不同空间尺度DEM对山区气温空间分布模拟的影响——以浙江省仙居县为例
作者简介:李 军(1974-),男,天津杨柳青人,博士,副研究员,主要从事农业遥感和地理信息系统应用研究。E-mail:junli@cqnu.edu.cn
收稿日期: 2011-12-20
要求修回日期: 2012-03-02
网络出版日期: 2012-11-20
基金资助
公益性行业(气象)科研专项项目(GYHY201106025)、国家自然科学基金项目(40701148)、重庆师范大学基金项目(11XLB050)资助
The Different Spatial-scaling Effect of DEM Resolution on the Simulation of Temperature Spatial Distribution in Mountainous Area: A Case Study in Xianju County, Zhejiang Province
Received date: 2011-12-20
Request revised date: 2012-03-02
Online published: 2012-11-20
Copyright
以浙江省仙居县为实验样区,通过气温空间分布的地形调节统计模型,使用10个气象站(哨)气温资料和4种不同空间分辨率的DEM(5 m,源于1∶1万数字化地形图;30 m,来源于Aster GDEM v2;90 m,来源于SRTM v4.1;900 m,源于GTOPO30’)模拟不同空间尺度年均气温空间分布,比较其误差大小及随宏观地形(海拔高度)和微观地形(坡度和坡向)的分布差异。结果表明:基于4种不同空间分辨率DEM模拟气温呈较大空间分布差异性;随着DEM空间分辨率减小,误差逐渐增加,空间差异性降低。微观地形因子(坡度和坡向)随空间分辨率的变化产生显著变化,明显影响气温空间分布,不同坡度和坡向间年均气温差最高可达到10~12.5℃,最小仅为1.9~2.6℃。
李军 , 黄敬峰 , 游松财 . 不同空间尺度DEM对山区气温空间分布模拟的影响——以浙江省仙居县为例[J]. 地理科学, 2012 , 32(11) : 1384 -1390 . DOI: 10.13249/j.cnki.sgs.2012.011.1384
In mountainous areas, the terrain factors (e.g., elevation, slope, aspect, hillshade) are the main factors that affect the spatial distribution of temperature. Calculating the temperature over rugged terrain is very difficult. In the mountainous regions of complicated landform and great height difference, the observation data of the existing weather stations are far from enough to reflect the spatial distribution of the air temperature. However, in recent twenty years, digital elevation model (DEM) and digital topography analysis of GIS technology provide a better way to research the spatial distribution of temperature in mountainous areas. Previous studies have shown that the accuracy of topographic factors derived from DEM with different resolutions varies greatly due to the scaling effect. Accordingly, the simulation of temperature spatial distribution also is influenced by DEM at different spatial scales. In this paper, Xianju County in Zhejiang Province is selected as the study area.The topography-adjusted statistical model is applied to simulate annual temperature with different resolutions based on temperature data from 10 meteorological stations and different resolutions (5 m, 30 m, 90 m, and 900 m) DEM data derived from 1∶10 000 digital topographic map, Aster GDEM, SRTM 90 m and GTOPO30’, respectively. It is hypothesized that the temperature map with 5 m resolution is relatively accurate and the errors between the other temperature map with different resolutions and 5 m temperature map are compared and analyzed. Moreover, the temperatures with different grid cell sizes differ significantly with topography in macro and micro scale. The topographic and spatial-scaling effects are analyzed on the temperature simulation in Xianju County. The results show that the spatial distribution of the simulated temperature based on different resolution DEM has great different characteristics. The simulated temperature error increases gradually with the decrease of DEM resolution and the spatial heterogeneity decreases. The terrain factors such as slope gradient and aspect in micro topography scale have significant change with DEM resolution and then have great effect on the spatial distribution of temperature. With the decrease of DEM resolution, terrain is smoothing, the mean value of slope decreases, and lapse rate of temperature decreases. The minimum effect of DEM resolution on temperature simulation is in low elevation (elevation < 100 m) area. The error of the simulated temperature is only less than 0.3℃. In the area , the elevation range is from 100 m to 200 m, and the error is about 1.1℃. The temperature error will reach 2.1-2.4℃ in higher elevation (elevation>200 m). It is found that the coarser the resolution is, the smoother the terrain is. Moreover, with the DEM grid size increasing, variation of aspect and slope cause the decrease in the spatial heterogeneity of the simulated temperature. The maximum temperature difference in different slope gradient and aspect may reach 10-12.5℃, while the minimum difference is only about 1.9-2.6℃.
Key words: DEM; resolution; mountainous area; temperature
Fig.1 Locations of 10 meteorological stations in Xianju County图1 仙居县气象站(哨)点位置 |
Table 1 The longitude, latitude and elevation of 10 meteorological stations in Xianju County and the description of temperature data表1 仙居县10个气象站(哨)的气温及其地理位置(经度、纬度和海拔高度) |
序号 | 气象站(哨)名 称 | 经度(N) | 纬度(E) | 海拔高度(m) | 资料年份 | 说 明 |
---|---|---|---|---|---|---|
1 | 仙居县气象站 | 120°43′20″ | 28°50′58″ | 50 | 1961~1990 | 完整 |
2 | 括苍山气象站 | 120°55′16″ | 28°48′36″ | 1382 | 1961~1990 | 完整 |
3 | 安岭乡气象哨 | 120°20′53″ | 28°33′45″ | 440 | 1984~1987 | 完整 |
4 | 淡竹乡气象哨 | 120°34′19″ | 28°40′36″ | 138 | 1982~1985 | 1982年缺少1~6月 |
5 | 广度乡气象哨 | 120°44′57″ | 28°56′45″ | 600 | 1984~1987 | 完整 |
6 | 横溪镇气象哨 | 120°28′2″ | 28°44′17″ | 106 | 1984~1987 | 完整 |
7 | 苗辽林场气象哨 | 120°47′36″ | 28°36′30″ | 730 | 1984~1987 | 1984年缺少1~3月, 1985年缺少9、10月 |
8 | 上张乡气象哨 | 120°43′30″ | 28°39′58″ | 335 | 1984~1987 | 完整 |
9 | 下各镇气象哨 | 120°50′54″ | 28°51′43″ | 16 | 1984 | 完整 |
10 | 埠头镇气象哨 | 120°30′31″ | 28°50′56″ | 290 | 1984~1987 | 1986年缺少12月 |
Fig.2 Digital Elevation Model(DEM)with 5 m resolution in Xianju County图2 仙居县5 m×5 m数字高程模型(DEM) |
Table 2 Regression relationship of annual temperature and longitude, latitude, and elevation in Xianju County表2 仙居县年平均气温与经度、纬度和海拔高度的回归关系 |
回归系数 | 复相关系数 | F | |||
---|---|---|---|---|---|
74.64 | -1.98 | -0.0055 | 0.9975 | 686.52 |
Fig.3 The spatial distribution of annual temperature in Xianju County with 5 m, 30 m, 90 m and 900 m resolution图3 仙居县4种空间尺度下年平均气温的空间分布 |
Table 3 Annual temperature statistics in different spatial resolutions表3 不同空间分辨率的年平均气温分布的统计分析 |
空间分辨率 (m) | 年平均气温(℃) | 绝对误差 (℃) | 相对误差(%) | 标准差 (℃) |
---|---|---|---|---|
5 | 13.39 | 0.00 | 0.00 | 5.73 |
30 | 14.01 | 0.62 | 4.63 | 4.92 |
90 | 14.37 | 0.98 | 7.32 | 4.20 |
900 | 15.51 | 2.12 | 15.83 | 1.72 |
Table 4 Annual temperature in 11 different elevation classes from DEM with different spatial resolutions表4 不同空间分辨率的DEM中不同海拔高度范围内的平均气温(℃) |
海拔高度 (m) | 空间分辨率(m) | |||
---|---|---|---|---|
5 | 30 | 90 | 900 | |
< 100 | 16.9 | 16.9 | 17.1 | 17.2 |
100~200 | 15.6 | 15.9 | 16.3 | 16.7 |
200~300 | 13.9 | 14.6 | 15.1 | 16.2 |
300~400 | 13.2 | 14.0 | 14.4 | 15.6 |
400~500 | 12.8 | 13.5 | 14.0 | 15.0 |
500~600 | 12.2 | 13.0 | 13.4 | 14.5 |
600~700 | 11.7 | 12.4 | 12.8 | 13.8 |
700~800 | 11.2 | 12.0 | 12.3 | 13.4 |
800~900 | 10.7 | 11.5 | 11.7 | 12.9 |
> 900 | 10.3 | 11.0 | 11.1 | 12.1 |
Fig.4 Variation of annual temperature with different slopes with different spatial resolutions图4 不同空间分辨率的年平均气温随坡度的变化 |
Fig.5 Variation of annual temperature with different resolutions at different aspects图5 不同坡向的年平均气温随空间分辨率的变化 |
The authors have declared that no competing interests exist.
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