The change of land cover and land use and its impact factors in upriver key regions of the Yellow River

Abstract

Owing to the influence of global change, land cover and land use have changed significantly over the last decade in the cold and arid regions of China, such as Madoi County which is located in the source area of the Yellow River. In this paper, land-use/cover change and landscape dynamics are investigated using satellite remote sensing (RS) and a geographical information system (GIS). The objectives of this paper are to determine land-use/cover transition rates between different cover types in the Madoi County over 10 years e.g., from 1990 to 2000. Second, the changes of landscape metrics using various indices and models are quantified. The impact factors of LUCC (Land-Use land cover Change) are systematically identified by integrating remote sensing as well as statistical data, including climate, frozen soil, hydrological data and the socio-economic data. Using 30 m630 m spatial resolution Landsat (Enhanced) Thematic Mapper (TM/ETM + ) data in our study area, nine land cover classes can be discriminated. Our results show that Grassland, Marshes and Water Bodies decrease notably, while oppositely, Sands -Gobi and Barren land increase significantly. The number of lakes with an acreage larger than six hectares decreased from 405 in 1990 to 261 in 2000. Numerous small lakes dried out. The area of grassland with a high cover fraction decreased as well, while the surface area of grassland with a medium level of cover fraction increased. The medium cover fraction grassland mainly originates from high cover fraction grassland. The desertification of land is a serious issue. (ii) The inter-transformations between Grasslands, Barren Land, Sands, Gobi, Water Bodies and Marshes are remarkable. The Shannon-Weaver Diversity Index (SWDI), the Evenness Index (EI) and the extent of Landscape Heterogeneity (LH) has improved. Marshes have become more fragmented hence, with less connected patches. (iii) In the recent 30 years, average annual temperature, the power of evaporation and the index of dryness did increase significantly. Moreover, soil moisture content (SMC) decreased and the drought trend accelerated. The degradation of frozen soil has impacted on the decrease of surface water area and induced a drop in groundwater levels. Monitoring LUCC in sensitive regions would not only benefit from a study of vulnerable ecosystems in cold and high altitude regions, but would provide scientifically based decision-making tools for local governments as well.

Monitoring and Assessment of Land Use and Land Cover Changes (1977 - 2010) in Kamrup District of Assam, India Using Remote Sensing and Gis Techniques

“…To quantitatively describe the LULC change, a Net Change Ratio (NCR) is used to enable the compression between the extents of LULC change between two land covers (Dong et al, 2010):…”

“…Therefore, remote sensing coupled with GIS recognized as a powerful and effective tool to monitor environmental changes at broad scale especially in detecting the LULC change (Samant and Subramanyam, 1998;Mas, 1999 Remotely sensed data for image analysis have been explored the various alterations of the earth resources including forest cover and water bodies in common (Hashiba et al, 2000;Giriraj et al, 2008). Remote sensing provides synoptic view of forest cover and condition on real-time basis (Lillesand and Kiefer, 1999 Dong et al, 2010). A field survey combined with satellite remote sensing is useful which provides thematic maps for vegetation types and floral/faunal distribution in certain define areas (Fuller et al, 1998).…”

Spatio-temporal analysis of land use/land cover pattern changes in Arasbaran Biosphere Reserve: Iran

“…LUCC identifies all kinds of human modification on the Earth's surface (Jokar Arsanjani et al 2013;Lambin and Geist 2006) and is a complicated process caused by various social and environmental factors in different spatial and temporal scales (Rindfuss et al 2004;Valbuena et al 2008). LUCC influence main ecological functions and critical issues of global environment (de Chazal and Rounsevell 2009;Dong et al 2009). …”

Social–ecological challenges in the Yellow River basin (China): a review

“…Currently, the upper reaches are more strongly affected by changes in natural conditions, such as variations in temperature and precipitation patterns. There has been an apparent trend of expansion of the Gobi desert, with the area affected by desertification increasing annually by around 2 % (Dong et al 2009;Hao et al 2012). The predominant grassland ecosystems in the arid and semiarid regions are extremely fragile, and their capacity for regeneration capacity is low.…”

“…Thus, they are very sensitive to climate variations and human disturbance (Ni 2011). Although the human influence in the landscape is weak, a clear trend of decline and serious deterioration of natural vegetation has been obvious in recent decades (Cui and Graf 2009;Dong et al 2009). …”