兰州新区人工生态需水类型划分及需水量计算

Division and calculations of the artificial ecological water demand types in the New District of Lanzhou city

研究兰州新区人工生态需水问题,对于指导新区生态建设灌溉实践和水资源的可持续开发利用具有重要意义。以兰州新区人工生态需水为研究对象,采用2016年高分一号遥感影像和ArcGIS 10.2软件,将研究区现状人工生态系统划分成3个大类、13个子类,统计其生态面积数据及绘制空间分布图,并采用不同的定量分析方法,计算出2016年、2020年和2030年生态需水量。结果如下:1)研究区现状年人工生态需水总面积39.55 km2,其中,植被生态需水、人工水体生态需水和城市建设生态需水面积分别为24.57、5.22和9.76 km2,其需水定额分别为675.5、820.3和731.0 mm;2)研究区2016年人工生态需水总量为2801万m3,其中植被生态需水量为1660万m3,人工水体生态需水量为428万m3,城市建设生态需水量为713万m3;3)研究区2020年人工生态需水总量5579万m3,其中,植被生态需水量3330万m3,人工水体生态需水量606万m3,城市建设生态需水量1643万m3;4)2030年研究区人工生态需水总量5844万m3,其中植被生态需水量3520万m3,人工水体生态需水量681万m3,城市建设生态需水量1643万m3。研究结果表明:生态需水面积和生态需水量呈现逐渐增加趋势,相关部门要根据各阶段生态建设的保护目标及不同生态类型的用水特点及权重供给充足的水资源,才能保障生态系统的健康稳定发展。

[Background]The research of ecological water demand is very beneficial for the ecological irrigation practice and sustainable development and utilization of water resources in this region.[Methods]In this paper,the New District of Lanzhou city was taken as the study area,and the current artificial ecosystem of this region was divided into three categories that consisted of 13 sub-items in total through consideration of the similarities of ecosystem functioning and water demand characteristics by employing the ArcGIS 10.2 software technology.The water demand of these three categories in 2016,2020,2030,which included the vegetation,the artificial water body and the ecological type of urban construction,were calculated by utilizing different methodologies,respectively,such as the combination of the Penman-Monteith method and crop coefficients,the recharge and evaporation of water surface,water quota per unit area.The implementations of these calculations are on the basis of several data sources such as remote sensing image,meteorological data and the regional ecological planning,et al.[Results]1)The total area of ecological water demand in 2016 was 39.55 km2,among of which,the ecological water demand of vegetation,artificial water body and urban construction were 24.57 km2,5.22 km2 and 9.76 km2 respectively,the water demand quota were 675.5 mm,820.3 mm,731.0 mm,respectively.2)The total ecological water demand in the study area in 2016 was 28.01×106 m3,including 16.6×106 m3 for vegetation,4.28×106 m3 for artificial water body and 7.13×106 m3 for urban construction.3)The total ecological water demand of the research area in 2020 was 55.79×106 m3,including 33.30×106 m3 for vegetation construction,6.06×106 m3 for artificial water body and 16.43×106 m3 for urban construction.4)The total ecological water demand of the research area in 2030 was 58.44×106 m3,including 35.20×106 m3 for vegetation,6.81×106 m3 for artificial water body and 16.43×106 m3 for urban construction.[Conculsions]The ecological area and water demand are gradually increasing,and the departments should provide sufficient water resources for the artificial ecosystem according to the characters and weights of the water utilization of different ecology types,which can be beneficial for the stable development of ecological system.