首都圈防沙治沙水土资源空间优化配置研究——以大兴、怀来、张北为例

首都圈是近年来北京沙尘暴天气日益严重的重要沙尘源区之一。研究区中大兴区代表的是华北平原北缘落叶阔叶林灌草丛典型区;怀来县代表的是桑干河、洋河盆地灌木草原典型区;张北县代表的是坝上高原西部干草原典型区。论文通过了解水土资源利用的变化情况,分析水土资源利用现状和存在问题;利用中国资源环境遥感数据库中的土地利用现状、中国1∶1000000土地资源图等数据,以水资源为最重要的限制因素,通过灰色线性规划模型,以防沙治沙和发展经济、实现区域可持续发展为目标,进行水土资源优化配置;结合不同区域水土资源利用的突出问题,将水土资源优化配置方案落实到空间;建立区域水土资源比较合理、有效利用的方案。大兴的重要措施是平原旱耕地转变为中覆盖度草地,怀来是陡坡地退耕,张北是提高草地的覆盖度。

Optimal spatial allocation of water-land resources for sand /dust storm prevention and control in different ecological regions of the capital circle

The capital circle including47counties and cities is one of the most important sand/dust storm source areas for sand/dust storms of recent years that have affected some metropolis such as Beijing and Tianjin.This situation is highly concerned by the whole society.According to the features of eco - geographical regions of the circle,Daxing is a case standing for the north rim of defoliated broad - leaved forest and shrub - grass region of North China,Huailai is for shrub and grassland of the Sangganhe River and Yanghe River Basins,and Zhangbei is for steppe of west Bashang Highland.Objectives of this study are to control and to reduce the possibility of sand/dust storm through re-allocation of the usage of water-land resources.Data for the study are from“Land Use Database”of China Resources and Environment Remote Sensing Data Base;1∶1000000Land Resources Map of China;and the local government statistics and field surveys.Analysis indicated that main problems for the causes of dust/sand storm occurrence are illogical land use structure,irrational land use allocation and unsatisfied water resource for land use requirement.Taking water resources supply and land-use types as the two most important restraining factors,gray linear programming model was applied to re-allocate water-land resources.Sand/dust storm prevention and control was taken as the first objective of the model.Economic development and sustainable regional development is the second.Different scenarios for different objective schemes were completed.Geographical information system(GIS)technology was employed to map the different scenarios /schemes.Land use type conversion based on water resources limitation is the main way to achieve the scenarios.Common measurements are sandy land controlling and bare land coverting.Converting parts of dry farmland to medium coverage grassland is the special measurements for Daxing;converting sloping(higher than15°)farmland to grassland is for Huailai;and reducing dry farmland and increasing coverage of grassland are for Zhangbei.