Estimate the Equilibrium Line of Water and Drought Quaternary Case study (Lake Maharlu)

The plane surfaces are from stagnant waters like wetlands, lake or pond which are specified with the height points in topographic maps. The extent of these surfaces are suddenly interrupted by tracing of the river networks and are symbolic in the shape of little two-directed rivers. Accordingly the most extend of Maharlu lake was reconstructed in Quaternary (1190.3 km2). The estimated area was 5 times than current condition which is unlikely to this area in accordance with the area of basin (4281). Climatology conditions of the basin was reconstructed and the oscillation of the lake surface was scrutinized and reconstructed to test of hydro geomorphologic conditions. So that the inner and outer climatic stations of the basin and monthly temperature and precipitation were selected. It was correlated between monthly/annual temperature and precipitation as dependent variables, with height as an independent variable then monthly/annual isohyet and isotherm maps draw by the use of evaluated relations and height layer of the basin. Monthly weight temperature and precipitation of basin, was calculated and correlated between monthly oscillations of basin with them by replacing the weight height in current equations. The equilibrium line of water and drought was rebuilt in Quaternary periods which the temperatures were 5, 8 and 12˚C less than current condition. The annual area, volume, depth, evaporation and runoff coefficient of the lake was estimated by evaluation of the volume of precipitation. The results showed that even with the decrease of quaternary temperature (12˚C), the lake didn’t have the permit of extraction more than 300 km. The most extent of the conditions reflected from hydro geomorphology could be related to the limestone effect in positive balance of water or the existence of more ponds than current conditions