title: Development, testing and application of DrainFlow : A fully distributed integrated surface-subsurface flow model for drainage study

authors: Shokri, Ali

subjects: Science & Technology

abstract: Hydrological and hydrogeological investigation of drained land is a complex and integrated procedure. The scale of drainage studies may vary from a high-resolution small scale project through to comprehensive catchment or regional scale investigations. This wide range of scales and integrated system behaviour poses a significant challenge for the development of suitable drainage models. Toward meeting these requirements, a fully distributed coupled surface-subsurface flow model titled DrainFlow has been developed and is described. DrainFlow includes both the diffusive wave equation for surface flow components (overland flow, open drain, tile drain) and Richard's equation for saturated/unsaturated zones. To overcome the non-linearity problem created from switching between wet and dry boundaries, a smooth transitioning technique is introduced to buffer the model at tile drains and at interfaces between surface and subsurface flow boundaries. This gives a continuous transition between Dirichlet and Neumann boundary conditions. DrainFlow is tested against five well-known integrated surface-subsurface flow benchmarks. DrainFlow as applied to some synthetic drainage study examples is quite flexible for changing all or part of the model dimensions as required by problem complexity, problem scale, and data availability. This flexibility enables DrainFlow to be modified to allow for changes in both scale and boundary conditions, as often encountered in real-world drainage studies. Compared to existing drainage models, DrainFlow has the advantage of estimating actual infiltration directly from the partial differential form of Richard's equation rather than through analytical or empirical infiltration approaches like the Green and Ampt equation.

text: Development, testing and application of DrainFlow : A fully distributed integrated surface-subsurface flow model for drainage study Hydrological and hydrogeological investigation of drained land is a complex and integrated procedure. The scale of drainage studies may vary from a high-resolution small scale project through to comprehensive catchment or regional scale investigations. This wide range of scales and integrated system behaviour poses a significant challenge for the development of suitable drainage models. Toward meeting these requirements, a fully distributed coupled surface-subsurface flow model titled DrainFlow has been developed and is described. DrainFlow includes both the diffusive wave equation for surface flow components (overland flow, open drain, tile drain) and Richard's equation for saturated/unsaturated zones. To overcome the non-linearity problem created from switching between wet and dry boundaries, a smooth transitioning technique is introduced to buffer the model at tile drains and at interfaces between surface and subsurface flow boundaries. This gives a continuous transition between Dirichlet and Neumann boundary conditions. DrainFlow is tested against five well-known integrated surface-subsurface flow benchmarks. DrainFlow as applied to some synthetic drainage study examples is quite flexible for changing all or part of the model dimensions as required by problem complexity, problem scale, and data availability. This flexibility enables DrainFlow to be modified to allow for changes in both scale and boundary conditions, as often encountered in real-world drainage studies. Compared to existing drainage models, DrainFlow has the advantage of estimating actual infiltration directly from the partial differential form of Richard's equation rather than through analytical or empirical infiltration approaches like the Green and Ampt equation.

year: 2016

title: Accidental rightness

authors: van Zyl, Liezl

subjects: accidental rightness

abstract: In this paper I argue that the disagreement between modern moral philosophers and (some) virtue ethicists about whether motive affects rightness is a result of conceptual disagreement, and that when they develop a theory of ‘right action,’ the two parties respond to two very different questions. Whereas virtue ethicists tend to use ‘right’ as interchangeable with ‘good’ or ‘virtuous’ and as implying moral praise, modern moral philosophers use it as roughly equivalent to ‘in accordance with moral obligation.’ One implication of this is that the possibility of an act being right by accident does not pose a problem for consequentialism or deontology. A further implication is that it reveals a shortcoming in virtue ethics, namely that it does not—yet needs to—present an account of moral obligation.

text: Accidental rightness In this paper I argue that the disagreement between modern moral philosophers and (some) virtue ethicists about whether motive affects rightness is a result of conceptual disagreement, and that when they develop a theory of ‘right action,’ the two parties respond to two very different questions. Whereas virtue ethicists tend to use ‘right’ as interchangeable with ‘good’ or ‘virtuous’ and as implying moral praise, modern moral philosophers use it as roughly equivalent to ‘in accordance with moral obligation.’ One implication of this is that the possibility of an act being right by accident does not pose a problem for consequentialism or deontology. A further implication is that it reveals a shortcoming in virtue ethics, namely that it does not—yet needs to—present an account of moral obligation.

year: 2009

title: Military Settlement in the Middle Waikato Basin

authors: Allen, Peter D.H.

abstract: Military settlement formed a brief but distinctive phase in the European occupation of the Middle Waikato Basin. Prior to the 1863 - 1864 Waikato War, few Europeans, other than a small number of missionaries and traders, were settled in the region. The setting of the Middle Waikato Basin was largely unmodified by Man, except along the major rivers where a dense Maori population was settled. 
During the 1850's, the encroachment of European settlers upon Maori tribal lands in many North Island regions, including the Waikato, led to an increase in tension between the two populations and open conflict. This conflict slowed down the progress of colonization in the North Island. To enable colonization to continue in those regions disturbed by Maori unrest, a scheme of military settlement was devised. The aim of this scheme was the formation of compact, self-sufficient defensive settlements to act as a deterrent to Maori unrest. These settlements would also provide an assurance to settlers of security for their life and property.
 Military settlement in the Middle Waikato Basin consisted of two phases. In the first phase, the nodal points of the military settlements, the townships, were established and occupied by the military settlers. In the second phase, farm districts were surveyed around the nodal points and the military settlers moved out from the townships to occupy and develop the land they were allocated. A number of factors, relating to deficiencies in the scheme of military settlement and to the particular problems of settlement in the region, contributed to the failure of the military settlers to successfully establish farms on the land they were allocated. 
The scheme of military settlement largely failed as a method of colonization in the Middle Waikato Basin. However, the pattern of human occupation, established in the initial phase of military settlement, remained when the need for defensive settlements had gone, and forms the basis of the present pattern of settlement.

text: Military Settlement in the Middle Waikato Basin Military settlement formed a brief but distinctive phase in the European occupation of the Middle Waikato Basin. Prior to the 1863 - 1864 Waikato War, few Europeans, other than a small number of missionaries and traders, were settled in the region. The setting of the Middle Waikato Basin was largely unmodified by Man, except along the major rivers where a dense Maori population was settled. 
During the 1850's, the encroachment of European settlers upon Maori tribal lands in many North Island regions, including the Waikato, led to an increase in tension between the two populations and open conflict. This conflict slowed down the progress of colonization in the North Island. To enable colonization to continue in those regions disturbed by Maori unrest, a scheme of military settlement was devised. The aim of this scheme was the formation of compact, self-sufficient defensive settlements to act as a deterrent to Maori unrest. These settlements would also provide an assurance to settlers of security for their life and property.
 Military settlement in the Middle Waikato Basin consisted of two phases. In the first phase, the nodal points of the military settlements, the townships, were established and occupied by the military settlers. In the second phase, farm districts were surveyed around the nodal points and the military settlers moved out from the townships to occupy and develop the land they were allocated. A number of factors, relating to deficiencies in the scheme of military settlement and to the particular problems of settlement in the region, contributed to the failure of the military settlers to successfully establish farms on the land they were allocated. 
The scheme of military settlement largely failed as a method of colonization in the Middle Waikato Basin. However, the pattern of human occupation, established in the initial phase of military settlement, remained when the need for defensive settlements had gone, and forms the basis of the present pattern of settlement.

year: 1969