No abstract

Irrigation continues to be the main water user on a global scale despite the increase in water use by sectors other than agriculture. More efficient water application technologies and water management practices are ways of realising potential water savings, thus moderating the negative impacts of higher water use on farm incomes and environmental impact on rivers and groundwater systems. This paper describes an integrated approach of agro-hydrological modelling for determining potential water savings achievable by adopting high-tech irrigation technologies at farm level and application of GIS techniques to upscale those benefits at the regional irrigation system level. The SWAP (Soil-Water-Atmosphere-Plant) model was used for the simulation of water use at the farm level. The results are promising, as the potential water saving ranges from 0.1 to 2.2 ML ha À1 (10-220 mm) for different broad-acre crops, 1.0 to 2.0 ML ha À1 (100-200 mm) in sprinkler and 2.0 to 3.0 ML ha À1 (200-300 mm) in drip irrigation for citrus, 1.0 to 1.5 ML ha À1 (100-150 mm) in sprinkler and up to 4.0 ML ha À1 (400 mm) in drip irrigation for vineyards and 0.5 to 1.0 ML ha À1 for vegetables (50-100 mm). SWAP simulations show crop water saving potential of 7% for maize, 15% for soybean, 17% for wheat, 35% for barley, 17% for sunflower and 38% for fababean from the current water use statistics in Australia. Spatial analysis in GIS environment is carried out to investigate the spatial variations of water use for a particular crop under different depths to water table and varying soil types. Maps of water need for all broad-acre crops are drawn and pixel-to-pixel comparison is performed to determine the water saving potential per unit area. The upscaling approach shows that considerable water amounts could be saved both in Murrumbidgee Irrigation Area (MIA) and Coleambally Irrigation Area (CIA) with potential water saving of 36 to 95 GL (MCM) in MIA and 42 to 72 GL (MCM) in CIA.

The Islamic museumwaserectedin1896.The buildingis situatedin theheart of Cairo (capitalof Egypt) and holdsmarvellous Islamic antiquities and priceless ancient hand-writing andrare books.Recently, a restoration scheme has been planned to secure the old building which suffers from weakened foundations.In addition, the wooden roofs will be replaced by concrete ones and an extra floor will be integrated into the building.Unfortunately, the architecture construction charts were neither available nor obtainable.Therefore, the structure of the foundations and the base walls of the building had to be outlined. At the time of construction, three major fundamental wall designs were dominant and were to be considered during the work approach. Ground-penetrating radar (GPR) and dipole^dipole resistivity imaging have been integrated to (define the structure of the foundation walls ofthe building. A Ramac2 system connected to a 500 MHz antenna has been utilized for conducting the GPR survey. In addition, a Terrameter SAS 1000 single channel device has been used for performing the resistivity profiles. At accessible spaces around the building GPR and resistivity profiles were obtained. The GPR analysis has revealed the depth of the foundation walls to be about 0.9 m from the ground surface with a width close to 0.6 m.The wall design is close to a straight wall style.Furthermore, the analysis ofthe dipole^dipole resistivity measurements has matched the geology of the area, where subsoil anomalies may be due to the scattered limestone blocks that occur in the area. Moreover, the foundation walls have resistivity values that fall into the range of fractured limestone or limestone blocks. A step-wise or inclined foundation wall style hasnot beenindicatedthroughtheparallelresistivityprofiles

This paper investigates a range of water savings options at irrigation system level and ranks these options according to the potential savings of each option and the economic return in terms of water saved (ML -megalitres) for each dollar invested. Most of the work was conducted on large-area farms of the Murrumbidgee Irrigation Area (MIA) and Coleambally Irrigation Area (CIA) in the Murrumbidgee River catchment, New South Wales, Australia. Field-based on-farm water savings for scenarios analysed ranged from 0.1 ML ha À1 up to 3.9 ML ha À1(10-390 mm). As capital can be a limiting resource to farmers, options that have the lowest cost per ML saved may be more appealing than options that have a higher cost but may also have higher net benefits over time. The water savings that derived the highest net benefit per megalitre saved were conversion to drip and subsurface drip for the case study farms and laser levelling which had net benefits ranging from A$ 1 64 to A$ 344 ML À1 saved per year. All of the other options had net benefits ranging from A$ 4 to A$ 37 ML À1 saved per year. All of the options that had a low annualised cost also had a relatively low net benefit (less than A$ 24 ML À1 saved per year). Marginal costs of off-farm water savings increase with the volume of water saved. In the MIA up to 20 GL ( souterraine pour les exploitations étudiées, ainsi que le planage au laser qui a rapporté de 64 à 344 AUD (dollar australien) par ML économisé par an. Toutes les autres options ont eu des bénéfices nets compris entre 4 et 37 AUD par ML économisé par an. Toutes les options qui avaient un coût annualisé faible ont aussi eu un bénéfice net relativement bas (moins de 24 AUD par ML par an). Les coûts marginaux de l'économie d'eau hors exploitation augmentent avec le volume d'eau économisé. Dans le MIA, un potentiel d'économie d'eau pouvant aller jusqu'à 20 GL (1 Giga Litre ¼ 1 MCM ou million de mètre cube) est possible à un coût marginal du capital de 1500 à 2000 AUD ML À1 . Ce coût augmente ensuite rapidement jusqu'à 4000 AUD ML À1 pour environ 38 GL, reflétant ainsi la tendance des coûts à augmenter pour des volumes inférieurs économisés.