Towards an integrated arid zone water management using simulation-based optimisation

For ensuring both optimal sustainable water resources management and long-term planning in a changing arid environment, we propose an integrated Assessment-, Prognoses-, Planning- and Management tool (APPM). The new APPM integrates the complex interactions of the strongly nonlinear meteorological, hydrological and agricultural phenomena, considering the socio-economic aspects. It aims at achieving best possible solutions for water allocation, groundwater storage and withdrawals including saline water management together with a substantial increase of the water use efficiency employing novel optimisation strategies for irrigation control and scheduling. To obtain a robust and fast operation of the water management system, it unites process modeling with artificial intelligence tools and evolutionary optimisation techniques for managing both water quality and quantity. We demonstrate some key components of our methodology by an exemplary application to the south Al-Batinah region in the Sultanate of Oman which is affected by saltwater intrusion into a coastal aquifer due to excessive groundwater withdrawal for irrigated agriculture. We show the effectiveness and functionality of a new simulation-based water management system for the optimisation and evaluation of different irrigation practices, crop pattern and resulting abstraction scenarios. The results of several optimisation runs indicate that due to contradicting objectives, such as profit-oriented agriculture versus aquifer sustainability only a multi-objective optimisation can provide sustainable solutions for the management of the water resources in respect of the environment as well as the socio-economic development.     

Petrographic and geochemical characteristics of iron-rich rocks and their significance in exploration for massive sulfide deposits, Bathurst, New Brunswick, Canada

About 25 economically significant, Kuroko-type massive sulfide bodies lie in a metamorphosed volcano-sedimentary complex (probable Middle Ordovician) known as Tetagouche Group, in Bathurst area, New Brunswick. Despite unresolved structural complexities, it does appear that they were deposited during a particular phase of volcanic activity and are, therefore, contemporaneous. Most of the sulfide bodies are closely associated with iron-rich rocks representing various facies of iron formation, and together with sulfides it constitutes the “ore horizon‘ which, therefore, is highly magnetic. Aero-magnetic and ground-magnetic techniques are useful to locate the ore horizon but problems are created because of the occurrence of iron-rich rocks with no sulfide, along another horizon in the Tetagouche Group.Petrographic and geochemical characteristics of various types of iron-rich rocks have been studied to see if the iron-rich rocks of the ore horizon can be distinguished from the iron-rich rocks of the other horizon. The iron-rich rocks found in the Tetagouche Group can be classified into five types: (1) cherty magnetitic rocks; (2) iron-rich chloritic rocks; (3) sideritic rocks; (4) basic iron formation; and (5) maroon shale. The basic iron formation, which is quite magnetic, gives a false indication of the ore horizon wherein the presence of any of the first three types of rocks is expected. Moreover, the basic iron formation is generally similar in appearance and mineralogy to some of the cherty magnetitic and chloritic rocks.Regarding major element composition, TiO₂, Na₂O, Al₂O₃ and CaO are higher whereas Fe₂O₃, FeO and MnO are lower in the basic iron formation than in the other iron-rich rocks. These geochemical characteristics can help distinguish the barren rocks of the basic iron formation from those of the ore horizon during the exploration programs.     

Acetylcholinesterase,glutathione and hepatosomatic index as potential biomarkers of sewage pollution and depuration in fish

The current study was designed to validate the biomarkers of sewage pollution in Mozambique Tilapia (Tilapia mossambica, Peters) reared in sewage treatment plant (STP) effluent in Ras Al Khaimah, United Arab Emerates, before and following depuration/detoxification. Cellular biomarkers, cholinesterase activity using acetylcholine as a substrate (acetylcholinesterase AChE) and reduced glutathione (GSH) and hepatosomatic index (HSI) were investigated in fresh water fish, Tilapia, raised in a fish farm (Group I/Clean, as Control), treated sewage water/TSW (Group II/Sewage) and thereafter exposed to fresh water in an aquarium for 6 weeks (Group III/Depurated) for depuration. The results showed significantly lower levels of AChE activities in liver (26% p < 0.01) and muscle (30% p < 0.01) of the fish reared in the STP water (Group II/Sewage) as compared to those recorded in the fish from fish farm (Group I/Clean). The depressed AChE level was fully restored in the muscle but partially in the liver after depuration (Group III/Depurated). In contrast, GSH levels were significantly raised in both liver (1.3-fold p < 0.01) and muscle (4-fold) of Group II fish as compared to Group I (control) fish raised in fish farm and following depuration in fresh water (Group III/Depurated) elevated GSH level in liver restored to control values, while remained unchanged in muscle. The average hepatosomatic index (HSI = weight of liver × 100/total fish weight), an indicator of hepatomegaly, in the Group II fish reared in TSW was also significantly higher than that in the reference Group I fish, but decreased to control level in Group III fish following depuration. This study suggests the importance of cellular biomarkers, AChE, GSH and hepatosomatic index in monitoring the impact of sewage water pollution on fish caused by a complex mixture of chemico-biological contaminants and its mitigation following depuration, an effective mean of fish detoxification.     

Addition of Phosphorus and Nitrogen Support the Invasiveness of Alternanthera Philoxeroides Under Water Stress

Coordination of plant functional traits with changes in the environment is helpful to understand the mechanisms underlying both invasiveness and adaptation of plants. Thus, to investigate the performance and functional traits in invasive Alternanthera philoxeroides (Mart.), an experiment of water stress is conducted with different nutrient concentrations. Alternanthera philoxeroides plants are grown under natural and nutrient soils and subjected to three levels of nitrogen (N) and phosphorus (P) solution: ambient P and N concentration (P?N?), P addition with an ambient N concentration (P+N?), and P addition with high N concentration (P+N+) in combination with three different irrigation water levels as 1) 100% irrigation, 2) 50% irrigation, and 3) 25% deficit irrigation. Based on results, A. philoxeroides produces significantly higher biomass in both soils under 100% irrigation with P+N? treatment and exhibits higher values of leaf area and root length. However, 25% irrigation with P?N? treatment in both soils exerts a significant negative effect on relative growth rate and root/shoot ratio of A. philoxeroides plants. Under 50% irrigation in soils with both P+N? and P+N+ treatments, high values of leaf nitrogen are recorded. Moreover, nutrient soil is more supportive to A. philoxeroides than natural soil.     

Seismic settlement of a strip foundation resting on a dry sand

Natural Hazards - Seismic settlement of shallow foundations constructed in seismic active areas should be considered for a reasonable estimation of the total settlement. However, the trend of the...