Maintaining the hyper-arid forests of Abu Dhabi by sustainable irrigation using treated sewage effluent in conjunction with groundwater : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (PhD) in Soil and Environmental Sciences, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| dc.contributor.author | Al Yamani, Wafa | |
| dc.date.accessioned | 2020-04-03T02:41:39Z | |
| dc.date.available | 2020-04-03T02:41:39Z | |
| dc.date.issued | 2019 | |
| dc.description.abstract | The late H.H Sheikh Zayed bin Sultan Al Nahyan, the founding President of the United Arab Emirates sought to ‘green the desert’ through planting of trees. These forests in the hyperarid desert of Abu Dhabi depend on irrigation with groundwater (GW). A wide range of valuable ecosystem services are delivered by the forests. In the 2017 State of the Environment Report, Environment Agency – Abu Dhabi (EAD) noted that “… considerable water resources are required to maintain these forests”. Over-consumption of GW, and the increasing salinity of the aquifers means that the GW of Abu Dhabi is under threat. To manage sustainably the GW resources, in 2016 the government of Abu Dhabi passed Law 5 on GW management and identified the requirement for limits to be placed on GW allocation for vegetation. The means to realise reductions in GW use are: minimised irrigation schedules for GW; and the replacement of GW with treated sewage effluent (TSE). To achieve this, a Government-to-Government partnership was established between EAD and the New Zealand Government. The NZ partners are Maven International and Plant & Food Research. This doctoral research was carried out under this larger partnership. The actual water uses, ETc, of the 3 major forest species of Al Ghaf, Al Sidr and Al Samr were measured by heat-pulse sapflow methods in trees irrigated with either GW or TSE. The impacts on ETc and tree health of the lower salinity TSE are detailed. The complex links between tree water-use, the reference ETo, and trees’ phenology are described. Relationships between the crop factor, Kc (=ETc/ETo), and tree canopy characteristics were inferred using a light-stick to measure the percentage light intercepted by the trees’ canopy. From this research, guidelines have been proposed for Law 5 for the water-allocation limits for these 3 species. These guideline values for GW are based on 1.5 ETc to account for a 25% factor-of-safety, and a 25% salt-leaching fraction. For TSE, there is no need for salt leaching. These recommendations will lead to GW savings of 35-70% compared to current practice. Eventually TSE should replace GW to sustain the forests. | en_US |
| dc.identifier.uri | http://hdl.handle.net/10179/15308 | |
| dc.language.iso | en | en_US |
| dc.rights | The Author | en_US |
| dc.subject | Forests and forestry | en_US |
| dc.subject | United Arab Emirates | en_US |
| dc.subject | Abū Ẓaby (Emirate) | en_US |
| dc.subject | Trees | en_US |
| dc.subject | Irrigation | en_US |
| dc.subject | Sewage irrigation | en_US |
| dc.subject | Groundwater | en_US |
| dc.title | Maintaining the hyper-arid forests of Abu Dhabi by sustainable irrigation using treated sewage effluent in conjunction with groundwater : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (PhD) in Soil and Environmental Sciences, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand | en_US |
| dc.type | Thesis | en_US |
| massey.contributor.author | Al Yamani, Wafa | |
| thesis.degree.discipline | Soil and Environmental Sciences | en_US |
| thesis.degree.level | Doctoral | en_US |
| thesis.degree.name | Doctor of Philosophy (PhD) | en_US |