This paper first discusses the responsibilities of geography as a social existence and its contributions to society. Geography must stimulate intellectual curiosity, especially that of scientists in related fields, and geographers must report on their specialty using common scientific concepts.
A map is a model of the actual world. Therefore all doings on maps should be called simulations in the broad sense of the term. We cannot suppose better commercial opportunity findings, location decisions and military operations without using maps. These simulations or processes of geographic thinking have become so common that it is not realized that they are simulations. Geographic simulations have been renewed by digitalization of maps or GIS.
A geographic simulation of vegetation zoning in Japanese Islands was initiated based on my previous studies. Using vegetation and climate grid data with 1-km resolution, I sought threshold values of thermal conditions that separated forest types of natural vegetation remaining such as evergreen broad-leaved, deciduous broad-leaved, evergreen needle-leaved, and alpine dwarf. Based on these values, I estimated potential vegetation for sites where native vegetation had been destroyed by human activities, and also those under climate conditions 7°C lower and 2°C higher than at present. The spatial correlation between the present geographic distribution of vegetation and its natural limitations is a key to the past and also to the future.
Two additional simulations in narrow or common sense were based on previous studies. One was on landform development of a small drainage basin. The fundamental equation (model) for the slope was a partial differential equation like as the heat conduction equation, and that of a river profile was the same but used a nonconstant diffusion coefficient, which is an exponential function of distance. Thus the drainage basin was divided into the two domains of slope and fluvial process. This scheme enabled the two-dimensional model to accept a set of rock control and climatic influences as the diffusion coefficient, and sea level change as a boundary condition. The simulation was run on a regular hexagonal DEM to determine future landforms on the assumption that climate and sea level change would continue for the future 100 ky in the same manner as in the past 100 ky.
The other simulation was of a probabilistic model of a drainage network. The network system is fundamentally regarded as a binary tree. The simulation models were composed of recursive functions that generated a network by adding a new branch after a random number (Monte Carlo method) and calculated properties of the network such as drainage area, Horton-Strahler's orders, bifurcation ratio, etc. In this case also, the regular hexagonal DEM provides greater convenience in the simplicity of model algorithms.
Explaining geography using the word “simulation” is the best strategy for acquainting the public with the field, because sciences are evaluated based on their prognostic ability.

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Cloud streets are often observed when a cold air mass advects over a warm sea around the Japanese Islands during the winter monsoon. Thick cloud streets often appear over the southern ocean off the Japanese Islands. Visible images obtained by geostationary meteorological satellite (GMS) were analyzed to investigate the characteristics of these cloud streets during winter (January, February, December) from 1997 to 2001. The dependence of each cloud street upon the ambient wind speed and direction were investigated using reanalysis data at the level of 850hPa.
The appearance frequency of the cloud streets differs greatly. The cloud streets in the Bungo Channel, in the lee of the east Shikoku Mountains and in the lee of the Kii Mountains are the most frequently observed. However, their frequency does not appear to depend simply on the shape of windward topography.
The frequency of cloud streets depends not only on the ambient wind direction but also on the ambient wind speed. Some cloud streets are generated more frequently under stronger ambient wind, while others are generated less frequently. For example, cloud streets are generated more frequently over the ocean east of Kyushu and over the south of Shikoku when the ambient wind is stronger. On the other hand, cloud streets appearing in the lee of the Kii Mountains and on the Kii Channel are observed less frequently when the ambient wind is stronger.
The position of the starting points of some cloud streets tends to shift depending on the ambient wind velocity. For example, the starting point of the cloud streets appearing in the lee of the eastern Shikoku Mountains shifts northeastward when the ambient wind velocity becomes greater.

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This research examines urban water use in developing countries. Bangalore, the capital of Karnataka state in South India, is one of the rapidly growing cities in Asia, and the water resources development and the distribution of water within the city are examined here as a case study.
Large-scale, continuous growth of commerce and industry in and around the city has accelerated the population growth of Bangalore in the last few decades; this was made possible due to the continuous development of water sources in the city. In the beginning, the city relied on the Arakavathy River by developing dams on the river. As this source became insufficient for the developing city, the Cauvery River, one of the major rivers of South India, was tapped in the next stage of the development of city water sources. The Cauvery River is 98km distant from the city, and the altitude of this source is about 500m lower than that of Bangalore.
With regard to water distribution to users in the city, however, it is insufficient and uncertain. Water distribution at the receiving end is effected by setting up sumps and overhead tanks constructed at the cost of the owners. There are also private water supply companies that supply water by tankers to consumers at fixed charges. Because the Cauvery River is far from the city and at a lower altitude, it requires a higher cost to pump the water from the source to the city, and this is reflected in the higher water charges that users pay for water. Most factories, hospitals, hotels, and other commercial establishments in the city use the private water supply companies or set up their own wells because of the high water charges and insufficient supply; they make a double investment for securing water.
Due to the revision of the water charges, low-income people are required to pay more than before. Also, those who have no contract with the water supply board, like squatters, are restricted in the amount of water they receive. Especially in developing countries, it is essential to consider the conditions of low-income groups in the questions concerning the provision of the minimum amount of water needed for living.

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