ROBUST HYDROLOGIC MODELLING FOR LAND AND WATER MANAGEMENT IN DATA-SCARCE ENVIRONMENTS

Tarawneh, E (2017) ROBUST HYDROLOGIC MODELLING FOR LAND AND WATER MANAGEMENT IN DATA-SCARCE ENVIRONMENTS. PhD thesis, University of Liverpool.

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Abstract

This study proposes a pre-calibration approach using the Soil and Water Assessment Tool (SWAT) to quantitatively assess variability in model performance derived from input data sources in data-scarce dryland environment (the Wala catchment, Jordan 1743 km2). Eighteen scenarios combining different local and global land-use, soil and weather datasets (1979 - 2002) are constructed. Model outputs are statistically assessed against observed discharge and empirically-derived sediment load using r2, Nash-Sutcliffe efficiency (NSE), root mean square error standard deviation ratio (RSR) and percent bias (PBIAS). Global reanalysis weather data considerably improve model performance over discontinuous local datasets, while detailed local soil data perform significantly better than global maps. The approach presented aids selection of the most robust input datasets in regions where availability and quality of data are questionable. Attempting to rationalise modelling in data-poor regions, the catchment delineation produced by the SWAT model is used to design field sampling in October 2013 of channel bed sediments and reservoir sediment cores to investigate potential relationships via geochemical analysis and provide measured sediment information that may interpret model prediction. XRF and particle size analyses were performed on all samples and the data analysed in respect of geochemical signatures. No strong evidence of discrete event-driven deposition is detected, likely due to alternating high-flood and drought periods. Variations in pollutants geochemistry are consistent with land-use pattern with relatively higher levels of Pb, Co, Cu and Cr associated with urbanised regions. Although these concentrations are mostly below thresholds for health concern, higher water and sediment loadings from these regions, as estimated by the model, may increase them. Hence, future management of water quality must be considered. The optimised and calibrated SWAT model is used to assess hypothetical and object-based integrated catchment management interventions and their implications for the useable lifetime of the Wala Dam within the context of the UN-funded BRP Project. The modelled catchment response to different scenarios varies spatially based on type and extent of application. Changes in annual loadings delivered to the Wala reservoir are linked to a simple model of dam functional lifetime to support decision-making.

Item Type:	Thesis (PhD)
Divisions:	Faculty of Science and Engineering > School of Engineering
Depositing User:	Symplectic Admin
Date Deposited:	19 Dec 2017 08:47
Last Modified:	19 Jan 2023 06:50
DOI:	10.17638/03012299
Supervisors:	Bridge, J Macdonald, N ORCID: 0000-0003-0350-7096
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3012299