吉林西部土地荒漠化预测研究——以吉林省镇赉县为研究区

Forecast of Land Desertification in Northern Jilin Province of China——Taking Zhenlai County as Example

以吉林西部土地荒漠化典型区之一的镇赉县为研究对象,在GIS的支持下,根据研究区两个时期的遥感影象,解译出土地利用图和荒漠化土地分布图,通过叠加处理把荒漠化土地作为单独地类从其他土地利用类型中剔除,得到两期包括荒漠化地类的土地利用类型图,进一步叠加,得到监测期内镇赉县荒漠化土地相对于其他土地利用类型的时空变化。介绍了马尔柯夫荒漠化预测模型的建立过程,并应用马尔柯夫模型预测和分析了镇赉县土地荒漠化的演化趋势,结果表明:如不采取有效措施,镇赉县荒漠化将继续发展,荒漠化土地将逐步蚕食掉现有的草地、林地和耕地,2050年,荒漠化土地将占研究区的32 49%。

Ecological environment in the western Jilin Province is deteriorating, and land desertification is threatening the grain base in the middle part of the Songnen Plain. Zhenlai County is one of the most typical desertification regions in western Jilin Province. Based on GIS and using Landsat TM images of 1988 and 2000, the land use and desertification land distribution maps of 1988 and 2000 are compiled. By the overlay analysis in Arcinfo and Arcview, the desertification land was removed from the other land use types and regarded as an independent land use type; land use type (including desertification land) maps of 1988 and 2000 were finished. These two maps were further overlain to get the transition state of the land use types, and then the transition probability matrix of different land use types from 1988 to 2000 was calculated. On the basis of Markov model, the change trend of the desertification land was forecast, the results showed that if no effective measures are taken to prevent land desertification, the desertification in Zhenlai County will further develop, and invade and occupy the grass land, the arable land and the forest land step by step. In the mean time, the results showed that most of land desertification area was originated from the arable land and the grass land; the land desertification area will go up day by day in the future, it will occupy 28.39% in 2010, 32.49% in 2050, and 46.6% when in a balanced stage. The result also indicates that the Markov forecasting model has highly practicing value.