Textile industries use large amounts of water in their production processes, with subsequent generation of large quantities of wastewater. With ineffective and/or inefficient water management protocols in place, these industries can have a large negative impact on the environment. In order to assist in the development/setting of suitable actions to negate environmental impacts from textile industries, it is essential that some form of water management, and more particularly a water balance, be in place. This dissertation investigated the current practices at a textile industry in Lesotho, CGM Industrial, as a case study with the ultimate objective to assess and present suitable water management actions to negate the company’s negative impact on the environment. An active water balance was compiled for one of the company’s factories, CGM 1, and illustrated that large volumes of water (up to 0,9 Ml/day) are discharged to the natural water course, often untreated. The water balance specifically addresses water usage for the four wet processing combinations present at CGM 1, and representative of the textile industry as a whole, namely stone washing/washing, stone washing/bleaching, stone washing/dyeing and stone washing/bleaching/dyeing operations. Based on the water balance results and general assessment of operating practices in place at CGM 1, suitable water management actions were recommended for reducing wastewater volumes, substitution and reduction of process chemicals, and investigating process modifications. / Dissertation (MSc (Environmental Technology))--University of Pretoria, 2008. / Chemical Engineering / unrestricted

Soil Water Balance (SWB) is a generic crop growth and irrigation-scheduling model. It improves on traditional methods of irrigation scheduling using evaporative demand by mechanistically and dynamically, quantitatively considering the soil–plant-atmosphere continuum. However, it needs specific crop growth parameters, which are not readily available for canola. The objective of this study was to determine crop growth parameters specific to canola and to identify the effect of water stress at different stages of growth on seed and oil yield. The study was conducted on the experimental farm of the University of Pretoria, South Africa, under a rain shelter during 2002 and in an open field during 2003. Weather data were recorded with an automatic weather station, phenological stages monitored frequently and growth analyses carried out every two weeks. Soil water content was measured with a neutron water meter weekly during 2002 and once every five days during 2003. Fractional interception of PAR was also measured with a sunfleck ceptometer. Specific crop parameters including specific leaf area, the leaf stem partitioning parameter, maximum rooting depth and thermal time requirements for crop development were generated from field measurements. These data form the backbone for accurate mechanistic simulations of the soil-water balance. The model was successfully calibrated and evaluated, proving its potential to be used as a generic crop irrigation-scheduling tool. Highest seed and oil yield was harvested from the unstressed treatment and lowest from the treatment stressed during the flowering stage. / Dissertation (MSc (Agric))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

The future projection of climate change suggests the strong need of improved systems to the re-source management systems. In Syria, the current water resource management systems are weak, and the country has no resilience to the scarcity of water resources in the region. In 2007 a drought has crippled the Syrian economy and impacted the life of millions of Syrian People, the devastating occurrence of the drought had larger impacts due to the lack of water resource management sys-tems and irresponsibility of use. This study investigates the current management systems that Syria has, and the supply and demand of the country, of which is aimed for with the term (water balance) that refer to the flow of water in and out of the system. Furthermore, a constructed wetland design is introduced as a system to treat municipal wastewater of the town Al-Haffah, located east of Latakia city of which is situated at the Mediterranean coast, on the Costal basin. All the data avail-able relevant to the investigation has been used in the case study, nevertheless some assumptions has been made due to lack of available data. The introduced system is later evaluated in regards of water need for agricultural purposes in Al-Haffah. The design with the assumed current value, in worst case scenario could save annually (48.57%) of the groundwater abstraction for agricultural purposes, Or (29.14%) of the total water demand for the agricultural practices in Al-Haffah. Whilst, in best case scenario, if two third of the required water for agriculture is met with rainfall the system saves (145.7%) of the assumed groundwater abstraction, Or (87.43%) of the total an-nual required water. / <p>2020-06-05</p>

<p> Soil moisture is at the centre of the water balance and is of great concern with regards to crop growth and yield, irrigation planning, fertilization, climate change and non-point source pollution control. Information on soil moisture is not widely available, resulting in researchers relying on mathematical models to gain insight into soil moisture conditions. This thesis primarily focuses on long-term soil moisture characteristics, under given climate, soil and vegetation conditions. Long-term soil moisture characteristics are best described by statistics such as average soil moisture, and its standard deviation and frequency/probability distribution. After an extensive review of existing explicit or implicit soil moisture models, a deterministic water balance model was developed to simulate soil moisture at a point within the root-zone. The hydrological processes involved in the water balance are modelled using well-established methods. The continuous simulation model is unique from other leading deterministic models as it introduces the ecohydrological perspective by modelling actual evapotranspiration as a function of plant access to soil moisture. The validation of the model demonstrates that simplified soil moisture modelling is rational and practical.</p> <p> Soil moisture modelling is dependent on various input parameters related to the climate, soil and vegetation. Both local and global sensitivity analyses were carried out to investigate which input parameters influence the soil moisture regime the most. The analyses concluded that parameters representing soil texture are most important and thereby indicated that evapotranspiration is the most dominant process as it is significantly controlled by these parameters. Due to concerns of the impact of climate change and urban stormwater management, a better understanding of urban area soil moisture dynamics is required. The applicability of the continuous simulation model was demonstrated by investigating the influence of global warming on long-term soil moisture and evapotranspiration. Statistical analyses carried out on the post-simulated long-term soil moisture values clearly showed that even though temperatures are increasing, soil moisture and evapotranspiration have also increased because of the overall increase in precipitation. This phenomenon gives insight into the precipitation characteristics being strong enough to overpower the soil moisture loss process of evapotranspiration. As a part of the overall research, an analysis on antecedent soil moisture values for the purpose of urban stormwater management was performed. Empirical equations were derived to obtain antecedent soil moisture values from soil characteristics. Antecedent soil moisture information is essential in the application of the design storm approach while designing urban stormwater management infrastructure.</p> <p> The main purpose for the development and use of the deterministic model was to better understand the statistics and sensitivity of soil moisture and not as a predictive tool.</p> / Thesis / Doctor of Philosophy (PhD)

No description available.

Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1982. / Includes bibliographical references (leaves 94-96).

There are many different controlling factors on the partitioning of rainfall into runoff. However, the influence of each of these controls varies across different temporal scales. Consequently, numerous water balance models have been developed in the literature for application across various time scales. These models are usually developed for a particular time scale so that the controls with the greatest influence on rainfall partitioning are captured. For example, the SCS curve number method was developed to simulate direct runoff at the event scale; the "abcd" model was developed as a monthly water balance model; and the Budyko model was developed for long-term water balance. More recently, the proportionality hypothesis, which traces its origins from the SCS curve number method, has been identified as the commonality between these three hydrologic models, suggesting that this hypothesis may be the unifying principle of hydrologic models across various time scales. The objective of this thesis is to develop a conceptual hydrologic model structure for continuous simulations for multiple time scales. The developed model is applicable to daily, monthly, and annual time scales. Direct runoff is computed by a proportionality relationship in the SCS curve number method. In the "abcd" model, evapotranspiration and storage at the end of each time period are computed by a proportionality relationship, however evapotranspiration is computed based on an exponential relationship of storage and potential evapotranspiration while base flow is computed based on a linear reservoir model. In the Budyko model, runoff and evapotranspiration are computed by a proportionality relationship. The primary difference with the proposed model in this thesis in comparison with the other three water balance models is the application of the proportionality hypothesis to the partitioning of surface runoff and continuing abstraction as well as the partitioning of continuing evapotranspiration and subsurface flow. The proposed model structure is implemented in Matlab. The developed model includes six parameters, which are estimated for 71 case study catchments in the United States using a genetic algorithm. The model performances at the daily, monthly and annual time scales are evaluated during calibration and validation periods, and compared with the "abcd" model and a Budyko-type model developed for multiple time scales. Evaluation of the models shows that the proposed model performs better or comparable to the other models at all time scales.

Clean water has become a scarce and pricey commodity. Companies, governments and the public are realising more and more the importance of efficient and effective water use and the conservation of South Africa’s natural water resources. Governments are implementing conservation and usage laws while companies are trying to get as much use out of their water while staying within the law. This dissertation focusses on the potable water measuring and billing practices taking place on the SASOL 1 site. A field study, interviews and questionnaires were used to gather the relevant data which was subsequently compiled into a Stakeholder Requirement Statement. The latter is a description of the ideal system that would meet all the requirements for measuring potable water and billing customers on the SASOL 1 site. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014

Clean water has become a scarce and pricey commodity. Companies, governments and the public are realising more and more the importance of efficient and effective water use and the conservation of South Africa’s natural water resources. Governments are implementing conservation and usage laws while companies are trying to get as much use out of their water while staying within the law. This dissertation focusses on the potable water measuring and billing practices taking place on the SASOL 1 site. A field study, interviews and questionnaires were used to gather the relevant data which was subsequently compiled into a Stakeholder Requirement Statement. The latter is a description of the ideal system that would meet all the requirements for measuring potable water and billing customers on the SASOL 1 site. / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014

A simple water balance model was applied to a micro-catchment water harvesting system for a semi-arid area in the North-Eastern part of Jordan. Two Negarim micro-catchment water harvesting systems were built at Al-Khanasri research station. A Randomized complete block design (RCBD) in factorial combination was used with six treatments and three replicates. Each plot was divided into two parts; a runoff area, and a run-on area. Two different treatments were used for the catchment area, these were: compacted (T1) and Natural treatments (T2). Three treatments were used for the run-on area, these were: disturbed (S1), stones (S2), and crop residue mulch (S3). Soil water content was measured over a depth of 0-1 m during the seasons 96-97 in these micro-catchments. In this model; daily rainfall, runoff, and evaporation were used. Runoff was calculated by the curve number method; evaporation was calculated by the Penman equation, the Priestley and Taylor method and the Class A pan approach. The least squares method was used for optimizing model parameters. The performance of the model was assessed by different criteria, such as root mean square error, relative root mean square error, coefficient of determination and the Nash-Sutcliffe efficiency method. The performance of the micro-catchments system was also evaluated. Results showed that with limited but reliable hydrological data good agreement between predicted and observed values could be obtained. The ratio of water storage in a one meter soil depth to the rainfall falling on each catchment indicated that T1S2 and T1S3 have the highest values in size1 plots while T2S1 and T2S2 have the highest values in size 2 plots. Modelling results showed that for all the size 1 plots, the required ratio of the cultivated to catchment area, (C/CA), required to ensure sufficient harvested water, was less than the actual ratio used in the experimental design. For the size 2 plots this was only true for the T1 treatments. Consequently for the majority of plot sizes and treatments, the results showed that a smaller catchment area is capable of providing sufficient harvested water to meet crop growth requirements. The experimental ratio was based on a typical yearly design rainfall for the region having either a 50% or 67% probability of occurrence. Results also indicated that using stones and crop residue as mulch on the soil surface in the cultivated area was effective in decreasing the evaporation rate. S3 was more efficient than S2 as it stored more water due to the higher infiltration rate (12.4 cm/hr) when compared to S2 (4.1 cm/hr).