The analysis of morphometric parameters in hydrological modeling using GIS

The analysis of the physical-geographical conditions determines and influences the formation and the regime of the water resources from a hydrographic basin. This paper aims to analyse spatial data based on raster models, more precisely the terrain analysis, later used in hydrological modelling. For the elaboration of the digital model of the terrain, methods of interpolation of certain data are used - the level curves - after which, by running the ArcGIS program will result the structure of the irregular triangulation network (TIN). Next, based on the TIN model, a set of analyses is obtained regarding the morphology of the terrain: the slope map; slope exposure map, etc. The slope is one of the most important factors for controlling surface and intermediate water runoff. The exposure of the slopes depends very much on the direction of the slope of the land. With the help of the analysis of the slope and slope exposure it is possible to: calculate the solar lighting for each location in a region; find all slopes in the southern part of a mountainous region to identify locations where the snowmelt process will start earlier than in other areas, thus avoiding the danger of flooding due to runoff from the slopes and the danger of soil erosion; the value and speed of surface runoff; identify the spread and abundance of flora and fauna, precipitation; identify the productivity classes of the land; find all the north-facing slopes on a mountain as part for the search of the best ski slopes.

ON ISSUE OF PLANNING THE EXPERIMENT CONDUCTING STUDIES ON NATURAL SURFACE RUNOFF FROM AGRICULTURAL FIELDS

Purpose: determination of significant parameters and sequence of field studies devoted to the study of features and nature of diffusion pollution of water bodies in areas of intensive agricultural activity. Materials and methods. Materials: works by Russian and foreign scientists, regulatory documents. Methods: comparison, analysis and synthesis of data. Results. As experience shows, significant parameters are: the source of the formation of surface runoff, the hydrographic characteristics of the catchment, the level of development of the territory, soil resources, the dissection of the relief and the slope of the terrain, methods of soil treatment, the timing and dose of fertilization, the use of pesticides, etc. All this influences the choice of the location of representative areas in the catchment area, their size, determination of constant and variable parameters during research. The paper discusses the issues of taking soil samples in the process of preliminary studies, determining the location of the alignment point for sampling water from a water body and the possibility of taking into account the amount of diffusion contamination in the samples obtained. The rationale for conducting preliminary laboratory studies is given. The plan was developed for carrying out field studies devoted to the study of the features and nature of diffusion pollution of water bodies in areas of intensive agricultural activity. Conclusions. It was revealed that to organize monitoring of diffusion pollution of water bodies, it is necessary to carry out a number of studies both in laboratory and in the field. For a preliminary assessment of the removal of nutrients from agricultural fields and their entry into the water body, it is necessary to make a preliminary sampling of soil and water. It is advisable to take soil samples along route lines from the boundaries of agricultural fields to a water body along the slope of the terrain. The site for sampling water from a water body must be coordinated with the location of organized sources of wastewater discharge into it and the boundaries of the action of agricultural fields.