Takeshi Hata

Estimation of crop water requirements in arid region using Penman–Monteith equation with derived crop coefficients: a case study on Acala cotton in Sudan Gezira irrigated scheme

The recommended Penman‐Monteith reference crop evapotranspiration (ET0) with derived crop coefficients (Kc) from the phenomenological stages of Acala cotton is used to estimate the crop water requirements (CWRs) of Acala cotton in the Gezira area of Sudan. The published basal crop factors of Acala cotton were used with Penman‐Monteith equation as well to estimate ET. The results were compared with the current practice that uses Penman evaporation (E0) from free water surface and crop factors (Kf) derived by Farbrother [Farbrother, H.G., 1970. Irrigation practices on Gezira clay-rates and intervals. Gezira miscellaneous paper no. 94. Gezira Research Station, Wad Medani, Sudan] and still in use in Sudan. The two methods were compared with the actual ET of Acala cotton measured by Fadl [Fadl, O.A., 1987. Water use of Acala cotton. Annual report 1978‐1979. Gezira Research Station, Wad Medani, Sudan, pp. 143‐147]. Penman‐Monteith equation was found to be better than Farbrother method in terms of the total predicted CWR, coefficient of determination (r 2 ), the slope of the linear regression line and the standard error of estimate with both basal and derived (Kc) values. The trends of weather examined for the period 1966‐1993 showed an increasing ET0 during the rainy season due to the recent drought conditions that prevailed in the region. Care must be taken when predicting CWR during such period. # 2000 Elsevier Science B.V. All rights reserved.

The application of a simple lumped river flow forecasting model to hillslope soil water storage estimation

For a number of applied geomorphological and hydrological problems, the prediction of hillslope soil water conditions from restricted data is frequently required. Physically based distributed models of catchment hydrology are currently regarded as too cumbersome to meet these requirements either operationally or in a ‘standard’ research context. A simple lumped sequential flow forecasting model is applied to a 0.73 km2 catchment and it is shown that if field permeability is available, there is significant potential for the scheme to estimate the mean soil water storage in catchment segments. In addition, the model is shown to provide reliable river flow forecasting. Further more extensive trials of the model are needed on catchments with differing topography to compare with the preliminary results reported here.

Necessary conditions for the development of waterfronts as desirable environments

Abstract Problems of waterfront development in Japan are discussed and summarized. Each point relates to water conservation problems directly or indirectly. The expectations of water vary from stage to stage, but the key factors are water and human needs in the small sites. The necessity of networking core sites, and the necessity of making water data open to residents, along with exchanging information between sites are discussed. Social scientific ways of conserving water are emphasized in this paper, because the preservation of sea water is related to all activities in the vast area of every river basin, and it is the problem of culture in related districts.