Modelling the response of vegetation restoration to changes in groundwater level, based on ecologically suitable groundwater depth

Li, Fawen; Wang, Yan; Zhao, Yong; Qiao, Jiale

Modelling the response of vegetation restoration to changes in groundwater level, based on ecologically suitable groundwater depth | Modélisation de la réponse de la restauration de la végétation aux changements du niveau piézométrique, en fonction d’une profondeur écologiquement appropriée de l’eau souterraine Modelado de la respuesta de la restauración de la vegetación a los cambios en el nivel del agua subterránea, en función de una profundidad ecológicamente adecuada del agua subterránea 基于地下水生态水位的植被恢复对地下水水位变化响应模拟 Modelagem da resposta da restauração da vegetação a mudanças no nível da água subterrânea, baseado em uma profundidade das águas subterrâneas ecologicamente adequada

2018

Li, Fawen | Wang, Yan | Zhao, Yong | Qiao, Jiale

Groundwater-level fluctuations at a large scale have a significant effect on the preservation and restoration of vegetation. This study determined suitable groundwater depth within which natural vegetation grows well, and analysed the effect of groundwater regulation on vegetation restoration in Tianjin City, northern China. Normal and lognormal distributions were used to fit the curve of the relation between vegetation and groundwater depth. The groundwater depth range corresponding to the higher frequency of vegetation distribution was regarded as the ‘suitable water depth’ range for vegetation growth. The suitable groundwater depth for shrub growth was 3–5 m and for grass growth 1–3 m. A groundwater flow model predicted the future changes of groundwater depths in the vegetation distribution area under the condition that the current levels of groundwater extraction are maintained. The results showed that there is potential for the extraction of groundwater in shrubland areas, but for grassland areas the water-table elevation showed a downward trend, meaning that water shortages in some areas may be more severe in the future. Finally, based on the current groundwater extraction regime, two regulation schemes were developed: (1) for shrubland, groundwater extraction was reduced by 10% in the ecological water deficit areas, and extraction was increased by 10% in the ecological water surplus and suitable areas, and (2) for grassland, groundwater recharge was increased by the restoration of the wetland areas. In conclusion, the groundwater depths in most of the area would be more suitable for vegetation growth under the regulation schemes.

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