Basant Maheshwari

River health assessment in peri-urban landscapes: An application of multivariate analysis to identify the key variables

An array of river health assessment approaches and water quality variables have been suggested in the past for assessing the level of river health. However, the selection of suitable variables to be monitored for the assessment remains ambiguous and often it is not practical to monitor all the suggested variables. In this study, we employ a multivariate data reduction technique, called Factor Analysis (FA), to identify the key river health variables for a peri-urban river system, viz., the Hawkesbury-Nepean River system in New South Wales, Australia. Out of 40 water quality variables included in the analysis, the FA identified nine key variables, under three varifactors (VFs), explaining 50% of the variance in the river water quality. Variables in the first, second and third VFs revealed anaerobic conditions, microbial quality and effects of eutrophication in the Hawkesbury-Nepean River. Thus, the present work shows a notable reduction in the number of variables and the application of FA for identification of key variables was found promising. The finding of this study has potential application in designing a cost-effective river health monitoring program by reducing the number of variables to be monitored in a peri-urban situation. It can also assist in partitioning variables according to their unique contribution to the total variance.

MAGNETIC TREATMENT OF IRRIGATION WATER AND SNOW PEA AND CHICKPEA SEEDS ENHANCES EARLY GROWTH AND NUTRIENT CONTENTS OF SEEDLINGS

The effects of magnetic treatment of irrigation water and snow pea (Pisum sativum L var. macrocarpon) and Kabuli chickpea (Cicer arietinum L) seeds on the emergence, early growth and nutrient contents of seedlings were investigated under glasshouse conditions. The treatments included (i) magnetic treatment of irrigation water (MTW), (ii) magnetic treatment of seeds (MTS), (iii) magnetic treatment of irrigation water and seeds (MTWS) and (iv) no magnetic treatment of irrigation water or seeds as control treatment. A magnetic treatment device with two permanent magnets (magnetic induction: 3.5-136 mT) was used for the above treatments. Seeds were sown in washed sand and seedlings were harvested at 20 days. The results showed that MTW led to a significant (P < 0.05) increase in emergence rate index (ERI; 42% for snow pea and 51% for chickpea), shoot dry weight (25% for snow pea and 20% for chickpea) and contents of N, K, Ca, Mg, S, Na, Zn, Fe and Mn in both seedling varieties compared to control seedlings. Likewise, there were significant increases in ERI (33% for snow peas and 37% for chickpea), shoot dry weight (11% for snow pea and 4% for chickpea) and some nutrients of snow pea and chickpea seedlings with MTS in comparison with the controls. The results of this study suggest that both MTW and MTS have the potential to improve the early seedling growth and nutrient contents of seedlings.

Reuse of greywater for irrigation around homes in Australia : understanding community views, issues and practices

We examined peoples views on a number of water issues and their motivation, practices and concerns about greywater reuse for irrigation of around homes. Survey participants (275) from different socio-economic background from 125 suburbs in the Western Sydney region, Australia took part in the study. Regardless of their age and gender, when asked which was the most important issue regarding water in their region from a prescribed list, the majority of participants identified water quality as the most important and availability without water restriction as the least important. About half of the participants reused greywater regularly or at some time during the last few years. The cost of plumbing and health risks to people, plants and soil are critical issues for greywater reuse and need attention. For the reusing widely and sustainably, there is a need for easily accessible, user-friendly information packages to create ‘greywater reuse literacy’ in the community.

Application of the optimization method for estimating infiltration characteristics in furrow irrigation and its comparison with other methods

Abstract The infiltration characteristics of a soil vary spatially and temporally, and due to this the available methods for estimating the characteristics in furrow irrigation are either not suitable or have restrictions for their field use. An optimization method based on the volume balance approach, originally developed for estimating infiltration parameters in border irrigation, and using multiple observations of arrival time of the wetting front was modified for furrow irrigation. The method was applied to 13 irrigation events on furrows monitored on a farm in northern New South Wales, Australia. The soil type at the experimental site has a high clay content (up to 67%) and develops cracks when dry. In addition to the optimization method, one-point and two-point methods using observations of arrival time reported in the literature were also used. The accuracy of different methods was evaluated by comparing the calculated total volume of water infiltrated into the furrow with that observed in the field. The optimization method was the most accurate and the one-point and the two-point were the least accurate among three methods considered in the present study. A possible explanation for a poor performance of the one-point and two-point methods might be related to the assumptions made in the derivation of the methods and the unsuitability of the Philip and the Kostiakov infiltration equations used for the field condition in the present study.

Modelling eutrophication and microbial risks in peri-urban river systems using discriminant function analysis

The methodology currently available to river managers for assessment of river conditions for eutrophication and microbial risks is often time consuming and costly. There is a need for efficient predictive tools based on easily measured variables for implementing appropriate management strategies and providing advice to local river users on river health and associated risks. Using the Hawkesbury-Nepean River system in New South Wales, Australia as case study, a stepwise discriminant function analysis was employed to develop two predictive models, one for river eutrophication risk and the other for microbial risk. The models are intended for a preliminary assessment of a river reach, particularly to assess the level of risk (high or low) for algal bloom and whether the river water is suitable for primary contact activities such as swimming. The input variables for both models included saturated dissolved oxygen and turbidity, while the eutrophication risk model included temperature as an additional variable. When validated with an independent data set, both models predicted the observed risk category accurately in two out of three instances. Since the models developed in this study use only two or three easy-to-measure variables, their application can help in rapid assessment of river conditions, result in potential cost saving in river monitoring programs and assist in providing timely advice to community and other users for a particular aspect of river use.

Options for alternative irrigation water supplies in the Murray–Darling Basin, Australia: a case study of the Shepparton Irrigation Region

Abstract Irrigated agriculture in the Murray–Darling Basin (MDB) currently faces serious challenges due to water scarcity, degradation of water quality, waterlogging and salinity resulting from inappropriate water and land use practices. In particular, there is now increasing risk of water quality degradation due to nutrient rich drainage water in the river system. Therefore, the future of irrigation will depend on the strategies that protect water quality and make best use of water available in the Basin. In this paper, we examine various options that irrigators have to augment water supplies on their farms using the Shepparton Irrigation Region (SIR), Victoria, as a case study. Here, we also discuss the suitability of the ‘Drainage Water Storage Scheme’ (DWSS) in providing additional water supplies to irrigators and in reducing the risk of water quality degradation due to flow of nutrient rich runoff into Basin’s river systems.

Treated effluent and saline water irrigation influences soil properties, yield, water productivity and sodium content of snow peas and celery

To determine the effects of irrigation water quality, plants were irrigated with normal potable water [0.25 dS m−1 electrical conductivity (EC), 25 mg L−1 sodium (Na), 55 mg L−1 chloride (Cl)], treated effluent (0.94 dS m−1 EC, 122 mg L−1 Na, 143 mg L−1 Cl) and saline water with low salinity (1.24 dS m−1 EC, 144 mg L−1 Na and 358 mg L−1 Cl) and high salinity (2.19 dS m−1 EC, 264 mg L −1Na and 662 mg L−1 Cl) for snow peas, and high salinity (3.07 dS m−1 EC, 383 mg L−1 Na and 965 mg L−1 Cl) and very high salinity (5.83 dS m−1 EC, 741 mg L−1 Na and 1876 mg L−1 Cl) for celery. The greater salts build up in the soil and ion toxicity (Cl and Na) with saline water irrigation contributed to significantly greater reduction in root and shoot biomass, water use, yield and water productivity (yield kg kL−1 of water used) of snow peas and celery compared with treated effluent and potable water irrigation. There was 8%, 56% and 74% reduction in celery yield respectively with treated effluent, high salinity and very high salinity saline water irrigation compared with potable water irrigation. The Na concentration in snow peas shoots increased by 54%, 234% and 501% with treated effluent, low and high salinity saline water irrigation. Similarly, the increases in Na concentration in celery shoots were 19%, 35% and 82%. The treated effluent irrigation also resulted in a significant increase in soil EC, nitrogen (N) and phosphorus (P) content compared with potable water irrigation. The heavy metals besides salts build up appears to have contributed to yield reductions with treated effluent irrigation. The study reveals strong implications for the use of saline water and treated effluent for irrigation of snow peas and celery. The salt build up within the root zone and soil environment would be critical in the long-run with the use of saline water and treated effluent for irrigation of crops. To minimize the salinity level in rhizosphere, an alternate irrigation of potable water with treated effluent or low salinity level water may be better option.

Natural spaces : how do they influence stewardship attitudes and actions of university students?

We examined how the background (urban/rural) of 282 tertiary students influenced their attitudes and actions including their use of natural areas. Most considered that protection of natural spaces was ‘important’. Childhood residence influenced time spent in natural areas as young adults. When time spent in natural spaces was compared with residence status, non‐urban dwellers more frequently visited natural areas than urban dwellers. Rural residents who visited natural spaces were likely to visit more frequently than urban dwellers. The different types of passive recreation carried out in natural spaces and whether the student was involved in environmental restoration activities were not matters influenced by residence status, although there was a difference as between passive or active recreation in natural spaces. Over 80% of participants considered that ‘protection of the natural environment’ was more important than the cost of fresh produce, reduced taxes, fuel prices or ‘better use of recycled material’.

Impact of land-use changes and sedimentation on the Muhammad Nur Reservoir, South Kalimantan, Indonesia

The Muhammad Nur Reservoir (MNR) is a major multipurpose reservoir located on the Riam Kanan River in the Indonesian Province of South Kalimantan. The MNR has a high sediment trap efficiency and there is concern that accelerated erosion in the catchment, resulting from inappropriate land use, poses a significant threat to the storage capacity and effective life span of the reservoir. Furthermore, on-going deforestation of large parts of the catchment may have changed the inflow pattern to the reservoir. This paper uses data from fieldwork and published information from different sources to examine the extent of erosion and sedimentation in the catchment and the sediment delivery to the reservoir. Water level variations in the reservoir over a 22-year period are examined for changes that might indicate an alteration of the hydrologic balance in the catchment.

Balanced Urban Development: Options and Strategies for Liveable Cities

A major challenge we face globally is that cities are growing rapidly and most of this growth is inevitably is occurring in peri-urban areas. The concept of balanced urban development is complex and is linked to liveability of urban areas along with water, food and energy security. Increasingly, liveability is becoming important for urban planners and governments at all levels. There are many environmental, economic, political and social challenges if the goals of achieving sustainable, liveable and productive urban regions are to be achieved. The concept of sustainable development and liveable cities symbolise the big visionary ideas for urban planning and balanced development but implementation of these popular visions can encounter a host of confl icts due to a range of interests and stakeholders involved. The process of achieving balanced urban development may require learning from the past successes and mistakes to identify what makes a good practice for balanced urban development and guide local governments, planning agencies and developers to plan and design future cities that are highly liveable. At present there is insuffi cient policy focus on the challenges of the peri-urban areas of growing mega-urban regions around the world, because they are not recognised as an integral part of the functional activities that drive the growth of these urban areas. Thus, policies for peri-urban regions have to be given priority at both national and global levels, if ‘globally just urban places’ are to emerge.