Browsing by Autor "J. Mendoza"

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A Pilot Study Assessing Student’s Problem and Information Identification Skills in an Introductory Engineering Design Course
(2024) Andrea Goncher; Mengyu Li; J. Mendoza
He teaches professional skills like systems thinking, design thinking, problem-solving and algorithmic thinking.Dr
Estimation of Glacier Melt Water Contribution for Human Consumption in the Royal Andes Considering Temperature Measurement Errors
(Scientific Research Publishing, 2014) V. Moya Quiroga; A. Mano; Yoshihiro ASAOKA; Keiko Udo; Shuichi KURE; J. Mendoza
Glaciers from the West side of the Royal Andes are an important source of fresh water for some of the most important Bolivian cities like El Alto. Temperature is an important datum for hydrological modelling and for glacier melt estimation. All temperature measurement devices have some degree of uncertainty due to systematic errors; thus, any temperature measurement has some errors. It is important to estimate the influence of such errors on the results from hydrological models and the estimation of melt water. The present study estimates the melt water contribution from the glaciers Tuni and Huayna West as a source of water supply for human consumption of El Alto considering the errors from temperature measurements. The hydrologic response of the basins was simulated with a hydrologic model. The glacier melt contribution was estimated as the difference between the discharge from the current scenario (with glaciers) and the discharge from a scenario without glaciers. Several volumes of melt water were estimated considering the temperature measurement and its possible errors. The uncertainty of such melt water volume was addressed by performing a Monte Carlo analysis of the possible melt water. The melt water contribution from glacier Tuni and Huayna West during the hydrologic year 2011-2012 was between 1.37 × 106 m3 and 1.72 × 106 m3. Such water volume is enough to meet the yearly water demand of between 6.81% and 8.55% of El Alto.
Modeling glacier melt and runoff in a high-altitude headwater catchment in the Cordillera Real, Andes
(2013) Tsuyoshi Kinouchi; T. Liu; J. Mendoza; Yoshihiro ASAOKA
Abstract. Runoff from catchments with partial glacier cover is an integrated process of glacier melt, snowmelt, and surface and subsurface runoff of meltwater and rain from glacierized and non-glacierized areas. Additionally, inherent characteristics of the tropical Andes such as large meteorological variability, high elevation and steep slopes, hydrological effects of wetlands and lakes, and rapid glacier retreat make it difficult to model glacio-hydrological responses under changing climate. In this study, we developed a semi-distributed conceptual model applicable to partially glacierized catchments in the tropical Andes that considers all of these aspects, and we applied the model to the Huayna Potosi West headwater catchment in the Cordillera Real, Bolivia. Based on the latest 2 yr dataset of meteorological and hydrological monitoring, we showed the spatial and temporal variability of air temperature and precipitation in the region, and the dataset was used to calibrate model parameters and validate the performance of the daily runoff simulation. Variations in the simulated streamflow agreed well with the observed seasonal and temporal variations, and the result also showed that uncertainty pertaining to the spatial and temporal variations in air temperature and precipitation as well as the retarding effect of a wetland and lake strongly affected the runoff hydrograph. The simulated runoff components indicated that runoff from glacier melt occurs mainly in the initial period of the wet season, from October to early December, and in the late period of the wet season, March and April, although the runoff is relatively small in the latter period. Between these two periods in the wet season, major runoff components were estimated to be subsurface runoff in the non-glacierized area and surface runoff due to snowmelt. Given the future meteorological conditions based on the observational data and a predictive general circulation model output, the model quantified the long-term changes in runoff, glacierized area, and cumulative glacier and snow mass balance. The glacier retreat is estimated to continue to 2050, with the magnitude of area decrease and negative cumulative mass balance depending on the increasing temperature trend used. For higher temperature trends, in particular, greater seasonal variation in runoff and larger contributions from subsurface runoff and surface runoff by rainfall were simulated to occur in the wet season, but the change in annual total runoff between the present and 2050 was not significant. These results suggest that it is important to consider how to best adapt to greater seasonal runoff variations in terms of water availability in the downstream region.
Probabilistic estimation of glacier volume and glacier bed topography: the Andean glacier Huayna West
(2013) V. Moya Quiroga; A. Mano; Yoshihiro ASAOKA; Keiko Udo; Shuichi KURE; J. Mendoza
Abstract. Glacier retreat will increase sea level and decrease fresh water availability. Glacier retreat will also induce morphologic and hydrologic changes due to the formation of glacial lakes. Hence, it is important not only to estimate glacier volume, but also to understand the spatial distribution of ice thickness. There are several approaches for estimating glacier volume and glacier thickness. However, it is not possible to select an optimal approach that works for all locations. It is important to analyse the relation between the different glacier volume estimations and to provide confidence intervals of a given solution. The present study presents a probabilistic approach for estimating glacier volume and its confidence interval. Glacier volume of the Andean glacier Huayna West was estimated according to different scaling relations. Besides, glacier volume and glacier thickness were estimated assuming plastic behaviour. The present study also analysed the influence of considering a variable glacier density due to ice firn densification. It was found that the different estimations are described by a lognormal probability distribution. Considering a confidence level of 90%, the estimated glacier volume is 0.0275 km3 ± 0.0052 km3. Considering a confidence level of 90%, the estimated glacier thickness is 24.98 m with a confidence of ±4.67 m. The mean basal shear stress considering plastic behaviour is 82.5 kPa. The reconstruction of glacier bed topography showed the future formation of a glacier lake with a maximum depth of 32 m.