Mathematical rainfall model for hydrographic demarcation of Manabi (Ecuador)

To determine the average annual rainfall at a specific site in a basin, it is necessary to count with rainfall information in the study area and topographic information. Counting with base information, is comes to the filling of them data missing with the help of any of them methods statistical existing for the effect. Thiessen polygons are built. Based on this procedure, may be elaborated isohyet or curves of equal rainfall, that are an input that can help also to estimate of precipitation in a specific geographical site. Here is a methodology that allows creating with the help of geographic information systems (GIS), a mathematical model to estimate very accurately the values of rainfall based only on the geographical coordinates. To achieve this objective, the basins of the Hydrographic Demarcation of Manabí have been chosen to develop the indicated mathematical model, which can be applied to other basins in the world.Keywords: multiple regression; mathematical model; GIS; Hydrology; rainfall

Моделирование деформаций русел, сложенных мёрзлыми породами, при повышении температуры окружающей среды

This paper is devoted to investigation of the influence of river flow and of the temperature rise on the deformation of the coastal slopes composed of permafrost with the inclusion of ice layer. The method of investigation is the laboratory and mathematical modeling. The laboratory experiments have shown that an increase in water and air temperature changes in a laboratory analogue of permafrost causes deformation of the channel even without wave action, i.e. at steady-state flow and non-erosive water flow velocity. The previously developed model of the bed deformation was improved to account for long-term changes of soil structure with increasing temperature. The three-dimensional mathematical model of coastal slopes thermoerosion of the rivers flowing in permafrost regions, and its verification was based on the results of laboratory experiments conducted in the hydraulic tray. Analysis of the results of mathematical and laboratory modeling showed that bed deformation of the rivers flowing in the permafrost zone, significantly different from the deformation of channels composed of soils not susceptible to the influence of the phase transition «water-ice», and can occur even under the non-erosive velocity of the water flow.Работа посвящена исследованию влияния речного потока и повышения температуры воды на деформации береговых склонов, сложенных многолетнемёрзлыми породами с включением пластов льда. Методы исследования – лабораторное и математическое моделирование. Лабораторные эксперименты показали, что при повышении температуры воды и воздуха изменения в структуре лабораторного аналога многолетнемёрзлого грунта вызывают деформации русла даже без волнового воздействия, т.е. при стационарном режиме течения и неразмывающих скоростях водного потока. В связи с этим возникла необходимость усовершенствования разработанной ранее модели деформации русла с целью учёта долгопериодных изменений структуры грунта при повышении температуры воды. В основу трёхмерной математической модели термоэрозии береговых склонов рек, протекающих в районах развития многолетней мерзлоты, и её верификации положены результаты лабораторных экспериментов в гидравлическом лотке. Анализ результатов математического и лабораторного моделирования показал, что русловые деформации рек, протекающих в криолитозоне, значительно отличаются от деформаций русел, сложенных грунтами, не подверженными влиянию фазового перехода «вода–лёд», и могут наблюдаться даже при неразмывающих скоростях водного потока

LABORATORY RESEARCH OF DEFORMATIONS IN THE LOWER BYEF ON THE EXAMPLE OF THE RYBINSK WATER-ENGINEERING SYSTEM

Currently, the Russian rivers created by hydro, ensuring the solution of a large number of tasks that combine issues of livelihood and work of major industrial regions of the country. These facilities have significantly changed the natural regime of rivers and surrounding coastal areas. One of the main problems encountered during the construction and operation of hydro - negative channel processes downstream such as washouts and riverbeds destruction shores. Today this task is urgent, and even acute in some areas. However, some issues of erosion of banks and the reorganization of riverbeds downstream waterworks and their impact on the environment is not well understood. When activated, the lateral erosion develops general erosion processes with heterogeneous composition of sediments. In urban areas there is a risk of contamination of river water and coastal areas, damage to pipelines, dams collapse, flooding and inundation of large areas. The study and assessment of the extent of the dynamics of channel processes, allows us to develop recommendations, methods of forecasting and regulatory relief in order to prevent the negative consequences. It is necessary to solve problems that are important for the protection of rivers and coastal areas, and for the proper functioning of the industry and maintain the security of life of the population in such areas. The research of deformation shores downstream waterworks (for example, Rybinsk), a laboratory model at different levels of releases. The simulation showed that the strain is directly dependent on expenditures. However, if there is a permanent presence of transit charges, and it will be gradually added to the cost of other sources, the strain will be considerably less than the sudden release of water without transit

INFLUENCE OF RAINFALL PRECIPITATION ON THE DEFORMATION OF THE RIVER BANK CHANNELS IN PERMAFROST

We studied in the lab the interaction of river runoff from frozen soil, simulating the upper, active-layer, changing the thermal (warming) and mechanical (impact of rain) external influences. We determined the time of thawing of ground and infiltration in soil, sediment transport along the lines under the influence of slope flows, caused by both natural thawing permafrost and storm flows. A mathematical model for predicting the dynamics of river channels in the permafrost under the influence of external factors is suggested

Modeling of river bed deformation composed of frozen sediments with increasing environmental temperature

This paper is devoted to investigation of the influence of river flow and of the temperature rise on the deformation of the coastal slopes composed of permafrost with the inclusion of ice layer. The method of investigation is the laboratory and mathematical modeling. The laboratory experiments have shown that an increase in water and air temperature changes in a laboratory analogue of permafrost causes deformation of the channel even without wave action, i.e. at steady-state flow and non-erosive water flow velocity. The previously developed model of the bed deformation was improved to account for long-term changes of soil structure with increasing temperature. The three-dimensional mathematical model of coastal slopes thermoerosion of the rivers flowing in permafrost regions, and its verification was based on the results of laboratory experiments conducted in the hydraulic tray. Analysis of the results of mathematical and laboratory modeling showed that bed deformation of the rivers flowing in the permafrost zone, significantly different from the deformation of channels composed of soils not susceptible to the influence of the phase transition «water-ice», and can occur even under the non-erosive velocity of the water flow

ВЛИЯНИЕ ОСАДКОВ В ВИДЕ ДОЖДЯ НА ДЕФОРМАЦИИ БЕРЕГОВОГО СКЛОНА РУСЕЛ РЕК В УСЛОВИЯХ МНОГОЛЕТНЕМЁРЗЛЫХ ПОРОД

We studied in the lab the interaction of river runoff from frozen soil, simulating the upper, active-layer, changing the thermal (warming) and mechanical (impact of rain) external influences. We determined the time of thawing of ground and infiltration in soil, sediment transport along the lines under the influence of slope flows, caused by both natural thawing permafrost and storm flows. A mathematical model for predicting the dynamics of river channels in the permafrost under the influence of external factors is suggested.Впервые в лабораторных условиях исследовалось взаимодействие речного стока с мёрзлыми грунтами при изменении термических (потепление) и механических (влияние дождя) внешних воздействий. Определялись время оттаивания грунта, инфильтрация в грунте, перенос наносов в русле под воздействием склоновых потоков, вызванных как естественным оттаиванием мёрзлых грунтов, так и дождевыми потоками. Предложена математическая модель прогнозирования динамики русла рек в многолетнемёрзлых породах под влиянием внешних воздействий