The spatial distribution of climatological variables such as rainfall and temperature is needed whenever hydrological modelling is undertaken at the watershed scale. These models can be used to simulate hydrological processes at a daily or hourly time step and the interpolation of climatological variables (in particular precipitation) at this time scale poses a particular problem due to its large spatial variation. This work analyzes the temporal variation of both minimum and maximum temperature and rainfall, its correlation with elevation and whether or not this relationship should be used when daily data are interpolated. In order to achieve this, the monthly distribution of these variables is derived from daily interpolations, which is compared to their monthly accumulated value for each climatological station. The interpolation methods used to undertake the analysis were Ordinary Kriging (OK), Kriging with External Drift (KED), Block Kriging with External Drift (BKED), Ordinary Kriging in a local neighborhood (OK l ) and Kriging with External Drift in a local neighborhood (KED l ). This analysis used daily climatological data from approximately 200 stations located in the Basin of Mexico for June 1978 and June 1985, from which accumulated monthly data were derived. The results of this analysis show that the interpolation of daily events is improved by the use of elevation as a secondary variable even when these variables show a low correlation. ª
[1] Numerical experiments were developed using different water table depths and soil textures to investigate the impact of aspen harvesting on hydrological processes on the Western Boreal Plain. The effect of harvesting on soil moisture dynamics, fluxes at the water table, and water table fluctuation were compared for different harvesting scenarios simulated under wet and dry climatic cycles. Strong interaction between shallow water tables (i.e., 2 m) and atmospheric variability is observed for all soil textures and is reduced as the vadose zone thickens, particularly after a dry cycle, as a series of positive net atmospheric fluxes are needed to reduce soil moisture storage in order for recharge to occur. Because of harvesting, the water table fluxes can increase by 50 mm month
À1, while on a yearly basis, this increase can reach 200 mm yr
À1, with rainfall events taking between 1 and 5 years to become recharge (i.e., time lag). Also, the water table is expected to rise between 1 and 3.5 m, with rainfall-water table rise time lags of 1-3 years; however, the peak manifestation of harvesting on water table elevation can take up to 7 years after harvesting. The effects of aspen harvesting are more pronounced during wet cycles, and the development of forestry activities in the Boreal Plain should consider not only preceding precipitation but also the preceding precipitation-reference evapotranspiration ratio, water table depth, and soil texture. The interaction of these factors needs to be considered in order to develop sustainable forestry plans and avoid waterlogging conditions.
e aquifer system of the Basin of Mexico is the main source of water supply to the Mexico City Metropolitan Zone. e management of the Basin's water resources requires improved undertanding of regional groundwater ow patterns, for which large amounts of data are required. e current study analyses the regional dynamics of the potentiometric groundwater level in the entire Basin using data collected in a new regional database called the Basin of Mexico Hydrogeological Database (BMHDB). In order to foster the development of a regional view of the Basin's aquifer system the BMHDB has been developed collecting data on climatological, borehole and runo variables from di erent sources. e structure and development of the BMHDB are brie y explained and then the database is used to analyze the consequences of groundwater extraction on the aquifer's con nment conditions using lithology data. e regional analysis shows that the largest drawdown rates are located north of Mexico City, in Ecatepec, a region that has not yet received attention in hydrogeological studies, due to two lines of wells that were drilled as a temporarily solution to Mexico City's water supply problem. is work also shows how the aquifer has changed from a con ned to an uncon ned condition in some areas, a factor that is responsible for the large subsidence rates ( cm/year) in some regions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.