Search Results (4)

Groundwater depletion in arid regions poses a significant threat to agricultural sustainability and rural livelihoods. This study employs geospatial analysis and economic modeling to address groundwater depletion in the arid Barind region of Northwest Bangladesh, where 84% of the rural population depends on agriculture. Using remote sensing and GIS, we developed an elevation map revealing areas up to 60 m above sea level, exacerbating evaporation and aquifer dryness. Field data collected through Participatory Rural Appraisal tools showed farmers exhibiting “ignorant myopic” behavior, prioritizing short-term profits over resource conservation. To address this, an Increasing Block Tariff (IBT) water pricing model was developed, dividing water usage into three blocks based on irrigation hours: 1–275 h, 276–550 h, and 551+ h. The proposed IBT model significantly increases water prices across the three blocks: 117 BDT/hour for the first block (from current 100–110 BDT/hour), 120 BDT/hour for the second block, and 138 BDT/hour for the third block. A demand function (y = −0.1178x + 241.8) was formulated to evaluate the model’s impact. The results show potential reductions in groundwater consumption: 59 h in the first block, 26 h in the second block, and 158 h in the third block. These reductions align with the principles of integrated water resource management (IWRM): social equity, economic efficiency, and environmental integration. The model incorporates economic externalities (e.g., well lifting costs) and environmental externalities (e.g., crop pattern shifts), with total costs reaching 92,709,049 BDT for environmental factors. This research provides a framework for sustainable groundwater management in arid regions, potentially reducing overextraction while maintaining agricultural productivity. The proposed IBT model offers a locally driven solution to balance resource conservation with the livelihood needs of farming communities in the Barind tract. By combining remote sensing, GIS, and economic modeling, this research provides a framework for sustainable groundwater management in arid regions, demonstrating the power of geospatial technologies in addressing complex water resource challenges. Full article

Groundwater depletion in Bangladesh’s Barind tract poses significant challenges for sustainable water management. This study aims to delineate groundwater recharge potential zones in this region using an integrated geospatial and Analytical Hierarchy Process (AHP) approach. The methodology combines remote-sensing data with GIS analysis, considering seven factors influencing groundwater recharge: rainfall, soil type, geology, slope, lineament density, land use/land cover, and drainage density. The AHP method was employed to assess the variability of groundwater recharge potential within the 7586 km² study area. Thematic maps of relevant factors were processed using ArcGIS software. Results indicate that 9.23% (700.22 km²), 47.68% (3617.13 km²), 37.12% (2816.13 km²), and 5.97% (452.70 km²) of the study area exhibit poor, moderate, good, and very good recharge potential, respectively. The annual recharge volume is estimated at 2554 × 10⁶ m³/year, constituting 22.7% of the total precipitation volume (11,227 × 10⁶ m³/year). Analysis of individual factors revealed that geology has the highest influence (33.57%) on recharge potential, followed by land use/land cover (17.74%), soil type (17.25%), and rainfall (12.25%). The consistency ratio of the pairwise comparison matrix was 0.0904, indicating acceptable reliability of the AHP results. The spatial distribution of recharge zones shows a concentration of poor recharge potential in areas with low rainfall (1200–1400 mm/year) and high slope (6–40%). Conversely, very good recharge potential is associated with high rainfall zones (1800–2200 mm/year) and areas with favorable geology (sedimentary deposits). This study provides a quantitative framework for assessing groundwater recharge potential in the Barind tract. The resulting maps and data offer valuable insights for policymakers and water resource managers to develop targeted groundwater management strategies. These findings have significant implications for sustainable water resource management in the region, particularly in addressing challenges related to agricultural water demand and climate change adaptation. Full article

Cropping systems in the Level Barind Tract (LBT) of Bangladesh are highly diverse, as Transplanted (T.) Aman and Boro (T. Boro) rice are a common practice in the area. Although. T. Aman is generally cultivated in the rainy (monsoon) season, but the T. Boro rice is the intensive irrigation-based winter rice with high establishment costs as a result of exhaustive tillage and high labours for transplanting of seedlings. Furthermore, pumping of a large amount of irrigation during T. Boro cultivation declines the level of groundwater, which is not environmentally friendly nor cost-effective. Therefore, the replacement of the T. Boro rice from the cropping pattern in the LBT area is the major concern of policymakers. In this context, a replicated three to four crop-based cropping systems (CS) field trial was conducted in LBT of Gaibandha, Bangladesh for consecutive three years (2018–2020) to evaluate productivity, profitability and sustainability of the multiple crop-based cropping systems. Among these CS, existing three crops based CS, CS1: T. Aman–Potato–T. Boro (introduction of the local potato in the existing cropping system) were compared with four crops based CS2: T. Aman–Potato–Cucumber–T. Aus (Introduction of high yielding potato, cucumber and T. Aus as an improved cropping system). After two years of observations, significantly higher system productivity (rice equivalent yield; REY) was found in the improved CS2 than that of existing CS1 in both years (two years’ average 49% or 11.1 t ha⁻¹). As a result of the introduction of the high yielding potato, cucumber and T. Aus rice instead of the T. Boro rice. The CS2 was also found profitable as compared to the CS1 in terms of higher gross margin (by 74%), net return (double) and benefit-cost ratio (BCR) (1.69 vs. 1.44) due to higher gross return with slightly higher (by 28%) production cost. It is due to farmers received higher prices for potato, cucumber and two rice crops in the improved CS2 than the existing CS1. On the other hand, protein and energy output was lower (by 17% and 9%, respectively) in the CS2 than the existing CS1, due to the less content of protein and energy value in the vegetable cucumber. The results of the study revealed that crops diversification in the existing T. Boro based CS with high yielding potato, cucumber, and T. Aus rice, improved the system productivity, profitability and sustainability; which lead to improve the food security of the increasing population and also reduce the adverse effect on the environment. Full article

Landscape scale assessment of temporal variations in soil organic carbon (SOC) contents and soil pH and the implications for long-term agricultural sustainability was determined using legacy datasets collected over two periods separated by 20 years: the 1990s and 2010s. Soil data on SOC and pH were categorized according to the prevailing land types (based on inundation as highland (HL), medium highland (MHL), and medium lowland (MLL)), and physiographic types (i.e., Himalayan Piedmont plain, Tista Floodplain and Barind tract/Terrace) to determine which variable or combination of variables was more influential in spatial and temporal changes of these properties. SOC contents in the physiographic types were generally found to be low, varying between 8 to 12 g/kg. While, SOC contents were significantly higher in MHL and MLL compared with HL that experienced less inundation. The change in SOC contents over 20 years was significant with a 14.5% increase of SOC. There was a greater influence of land type compared with physiography on SOC contents over time. Inundation land types and associated cropping intensity were considered likely to influence SOC of soils under rice-based cropping systems. Furthermore, the levels of soil pH decreased by 0.5 units over 20 years with an approximately 50% increase in soils within a pH category of 4.6–5.5. The majority of soil pH results shift from slightly acidic to strongly acidic in the intervening 20-year period between samplings. Soil acidification is potentially a combination of inefficient and excess use of ammonium-based fertilizers with higher application rates and low input from residues. We conclude that acidification may continue with more intensive land use. However, trends in SOC contents over time under certain combinations of physiography and land type either increased slightly or showed a significant loss and in the latter, specifically, the role of land management is not clear. The legacy datasets would be useful for monitoring spatial and temporal soil quality trends at a regional scale, but has limited capacity to capture field level variations in soil properties as data on smallholder cropping practice and management were not collected. Therefore, future research examining the role of management in SOC and pH dynamics at the field-scale would guide the use of fertilizers, crop residue management, and amelioration of acidic soil, to improve the sustainability of rice-based cropping systems in Bangladesh. Full article