3.2 Learning by experience It's a familiar idea but it implies two activities: learning and experiencing. Both activities need to happen if I am to say that learning from experience has happened. Experiencing seems to have two components. The first is the quality of attention that allows me to notice the experience and its components. The second is memory. Calling experience to mind allows me to examine the experience and to think about it in ways that were not possible at the time. Learning is what I take away from th
3.1 What are you hoping to learn? Anticipations and preconceptions are an important determinant of how people learn, so before you read on, I would like to you to record some of what you are experiencing now as you begin the course. It's important to get these impressions noted down now, because new ideas and new impressions will quickly overlay the experience. What you are experiencing now will be re-interpreted as new understandings emerge. You are also likely to form some judgements about your expectations. So before
2 Part 1 Starting the unit Welcome to T306_2 Managing complexity: a systems approach – introduction. As I write, I experience a sense of excitement. For me, as for you, this is the beginning of the unit. These are the first few sentences I'm writing and so, although I have a good idea of how the unit is going to turn out, the details are by no means clear. Nevertheless, the excitement and anticipation I, and maybe you, are experiencing now is an important ingredient in what will become our experiences of the u
7 Ergonomics and human factors This section discusses designing for human capabilities and limitations. It introduces the study of ergonomics which can offer general guidelines as well as specific suggestions for good, user-centred product design. Taking the user as the central point of reference for the design and evaluation of products is the approach encouraged by ergonomists. The field of ergonomics (also known as human factors engineering) is the systematic study of human capabilities, limitations and requ
3.3.1 Turbidity, colour and suspended solids As water runs off the land, there are some substances which do not dissolve but are taken along as
suspended solids. Then, depending on their sizes and the velocity of the river, the solid particles may settle out at a certain point or be carried on further. Quantities are affected by seasonal changes and tend to be higher in winter because of increased storm
runoff
due to higher rainfall and melting snow. The quantity of suspended solids (measured in g m<
3.1 Water, the medium of life The list of necessities for the provision of life includes various nutrients and water: water is one of the basic resources needed for the process of photosynthesis. Since it is an excellent solvent, water, even in its ‘natural’ state, is never pure H2O but contains a variety of soluble inorganic and organic compounds. Water can also carry large amounts of insoluble material in suspension. The amounts and types of impurities vary with location and time of year, and determine so
2.11 Storage In a given fixed space at any phase of the hydrological cycle, there is an inflow and an outflow of water, the rates of which vary with time. The total cumulative difference between inflow and outflow is the storage. So within that space there is a body of water whose mass is not directly controlled by instantaneous values of inflow and outflow. For example, in river flow the movement of the whole body of water in the channel is generally downstream, yet a given reach contains a volume whose
2.10 Aquifers
Groundwater
is water that, after infiltrating and percolating through surface soils, flows into an
aquifer, an underground water-bearing layer of porous rock. About one-third of the UK's drinking water is drawn from aquifers. To permit economic development, an aquifer must be able to transmit large quantities of water from one point to another and therefore it must have a high permeability. The groundwater contained in aquifers is released from springs an
2.6 Precipitation
Precipitation
is defined as the depth of rainfall, or the water equivalent of snow, sleet and hail falling during a given measurement period. It may be in the form of rain, snow, sleet or hail, or in minor forms such as dew and hoar frost, but existing theories do not yet satisfactorily account for all the observed characteristics. In tropical climates, precipitation occurs as a result of the gradual coalescence of the tiny condensed droplets as they collide within the cloud
2.3 Transpiration If there were no vegetation, the rate of evaporation from land surfaces after rain would diminish rapidly to a very low value. Plants increase this rate by transpiration. In this process, water is transferred from the soil through the roots to the leaves by osmosis and capillary action. Water evaporates from the surface of the leaves and the resulting vapour diffuses into the atmosphere. For hydrological measurements, this phenomenon is frequently lumped with evaporation because the two proce
2.1 Introduction The hydrological cycle, the continuous cycling of water between land, open water surfaces and the sea, either directly or indirectly, is an extremely complex process which has been known for a long time (Figure 1). The identifiable mechanisms of the cycle are complicated not only by the characteristics of air-water-land interfaces across which the cycle operates, but also by climatic factors which vary in both time and space. The various operations and mechanisms within the cycle are illustra
1 Some facts about water