A landscape approach to quantifying land cover changes in Yulin, Northwest China

Abstract

In this study we quantified land cover changes in the arid region of Yulin City, Northwest China between 1985 and 2000 using remote sensing and GIS in conjunction with landscape modeling. Land covers were mapped into 20 categories from multitemporal Landsat TM images. Five landscape indices were calculated from these maps at the land cover patches level. It was found that fallow land decreased by 125,148 ha while grassland and woodland increased by 107,975 and 17,157 ha, respectively. Landscape heterogeneity, dominance and fractal dimension changed little during the 15-year period while landscape became more fragmented, with an index rising from 0.56 to 0.58. The major factors responsible for these changes are identified as the change in the government policy on preserving the environment, continued growth in mining, and urbanization.

Wetland Transitions and Protection under Rapid Urban Expansion: A Case Study of Pearl River Estuary, China

“…Different methods, such as rate of change of total wetland area [16][17][18], transition matrices for the process of wetland loss [9,19,20], and landscape pattern indices for wetland development [21][22][23], have been used to measure and evaluate wetland changes with absolute amounts by comparing their state at two time points. However, because the differences between newly increased wetlands and well-preserved ones, as well as between the same wetland types, are significant in structure and function due to their development period and location [13], understanding the internal transitions together with analyses of wetland changes plays an important role in conservation and restoration of wetlands [24].…”

Remote sensing monitoring recent rapid increase of coal mining activity of an important energy base in northern China, a case study of Mu Us Sandy Land

“…In particular, multispectral satellite imagery, such as that provided by Landsat TM, ETM, and OLI images, is a precious resource for long-term analyses of surface processes . In the past decade, many efforts have been devoted to study the ecological environment problems due to aeolian desertification in the MUSL region using remote sensing technique (Luk, 1983;Runnström, 2003;Yan et al, 2013;Zha et al, 2008). For example, the degradation of the dry semiarid ecosystems in the MUSL region between 1978 and 1996 was explored by monitoring both changes in grassland biomass production and reclamation activities (Runnström, 2003).…”

“…For example, the degradation of the dry semiarid ecosystems in the MUSL region between 1978 and 1996 was explored by monitoring both changes in grassland biomass production and reclamation activities (Runnström, 2003). Subsequently, the land cover changes of Yulin City located in the eastern part of MUSL region between 1985 and 2000 were quantified and the major factors responsible for these changes were identified as the change in the government policy on preserving the environment, continued growth in coal mining activity, and urbanization (Zha et al, 2008). Recently, the aboveground biomass between 1988 and 2007 was also estimated using Landsat spectral derived vegetation indices (Yan et al, 2013).…”

The measurement of wind erosion through field survey and remote sensing: a case study of the Mu Us Desert, China

“…There are debates on the causes and driving forces of desertification in the region (Wang et al 2005b(Wang et al , 2006; most desert areas with vegetated dune systems in arid and semiarid northern China, however, are used for farming or grazing (Mason et al 2008). Activities such as overreclamation, over-grazing, and over-cutting Wang and Zhu 2001;Wu 2001;Runnström 2003;Ci 1998, 2002;Zha et al 2008;Zhang et al 2008;D'Odorico et al 2013) could thus significantly affect land cover and lead to desertification in the area. On the other hand, continued growth in mining and urbanization has also had an adverse impact on the landscape.…”

“…At present, regional economic development is in direct conflict with the protection of vegetation cover. The conflict has caused damage to land resources and the fragmentation of the landscape, accompanied by desertification (Zha et al 2008). Moreover, these activities will eventually lead to increased wind erosion.…”