Driving Forces of Land Use Changes in Irrigated Agriculture
灌区土地利用变化驱动因素分析——以内蒙古河套灌区为例

Land use/cover change and its driving force have become the hot topic of geographers and ecologists within recent years.Study areas involved cities,towns,deserts and oasis,while less attention was paid to irrigated agriculture.More attention was paid to water-saving irrigation,pollution and canal system modification in irrigated agriculture.In fact,study on land use/cover change and its driving forces in irrigated agriculture have an important theoretical significance.In irrigated agriculture,canal system and soil types have an important impact on land use change.Hetao irrigated agriculture in Inner Mongolia was taken as a case study and the impact of irrigation canal distribution and soil type on land use pattern change was analyzed based on GIS technology.The mean distance to irrigation canal of each land use type and area percentage of different land use type on different soil types was computed with the support of GIS software ArcINFO and ArcView.It is found that the area of alkali-saline land increases near the irrigation canal while the area of farmland declines and wasted grassland increases in the areas far from the canal system.The former is mainly due to elevated groundwater level with long time irrigation and poor drainage system and the latter is mainly caused by limited water resources.Poor soil quality with long time tillage and no rational conservation practice cause some farmland degraded to wasted grassland and alkali-saline land.Land use/cover change and driving forces in Hetao irrigated agriculture are complicated,and it is a product of human activities and natural forces in a long-time period.In further study,water diversion form the Yellow River,groundwater level materials,natural factor including temperature and precipitation,social factors including population,economy and government regulation and factors mentioned above should be analyzed by synthesis method to better understand land use dynamics and promote sustainable development in Hetao irrigated agriculture.