西北干旱区退耕还林(草)后水土资源开发的优化模式研究

STUDY ON OPTIMIZING MODES OF LAND AND WATER RESOURCES EXPLOITATION ATFER RETURNING FARMLAND TO FOREST AND GRASSLAND IN ARID AREA OF NORTHWESTERN CHINA

在综合分析以往水土资源开发中存在的问题基础上 ,提出了实施退耕还林后西北干旱区水土资源开发的基本思路。根据水量平衡原理 ,建立了以土地利用、植被变化对地下水影响为主线的数值模型 ,并预测了在水土资源开发的现状模式下 ,流域水土资源的变化。所建模型概念明确 ,形式简单 ,所需资料容易获得。以民勤绿洲为例 ,把土地利用的影响作为源汇项处理 ,根据土地利用模式对地下水时空变化影响的分析结果 ,提出了兼顾生态环境与经济社会两方面效益 ,以绿洲水土资源利用矛盾最小为核心目标的水土资源开发模式。以新疆三工河流域为例 ,把植被变化的影响作为源汇项处理 ,根据植被变化对地下水时空变化影响的分析结果 ,提出了兼顾生态环境与经济社会两方面效益 ,以重点调控绿洲内部垂向水分消耗、合理控制地下水开采为核心目标的水土资源开发模式。上述研究范例 ,从理论上解决了水利和水文地质部门长期以来有关地表水和地下水到底如何开发才算合理的争论 ,也证实了上述水土资源开发模式不但在经济上合理 。

Based on analyses on the problems in the water and land resources exploitation in previous period, the paper puts forth the basic thoughts on land and water resources exploiting after implementing the policy of returning farmland to forest and grassland in arid area of Northwest China. With the principle of water balance, a quantitative models on the main line of impacts of land use and vegetation variation to groundwater is set up, and the forecast on land and water resources variation is given under the present model of land and water resources developing. With definite conceptions, the model has simple form and applies easily acquired data. Taking the Minqin Oasis of Gansu Province as an example, the mode of land and water resources exploiting with the core aim of realizing the minimum utilization contradictions between land and water resources in the oasis and giving both considerations to eco environmental benefit and socio economical benefit is presented based on taking the influence of land use as source and concentrating item to process and the analyzed results of the impact of land utilizing mode to temporal and spatial variation of groundwater. Taking the Sangonghe River Basin of Xinjiang as another example, the mode of land and water resources exploiting with the core aim of controlling vertical water consumption within oasis and groundwater exploitation rationally and giving both considerations to eco environmental benefit and socio economical benefit is presented based on taking the influence of vegetation variation as source and concentrating item to process and the analyzed results of the impact of vegetation variation to temporal and spatial variation of groundwater. According to the case studies, the paper presents a theoretical way used to solve the long term disputes on how to exploit surface water and ground water rationally between the water conservancy department and hydrogeological department and confirms that the modes of land and water resources exploiting are rational in economic effects and favorable in ecological effects.