干旱半干旱地区地下水埋深与土地利用变化关系分析——以喀什三角洲为例

An Analysis of the Relationship between the Groundwater Depth and the Land Use Change in Arid and Semi-arid Areas:Taking Kashgar Delta as an Example

干旱半干旱地区生态环境相对脆弱,因地下水开采和灌溉效率低引起的地下水水位下降趋势明显。该类地区地下水资源和土地利用类型之间的相互影响机制研究仍相对有限,尚需进一步探索。以喀什三角洲地区为研究区域,结合克里金(Kriging)插值法、土地利用动态度模型、转移矩阵3种方法,研究其地下水埋深与土地利用变化关系及土地利用变化对地下水水资源的影响机制。研究结果显示:①喀什三角洲地区2010-2018年期间,耕地、建筑用地面积均呈增大趋势,林地、草地及未利用地呈现减小趋势。②地下水位埋深呈现西北高、中南部低的特点,埋深范围为0.5~31 m。北部埋深范围介于10~31 m,中、南部地下水位埋深较浅,一般介于0.5~10 m。③研究区2018年较2010年在各土地利用类型中地下水埋深5~10 m的占比越来越大,其他埋深区间特别是0~5 m占比越来越小,不同土地利用类型的地下水平均埋深范围在5~10 m。因地下水水资源为研究区主要供水水源与耕地灌溉水源,耕地面积所对应的地下水埋深增幅更为明显。研究结果表明干旱半干旱地区地下水位埋深对因人类活动导致的土地利用类型变化敏感,该类地区地下水水资源与土地利用类型息息相关。研究对干旱半干旱地区地下水水资源保护和合理开发及区域生态文明建设提供了有力理论依据。

The ecological environment in arid and semi-arid areas is relatively fragile,and the groundwater level decreases obviously due to the low efficiency of groundwater exploitation and irrigation.The research on the interaction mechanism between groundwater resources and land use types in these areas is still relatively limited,and a further exploration is needed.This paper takes the Kashgar Delta as the research area,combining Kriging interpolation method,land use dynamic degree model and transfer matrix to study the relationship between groundwater depth and the land use change and the impact mechanism of land use change on groundwater resources.The results show that:①during 2010-2018,the area of cultivated land and construction land in Kashgar Delta is increasing,while the area of forest land,grassland and unused land is decreasing.②The depth of groundwater is high in the northwest and low in the middle and south,and the depth ranges from 0.5 to 31 m.The depth of underground water in the north is between 10~31 m and that in the middle and south is shallow,generally between 0.5~10 m.③Compared with 2010,the groundwater depth of 5~10 m accounted for an increasing proportion of all land use types in the study area in 2018,while other land use depths,especially 0~5 m,accounted for an increasing proportion.The average groundwater depth range of different land use types was 5~10 m.Groundwater resource is the main water supply source and irrigation water source of cultivated land in the study area,the increase in groundwater depth corresponding to cultivated land area is more obvious.The results indicate that the groundwater depth in arid and semi-arid areas is sensitive to the changes in land use types caused by human activities,and the groundwater resources in these areas are closely related to land use types.This study provides a strong theoretical basis for protection and rational development of groundwater resources and the construction of regional ecological civilization in arid and semi-arid areas.