جستجوی مقالات مرتبط با کلیدواژه « land » در نشریات گروه « مهندسی آب »

Land-use changes by human activities are important issues in regional planning. The distributed hydrologic model is a suitable model to survey land-use changes and to estimate their quantities. This study aims to evaluate the effects of land-use changes (the expansion of residential areas) on the hydrological parameters using WetSpa model in the Ziarat Watershed, which has an area of 95.15 square kilometers. In order to execute the model, during the four-year period (2007-2010), the hourly hydrometeorology data including rainfall, temperature, evapotranspiration, and discharge rate are used as inputs. Additionally, three base maps of the digital elevation model (30meter cell size), soil map (soil texture), and land-use are also applied. As a result, there is a good agreement between the simulated and observed hydrographs. The scenarios of land-use changes (the expansion of residential area) have been used as input maps for the calibrated model in a GIS environment. The results show that some hydrological parameters such as the peak discharge, potential runoff coefficient and flow velocity increase in the all scenarios, but the Manning’s roughness coefficientis reduced.

Land use change is a gradual process that entails dire consequences for groundwater quality and quantity. Quantitative changes in groundwater can be usually monitored by controlling the annual groundwater balance. Monitoring qualitative changes in groundwater, however, is both time-consuming and expensive. DRASTIC and SINTACS models exploit aquifer properties to predict its vulnerability. In this study, aquifer vulnerability assessment was performed by the DRASTIC & SINTACS models for future land use management in Khovayes, southwest Iran. The DRASTIC Model is based on hydrological and hydrogeological parameters involved in contaminant transport. SINTACS parameters are the same as those of the DRASTIC model, except that weighting and ranking the parameters are more flexible. Once vulnerability maps of the study region had been prepared, they were verified against the nitrate map. A correlation coefficient of 0.4 was obtained between the DRASTIC map and the nitrate one while the correlation between the SINTACS and the nitrate maps was found to be 0.8. Map removal and single-parameter sensitivity analyses were carried out, which showed the southwestern stretches of the study area as the region with the highest risk of vulnerability.

Infiltration is one of the most important parameters of hydrologic cycle. To prevent soil erosion and to utilize water resources, soil infiltration characteristics should be determined. The present study aimed to determine the effect of land-use changes on infiltration and then to choose the best infiltration model of each land-use. Field experiments were conducted in 3 various landuses including pasture, agriculture and garden land-use. Then, agriculture and garden land use engender from pasture land-use, in 5 various tensions (0, 3, 6, 10, 18 cm-H2O) and 3 replication. Infiltration models of Kostiakov, Lewis Kostiakov, Horton, Green- Ampt, Philip and SCS were evaluated. Simulation cumulative infiltration and infiltration rate were compared with the observation data using relative error (RE) and root mean square error (RMSE) parameters. The results indicated that land-use changing from pasture to agriculture or garden leads to an increase in infiltration rate and cumulative infiltration. The comparison of infiltration models indicated that in pasture and agriculture land-use, Kostiakov and Philip models have higher accuracy than other models, but in garden land-use, Horton and Kostiakov models were better than the other ones.