近20年疏勒河流域生态承载力和生态需水研究

水资源是一切生物赖以生存和不可替代的基本自然资源,生态需水在维持流域生态系统平衡和生态承载力可持续性方面扮演着极其重要的角色,干旱区内陆河流域尤为突出。以疏勒河流域和其所辖县区为不同尺度区域,利用LandsatTM/ETM+/OLI遥感数据(30 m分辨率),解译该流域近20年5期土地利用数据,同时在收集和整理流域多年水文水资源基础数据的基础上,以流域生态需水为研究主线,运用多学科方法和原理,结合遥感技术、GIS技术,通过现场调查和观测,计算了流域及其所辖县区近20年生态承载力和天然植被生态需水量。结果表明:近20年来,伴随流域生态承载力的增加,生态需水量也呈增加趋势,两者呈非常明显的正相关关系,相关系数达0.6076;县域尺度上,生态需水与生态承载力正相关关系也较高,其中林、草地的生态需水与生态承载力拟合优度R~2分别达0.8519、0.7235,说明林、草地生态承载力的变化对生态需水变化的解释能力更强,二者之间的关系更为紧密;基于空间热点分析,该流域生态承载力和生态需水的热点和冷点区域均呈现相似的空间格局,说明二者之间在空间尺度上也呈正相关关系。研究结论可为疏勒河流域生态水资源量的科学配置和调控提供重要的决策依据。

Biocapacity and ecological water demand in Shule River Basin over the past 20 Years

Water is a basic natural resource that all living creatures need to survive and cannot be replaced. Ecological water demand plays an extremely important role in maintaining the balance beween the ecosystem and the sustainability of the biocapacity of river basins, especially arid inland basins. In this study, the basin-and county-scale Shule River Basin Landsat TM/ETM+/OLI remote sensing data (30 m resolution) were used to interpret the Shule River Basin (SRB) land use data for the past 20 years. The analysis was based on the five phases of land use data, multi-year hydrology and water resources basic data, and SRB field surveys and observations, The multi-year hydrology and water resources basic data for the basin and the field surveys and observations results were used to calculate the ecological water demand of the SRB over the past 20 years. The spatial-temporal evolution of ecological water demand and biocapacity in the SRB were also investigated. Over the past 20 years, the total biocapacity of the SRB showed an increasing trend. The ecological water demand of the natural vegetation in the basin also increased significantly. A statistical analysis of watershed biocapacity and ecological water demand showed that biocapacity and overall ecological water demand had increased over the past 20 years. Furthermore, there was also a significant positive correlation between watershed biocapacity and the ecological water demand (0.6076). At the county scale, the correlation between the ecological water demand and biocapacity was significantly positive. In particular, the positive correlations between ecological water demand and the biocapacities of forest and grassland were the strongest, and the goodness of fit (R²) reached 0.8519 and 0.7235, respectively, which indicated that the ability to explain forest and grassland ecological water demand changes was stronger when there were changes in the biocapacity of forest and grassland and the coupling relationship between the two was closer. Based on spatial hotspot analysis, the hot and cold regions of biocapacity and ecological water demand show similar spatial pattern, which indicates a positive correlation between them on the spatial scale. Furthermore, if the future trend in biocapacity is constrained, the ecological water demand can be optimized and controlled, and the utilization of water resources will improve.