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A conceptual framework for the economic evaluation of water harvestingScrimgeour, Francis Gordon January 1989 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1989. / Includes bibliographical references. / Microfiche. / xiii, 145 leaves, bound ill. (some col.) 29 cm
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An economic evaluation of water harvesting technologyCoupal, Roger H. January 1985 (has links) (PDF)
Thesis (M.S. - Agricultural Economics)--University of Arizona, 1985. / Includes bibliographical references (leaves 95-97).
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Development of computer aided design for the effective design of micro-catchments in arid climatesNoura, Nader January 2002 (has links)
No description available.
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Evaluation of soil moisture in a water harvesting system with supplemental bubbler irrigation systemAchour, Hichem. January 1985 (has links) (PDF)
Thesis (M.S. - Soils, Water and Engineering)--University of Arizona, 1985. / Bibliography; leaves 70-72.
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Simulation of micro catchment water harvesting systemsNamde, Noubassem Nanas,1955- January 1987 (has links)
A mathematical model for personal computers was prepared as a planning tool for development of micro catchment water harvesting systems. It computes runoff from natural or treated catchments, using estimated or actual parameters. The model also computes the water balance of the soil zone in the cultivated area and the water balance of the reservoir system which serves it. The model was calibrated with hydrolologic data and site characteristics for a location near Tucson, Arizona. Its prediction of cotton and grain sorghum yields was comparable to that of Morin (1977). An attempt was made to use weekly or monthly rainfall data for areas where daily data are unavailable. Lack of direct rainfall and runoff durations and infiltration characteristics made this attempt unsuccessful. This option cannot be used with the model in its current form.
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Contour ridge modelling using fuzzy logic and process based approaches for improved rainwater harvestingMhizha, Alexander January 2017 (has links)
A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements of the degree of Doctor of Philosophy.
Johannesburg, February 2017 / Rainwater harvesting is used as a way of improving crop yields in rain fed agriculture by
capturing excess rainfall and storing it in-situ or in reservoirs for use during dry spells.
Contour ridges are one of the many rainwater harvesting technologies that are used
although little is known about their effectiveness. Contour ridges harvest runoff generated
in the cropped field upstream of the ridges.
The traditional contour ridge type in Zimbabwe was introduced by the government in the
1950s to control soil erosion through safely draining away runoff from cropped fields and
is commonly referred to as graded contour (GC) ridges. In the 1990s the country
experienced severe and more frequent droughts leading stakeholders to experiment on
contour ridges that retain the runoff instead of draining it away which are known as dead
level contour (DLC) ridges. There was therefore the need to find out if there are benefits
derived from this change and assess conditions under which benefits would be
experienced. Previous studies have shown that rainwater harvested by contour ridges
can improve water availability in downstream fields. However these studies did not
investigate the conditions under which such benefits are realised. In addition no attempt
to model water harvesting by contour ridges have been made in Zimbabwe while the
contour ridges are widely being used for soil and water conservation. This research
investigated the effect of contour ridges by comparing soil moisture between plots with
DLC and GC ridges using plots with no contours as a control.
Experimental work was carried out in Zhulube, in Matebeleland South Province of
Zimbabwe. Matebeleland South Province falls within the semi-arid area in which rainfall
is characterised by mid-season dry spells leading to frequent crop failure. In addition, the
area often receives high rainfall intensities leading to soil erosion and sedimentation of
rivers. DLC and GC ridges were constructed in farmers’ fields where maize crops were
planted. Soil moisture measurements were done using a micro gopher soil moisture
profiler while runoff plots were used to measure runoff generation. A fuzzy model was
developed using data from this experiment and a previous study in Masvingo Province of
Zimbabwe to simulate runoff generation at field scale while a process based water
balance model was also developed to simulate soil moisture changes within the root zone
of the cropped area.
The results from this study indicate that DLC are effective in clay and loamy soils where
runoff generation is significant and not in sandy soils due to insignificant generation of
runoff under the rainfall regimes of semi-arid areas. Fuzzy logic was found to be a useful
method of incorporating uncertainty in modelling runoff at field scale. A mass water
balance model developed on process based principles was able to model soil moisture
in the root zone reasonably well (NSE =0.55 to 0.66 and PBIAS=-1.3% to 6.1%) and could
help to predict the water dynamics in contour ridged areas as would be required in
determining the suitable dimensions and spacing of contour ridges. Further research is
required to improve the fuzzy component of the model for estimation of runoff when more
data becomes available. In addition experiments to validate methods of estimating macro
pore fluxes and lateral transfer of water from the contour ridge channel to the downslope
field are also recommended. The model structure can be improved by adopting the
representative elementary watershed approaches to include momentum and energy
balances in addition to mass balance that was used in this study. / MT2017
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Altering hydrologic regime to revgetate crusted soils on semiarid rangelandWentz, Amy Leigh 15 November 2004 (has links)
Dysfunctional rangelands lose nutrients and material faster than they capture or create them. The objective of this study was to determine the effectiveness of contour furrows, drill seeding, and aeration treatments in capturing overland flow, concentrating resources, and establishing perennial bunch grasses to convert dysfunctional semiarid rangeland to a functional rangeland. The site, located on the Edwards Plateau in west Texas, USA, had bare, structurally crusted soils with sparse short-grasses (Scleropogon brevifolius). The site had a low infiltration rate contributing to excess overland flow and loss of nutrients, organic matter, and soil. Contour furrows were installed with varying intra-furrow distances (0.6 to 61 m) and then broadcast seeded to determine if furrow spacing would produce a vegetative response. Portions of the intra-furrow areas were aerated and drill seeded. All seed mixes contained warm season, perennial bunch grasses (Bouteloua curtipendula, Leptochloa dubia, and Setaria leucopila). Soil beneath furrows had greater soil water content (p-value < 0.05) than intra-furrow areas. Furrow plots had greater density of seeded grasses and total vegetation (19 individuals m-2 and 191 individuals m-2, respectively) than intra-furrow plots (0 individuals m-2 and 89 individuals m-2, respectively). This study supports other findings that suggest 1.5 m to 1.8 m is optimum intra-furrow spacing. Vegetative responses to drill seeding and aeration treatments were insignificant. Observations suggest that contour furrows are effective at establishment and support of perennial vegetation by capturing and retaining water that otherwise would be lost to runoff from untreated soil.
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Altering hydrologic regime to revgetate crusted soils on semiarid rangelandWentz, Amy Leigh 15 November 2004 (has links)
Dysfunctional rangelands lose nutrients and material faster than they capture or create them. The objective of this study was to determine the effectiveness of contour furrows, drill seeding, and aeration treatments in capturing overland flow, concentrating resources, and establishing perennial bunch grasses to convert dysfunctional semiarid rangeland to a functional rangeland. The site, located on the Edwards Plateau in west Texas, USA, had bare, structurally crusted soils with sparse short-grasses (Scleropogon brevifolius). The site had a low infiltration rate contributing to excess overland flow and loss of nutrients, organic matter, and soil. Contour furrows were installed with varying intra-furrow distances (0.6 to 61 m) and then broadcast seeded to determine if furrow spacing would produce a vegetative response. Portions of the intra-furrow areas were aerated and drill seeded. All seed mixes contained warm season, perennial bunch grasses (Bouteloua curtipendula, Leptochloa dubia, and Setaria leucopila). Soil beneath furrows had greater soil water content (p-value < 0.05) than intra-furrow areas. Furrow plots had greater density of seeded grasses and total vegetation (19 individuals m-2 and 191 individuals m-2, respectively) than intra-furrow plots (0 individuals m-2 and 89 individuals m-2, respectively). This study supports other findings that suggest 1.5 m to 1.8 m is optimum intra-furrow spacing. Vegetative responses to drill seeding and aeration treatments were insignificant. Observations suggest that contour furrows are effective at establishment and support of perennial vegetation by capturing and retaining water that otherwise would be lost to runoff from untreated soil.
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Rainwater harvesting :a sustainable practice for low-income housing in South AfricaEnninful, Josephine Peace 04 February 2014 (has links)
This report gives an overview on issues surrounding sustainable water management practices, specifically, rainwater harvesting (RWH), for low income households in South Africa. The agenda for sustainable development in South Africa has over time, downplayed the importance of Rainwater Harvesting. However, the South African Region is already a water scarce area, experiencing environmental and other threats to its limited water resources such as rapidly increasing demand for water from a growing population and economic sectors.
A purely qualitative research method was used to conduct this Research Report which demonstrated that Rainwater Harvesting across the world can bring immense socio-economic and environmental benefits such as increased food security, improved sanitation and quality of the natural environment. A key question of this Research Report was to establish whether Rainwater Harvesting could be feasible for use in Low-income households in South Africa. This research revealed that the DoH and DWAF can constitute projects for Rainwater Harvesting for Low-income households in their programmes.
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DETERMINATION IN-SITU RUNOFF HARVESTING (IRH) POTENTIAL OF WATERSHEDS IN ARID AND SEMI-ARID AREASGuler Demir (11199066) 29 July 2021 (has links)
<p>Rainwater
harvesting techniques are ancient practices that have been used for many years
by different countries and civilizations. Runoff water harvesting is a
promising technique to collect water and store it effectively in surrounding
plant or crop areas. With global warming and climate change, water availability
and accessibility are becoming even more critical, particularly in arid and
semi-arid areas of the world. Annual rainfall is either scarce or insufficient
to support farming practices in many areas. Thus, it is necessary to capture,
store, and utilize water when it is sufficient for the growing season of
different crops. In this sense, it is also important to evaluate differences in
watersheds in terms of determining where the water flows (runoff areas) and
where it can be collected for in situ use (run on areas). Based on land use,
surface types, land cover, and soil group parameters, the amount of water
changes within a watershed so it is crucial to determine and combine those
factors. The aim of this study is to develop methodologies for determining the
runoff harvesting potential of watersheds in arid and semi-arid areas.
Specifically, to: 1) Identify potential areas for in-situ runoff harvesting
(IRH)within watersheds; and 2) Estimate surface runoff volumes in areas as
identified. The pilot study area for this study is Winters Wash Watershed,
which is a sub-watershed of Centennial Wash located in Arizona (HUC number:
15070104). This watershed serves as a
proxy for arid and semi-arid areas and was selected because it has sufficient
data for the planned analysis. Based on the analysis, <a>17,615
ha (25% of the watershed area) were classified as being suitable or highly suitable
as runoff sources, while 14,092 ha (20% of the watershed area) were better
suited as run on collection areas. Total collectible runoff was determined on
an average annual basis.</a> Finally, recommendations on suitable water
harvesting techniques were made based on land use, soil, surface structure, and
slope in the watershed. The results will provide a methodology for the
decision-making process for identifying both run on and runoff areas and
examples of real practices that could be used in places that are arid and
semi-arid. </p>
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