The fate of agriculture in Pakistan is predominantly concerned with excessive water mining threats to the subsurface water resources. The current study integrates the Visual MODFLOW-2000 application to estimate the water balance of an aquifer bounded by the Chenab River in the West and the Ravi River in the East, which covers an area of about 2.98 million hectares. An assimilated method of groundwater flow is employed to characterize the flow dynamics of the Rechna Doab aquifer. The Digital Elevation Model (DEM) produced by the Shuttle Radar Topography Mission (SRTM) and a mesh of discretized cell size (2500 m) were incorporated into the model design. The conceptual model of the alluvial aquifer involves trifold vertical boundaries (an initial fold thickness set up to 150 m). The model input parameters are precipitation, seepage through irrigation, return flow, recharge, hydraulic conductivity and evapotranspiration. Empirical relations are established (at the basin scale) for the discharge input of irrigation canals. Model results confirm that groundwater flow follows the topographic configuration of the study area (i.e., northeast to southwest), and the seepage from irrigating canals and rainfall appeared to be the main source of groundwater recharge among various resources. The zone budget study under steady state simulation showed that the total direct recharge to the aquifer is calculated as 522,910 acre foot. The simulated water balance of the studied aquifer reflects more fluctuations in river leakage. The predictive optimized model reflects an adaptation of canal lining and installation of additional tube wells that will minimize canal seepage by 70% and lead to the reclamation of 37,000 acres of water-logged land for normal cropping.
1 January 2018 in Polish Journal of Environmental Studies
We evaluated morphometric parameters of the Haro River drainage network to determine flooding potential in the river basin. The drainage network is derived from topographic maps while using shuttle radar topography mission digital elevation model (SRTM-DEM) and geographic information systems (GIS). A total of 2917 streams (dendritic to semi-dendritic) are recognized, among which 1,536 are identified as first-order streams, followed by 731 as second order, 360 as third order, 173 as fourth order, 78 as fifth order, and 39 as sixth order. Linear and areal morphometric parameters revealed lower values for form factor (0.25), stream frequency (0.99), and drainage density (0.84 km/sq. km), which suggest that the basin is being elongated with permeable strata; whereas lower values of mean bifurcation ratio (2.0) and relief ratio (20.68) indicate less potential for flooding in the main river channel. Understanding drainage morphometry could bring better hydrological solutions for similar studies.
High strength concrete is widely used in engineering structures. Present work is an effort for suitability assessment of river bed aggregates in high strength concrete to be used at structural units of Dam (Spillway & Powerhouse) and the vulnerability of placed concrete expansion. Multiple sizes of coarse aggregate (5-20mm, 20-40mm, and 40-80mm) from Beor river bed material have been tested for physical (water absorption, crushing index, soundness, shape, and bulk density), and mineralogical characterization. Concrete Mix Design (CMD) for Spillway has been optimized using Fly ash and river aggregate that achieved the Unconfined Compressional Strength (UCS) up to 32.5 MPa. The accelerated mortar bar test (AMBT) has been introduced to gauge the reactive aggregates used in CMD.. Expansive properties of concrete were observed at the age of 7 days and 28 days that demonstrate more expansion of the specimen with slag rather than the Fly ash. Results of AMBT suggest that a minimum proportion of GGBS (40%) is needed to limit the AMBT expansion to less than 0.1% for crushed river bed aggregate and sand from the Beor source. The petrographical characterization of coarse aggregate shows the presence of deformed quartz in the coarse aggregate, which directly relates to water absorption (Wa), suggesting its suceseptility to Alkali-Silica Reaction (ASR). Modifications in Pozzolanic additives in CMD indicates that 30% mixing of Fly ash can reduce the expansion rate of concrete up to 96.15%.