塔里木河下游地下水抬升的地表植被恢复价值初探

Ecological-economic values of the natural vegetation restoration after groundwater elevation at the lower reaches of the Tarim River

基于塔里木河下游生态输水前后地下水动态变化和地表植被响应的长期监测资料,以输水后地下水动态变化引起的地表植被生物量差异为出发点,借鉴国内外生态经济价值量化的计算方法,从地表植被响应的生态经济价值和地下水抬升的潜在恢复价值来计算生态输水后植被恢复的地表生态经济价值。目的是为量化生态输水工程的恢复效益提供理论依据。结果显示:在塔里木河下游典型的考干断面,垂直河道方向为长的2 000 m、平行河道方向为宽的100 m的样带内,地下水位出现了明显的抬升,水位抬升幅度以河道为中心由近到远逐渐降低,这点突出地反映在以柽柳灌丛为主的地表生物量的明显变化上。根据5年的河道区间耗水量资料,计算出该区间100 m宽的样带因输水而投入的水资源价值为0.65×104元,而输水后从地表植被生物量变化引起的地表生态响应价值为1.119×104元,投入产出比为1?1.72;地下水抬升的潜在经济价值是3.741×104元,总的投入产出比为:1?7.477,表明输水有显著的生态效益。

Based on the long-term monitoring data of the groundwater dynamic change and the natural vegetative responses before and after ecological transpotation to the lower reaches of the Tarim River, the differences are considered on aboveground vegetation biomass caused by the groundwater change after ecological water transportation. By means of the methods of quantifying ecological-economic values, the purpose of the paper is to calculate the ecologi- cal-economic value of aboveground vegetation restoration which is composed of both the potential values of groundwater elevation and ecological economic values of vegetative responses after ecological water transportation. The study aims to provide theoretic reference for quantifying the restoration benefits of the ecological water transportation project. The result shows that in the Kaogan section （a typical section with a belt of 100 m wide and 2000 m long） at the lower reaches of the Tarim River, the groundwater level increases significantly. The groundwater elevation degree is reduced gradually from the water channel center to both sides of channel. This change characteristic is prominently reflected by the change of above-ground biomass of Tamarix shrubs. According to the five years data of water consumption in the certain range of the water channel, the paper calculates that the total input value of water resource in the belt sample is 0.65 × 10^4 yuan, while the ecological response value caused by the changes of aboveground vegetation biomass after the watering is 1. 119 × 10^4 Yuan, and the input-output ratio isl ：1.72. The potential ecological economic value of the groundwater elevation is 3. 741 × 10^4 Yuan, and the total input-output ratio isl ：7. 477. These results indicate that the ecological-economic benefits of the water transportation project are significant.