为了解研究区生态功能区内生态需水的分布特征,明确区域水土资源利用方向和生态整治重点,以关中—天水区为对象,将RS和GIS技术结合,完成其生态功能区划指标体系的建立与功能区划分,利用植被和土壤生态需水测评模型对该地区植被—土壤复合系统生态需水量和空间分布规律进行计算和分析,并借助CA-Markov模型对各生态功能区2020年、2025年的单位面积生态需水进行了模拟预测。结果 表明:关中—天水区生态环境功能区可划分为河道保护区、防旱抗旱区、农业种植区、植被保护区、水源涵养区和古城保护区6类; 林地—黏壤土的生态需水最大,约为659.60 mm,草地—砂砾质壤土的生态需水最低,约为366.34 mm,极差为293.26 mm; 功能区内林地、耕地、草地分布范围越广,生态需水量越大,其中单位面积生态需水量最小的为古城保护区,生态需水总量最小的为河道保护区; 预测结果显示,2015年、2025年单位面积生态需水量最大的为植被保护区,2020年则为水源涵养区,而各年份生态需水总量最大的均为植被保护区。研究表明生态需水与土地利用方式和生态功能分区关系密切。
In order to understand the distribution characteristics of ecological water demand in the ecological function area of the study area, to clarify the direction of regional water and soil resources utilization and the key points of ecological improvement, Guanzhong—Tianshui area was taken as the research object, the ‘RS' and ‘GIS' technology were used to complete the establishment of its ecological function division index system and functional area division. Then, evaluation ecological water requirement and spatial distribution characteristics of vegetation-soil complex system in the study area were analyzed by using vegetation ecological water demand assessment model and soil ecological water demand assessment model, the spatial distribution of land use in the study area in 2020 and 2025 was simulated and predicted by using CA-Markov model, on this basis, the ecological water demand of each ecological function area in 2020 and 2025 was measured and analyzed. The results showed that the eco-environmental functional areas in Guanzhong—Tianshui area could be divided into river protection area, drought and drought-resistant area, agricultural planting area, vegetation protection area, water conservation area, ancient city protection area; on the landscape scale, the ecological water requirement per unit area of woodland-clay loam was the largest, about 659.60 mm, the ecological water requirement per unit area of grassland-gravel loam was the lowest, about 366.34 mm, the difference between the maximum value and the lowest value was about 293.26 mm; on the scale of eco-environmental function zoning, the wider the distribution of forest land, cultivated land, and grassland in the functional area, the greater the ecological water demand, among which the smallest ecological water requirement per unit area is the ancient city protection area, and the smallest total ecological water demand is the river protection area; the largest ecological water requirement per unit area is the vegetation protection area in 2015 and 2025, the largest ecological water demand per unit area in 2020 is the water conservation area, and the largest total ecological water demand in each evaluation year is the vegetation protection area. This study shows that ecological water demand is closely related to land use patterns and ecological function zoning.
