈下降趋势,分别由2000年的553.23万hm2缩减至2013年的530.33万hm2和由2000年的642.48万hm2缩减至2013年的569.54万hm2,其中以河北平原北部缩减趋势最为显著,天津-廊坊一带和保定地区甚至出现冬小麦主要种植区“弃耕”的现象。华北平原棉花14年的平均种植面积约84.01万hm2,其中河北平原南部棉花面积占研究区棉花总面积的一半以上(53%),年际间波动较大,整体上呈增加趋势。林果平均种植面积约63.55hm2,四个分区在近14年间整体上均呈增加趋势,其主要影响因素是经济收益和政府导向。(3)从粮食作物/经济作物种植转换的角度来看,华北平原的粮食/林果转换区主要集中在有林果种植历史的区域,如:环北京周边、唐山、沧州和山东的滨州一带,转换区面积约为95.53万hm2,占华北平原耕地面积的11.15%。粮食/棉花转换区主要集中于华北平原南部的产棉区周边及吴桥-东光-南皮一带,转换区面积约为64.89万hm2,占华北平原耕地面积的7.58%。(4)基于多年的分类结果来统计作物的种植概率进而表现不同土地条件和其他人为因素对作物的选择,能较好地反映作物种植的主产区,这为农业土地利用变化研究中分析作物种植面积变化提供一种新思路。
[Abstract]:Agricultural land use is an important factor affecting the balance of surface water. The North China Plain is an important production base of China's cotton and fruit and fruit. In the past few decades, the extraction of groundwater irrigation has caused serious water shortage. Therefore, the accurate extraction of spatial distribution information of different crops in the North China plain can be used to estimate the water consumption of crops, and the water resources can be held. In order to solve the multiple year, the different training samples or classification rules can not reflect the change of the spatial and temporal pattern of crop planting area in order to solve the multiple year. The main crop phenological data obtained the characteristics of the typical phenological phase of main crops, rebuilt the MODIS NDVI time series data by Savitzky-Golay, then extracted the NDVI time sequence curve of different crops, combined with the compound index obtained by the two difference method, and discussed the difference based on the growth period of different crops, and used CART (Classificati). On and Regression Tree) algorithm is used to analyze the feasibility of remote sensing classification of different crops in the North China Plain for many years, and then the planting area of winter wheat, corn, cotton and fruit trees of the North China Plain from 2000 to 2013 is extracted, and the precision evaluation of the agricultural statistics and field samples at the county level is carried out, and the final analysis is made. The changes in the spatial pattern of main crops in the North China Plain during the last 14 years and their reasons were obtained. (1) the correlation coefficient between the monitoring planting area and the agricultural statistical area of the winter wheat, corn and cotton in the last 13 years was 0.78,0.71 and 0.83 (the confidence level was 95%), respectively. The obfuscation matrix established with the classification results showed that the Kappa coefficient of the classification results of 14 years was between 0.72~0.96; the overall accuracy was between 79%~97% and 85% years only 2 years. From the overall point of view, the classification precision was feasible for nearly 14 years. (2) from the spatial distribution characteristics of the crops, the winter wheat and summer maize in the North China Plain were mainly distributed in Shandong. The Yellow irrigated area of province and Henan province and the plain area of Taihang Mountain in front of the mountain; the fruit is mainly distributed in Jinzhou Zhaoxian County Shenzhou area, Botou Cangxian area, Leting Changli area, Xinyang Huimin Binzhou area and periphery of Beijing. The cotton is concentrated in the middle of North China Plain. In time change, the area of Winter Wheat in North China Plain and the area of corn are all present The downward trend was reduced from 5 million 532 thousand and 300 hm2 in 2000 to 5 million 303 thousand and 300 hm2 in 2013 and from 6 million 424 thousand and 800 hm2 in 2000 to 5 million 695 thousand and 400 hm2 in 2013, among which the most significant reduction trend was in the northern Hebei plain. The phenomenon of "abandonment" in the main area of Winter Wheat in the Tianjin Langfang area and Baoding area. The North China plain cotton 14 The average planting area of the year is about 840 thousand and 100 Hm2, of which the cotton area in the southern part of the Hebei plain accounts for more than half (53%) of the total cotton area in the study area. The interannual fluctuation is larger and the overall growth trend is increasing. The average planting area of the forest fruit is about 63.55hm2, and the four zoning is increasing in the last 14 years. The main influencing factors are economic returns and the main factors. (3) from the point of view of the conversion of grain crops / crop planting, the grain / fruit conversion area of the North China Plain is mainly concentrated in the region with the history of forest fruit planting, such as the surrounding area around Beijing, Tangshan, Cangzhou and Binzhou in Shandong, the area of the conversion area is about 955 thousand and 300 Hm2, which accounts for the grain / cotton rotation of the cultivated land in the North China Plain. The change area is mainly concentrated in the vicinity of the cotton producing area in the south of the North China Plain and the Wuqiao Dongguang Nanpi area. The area of the conversion area is about 648 thousand and 900 Hm2, and the area of the cultivated land in the North China Plain is 7.58%. (4). Based on the years of classification results, the planting probability of the crops is counted and the selection of different land conditions and other human factors is better. It reflects the main production area of crop planting, which provides a new idea for analyzing the change of crop acreage in the study of agricultural land use change.
【学位授予单位】：青海师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S127

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