Using remote sensing to assess impacts of land management policies in the Ordos rangelands in China

Implementation of land management policies influences land use and hence
causes environmental change. Taking the Ordos rangelands in China as a case
study, this paper explores the potential of remote sensing to assess in dryland
areas the impacts of policies on the environment. Thirteen Landsat images of the
period 19782010 were acquired and those corresponding to the starting dates of
implementation of different policies were selected for land-cover change analysis;
others were used to check the detected change and track the normalized
difference vegetation index (NDVI) trajectory matched with time series of
meteorological data for calibration of natural response of rangelands to rainfall.
The results indicate that policy impacts are complex and include both positive
and negative aspects depending on the locality in space. On one hand, policies
have aroused the enthusiasm of people in agricultural production and sandcontrol
leading to the recovery of about 2618 km2 of desertified rangeland and
sandy land, and economic growth, on the other hand, provoked vegetation
degradation with an accumulated area of 2439 km2 when policies cannot
reconcile the conflict between environmental protection and the interest of rural
people. However, degradation is not absolute and can be mitigated by the
implementation of rational policies.