1. Satellite Environment Center, Ministry of Environmental Protection, Beijing 100094, China 2. Chinese Research Academy of Environmental Sciences, Beijing 100012, China 3. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 4. Ecological and Environmental Monitoring Center of Remote Sensing of Qinghai Province, Xining 810007, China
Watershed is the basic and important spatial scale unit of ecosystem. The scientific analysis of watershed scale landscape pattern depends heavily on the accuracy of the selection of the optimal grain size. In this paper, Qinghai Lake watershed was selected as the study area. Based on the object-oriented classification method, the authors interpreted satellite remote sensing data to generate watershed landscape data. Resampling method was used to obtain different spatial grain size watershed landscape data. Then the landscape pattern indexes were calculated and statistical relation curve was drawn between each landscape pattern index and grain size. Thus the scale effect of landscape pattern index could be identified. Finally, landscape pattern index information loss caused by increasing grain size was used to determine the optimum spatial grain size of watershed scale landscape pattern analysis. The result showed watershed landscape pattern index changed significantly with the increase of spatial grain size, but laws of change were different. Taking into account the landscape pattern spatial grain size effect and the change characteristics of information loss, the authors hold that the best spatial grain size choice of watershed landscape pattern analysis was 90 m.
Hou P, Wang Q, Wang C Z , et al. Ecological effect of land-use and land-cover change in a watershed scope[J] Geographical Research, 2012,30(11):2092-2098.
Zong X Y, Liu G H, Qiao Y L , et al. Study on dynamic changes of wetland landscape pattern in Yellow River delta[J]. Journal of Geo-Information Science, 2009,11(1):91-97.
Zhang S, Shao Q Q, Liu J Y , et al. Land use and landscape pattern change in Madoi County,the source region of Yellow River[J]. Geo-Information Science, 2007,9(4):109-115,128.
Bi R T, Gao Y . Analysis of multi-scale effect of landscape indices of classical landforms in Yuncheng City,Shanxi Province[J]. Journal of Geo-Information Science, 2012,14(3):338-343.
Sun X Y, Su F Z, Lyu T T , et al. Analysis on landscape spatial pattern changes of land use and its driving forces in coastal zone of western Pearl River estuary[J]. Journal of Geo-Information Science, 2009,11(4):436-441.
Shen W J, Wu J G, Lin Y B , et al. Effects of changing grain size on landscape pattern analysis[J]. Acta Ecologica Sinica, 2003,23(12):2506-2519.
[13]
Turner M G, O’Neill R V,Gardner R H ,et al.Effects of changing spatial scale on the analysis of landscape pattern[J]. Landscape Ecology, 1989,3(3/4):153-162.
doi: 10.1007/BF00131534
[14]
Wu J G, Shen W J, Sun W Z , et al. Empirical patterns of the effects of changing scale on landscape metrics[J]. Landscape Ecology, 2002,17(8):761-782.
doi: 10.1023/A:1022995922992
[15]
Wu J G . Effects of changing scale on landscape pattern analysis:Scaling relations[J]. Landscape Ecology, 2004,19(2):125-138.
doi: 10.1023/B:LAND.0000021711.40074.ae
Yu L, Zhao Y W, Zhang Y , et al. Landscape pattern analysis of wetlands in the Daliaohe Watershed,based on optimal grain size[J]. Acta Scientiae Circumstantiae, 2011,31(4):873-879.
You L P, Lin G F, Yang C Z , et al. The effects of spatial scales on landscape indices——A case study of the landuse pattern of Xiamen Island[J]. Geo-Information Science, 2008,10(1):74-79.
Chen L D, Fu B J, Xu J Y , et al. Location-weighted landscape contrast index:A scale independent approach for landscape pattern evaluation based on "Source-Sink" ecological processes[J]. Acta Ecologica Sinic, 2003,23(11):2406-2413.
Cui B L, Chang X L, Zuo D H , et al. Rasterizing vector data and its scaling effect for a sand landscape[J]. Acta Ecologica Sinic, 2009,29(5):2463-2472.
Lyu Z Q, Wu Z F, Zhang J H . Landscape pattern analysis of Guangzhou based on optimization-scale[J]. Geography and Geo-Information Science, 2007,23(4):89-92.
Zheng J R, Jiang W G, Zhou T G , et al. Selection of wetland landscape indices and analysis of landscape pattern in Dongting Lake area[J]. Resources and Environment in the Yangtze Basin, 2010,19(3):305-310.
Xing Y . Spatial responses of wetland change to climate in 32 years in Qinghai-Tibet Plateau[J]. Remote Sensing for Land and Resources, 2015,27(3):99-107.doi: 10.6046/gtzyyg.2015.03.17.
Jiang C H, Li G Y, Cheng T , et al. Spatial-temporal pattern variation and impact factors of ecosystem service values in the Qinghai Lake Watershed[J]. Resources Science, 2016,38(8):1572-1584.
Yang Y N, Wang J L, Chen G J , et al. Relationship between land use pattern and water quality change in Fuxian Lake basin[J]. Remote Sensing for Land and Resources, 2016,28(1):159-165.doi: 10.6046/gtzyyg.2016.01.23.