Development of a GIS Based Water Management Tool for a Large Scale Rice Irrigation Scheme

A GIS based model was developed to integrate the vast amounts of spatially distributed information from the Kerian Irrigation Scheme comprising eight compartments which are further subdivided into 28 blocks. The model consists of three modules. The "Scheduling" program computes irrigation deliveries based on spatial and temporal demand of the paddy field by each compartment, block or secondary canal. The "Monitoring" program gives information by compartment and by block on the uniformity of water distribution and the shortfall or excess. Relative Water Supply (RWS), Water Use Efficiency (WUE), Cumulative Relative Water Supply (CRWS), and Water Productivity Index (WPI) were computed by the "Evaluation" module. The post-season analysis uses weekly information on hydro-climatic parameters, irrigation delivery and irrigation indices by block within each compartment. On a weekly basis, RWS and WUE were found to range from 1.01 to 2.24 and 45% to 99% respectively in the main season and 1.01 to 1.87 and 53.57% to 96.15% respectively in the off season. The average values of RWS and WUE were found to be 1.53 and 68.15% in the main season and 1.33 and 78.47% in the off season respectively. The average values of WPI were also found to be 0.13 and 0.22 kg/m3 in the main season and off seasons respectively. Color-eoded thematic maps were produced for the monitoring of Seasonal Yields and Cropping Intensity (CI) by block and compartment of the scheme. The results are displayed allowing the manager to view maps, tables and graphs in a comprehensible form to ease decision making as the season progresses. This study would be useful to improve the irrigation system management based on feedback of field information

A modified empirical model for estimating the wetted zone dimensions under drip irrigation

Drip irrigation system has become one of the most common irrigation systems especially in arid and semi-arid regions due to its advantages in saving water. One of the most essential considerations in designing these systems is the dimensions of the wetted soil volume under emitters. These dimensions are significant in choosing the proper emitter spacing along the laterals and the suitable distance between laterals. In this study, a modified empirical equations for estimating the horizontal and vertical extend of the wetted zone under surface emitters were suggested. Data from published papers includes different conditions of soil properties and emitter discharge were used in deriving the empirical model using the nonlinear regression. The developed model has high value for coefficient of determination, R2. The results from the developed model were compared with results of other empirical models derived by other researchers. Some statistical criteria were used to evaluate the model performance which are the mean error ME, root mean square error RMSE, and model efficiency EF. The results revealed that the modified model showed good performance in predicting the wetted zone dimensions and it can be used in design and management of drip irrigation systems

Improving irrigation water delivery performance of a large-scale rice irrigation scheme

The availability of irrigation water and its equitable allocation in a large-scale rice irrigation scheme of Malaysia have been modeled. The model reliably estimates available water for irrigation at the intake of the main canal and simulates the recommended irrigation deliveries for 120 tertiary canals. Different water allocation and management scenarios were evaluated based on the sensitivity of the growth stages of rice to water, varying field-water demand, and perceived water shortages. The model provides a quantitative assessment not only of water allocation for irrigation but also of day-to-day or periodic irrigation delivery performances for a large-scale rice irrigation system. It provides 86% adequacy and 87% equity of irrigation delivery in the main season (August-December). The corresponding performance indicators provided by the model are 74 and 89% in the off-season (February-June). The dependability of water supply is higher in the off-season than in the main season, while the relative water supply (RWS) is the converse. RWS often becomes >1.0 in the main season, while such a RWS is rarely obtained in the off-season. The model augments the water delivery performance of the scheme and hence would serve as a useful tool for irrigation managers in decision making

Rainfall-runoff models with fractional derivatives applied to kurau river basin, Perak, Malaysia

The 5th International Conference on Agricultural and Food Engineering (CAFEi) 2021Kurau River Basin (KRB), which covers an area of 322 km² and is the main drainage artery pouring into Bukit Merah Reservoir (BMR), is located in Perak State of Malaysia. The study of rainfall-runoff processes in KRB is important because BMR plays a vital role in rice production, flood control, ecosystems, and tourism in the region. This study proposes a new approach to rainfall-runoff modeling based on the fractional calculus. A dataset of daily rainfall and streamflow has been acquired. Then, the standard linear autoregressive with exogenous input (ARX) model is identified from the dataset in the sense of least square error. We consider the ARX model as a discretized differential equation with fractional orders. Such a model with fractional derivatives is versatile to represent hysteresis, which is intrinsically linked to the real runoff processes in tropical catchment basins like KRB

Translation and Validation of Enhanced Asian Rome III Questionnaires in Bengali Language for Diagnosis of Functional Gastrointestinal Disorders

Background/AimsFunctional gastrointestinal disorders (FGIDs), diagnosed by symptom-based criteria due to lack of biomarkers, need translated-validated questionnaires in different languages. As Bengali, the mother tongue of Bangladesh and eastern India, is the seventh most spoken language in the world, we translated and validated the Enhanced Asian Rome III questionnaire (EAR3Q) in this language.MethodsThe EAR3Q was translated in Bengali as per guideline from the Rome Foundation. The translated questionnaire was validated prospectively on Bengali-speaking healthy subjects (HS, n = 30), and patients with functional dyspepsia (FD, n = 35), irritable bowel syndrome (IBS, n = 40) and functional constipation (FC, n = 12) diagnosed by clinicians using the Rome III criteria. The subjects were asked to fill-in the questionnaire again after 2 weeks, to check for its reproducibility.ResultsDuring translation, the original and the backward translated English versions of the questionnaire demonstrated high concordance. Sensitivity of the Bengali questionnaire to diagnose patients with FD, IBS, FC, and HS was 100%, 100%, 75%, and 100%, respectively, considering diagnosis by the clinicians as the gold standard. On test-retest reliability analysis, Kappa values for FD, IBS, FC, and HS were 1.0, 1.0, 0.83, and 1.0, respectively. The Bengali questionnaire detected considerable overlap of FD symptoms among patients with IBS, IBS among patients with FD, and FD among patients with FC, which were not detected by the clinicians.ConclusionsWe successfully translated and validated the EAR3Q in Bengali. We believe that this translated questionnaire will be useful for clinical evaluation and research on FGIDs in the Bengali-speaking population

The influence of magnetized water on soil water dynamics under drip irrigation systems

Soil water dynamics under drip irrigation systems are of considerable importance in designing, managing and operating these systems. Emitter discharge, soil type, soil chemical properties, crop water-requirements, and quality of applied water are the main factors affecting soil water dynamics under drip irrigation. In this study, laboratory experiments were conducted to study the effect of magnetized water on wetting pattern dimensions and water content distributions under surface emitter. Passing water through permanent or electro magnets installed on feeding pipeline resulted in producing magnetized water. Two emitter discharges (3 and 4.5 l/h, in average), two soil types (sand and clay), two soil profiles (homogeneous and layered-textural) and two water types (plain and magnetized water) were considered in the experiments. It was found that using magnetized water led to increase surface wetted radius by 6.2% and decrease vertical wetted depth by 6.3% in homogeneous soil profiles. In layered-textural soil profiles, the surface wetted radius slightly decreased by 1.8% while the vertical wetted depth increased by 7.0% in case of sand over clay and decreased by 2.0% in case of clay over sand when using magnetized water. As a result of using magnetized water, the total wetted area decreased for homogeneous profiles and increased for layered-textural profiles. It was concluded that the impact of magnetized water is statistically significant on wetted bulb dimensions and not statistically significant on water content distributions. The results revealed that using magnetized water is recommended especially in homogeneous soil profiles

Estimated evapotranspiration of rice based on pan evaporation as a surrogate to lysimeter measurement

Reference crop evapotranspiration (ET o), used to determine actual crop evapotranspiration, is often estimated from pan evaporation (EP) data. However, uncertainties in the relationship between ET o and EP often result in unreliable estimate of crop evapotranspiration. This study investigated the relationship between measured and estimated crop evapotranspirations, ET m and ET e, respectively, at tillering (9–30 days after transplanting, DAT) and mid-growth (51–72 DAT) stages of a rice variety. ET m was measured with a Marriott Tube-type Micro-lysimeter (hereafter referred to Micro-lysimeter) in a ponded rice field and ET e was estimated from EP, which was measured by employing the US Weather Bureau Class ‘A’ Evaporation Pan (hereafter referred to Class A Evaporation Pan). A strong linear relation (r 2 = 0.89) at the tillering stage and a weak relation (r 2 = 0.48) at the mid-growth stage were obtained between ET m and EP. The slope of this plot provided a pan-crop factor (K p K c), which was 0.81 at the tillering stage and 0.79 at the mid-growth stage. The ET e versus ET m relationship was also strongly linear (r 2 = 0.90) at the tillering stage but weakly linear (r 2 = 0.50) at the mid-growth stage. The pan-based method thus provided reliable estimates of evapotranspiration during the tillering stage of rice

Optimization of equitable irrigation water delivery for a large-scale rice irrigation scheme

Equitable water allocation is essential in an irrigation scheme for obtaining potential crop yields from the entire scheme, especially when water supply is inadequate. An optimization model achieved this goal by coupling an optimal water allocation model with available water supply and irrigation water demand for a river-fed rice irrigation system in Malaysia. This model consists of a paddy field water balance module and an optimization module. The outputs from the module are daily irrigation demand and surface runoff, if there is any. The optimization module consists of an objective function, which minimizes water shortage across the scheme area while maintaining equity in water allocation. This model performs optimization subject to several system constraints, and the decision variable of the model is daily releases or supply to the tertiary canals. Performance of this model remained unaffected under different water supply conditions, and the optimization model reliably examined the effects of alternate water allocation and management rules with field information. It improves efficiency and equity in water allocation with respect to crop growth stages and water shortages rather than simply cutting irrigation supply on a proportional basis to overcome water shortages

Comparison of percutaneous coronary intervention outcomes in diabetic patients with non-ST-elevation myocardial infarction having multivessel disease

Background: Diabetic patients with non-ST-elevation myocardial infarction (NSTEMI) and multivessel coronary artery disease (MVD) present unique challenges in revascularization strategy selection. This study compares the clinical outcomes of multivessel (MVR) versus single-vessel revascularization (SVR) using percutaneous coronary intervention (PCI) in such patients. Methods: A prospective observational study was conducted at a tertiary center in Bangladesh including 110 diabetic NSTEMI patients with angiographically confirmed MVD. Patients underwent either MVR (n=58) or SVR (n=52). Outcomes assessed over a 6-month follow-up included major adverse cardiovascular and cerebrovascular events (MACCE), left ventricular ejection fraction (LVEF), functional capacity (METS), and survival. Results: Baseline characteristics were comparable between groups. The MVR group had significantly more stents (2.36±0.49 vs. 1.17±0.38; p<0.01) and longer stent length (58.76±10.22 mm vs. 33.46±10.93 mm; p<0.01). MACCE was significantly lower in the MVR group (6.89% vs. 30.77%; p=0.001), with reduced myocardial infarction and revascularization rates. Both groups showed significant improvement in LVEF and METS post-PCI, with no significant intergroup difference. Kaplan–Meier analysis revealed superior event-free survival in the MVR group. Conclusions: Multivessel PCI offers superior clinical outcomes and event-free survival in diabetic NSTEMI patients with MVD, without increasing periprocedural risks. Individualized risk-benefit assessment remains essential