山西省农业干旱时空变化特征及其与气象因子的响应研究

发布时间：2018-06-30 01:55

本文选题：地表温度 + 植被指数　；参考：《太原理工大学》2017年硕士论文

【摘要】：农业干旱是由于水分供应不平衡造成土壤缺水,影响农作物的生长发育,直接导致粮食减产,严重时影响粮食安全和社会稳定。干旱季节容易诱发各种其他自然灾害,如森林火灾、蝗灾、农作物减产、水资源短缺、土地沙漠化、地下水位下降等。准确监测农业干旱,长期以来都是学者们关注的重点,研究并掌握其发展特征是国家预防农业干旱及其他灾情发生的重中之重。本文在传统农业干旱监测及遥感干旱监测模型基础上,对地表温度(Land Surface Temperature,LST)进行数字高程模型(Digital Elevation Model,DEM)和纬度校正得到修正后的LST,结合归一化植被指数(Normalized Difference Vegetation Index,NDVI)初步构建温度植被干旱指数(Temperature Vegetation Dryness Index,TVDI)模型;在此基础上进行拟合干边改进,形成具有区域特色的山西省农业干旱TVDI遥感监测模型。将其应用于研究区,得到1984-2016年山西省农业干旱监测结果,探讨并分析研究区33年间的干旱特征和演变特征,以及农业干旱动态变化与气候变化之间的响应。通过研究,得到以下主要结论:1.与改进前的模型相比,改进后的TVDI模型不仅修正了地区之间由于纬度差异带来的干旱监测误差,而且对提高高海拔地区的农业干旱监测精度效果显著。2.山西省农业干旱总体上呈减缓趋势,历年均有干旱发生,旱情由西到北呈现无旱到轻旱再到中旱的垂直分带现象;全省农业干旱普遍态势表现为2-4月北部重旱,其余地区轻旱或无旱,5-9旱情减缓,10月-次年1月区域内大部地区为轻旱或中旱;全省季际旱情除春季旱情呈现加重趋势外,其余三季均呈现出减缓趋势。3.1984-2016年间,山西省农业干旱的空间空间分布特征为:中旱或重旱区由西北部蔓延至西部,再到东部和中部,最后到西北地区;轻旱区由中部蔓延至中部和东部,最后到除中旱或重旱区的大多数区域。无旱区以运城大部为主,夏季面积达到最大。秋季旱情与DEM高程分布呈现出显著相关。4.分析TVDI与温度、降水的关系发现:年均TVDI与温度相关性不显著,正、负相关关系面积比例均衡,分别占全省总面积的57.3%和43.7%,相关系数绝对值东部高于西部;全省大部年均TVDI与降水呈现显著负相关关系,研究区内79%以上区域呈现负相关,60%以上范围相关系数绝对值达到0.5以上,且以吕梁山为界,东部相关性高于西部。
[Abstract]:Agricultural drought is caused by water supply imbalance resulting in soil water shortage, affecting the growth and development of crops, directly leading to grain production, seriously affecting food security and social stability. Drought season can easily induce other natural disasters, such as forest fire, locust disaster, crop yield reduction, water resources shortage, land desertification, groundwater level decline and so on. Accurate monitoring of agricultural drought has been the focus of scholars for a long time. It is the most important for the state to prevent agricultural drought and other disasters to study and grasp its development characteristics. Based on the traditional agricultural drought monitoring and remote sensing drought monitoring models, The Land Surface temperature Model Dem (Digital elevation Model Dem) and the modified LSTs after latitude correction are used to construct the Temperature vegetation dryness Index (TDI) model combining with the Normalized difference vegetation Index (NDVI). The TVDI remote sensing monitoring model of agricultural drought in Shanxi Province with regional characteristics was formed. The results of agricultural drought monitoring in Shanxi Province from 1984 to 2016 were applied to the study area. The drought characteristics and evolution characteristics in 33 years and the response between agricultural drought dynamics and climate change in the study area were discussed and analyzed. The main conclusions are as follows: 1. Compared with the improved model, the improved TVDI model not only corrects the drought monitoring error caused by the latitude difference among different regions, but also improves the precision of agricultural drought monitoring in the high altitude area. Generally speaking, agricultural drought in Shanxi Province has slowed down, and drought has occurred over the years, and the drought situation from west to north shows a vertical zonation of no drought to light drought and then to moderate drought, and the general situation of agricultural drought in Shanxi Province is severe drought in the northern part of the province from February to April. The drought in the rest of the region slowed down from 5 to 9, and in most of the regions from October to January of the following year, there was a moderate or moderate drought, and the interseasonal drought in the whole province showed a slowing trend except the increasing trend of drought in spring. 3. During the period 1984-2016, the interseasonal drought in the whole province showed a slowing trend. The spatial distribution characteristics of agricultural drought in Shanxi Province are as follows: moderate or heavy drought areas spread from the northwest to the west, then to the east and the middle, and finally to the northwest, and the light arid areas from the central to the central and eastern, Finally to most areas except moderate or heavily arid areas. The dry-free area is dominated by Yuncheng, with the largest area in summer. There was a significant correlation between drought and Dem height distribution in autumn. By analyzing the relationship between TVDI and temperature and precipitation, it is found that the average annual correlation between TVDI and temperature is not significant, and the proportion of positive and negative correlation area is balanced, accounting for 57.3% and 43.7% of the total area of the province, respectively. The absolute value of correlation coefficient in the east is higher than that in the west. There is a significant negative correlation between TVDI and precipitation in most of the provinces. The absolute value of range correlation coefficient is above 0.5 in more than 79% of the regions in the study area, and the correlation is higher in the east than in the west.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S423

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