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The stilling basin of the Taunsa barrage is a modified form of the United States Bureau of Reclamation (USBR) Type-III basin, which consists of baffle and friction blocks. Studies revealed uprooting of baffle blocks due to their vertical face. Additionally, the literature highlighted issues of rectangular face baffle blocks: less drag, smaller wake area, and flow reattachment. In contrast, the use of wedge-shaped baffle blocks (WSBBs) is limited downstream of open-channel flows. Therefore, this study developed numerical models to investigate the effects of USBR and WSBB basins on the hydraulic jump (HJ) downstream of the Taunsa barrage under lower tailwater conditions. Surface profiles in WSBB and modified USBR basins showed agreement with previous studies, for which the coefficient of determination (R2) reached 0.980 and 0.970, respectively. The HJ efficiencies reached 57.9 and 58.6% in WSBB and modified USBR basins, respectively. The results of sequent depths, roller length, and velocity profiles in the WSBB basin were found more promising than the modified USBR basin, which further confirmed the suitability of the WSBB basin for barrages. Furthermore, WSBB improved flow behaviors in the basin, which showed no fluid reattachment on the sides of WSBB, increased wake regions, and decreased turbulent kinetic energies. HIGHLIGHTS Investigation of hydraulic jumps in the WSBB basin at lower tailwater using FLOW-3D was studied.; Also, comparison of hydraulic jumps and energy dissipating index between WSBB and modified USBR baffle block basins was studied.; Performance assessment of different hydraulic parameters was carried out by employing regression analysis.;

The hydraulic performance of stilling basins is affected by their size and geometry. Taunsa Barrage, Pakistan, was constructed in 1958 and remodelled in 2008. In remodelling, baffle and friction blocks were replaced by chute blocks and dentated sill. After remodelling, sounding, and probing data during 2010–2014 revealed that flexible apron in front of some bays was washed away. This study quantified hydraulic parameters such as free surface, flow depth, Froude number, roller length, velocity, hydraulic jump efficiency, and turbulent kinetic energy for stilling basins before and after remodelling using FLOW-3D. Comparing results with the literature showed that results in the old stilling basin were closer to the literature results. The results of old stilling basin showed linear trends of tailwater depths with Froude number and roller lengths. Results of the new stilling basin deviated from the literature results because relatively weak trends of tailwater depths with the Froude number and roller lengths were revealed; velocities were higher on the basin's floor; energy dissipation was less, and there was more turbulent kinetic energy on downstream. In conclusion, hydraulic studies for other discharges, tailwater levels, and turbulence models have to be conducted to analyze hydraulic issues in the new stilling basin. HIGHLIGHTS Investigated the flow behaviour in different stilling basins using FLOW-3D.; Assessment of energy dissipation in the stilling basins using numerical models.; Investigated the hydraulic jump and its effective parameters in the stilling basins.;

The Indus River System is a major source of life in Pakistan. A vast array of Pakistan's agricultural and domestic consumption needs are critically dependent on the Indus River System. The Indus River contributes towards 25% of the country's gross domestic product, providing water for almost 90% of the food production in Pakistan. Linked to the water security issues, Pakistan is potentially at risk of facing a severe food shortage in the near future. The World Bank report of 2020–2021 estimates that the water shortage will increase to 32% by 2025, which will result in a food shortage of almost 70 million tons. Water shortage could also result in confrontation between the provinces as river sharing has always been a source of problem for Pakistan. According to recent estimates, siltation and climate change will reduce the water storage capacity by 2025 to almost 30%. As for the per capita water storage capacity in Pakistan, it is about 150 m3, which is quite meagre in comparison with that in other countries. Irrigated agriculture will soon be adversely affected due to the reduced surface water supplies and the consequent increase in groundwater abstraction. To make matters worse, over the past decades, a great deal of distrust has developed among the provinces of Pakistan regarding the water distribution issue, and the successive federal governments have failed to formulate a cohesive inter-provincial National Water Policy. Along with the shortages and increasing demand for water, administrative corruption also plagues the water sector and is quite common. The beneficiaries of this water reallocation system are not only the rural elite, for example the large and politically influential landlords, but also the small and medium capitalist farmers. If not properly addressed, these complications of decreasing water resources could result in serious political and economic hostility among the provinces. If it wants to harness its potential to increase storage capacity, Pakistan must improve its water-use efficiency and manage its groundwater and surface water resources in a sustainable way. Strengthening the institutions and removing mistrust among the provinces are the key elements for maintaining a sustainable irrigated agriculture in the Indus Basin. HIGHLIGHTS Indus River, a major source of life in Pakistan.; River sharing has always been a source of problem and confrontation between the provinces of Pakistan.; The paper highlights various problems in Pakistan's Indus Basin.; It also gives several recommendations for improving sustainability in Pakistan's Indus Basin.;

Pakistan’s biggest province in terms of area, Baluchistan appears to have been affected from the climate variability since last few decades. No substantive research works have been carried out in analyzing the precipitation variability in Baluchistan and linkage to large-scale teleconnection. The goal of this paper is to determine possible linkages of precipitation with large scale atmospheric and oceanic circulation indices in the months which have shown changes in precipitation trends in Baluchistan. These climate indices may be the possible predictors for the precipitation in Baluchistan in the respective months. Mann-Kendall (MK) statistical test was used to identify the monthly significant precipitation trends in thirteen meteorological stations located in four regions of Baluchistan. The noteworthy trend out of significant trends is selected using Theil and Sen’s slope (TS). Decreasing trend is identified in January whereas increasing trend is identified in June mostly in stations located in North Eastern region of Baluchistan (Region1). The changes in the significant trend in January and June under the influence of climate indices are then determined by Partial Mann-Kendall (PMK). Empirical Orthogonal Function (EOF), Principal Component Analysis (PCA), correlation technique between Principal Components (PC) of Region1 precipitation and climatic Indices are used to filter out the relevant climatic indices. It is found out that North Atlantic Oscillation (NAO), Equatorial Indian Ocean Zonal Wind Index (EQWIN), ENSO Modoki Index (EMI) on annual scale whereas Pacific Decadal Oscillation (PDO), Atlantic Multi-decadal Oscillation (AMO) on decadal scale are influencing the January precipitation. It is also found out that El Nino Southern Oscillation-Multivariate ENSO Index (ENSO-MEI), EMI, NAO, PDO and AMO are influencing the June precipitation. These are the dominating indices explains the precipitation variability in January and June in this Region1. This research will impart awareness in the society from the impact of precipitation trend variability.

Drought has great negative impacts on crop growth and production. In order to select appropriate drought indices to quantify drought influences on crops to minimize the risk of drought-related crops as much as possible, climate and spring wheat yield-related data from eight sites in the Qinghai Province of China were collected for selecting better drought index between standardized precipitation evapotranspiration index (SPEI, denoting meteorological drought) and soil moisture deficit index (SMDI, denoting agricultural drought) as well as the key parameters (timescale and month) in denoting drought impacts on spring wheat yields. The spring wheat yields during 1961–2018 were simulated by the DSSAT–CERES–Wheat model. Pearson correlations were used to investigate the relationship between SPEI and SMDI and between spring wheat yields and drought indices at different timescales. The results showed that: (1) SMDI reflected more consistent dry/wet conditions than SPEI when the timescales changed and (2) There were one- and two-month lags in SMDI compared to SPEI (with the higher correlation coefficients values of 0.35–0.68) during May to August and (3) May (the jointing period of spring wheat) and the two-month timescale of SMDI0–10 (with the higher correlation coefficients values of 0.21–0.37) were key parameters denoting drought influences on spring wheat yield and (4) The correlations between the linear slopes of spring wheat yield reduction rate and linear slopes of SMDI0–10 in May at the studied eight sites were considerable between 1961–2018 (r = 0.85). This study provides helpful references for mitigating the drought risk of spring wheat.

Inhabited by almost 20 million people, Karachi, also known as the “city of lights”, houses almost 60 percent of the industries in Pakistan and is considered as the financial and industrial center of the country. The city contributes almost 12–15 percent to the gross domestic product (GDP), showing its significance in Pakistan’s economy. Unfortunately, with the increase in population, the city is facing a serious shortage of water supply. The current allocation of water among the city’s districts is not equitable, which has caused water scarcity and even riots in some areas. Surface water and ground water are the two primary sources of water supply in the city. The water supply provided by Karachi Water and Sewerage Board (KWSB) is approximately 650 million gallons per day (MGD) against a demand of 480–866 million gallons per day (MGD), resulting in a serious shortfall. Keeping a holistic view in mind, this paper focuses specifically on proposing measures to address the gap in proposing concrete solutions to manage Karachi’s increasing water woes. It also proposes a water allocation mechanism and uses Nash bargaining theory to address the inefficient and unequal water distribution. Results indicate that our suggested policies and water allocation mechanism have the potential to simultaneously resolve the supply–demand mismatch and water shortage problems of the city.

Cotton leaf curl is devastating disease of cotton characterized by leaf curling, vein darkening and enations. The disease symptoms are induced by DNA satellite known as Cotton leaf curl Multan betasatellite (CLCuMuB), dominant betasatellite in cotton but another betasatellite known as Chili leaf curl betasatellite (ChLCB) is also found associated with the disease. Grafting experiment was performed to determine if host plant resistance is determinant of dominant population of betasatellite in cotton (several distinct strains of CLCuMuB are associated with the disease). Infected scion of Gossypium hirsutum collected from field (the source) was grafted on G. arboreum, a diploid cotton species, resistant to the disease. A healthy scion of G. hirsutum (sink) was grafted at the top of G. arboreum to determine the movement of virus/betasatellite to upper susceptible scion of G. hirsutum. Symptoms of disease appeared in the upper scion and presence of virus/betasatellite in the upper scion was confirmed via molecular techniques, showing that virus/betasatellite was able to move to upper scion through resistant G. arboreum. However, no symptoms appeared on G. arboreum. Betasatelites were cloned and sequenced from lower scion, upper scion and G. arboreum which show that the lower scion contained both CLCuMuB and ChLCB, however only ChLCB was found in G. arboreum. The upper scion contained CLCuMuB with a deletion of 78 nucleotides (nt) in the non-coding region between A-rich sequence and βC1 gene and insertion of 27 nt in the middle of βC1 ORF. This study may help in investigating molecular basis of resistance in G. arboreum.

Environmental changes and global warming have direct impact on human life. Estimation of these changes in various parameters of hydrologic cycle is necessary for future planning and development of a country. In this paper the impact of environmental changes and global warming on temperatures of Pakistan has been studied. The temperature changes in Pakistan have been extracted from simulations made using EdGCM model developed at Columbia University. Simulation study to the end of 21st century is executed using the model for GHG (Greenhouse Gases) scenario with doubled_CO2 and scenario of Modern_Predicted SST (Sea Surface Temperature). The model analysis has been carried out for seasonal and annual changes for an average of last 5 years period from 2096-2100. Maps are generated to depict global temperature variations. The study divides Pakistan into five (05) main areas for twenty six (26) stations. A part-plan of globe focusing Pakistan is generated showing the five divisions for twenty six (26) data stations of Pakistan. This part plan is made compatible with grid-box resolution of EdGCM. Eagle-Point Engineering software has been used to generate isohyets of interval (0.5oC) for downscaling GCM (Global Climate Model) grid data to data stations. The station values of different seasons and annual changes are then compared with the values of base period data to determine changes in temperature. It is observed that impact of global environmental changes on temperature are higher (i.e. there is an increase in annual temperature for double_CO2 experiment) at places near the Arabian Sea than areas located away from this sea. It is also observed that the temperature increase will be more in winter than that in other seasons for Pakistan.

Inorganic hollow spheres have a great potential in many fields, such as calcium phosphate (Ca 3 (PO 4 ) 2 ) as carriers of active ingredients and local delivery. They are typically synthesized by the methods that reply on template-based strategies. However, the template residue and energy consumption during template removal are drawbacks. Currently developed template-free methods remain challenges such as time, cost and complicated procedures. In this paper, we introduce a general low-cost and template-free precipitation method with simple procedure. A series of inorganic hollow spheres, including calcium phosphate, calcium fluoride, strontium phosphate, strontium fluoride, barium phosphate and barium fluoride via magnesium were successfully synthesized, respectively. Based on these experimental results, a new model is proposed to explain the mechanism of the hollow inorganic spheres formation. This paper provides a general method to synthesize inorganic hollow spheres, which may have an important indication to other systems. [ABSTRACT FROM AUTHOR]