Hydrologic Information System Research Articles

Development of Hydrological Information System in The Chao Phraya River Basin

Development of Hydrological Information System in The Chao Phraya River Basin

Catchment infiltration II: Contributing areas

This study considers two issues of interest to the hydrologic and geographical information systems community. One deals with identifying the spatial distribution of infiltration and runoff contributing areas. The other addresses process modelling within a GIS framework. The study operates on the premise that partitioning of precipitation into runoff or infiltration depends on rainfall intensity and on soil properties. The problem is that neither local rainfall intensity, nor soil properties such as infiltration capacity and macroporosity are known well enough for all points of a catchment and need to be estimated. We infer local intensity from the interpolated distribution of cumulated rain depths over the catchment and record duration at the official met site. Measured values of sorptivity and hydraulic conductivity define infiltration. Negative head infiltration describes macroporosity. To scale‐up measured point values to larger areas and to model infiltration and macropore continuity at a catchment scale we use geostatistical kriging and conditional simulation together with standard GIS techniques of overlay manipulation. Results delineate areas contributing to runoff and infiltration and relate them to macroporosity. By intersecting overlays of precipitation with those of infiltration we create alternate GIS masks targeting specific portions of the watershed as either runoff or infiltration contributing zones. Choice of cell size and time interval define the scales of averaging for the application. Kriged surfaces illustrate the distribution of catchment infiltration, while conditional simulation provides a mechanism to define model uncertainty.

TraPhyC-BV: A hydrologic information system

Digital Elevation Models are used to automatically map the drainage network, the stream channel and divide networks of a watershed. This has been done with the TraPhyC-BV software package. Construction of a code describing the network may form the basis for an efficient hydrologic information system. This form of discretization of a watershed produces natural units for problems involving surface or subsurface water flow. This methodology is designed to aid in the parametrization of a distributed components approach to watershed simulation in the fields of hydrology, sedimentology and geomorphology.

Value of On-Line Hydrologic Information for the Operation of a Multi-Purpose Reservoir

In this paper, a contribution is given to assess the benefits coming from on-line hydrologic information systems for the operation of multi-purpose reservoirs. Such systems are particularly useful for short-term analyses and hence the value of that information is estimated herein in terms of its use to study rapid hydrolonic events, namely high flows periods. Using data coming from a real system, developed in river Mondego (Portugal), this estimation is carried out for the operation of the reservoir during such periods as well as for the adaptive control of the flood detention storage, V, which implies the substitution of the well-known “upper guide curve” by an alternative concept of “upper guide function” which is proposed herin. For a given V, the annual flood risk, a, can be significantly decreased by elementary hydrolonic forecasts and for a given α a substantial reduction of expected V can be achieved by the adaptive control of V which is equivalent in this case to an average increase of the annual newer generation equal to 15 Cwh (about 780, 000 US dol. using 1931 prices).