Original Research Paper
Water Harvesting
Binata Roy; G M Tarekul Islam; A.K.M. Saiful Islam; Biswa Bhattacharya; Md. Jamal Uddin Khan
Abstract
Pre-monsoon (March-May) flash flood in the northeast Haor region of Bangladesh has drawn much attention due to its early onset, high frequency, and adverse impact on the Boro crop. To understand its past changes and future occurrences, a trend analysis is carried out on the observed 3 - hourly water ...
Read More
Pre-monsoon (March-May) flash flood in the northeast Haor region of Bangladesh has drawn much attention due to its early onset, high frequency, and adverse impact on the Boro crop. To understand its past changes and future occurrences, a trend analysis is carried out on the observed 3 - hourly water level data and daily rainfall data of the Haor region using the Mann-Kendall test, Trend-Free Pre-Whitening test, and Sens slope estimator. A statistically significant increasing trend is found for the relative water level. The trend in rainfall is increasing, though it is not statistically significant. From the observed record, the peak of the flash floods is found to be arriving early in late March-early April (instead of late April-early May), coinciding with the harvesting period of the Boro crop. The early arrival of the flash flood can cause catastrophic damage to the Boro crop in future flash floods. None of the current Boro varieties BRRI dhan28, BRRI 36, BRRI dhan69, BRRI dhan88 are safer to save Boro from early flash floods experienced in recent years. To escape the Boro crop from an early flash flood, Boro varieties with a shorter growth duration should be introduced. This helps crop productivity.
Original Research Paper
Irrigation Efficiency
Seyed Mostafa Tabatabaee Amiri; M. H. Ahmadpour; M. M. Doustmohhamadi; Mousa Maleki
Abstract
In this study, irrigation evaluation of different cultivars of Rapeseed and barley in 2017-2018 crop year was performed in Sharifabad farm of Qamroud section of Qom. The result led to optimization of cultivation and improved productivity water is in two products, Brassica napus and barley. The Groundwater ...
Read More
In this study, irrigation evaluation of different cultivars of Rapeseed and barley in 2017-2018 crop year was performed in Sharifabad farm of Qamroud section of Qom. The result led to optimization of cultivation and improved productivity water is in two products, Brassica napus and barley. The Groundwater EC of this farm is salty. Due to the salinity tolerance threshold of barley, barley was predicted without yield reduction. But in canola crop due to less tolerance to salinity, crop reduction was predicted. During one crop season, Brassica napus was cultivated in eleven cultivars by irrigation method, the planting date started from October 26 to October 17, In tape irrigation, it was irrigated between 10 and 13 times. The objectives of this study were a case comparison between different cultivars of Brassica napus, both foreign and domestic, resistance of cultivars to cold and water consumption and productivity and yield and most importantly a comparison between irrigation methods in terms of water consumption and water efficiency. Meanwhile, Hayola Shirazi cultivar had the highest yield among all cultivars in the type irrigation system with the lowest water consumption. The efficiency of this figure is about 0.77 kg/m3 was calculated in the type irrigation method with water efficiency of 0.66 kg/m3 compared to gravity irrigation (surface) which has a productivity of 0.20 kg/m3. In hydroflow irrigation, it performed better than the previous two methods, but consumed more water (about 34.2%) than type irrigation. Regarding barley, it was cultivated in three cultivars and two types of irrigation methods, Fajr 30 cultivar increases water productivity by 2.2 by irrigating the type.
Original Research Paper
Irrigation Network
Khairul Rahmah Ayub; Aminuddin Ab. Ghani
Abstract
In stormwater management systems, a swale is one of the flow control-at-source facilities. The application of swale with a subdrainage channel in Malaysia urban areas is new and promising to control urban flash floods. Rainfall-runoff infiltrate to the subdrainage can be stored and become proper irrigation ...
Read More
In stormwater management systems, a swale is one of the flow control-at-source facilities. The application of swale with a subdrainage channel in Malaysia urban areas is new and promising to control urban flash floods. Rainfall-runoff infiltrate to the subdrainage can be stored and become proper irrigation sources and increase the benefits of water productivity due to maximize the income and profits either in agricultural yield or as non-portable water supply. Observed flow rates gained in this study, were used to validate Manning’s (n) equation that developed through the previous study that recommended to be used in designing subdrainage channel. The performance of flow capacity in a single module of the swale subdrainage channel is also discussed. An experimental setup was carried out in a six-meter flume by using the River Engineering and Urban Drainage Research Centre (REDAC) module as a subdrainage channel or ecological subsurface module. These physical model test runs were conducted to evaluate the efficiency of hydraulic capacity due to backwater or blockage effects at the end of the channel. Three gate scenarios were applied to represent the blockage. Manning roughness coefficient influenced inversely proportionate by flow capacity with maximum value is 0.020. It shown in the subdrainage module, the main parameter that controls the flow attenuation is module roughness itself. It is concluded that the developed equation for Manning’s prediction has been validated through a good and significant agreement between predicted and observed results with an R2 value of 0.77.
Original Research Paper
Groundwater Productivity
TANVI ARORA
Abstract
The electrical conductivities of rocks and soils are highly dependent of the water saturation. Variations in electrical resistivity are monitored by time lapse electrical resistivity tomography (TLERT) during a long duration pumping test. This experiment is carried out in the Experimental Hydrogeological ...
Read More
The electrical conductivities of rocks and soils are highly dependent of the water saturation. Variations in electrical resistivity are monitored by time lapse electrical resistivity tomography (TLERT) during a long duration pumping test. This experiment is carried out in the Experimental Hydrogeological Park (EHP) located in Choutuppal, 45 km south-east of Hyderabad. Vadose zone of EHP comprises an uppermost thin layer of red soil (<1m), sandy regolith (1m-3m), saprolite (3 m – 15 m), and then the fissured granite. The pumping test lasts for 5 days and the piezometric variations are between 13 m and 18 m during pumping in CH03 borehole. This fissured granite is characterized by an important horizontal fracture density controlling the flow. An East West profile was laid with 48 electrodes and 3 m spacing interval. CH03, pumping well, was in the center of the profile covering 8 observation wells in both directions. 27 time-lapse datasets were inverted using Res2Dinv adopting least square inversions. The inverted resistivity datasets seem to be correlated with weathered profile and the variations of resistivity may be correlated with variation of hydraulic head. The variations of resistivity are more important close to CH03 and decreases with distance away from it. This behavior is coherent with the depression cone created by the pumping. Moreover, resistivity variations in the vadose zone highlight an influence of the pumping on the water content evolution of this zone. The observed heterogeneous response seems to be correlated with the geological media heterogeneity. TLERT appears to be a powerful tool to follow dynamic behavior of both saturated level and vadose zone for a given event. Grounwater punping monitoring helps to the water content evolution and groundwater productivity.
Original Research Paper
Ecohydrology
Shafi Noor Islam; Sandra Reinstädtler; Albrecht Gnauck
Abstract
The physical characteristics of geographic location, river morphology, and the monsoon climate render Bangladesh highly vulnerable to natural disasters, primarily floods and cyclones. River flood has exerted a more significant impact on the culture, society, and economy of Bangladesh. The Ganges-Brahmaputra-Meghna ...
Read More
The physical characteristics of geographic location, river morphology, and the monsoon climate render Bangladesh highly vulnerable to natural disasters, primarily floods and cyclones. River flood has exerted a more significant impact on the culture, society, and economy of Bangladesh. The Ganges-Brahmaputra-Meghna (GBM) river carries 2.4 billion tonnes of sediments annually, and these sediments are settled on the bed of the major rivers channel and the remaining portion carried into the Bay of Bengal. The newly emerged land in the river channel is called char or diara. Purba Khas Bandarkhola Mouza is a unique char and revenue village located in the Padma River basin. The char people and the settlements of char-lands are under threat due to floods and char-lands erosion. The Padma is a meandering river and has a high river bank and char-land erosion and accretion character in the channel. The excess water during the monsoon causes widespread flooding that damages char-land settlements, agricultural crops, infrastructures, communication networks, and livelihood. Purba Khas Bandarkhola Mouza of Char-Janajat union is highly affected by annual floods and char-lands erosion. As a result, char people have to move, and settlements have to be relocated from one place to another, within the char/or outside the char. The dwellers are displaced from the char and again come back to the native char when the new land emerges in the river channel. This study aims to develop a comprehensive plan for char-land sustainable settlement, people sustainability, and livelihood in the Padma River channel. The study is carried out based on primary and secondary data sources. The results show that the average interval of displacement is every five years at Purba Khas Bandarkhola Mouza. The cyclic dislodgment range is 90 km² ranges and pulls, and push factors are the root cause of displacement. Therefore an integrated management plan is necessary for the char-land livelihood, migration, and settlement sustainability.
Original Research Paper
Groundwater Productivity
Mushtak Ahmed Gharbi; Abdulkarem Ahmed Alalwany; Ahmed Fawzi Shfig; Saeideh Parvizi
Abstract
The present study examines the chemical properties of the groundwater in the Wadi Al-Mohammadi basin, which is located between the cities of Ramadi and Hit in the Upper Euphrates region. The study is conducted based on the field, geomorphological and geological study of the study area. The water quality ...
Read More
The present study examines the chemical properties of the groundwater in the Wadi Al-Mohammadi basin, which is located between the cities of Ramadi and Hit in the Upper Euphrates region. The study is conducted based on the field, geomorphological and geological study of the study area. The water quality of some wells in the region was monitored during 2017, for irrigation according to the FAO Standard and their classification according to Richards. The results of the laboratory analysis showed that all of the well water under study exceeded the criteria for use of irrigation. Therefore, it is not recommended to use it in the Wadi Al-Mohammadi basin because it is saline water, where the values of electrical conductivity, which is a factor affecting agricultural use, ranged between 3.68-7.51dS/m-1 for wells 7 and 5, respectively, while the SAR ratio ranged between 7.20 - 183.6 for wells 7 and 2, respectively. Wells (5,4,1), according to Richard's chart, 1954, were classified as C4-S2, medium and very high, and wells (2,6,3,7) C4-S4, C3-S3, C4-S3, C3-S1, respectively. With continuous use, salt accumulations are formed which eventually lead to salinization of the soil and increasing the state of the problem of desertification and conversion of agricultural lands from producing to unproductive lands. In the case of its use, the methods for accuracy management intentions and selection of soil types as well as cultivation and selection of plants resistant to salinity and reducing the state of degradation of those soils within the valley should be followed. This causes increasing crop productivity.
Original Research Paper
Water and Soil Conservation
Shiva Mohammadian Khorasani
Abstract
Improving water and soil productivity and its management by considering soil structure, soil textures and soil physics parameters are an important criterion for the suitable management of soil and water resources. One of the relatively new methods proposed to explain soil structure in a quantitative ...
Read More
Improving water and soil productivity and its management by considering soil structure, soil textures and soil physics parameters are an important criterion for the suitable management of soil and water resources. One of the relatively new methods proposed to explain soil structure in a quantitative manner is the so-called fractal geometry concept. In this concept, by determining the fractal dimension of bulk soil, the stability of aggregates can be quantitatively analyzed at different scales. The objective of this study has been to quantify the soil structure stability using some classic indicators and also fractal approach in a large scale. Consequently, 41 intact soil samples were taken from an agricultural area and their particle size distribution, soil bulk density and aggregate bulk density, were measured. The weighted mean diameter and geometric mean diameter of both dry and wet aggregates were measured using the dry and wet sieving method. The fractal dimensions of all dry and wet aggregates were obtained using the fractal models of Mandelbrot, Tyler-Wheatcraft and Rieu-Sposito. The results indicated that fractal dimensions of the number-size model of Mandelbrot for dry sieve series and the number-size model of Rieu-Sposito in the wet sieve series perform quite well (R2=0.82). These two models could have the suitable determination coefficient with classical geometric mean and weighted mean diameters of aggregates (R2=0.69).
)
