Land use and cover change detection and modelling for North Ningxia, China1 Weicheng Wu*+,Eric F. Lambin* and Marie-Françoise Courel+ +Department of Geography, University of Louvain, Place Louis Pasteur, 3 1348 Louvain-la-Neuve, Belgium *PRODIG-UMR8586/CNRS, 191 Rue St-Jacques, 75005 Paris, France E-mail of the corresponding author: wuwc@univ-paris1.fr Introduction North Ningxia, extending from longitude 105°45'E to 107°00'E and latitude 38°20'N to 39°30'N, including 50% of the Helan Mountains and 80% of the Yinchuan Plain and surrounded by Inner Mongolia on the east, north and west (figure 1), is an arid and semi-arid region in Northwest China. The annual precipitation ranges from 78 to 295mm (the maximum, 430 mm, appears in the Helan Mts), annual evaporation from 1473 to 2318mm and annual average temperature from 8.2°C to 9.6°C in the recent decades (Ningxia Statistical Yearbook, 1988, 1990, 1992, 1997 and 2000). The analysis on meteorological data in the past half century indicates that the annual temperature has been increasing and precipitation decreasing in Yinchuan region. It is probably a local indicator of the global warming. The climate has been getting dryer and warmer and the natural conditions more and more difficult. Land use, especially, in agriculture, has a long history in this region. As early as 35,000 to 25,000 years B.P., people already begun their activities (Geng et al, 1992). In the dynasty Qin (221 to 207 B.C.), the first irrigation canal came into existence. This signalled the launch of an agricultural era in the Yinchuan Plain. In the successive dynasties Han (206 B.C to 220 A.D.) and Tang (618 to 907 A.D.), the irrigation system was further developed and improved. But due to the frequent wars and large scale of emigrations in history (Geng et al, 1992), it did not have a stable development until recent decades. With the execution of the 'reform-and-open' policy in 1980s in China, land use and cover change has taken place rapidly owing to the agricultural, industrial developments and population growth. Recently, with more and more development programmes of the Chinese central government focused on Northwest China, North Ningxia becomes one of the hotspots. It is therefore of first importance to undertake a synthetic land use and cover investigation, change rate measurement, driving force analysis and develop a dynamic monitoring system in order to generate fundamental land use data, a management prototype and some useful references for the local governments in their sustainable land use planning and decision making. It is the objective of the research and one of the tasks scheduled in the Sino-Belgian co-operation project on Northwest China. In correspondence to the implementation of the new land use policy in 1980s in China, the period from late-1980s to late-1990s was chosen to conduct a land use and cover change detection, monitoring and modelling utilising the multi-temporal remotely sensed data (Landsat TM dated 1987, 1989 and ETM 1999) and county-level socio-economic and meteorological data. Methodology A multidimensional synthetic method from space to ground and from human activities to environmental changes was applied in this research.
1.This paper is a part of the outcomes of the Sino-Belgian cooperation project on Northwest China in the University of Louvain, B1348, Belgium. The research was funded by the OSTC of the Belgian government under contract BL/10/C15. 2.The dataset of Landsat TM image (129/33, Sept.20, 1987) belongs to the data archive of Fukui Research Group, Keio University, Japan. We use it with their permission.
Page 1 of 4
| Next | |
