半干旱区土地利用变化及其驱动力与土地可持续利用——基于内蒙古自治区伊金霍洛旗的案例分析

Land Use Change and Its Driving Forces and Land Sustainable Utilization in Semi-Arid Areas

在半干旱区,气候干旱是荒漠化发生的自然背景条件,而不合理的土地利用则加速了荒漠化。20世纪70年代中期以前,由于过度开垦和放牧,伊金霍洛旗的荒漠化发展得非常严重。自1976年以来,通过生态退耕,调整土地利用结构,改变放牧为圈养,增加灌溉、化肥等农业投入等,抑制了荒漠化,土地利用走向可持续。恢复以林草为主的土地利用结构是半干旱区土地可持续利用的基础,而在人口超过农业所能够支撑的能力时,必须发展工业化和城市化,创造非农就业机会,使得农民可以离开土地谋生,减轻人口对土地的压力,才可能实现生态退耕和土地利用结构调整。伊金霍洛旗正是因为由煤炭开采带来的工业化和城市化,使得许多农民离开土地,进行生态退耕,才得以恢复与重建稳定的可以抵御荒漠化的生态系统。单位面积土地承载更多人口的工业化和城市化是保证该区以林草覆盖为主的土地利用结构,防止荒漠化的必由之路。在这个地区搞建设用地占补平衡是不适宜的。

Desertification is primarily controlled by natural factors. Population pressure on land and unsuitable land use make desertification accelerating over semiarid areas. Because the demand for food of people exceeded the bearing capacity of grazing products, people had to cultivate the land and grow crops for survival. After cultivation, desertification will be aggravated over areas without vegetation coverage. Also, overgrazing caused grasslands to be degraded. Before the mid-1970s, desertification was rapidly developed in Ejinhollo, one of counties in Inner Mongolia located in a semiarid area of China. Since 1976, the government and people have been conducting a variety of measures to combat desertification, including reforestation, railing animal husbandry, and increasing agricultural inputs. With the eco-restoration, the land use structure was being changed. The desertification was consequently controlled and the land use tended to be sustainable. The land use structure consisting primarily of grass, shrub, and forest was found to be a reasonable. Coal mining was found to be the driver of industrialization and urbanization in Ejinhollo. With rapid industrialization and urbanization, farmers can get more job opportunities except from agriculture. Population pressure on land was decreasing. Eco-restoration and reforestation were implemented. Therefore, the land use structure was converted into a suitable pattern. With increasing fiscal revenue, the local government has increased input for eco-restoration, converting farmlands into grasslands or forestlands and changing grazing to railing animal husbandry. Because of the suitable land use structure and land use patterns, the desertification was controlled. Only industrialization and urbanization can sustain people and keep a suitable land structure that can prevent land from desertification.