Resource information
Flooding regimes in arid and semi-arid regions are heavily influenced by climate change and water shortage, water regulations, and increased water demands. Wetlands managed as part of regulated water systems in agricultural landscapes often require external water supplies to sustain or support desired properties or services. Therefore, water resource managers must weigh water requirements necessary to support wetland functions alongside other water demands. This paper presents a simple method of using a modified climate diagram to display net water requirements for a managed wetland in Xi'an, China. The net water requirements were estimated using the DRAINMOD simulation model by assuming that evaporation is the only path for water loss. For this case study, the ratio of water supply to air temperature was adjusted to 1:1. Three water supply estimates were generated to support a desired water table depth of 30cm for 5%, 12.5%, and 25% of the growing season in Xi'an. When water supply reaches or exceeds a curve, it creates a wetter condition than that represented by the curve. The results also indicate that timing of recharge is very important in preserving wetland hydrology in dry regions. This modified climate diagram prompts an intuitive understanding of the relationship between recharge and consequent wetness of a wetland. It may be used as a standard tool for determining adequate water demand in arid regional water resources management that considers wetland protection or restoration.
