河西走廊中段临泽绿洲水资源供需平衡及承载力分析

Regional supply-demand balance and carrying capacity of water resources for Linze Oasis in the middle of Hexi Corridor

水资源管理制度改革及种植业结构调整是提高西北干旱区绿洲水资源承载力的有效途径。结合2000—2015年临泽绿洲地表水与地下水资源利用、种植业分布格局、水利设施建设等资料,采用水资源承载力平衡指数(IWSD)和地下水开采潜力指数分析了临泽绿洲水资源供需平衡的年际变化,并利用适宜灌溉规模对绿洲水资源最大承载力进行了研究。分析得出:2000—2015年期间,在P=50%来水情况下仅蓼泉和板桥灌区能维持水资源供需平衡且地下水开采不超过最大允许开采量;受水资源管理改革、种植业结构调整等因素影响,绿洲单位面积耗水量下降0.35×10~4m^3·hm^(-2);优先保证绿洲内部生活、工业及生态用水,2020年规划下可承载灌溉面积为(3.51~3.91)×10~4hm^2。适当缩减绿洲边缘灌溉面积,协调各灌区井渠灌溉是实现绿洲"水—生态—经济"可持续发展的有效途径。

It is an effective way to increase the carrying capacity of water resources in the arid areas of northwest- ern China by reforming water resources management policies and adjusting local planting industry structure. Taking- Linze Oasis in the middle reaches of Heihe River as the study area, the inter annual variation of the supply-demand balance about water resources was analyzed using the index of water supply and demand （IWSD） and the index of groundwater exploitation potential （P） based on the data about the utilization of surface water and groundwater,the agricultural irrigation, the distribution patterns of local planting industry and the projects of water conservancy facili- ties from 2000 to 2015. The maximal carrying capacity of water resources was further studied using the suitable irri- gation scale. The results indicated that the balance between supply and demand of water resources was relied on the allocation of water resources in the high water years during the period from 2000 to 2015. The most areas of Linze Oasis showed a moderate supply-demand mismatch or the amount of water supply didn＇ t meet the demands except for Liaoquan and Banqiao in P = 50% water warranted efficiency. Shahe and Yanuan were facing the most serious issue of water resource security with the IWSD less than - 0.3. There was a significant water supply deficit in Ping- chuan and its groundwater exploitation has been continuously surpassing the maximal allowable amount.. The bal- ance between water supply and demand in Liyuanhe was squeaked through by increasing groundwater exploitation under the condition of P = 50% water warranted efficiency. The late reforming of water resources management poli- cies and the adjusting of local planting industry as well as the construction of water conservancy facilities has made the water consumption per unit oasis area declined from 1.09 m3 · hm-2 in 2000 to 0.74 m3 ·hm-2in 2015. Al- though the increase of water resources utilization efficiency can help bear an oasis of larger scale, there is a water deficit of 0.65 × 10^8 - 0.98 × 10^8 m3 in order to support the current oasis area. This might be an efficient path to implement a sustainable development as ＂water-eco-economy＂ in the oasis area by appropriately reducing the agri- cultural irrigation area in its marginal transition zones and rationally planning the allocation of water resources in ev- ery irrigation area.