长三角地区不同下垫面陆—气相互作用的对比分析

发布时间：2017-12-27 10:06

本文关键词：长三角地区不同下垫面陆—气相互作用的对比分析　出处：《南京大学》2017年硕士论文　论文类型：学位论文

【摘要】：长三角地区位于我国典型东亚季风区,快速的城市化、工业化、农田扩张以及伐林造林等人类活动使得该地区土地利用/覆盖变化(LUCC)十分复杂。LUCC使得地表反照率、粗糙度以及波文比等陆面因子发生改变,这些变化通过影响地表-大气间的能量和物质通量,最终引起地表微气候要素的变化。为了更清楚地认识该地区陆-气相互作用的机理,理解不同类型LUCC在长三角地区的气候效应,本文利用南京周边包括城区党校站、城郊仙林站、郊区溧水农田站和溧水草地站四站在内的一组配对站资料,对不同下垫面类型的微气候要素、地表能量通量和CO2通量以及不同陆面过程因子进行了对比分析。进而定量计算不同陆面因子对于微气候要素差异的贡献大小,试图找出控制该地区陆-气相互作用的关键陆面因子。论文研究结果表明:不同下垫面陆-气相互作用差异显著,其中(1)地表微气候要素逐日变化的差异主要出现在城市和农田站,并且在降水较少时段最为明显,其中气温、地温和相对湿度的最大差值分别达3.21℃,7.26℃和22.79%;城市热岛效应在夜间最为显著,使得城区气温比周边高2℃;农田的蒸发降温作用使地表温度降低,LE在热量输送中占主导,夏季出现负感热;(2)地表性质引起的辐射差异主要体现在与反照率有关的向上短波辐射(USR)和与地表温度有关的向上长波辐射(ULR),而USR的最小值和ULR的最大值都出现在城区党校站;(3)城市和农田站地表感热(H)和潜热(LE)通量逐日变化的差异最大,分别达45和95Wm-2,其中LE在净辐射(Rn)中所占的比重从春到夏不断增加。通过对LUCC的微气候效应进行归因分析,定量计算不同土地利用类型对地表温度改变(ΔTs)的贡献大小,该研究发现:城市热岛和农田降温虽然作用相反,但在长三角地区都很明显,分别使地表气温增加了 1.25℃和降低了-1.76℃。地表反照率、粗糙度、波文比以及大气背景场的差异都对ATs有贡献作用。其中,蒸发引起的波文比变化在ATs中起主导作用,对农田降温贡献达-1.40℃,对城市增暖贡献达2.29℃。而气温所代表的大气环流背景场也是陆-气间反馈的重要因素之一,对城市热岛和农田降温都有促进作用。
[Abstract]:Located in the Yangtze River Delta region of China's typical East Asian monsoon area, rapid city, industrialization, the expansion of farmland and forest afforestation etc. because of human activities on land use / cover change in the area (LUCC) complex. LUCC makes the surface albedo, roughness and Bowen ratio etc. land surface factor changes, these changes affected by the surface atmosphere between the energy and material flux, resulting in changes in surface micro climate. In order to get a better understanding of the mechanism of regional land atmosphere interaction, understanding the climatic effects of different types of LUCC in the Yangtze River Delta region, the Nanjing City Party school station, including the surrounding suburban suburb of Lishui, Xianlin Railway Station and Lishui station station station of farmland grassland, a pair of data of different types of underlying surface micro climate the elements, surface energy flux and CO2 flux and different land surface process factors are analyzed. Then the contribution of different land surface factors to the difference of microclimate factors is calculated, and the key land surface factors to control the land - gas interaction in this area are found. The results of this study showed that the difference of surface land atmosphere interaction significantly different (1), the difference of surface micro climate elements daily variation mainly occurred in the city and farmland station, and in less precipitation period is most obvious, the biggest difference between air temperature and relative humidity were up to 3.21 C, 7.26 C and 22.79%; urban heat island effect in the night is the most significant, makes the city temperature higher than the surrounding 2 DEG C; the cooling effect of the farmland evaporation surface temperature decreased, LE in heat transfer is dominant in the negative sense, summer heat; (2) the difference of surface properties caused by radiation is mainly reflected in the related albedo (the upward shortwave radiation USR) and related to the surface temperature of the upward longwave radiation (ULR), and the maximum and minimum value of ULR and USR have appeared in the city party school; (3) city and farmland station (H) surface sensible heat and latent heat flux (LE) differences in the daily variations of the Large, 45 and 95Wm-2 respectively, and the proportion of LE in the net radiation (Rn) increased from spring to summer. Attribution analysis by micro climate effects on LUCC, quantitative calculation of different types of land use change on land surface temperature (Ts) of the contribution, the study found that: the city heat island and farmland cooling although the opposite effect, but in the Yangtze River Delta region is very obvious, are that the surface temperature increase of 1.25 degrees C and reduced -1.76. The surface albedo, roughness, Bowen ratio and difference of atmospheric background field to contribute ATs. Among them, the evaporation caused by Bowen ratio changes in ATs plays a leading role in farmland cooling contribution rate of -1.40 DEG C, the city with up to 2.29 degrees warming. The atmospheric circulation background field represented by the air temperature is also one of the important factors of the land gas feedback, which can promote the cooling of the urban heat island and the farmland.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P463

【参考文献】