جستجوی مقالات مرتبط با کلیدواژه « system analysis » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Automatic flood control approach can prevent dam overtopping and downstream flooding. Doing so, in addition to controlling the optimal storage capacity, flood threats will turn into opportunities for water resources systems. Model-based Predictive Control (MPC), can take the future predicted rainfall runoff, physical and operational constraints, and safety limitations of the water system into account. In a suitable timeframe before destructive floods, MPC creates essential and optimal capacity in the dam’s reservoir to contain floods. In this research, water system modeling method is studied by a control-oriented approach, and the flood automatic control operation using a model predictive control approach. To this end, modeling of the Karun and Dez river system containing six reservoir dams is considered as the case study to model and simulate under the designed MPC. The state space model will extract to design and apply the predictive controller for a prediction horizon of 10 days and eight hours in MATLAB software. The results will show long prediction horizon gives the controller enough time to create the necessary capacity for flood control according to the system constraints, while a short prediction horizon, similar to other controllers without predicting, does not have an effective performance.

This study uses a system analysis to evaluate the effects of outdoor activities on some physical properties of the soil (soil bulk density, porosity and soil moisture content) and vegetation status (density, diversity and abundance) in the Qhamishloo national park and wildlife refuge has been researched.In order to achieve the desired objectives, by using the overlaying method, a map of environmental units of the region was obtained and after identifying the ecological units for the slopes, directions, elevation, resistance coefficient of rock, physical features of soil (erosion, pebbles, evolution, drainage, texture and depth of soil) and vegetation (density, pasture tendency and total production per hectare), in 38 units of the recreation zones and 38 units corresponding in untouched zones, one plot were taken (2m×2m) to assess vegetation.Action sampling of the soil profile with three replicates of the depth 0-5 cm and if there is, of the depth 5-10cm by using the method of the cylindrical-metal was performed. The results showed that the difference between vegetation status and physical properties of soil (depth 0-5 cm) in similar units with a 99% confidence was significant.However, the difference between the physical properties of soil at a depth of 5-10 cm was not significant at 5% level.In general, the results of this study showed that recreation has caused negative effects on the quality of soil and vegetation in the recreational zones of the study area.

The aim of this research was to evaluate and select of appropriate indicators for different zones of Baghe shadi region where it have six different zones (restricted zone, protected zone, restored zone, inhibition zone, recreational zone and other uses zone). To do so, first top-down approach and Likert scale questionnaire was used for voting from 32 experts. After that using influence matrix, influence and importance of indicators were determined and the most important indicators as well. Then using system analysis and influence matrix, for the first five indicators of each criterion, influence and importance of indicators were determined in different zones and indicators were evaluated and then appropriate indicators were determined for each zones. Regarding to results of indicators evaluation, indicators related to area of forests and protective functions have the most importance and application in restored zone. Area of forests and other wooded lands, extent of area by forest type relative to total forest area, area of natural forests with healthy regeneration were appropriate indicators in restricted and protected zones. Also, Existence & implementation of management plan & protection for spectacular landscape area in region, extent of forest lands considered for recreation, accessibility for recreation and expenditure for access to tourism area were appropriate indicators in recreational zone.