Muhammad Azmat

Estimation of Water Resources Availability and Mini-Hydro Productivity in High-Altitude Scarcely-Gauged Watershed

Streamflow prediction in high-altitude scarcely-gauged catchments is essential for efficient water resources management and hydropower generation. Aim of this study is to estimate water resources availability (WRA) by the application of a standard rainfall-runoff model and to study its impact on mini-hydropower production with application to Mangla basin. The Mangla basin is a scarcely gauged catchment situated in the snow- and glacier-fed Himalayan and Pir Panjal Range. Daily streamflow forecasting has been performed by the application of a GIS (Geographic Information System) based hydrological modeling system (HEC-HMS) with observed and TRMM (Tropical Rainfall Measuring Mission) rainfall data to cover the ungauged part of the catchment. The obtained results suggest that HEC-HMS can efficiently reproduce daily streamflows in snow-fed glacierized catchments with Nash-Sutcliffe (NS) coefficients in the range 0.71–0.80. The WRA was estimated at the Mangla dam to analyze its impact on mini-hydropower generation at Upper Jhelum Canal (UJC). The gross mini-hydropower potential energy on the UJC was found to be 196 and 360 GWH for average and design discharge, respectively, demonstrated that mini-hydro power generation could be a significant addition for the energy sector of Pakistan.

Precipitation variability assessment of northeast China: Songhua River basin

Variability in precipitation is critical for the management of water resources. In this study, the research entropy base concept was applied to investigate spatial and temporal variability of the precipitation during 1964–2013 in the Songhua River basin of Heilongjiang Province in China. Sample entropy was applied on precipitation data on a monthly, seasonally, annually, decade scale and the number of rainy days for each selected station. Intensity entropy and apportionment entropy were used to calculate the variability over individual year and decade, respectively. Subsequently, Spearman’s Rho and Mann–Kendall tests were applied to observe for trends in the precipitation time series. The statistics of sample disorder index showed that the precipitation during February (mean 1.09, max. 1.26 and min. 0.80), April (mean 1.12, max. 1.29 and min. 0.99) and July (mean 1.10, max. 1.20 and min. 0.98) contributed significantly higher than those of other months. Overall, the contribution of the winter season was considerably high with a standard deviation of 0.10. The precipitation variability on decade basis was observed to increase from decade 1964–1973 and 1994–2003 with a mean value of decadal apportionment disorder index 0.023 and 0.053, respectively. In addition, the Mann–Kendall test value (1.90) showed a significant positive trend only at the Shangzhi station.

Optimizing Irrigation Deficit of Multipurpose Cascade Reservoirs

Reservoirs play a strategic role in the rapid monetary growth of the world by providing numerous benefits. However, the reduction in appropriate sites along with environmental and social apprehensions has resulted in curtailment of new reservoirs around the world in twenty-first century. There is a potential of benefits available from existing reservoirs which can be best capitalized through their optimized operation. Reservoirs Operation Optimization considering Sediment Evacuation (RESOOSE), recently developed model which combines multiple reservoirs operation and sediment evacuation with Genetic Algorithm based optimization module, has been used in the study. The objective of the study was to optimize the irrigation deficit through cascade reservoirs with consideration to hydropower, sediment evacuation and flood damages reduction benefits. The RESOOSE model was applied to optimize the irrigation deficits of Tarbela and Diamer Basha Reservoirs in Pakistan using developed objective function. The article computed and compared the benefits of optimized and existing rule curves. The hydropower benefits of 36.92 Billion Kw, sediment evacuation benefits of 21.534 Million m3 and flood damages of 616.19 Million US

Flow duration curve regionalization with enhanced selection of donor basins

due to existing rule curves were considered as minimum benefits for achieving the optimized rule curves to minimize irrigation deficits. The developed optimized rule curves reduced the irrigation shortages of case study reservoirs from 6.9 to 5.8 Billion m3 (16% enhancement) annually as compared to existing rule curves. The optimized rule curves minimized the irrigation deficits by maintaining the existing benefits and without lowering the minimum operating levels of case study reservoirs. The study suggests change in existing rule curves of Tarbela and Diamer Basha Reservoirs due to less irrigation shortages. The RESOOSE model can be applied to other cascade reservoirs for optimizing the rule curves.

Rainfall Extremes: a Novel Modeling Approach for Regionalization

A non-parametric regionalization procedure for the assessment of flow duration curve (FDC) at ungauged basins is presented. This modeling approach is fundamentally based on the quantification of dissimilarity between FDCs, thus allowing the grouping of most similar basins. An analogous grouping procedure, performed in the space of selected basin characteristics, allows the estimation of FDCs also at ungauged sites; however, for a fixed set of basin characteristics, some ungauged basins cannot be properly represented due to the scarcity of close (similar) donor basins. For these cases, the proposed method allows for the selection of an alternative set of basin characteristics as a support for similarity grouping. The results of the study show that the statistical error can be significantly reduced by following the proposed methodology. About 10% of all the basins involved in the analysis can benefit from the model swapping procedure, thus improving the final predicted curve.

Regional Groundwater Quality Management through Hydrogeological Modeling in LCC, West Faisalabad, Pakistan

The rainfall events of extreme magnitude over the past few decades have caused destructive damages to lives and properties, especially in the subcontinent (e.g. Pakistan, India, Bangladesh etc). Rainfall hazard maps for these areas can be of great practical and theoretical interests. In our work, we used extreme value analysis and spatial interpolation techniques to provide such maps through a combination of the Tropical Rainfall Measuring Mission Precipitation (TRMM) 3B42 product and raingauge data. This mixed approach takes advantage of both the long time series available at a limited number of stations, and the large spatial coverage of the satellite data which, instead, has a poor temporal extent. The methodology is implemented by (1) creating a unique growth curve for the homogeneous region by utilizing in-situ rainfall data and (2) mapping the parameters of intensity-duration functions for the entire length of the study area by using TRMM 3B42 product. The regional results obtained by using mixed approach and TRMM 3B42 are compared with the estimates obtained by using in-situ data. The comparison showed that the overall output of mixed approach is more consistent with what transpired by in-situ data for a pre-defined return period.

Hydrological modeling to simulate streamflow under changing climate in a scarcely gauged cryosphere catchment

The intensive abstraction of groundwater is causing a number of problems such as groundwater depletion and quality deterioration. To manage such problems, the data of 256 piezometers regarding groundwater levels and quality were acquired for the period of 2003 to 2012 in command area of Lower Chenab Canal (LCC), West Faisalabad, Pakistan. MODFLOW and MT3D models were calibrated for the period of 2003–2007 and validated for years 2008–2012 with respect to observed groundwater levels and quality data, respectively. After the successful calibration and validation, two pumping scenarios were developed up to year 2030: Scenario I (increase in pumping rate according to the historical trend) and Scenario II (adjusted canal water supplies and groundwater patterns). The predicted results of Scenario I revealed that, up to year 2030, the area under good quality groundwater reduced significantly from 50.35 to 28.95%, while marginal and hazardous groundwater quality area increased from 49.65 to 71.06%. Under Scenario II, the good quality groundwater area increased to 6.32% and 12.48% area possesses less hazardous quality of groundwater. It was concluded that the canal water supply should shift from good quality aquifer zone to poor quality aquifer zone for proficient management of groundwater at the study area.