Hydrogeological characteristics of waterlogged areas in Natore District,Bangladesh

Waterlogging (WL) refers to the process by which water flow is resisted in vertical and horizontal directions and thus water stagnates for a short or long span of time; it is induced by a combination of human and natural factors. In the southwestern region of Bangladesh, including Natore District, WL is a significant issue that needs to be addressed if agricultural activity is to be successful. This study aimed to identify surface WL in Natore District and to characterise the WL scenario in the study area in terms of hydrogeology. Waterlogged areas were identified with a geographic information system using satellite images corresponding to the premonsoon and postmonsoon periods. Using groundwater level data (1990–2017), the pre- and postmonsoon scenarios of the waterlogged areas were indicated by seasonal and perennial types of WL. Groundwater recharge scenarios were classified as long and short lag times. Most of the study area was characterised by thick clay or silty clay surficial layers with low water penetration rates, resulting from low porosity and low hydraulic conductivity. The cross-correlation between rainfall and groundwater level revealed the response of groundwater to rainfall, with a lag time of 1–5 months. Long lag time areas exhibited slow groundwater recharge and significant groundwater level fluctuation, with lower hydraulic conductivity values of 49.37–76.24 m/day. In contrast, short lag time areas displayed rapid groundwater recharge and small groundwater fluctuation due to a good proportional relationship with rainfall and higher hydraulic conductivity values of 74.74–117.79 m/day.

     

江苏典型地区水稻与小麦字实中元素生物富集系数（BCF）初步研究

在分析研究了约500套水稻籽实-耕层土及约300套小麦籽实-耕层土样品相关元素含量等地球化学调查数据基础上,报道了江苏典型地区水稻与小麦籽实中Cd、Hg、Cu、Pb、Zn、Cr、As、Se、Mo、Mn、Fe、K、Ca、Mg等14个元素的生物富集系数(BCF)分布状况,统计结果显示,各元素的BCF值差异较大,通常Pb、Cr、Fe等元素BCF多小于1%,Hg、As、Mn、Ca等元素BCF多为1%～10%,Mo的平均BCF最大、Fe的平均BCF最小。研究发现,水稻与小麦籽实中Pb与Cd超标率分别超过15%、6%,BCF值差异与稻谷、小麦的元素含量无直接关系,部分元素的BCF与土壤pH、TOC、CEC、B含量等具有统计上的相关性,其中土壤pH与Cd、Ca、Mg元素的BCF呈显著负相关,而土壤的有机碳含量、阳离子交换量及B含量等也对部分元素的BCF值有一定影响。     

Delineating flood risk areas in Greater Dhaka of Bangladesh using geoinformatics

This paper illustrates the development of flood hazard and risk maps in Greater Dhaka of Bangladesh using geoinformatics. Multi-temporal RADARSAT SAR and GIS data were employed to delineate flood hazard and risk areas for the 1998 historical flood. Flood-affected frequency and flood depth were estimated from multi-date SAR data and considered as hydrologic parameters for the evaluation of flood hazard. Using land-cover, gemorphic units and elevation data as thematic components, flood hazard maps were created by considering the interactive effect of flood frequency and flood water depth concurrently. Analysis revealed that a major portion of Greater Dhaka was exposed to high to very high hazard zones while a smaller portion (2.72%) was free from the potential flood hazard. Flood risk map according to administrative division showed that 75.35% of Greater Dhaka was within medium to very high risk areas of which 53.39% of areas are believed to be fully urbanized by the year 2010.     

Geomorphological features of Northwestern Bangladesh and some problems on flood mitigation

The northwest region of Bangladesh is divided into four geomorphological units which show different flood features. The region has suffered severe flood damage both in 1987 and 1988. After these floods Bangladesh Action Plan for Flood Control was established by the World Bank. In the northwest region the plan proposed two major projects, namely, an interceptor drain and a diversion channel. A Polder Project is also going on in this region. However these major projects are mainly on structural methods and require much cost for long embankments. The author suggests smaller but reasonable projects combining structural and non-structural methods in the region.     

机电井地下水灌溉系统分析及其技术效率——河北省机电井地下水灌溉系统的实证研究

基于对河北省机电井系统的实地调查,建立了机电井系统供水量的随机边界生产函数模型.研究结果表明,所有制、治理机制和系统规模等是影响机电井系统技术效率的主要因素,非集体所有制的技术效率明显优于集体所有制.同时对如何引导灌溉系统的持续高效发展提出了一些政策建议.     

Challenges of value chain actors for vegetable production and marketing in North-East Bangladesh

GeoJournal - Vegetable farming in Northeast Bangladesh has developed rapidly over the last 10 years, with limitations to field management and marketing. A survey was conducted in...     

Biotechnology and the future of rice production

Rice breeders are looking to basic bioscience and biotechnology for help in the solution of important problems that conventional breeding methods have not satisfactorily solved. Among these problems are durable resistance to recalcitrant pests and diseases such as yellow stem borer, gall midge, sheath blight, bacterial leaf blight, blast and tungro virus, and tolerance of abiotic stresses such as drought, salinity and submergence. Nutrient use efficiency, yield potential and efficient hybrid rice production are additional problems for which biotechnology solutions are envisioned. IRRI's biotechnology program emphasizes techniques such as molecular markers, anther culture and DNA fingerprinting that accelerate conventional breeding, and also techniques such as wide hybridization and genetic engineering that broaden the gene pool that breeders can exploit. IRRI's experience in adopting and adapting biotechnology for use in its own breeding program is shared with the national agricultural research systems of Asia through the Asian Rice Biotechnology Network.     

2-D electrical imaging in some geotechnical investigation of Madhupur clays,Bangladesh

Electrical imaging or electrical tomography is a survey technique suitable for the investigation of areas of shallow complex geology, where the use of other electrical and electromagnetic techniques is less effective. An electrical image has been delineated at a site located in front of the Department of Geological Sciences, Jahangirnagar University, Dhaka, Bangladesh. 16 soil samples were collected from two boreholes located on the image line and geotechnical parameters such as unit weight, water content, grain size, plastic limit, liquid limit and plasticity index were measured in the laboratory. These geotechnical parameters were compared with the measured electrical resistivity.     

Holocene deformation and crustal movements in some type areas of India

Recent crustal movements have been observed and studied in several parts of India including the Himalayan and sub-Himalayan regions, the Precambrian shield of peninsular India and also the coastal tracts. The results of studies of Holocene deformation and crustal movements in two type areas are presented, one in the extreme southeastern part of the peninsula and the other in northeastern India.The Precambrian shield in the extreme southeastern part is characterised by a major NE—SW trending fault zone in the Tirupattur—Mattur areas of Tamil Nadu with some major extended faults, one of which apparently cuts through the entire crust and Moho as indicated by gravity data and which is associated with occurrences of alkaline and basic intrusions and carbonatite complex. Evidence of Recent crustal movements in this zone is afforded by geomorphic features and recent and current seismicity of a mild nature which is apparently to be attributed to slow movements along the fault plane.The Shillong plateau in northeastern India occurs as block-uplifted horst, comprising for the most part Archaean crystalline rocks with plateau basalts and Cretaceous and Tertiary sediments occurring on its southern margin. The plateau is bounded by major faults and is located in a zone of high seismicity lying astride and parallel to the eastern Himalayas intervened by the alluvium of the Brahmaputra Valley. Geomorphic features such as raised terraces, straight-edged scarps, etc., provide evidence for Recent crustal movements with dominant vertical movements along the fault planes which have continued through Tertiary and Recent times. Repeated precision levelling measurements conducted by the Survey of India indicate a rate of uplift of 4–5 cm per 100 years during the period 1910–1975.The gravity data pertaining to this region are also discussed in relation to the crustal movements.     

Seismotectonic studies of the coastal areas of India,Pakistan, Bangladesh,and Burma

Major geotectonic elements that are seismically active in the near-shore areas of the Indian subcontinent are the Mekran fault off the coast of Pakistan, the western part of the Narmada-Son lineament, the West Coast Fault off the west coast of India - a southward extension of the Cambay Rift, the Palghat Gap, the Godavari and Mahanadi grabens, transecting rather at an angle to the eastern coast of India and the Arakan-Yoma arcuate belt of Burma, which is a part of the global Alpine-Himalayan orogenic belt, continuing southwards into the Andaman-Nicobar island complex and the Java-Sumatra trench on the ocean floor of the advancing Indo-Australian Plate.The coastal belt exhibits varied degrees of seismicity from intensely seismic areas, like the Mekran coast off Pakistan, Kutch (India) and the Arakan-Yoma belt of Burma, with earthquake magnitudes of more than 8.0, while the intervening coastal areas of the Peninsular India are moderately seismic to aseismic. The remaining areas, namely, the major part of the coastal belt of Bay of Bengal in India and Bangladesh are broadly aseismic. However, the active Godavari graben and the eastern part of the coast of Bangladesh are frequented by low to moderate magnitude earthquakes. An extension of the active Arakan-Yoma belt in the Bay of Bengal in the form of the Andaman-Nicobar Island complex is highly seismic with a maximum earthquake magnitude of more than 8.0, while the Lakshadweep-Minicoy island complex, situated on the Chagos-Laccadive ridge is moderately seismic. This broad picture of coastal and marginal seismicity is corroborated by the geodynamics of the northern part of the Indo-Australian Plate.Observations along the coastal areas during historic and recent times, however, confirm the absence of significant tsunamis, though very mild tsunami surges have occasionally been observed along the coastal areas of the Bay of Bengal. No active volcanoes are known to exist in the coastal areas.Water reservoirs situated near the marginal areas of the Peninsular Shield exhibit moderate to intense seismic activities, viz. Ukai, Bhatsa, Koyna, Parambikulam, Sholayar, Idduki, and Kinnersani.     

Variations in technical infrastructure and private economic activity in the rural areas of Southern Poland

Restructuring the Polish countryside is a complex and urgent task. Adapting agriculture for EU entry will mean a considerable reduction in employment and rural diversification is needed because other sectors of the national economy will not be able to absorb all the displaced people if they arrive in the towns. However, providing non-agricultural employment in rural areas depends to a large extent on the technical infrastructure available: running water, sewerage systems, gas supply and telecommunications. The paper deals with voivodeships in southern and southwestern Poland (formerly Galicia) and shows that while much progress has been made since the end of the communist period, the inherited inequalities are being perpetuated and in some cases increased. However, even where the infrastructure is satisfactory, private business does not develop at a uniform rate and action is needed to stimulate communities in remoter rural areas, particularly in the eastern part of the study region. This revised version was published online in July 2006 with corrections to the Cover Date.     

Stable isotope of some selected Egyptian pectinids and their paleoenvironmental implications

Eight pectinid shells were collected and subjected to quantitative study using δ¹⁸O and δ¹³C isotopic analysis in order to study the paleoenvironment which prevailed during their calcification. The scalerochronological variations in δ¹⁸O and δ¹³C values, among these shells are also discussed. The Early Miocene pectinid shells display highly depleted δ¹⁸O and δ¹³C signature as a result of paleo-meteoric water with heavy rainfall that was produced by Tropical Cyclones when the Mediterranean Sea was open. The Early Pliocene pectinid shells reveal depleted δ¹⁸O values, related to the influx of fresh water influenced by monsoonal activity following the formation of the Tibetan Plateau. Their enrichment in the δ¹³C isotopic excursion is referred to high productivity of the Indian Ocean, which was the main source of the Red Sea water. The Pleistocene pectinid shell shows highly depleted δ¹⁸O and δ¹³C signature with obvious diagenetic shell structure, indicating that a wetter humid climate prevailed during the Early–Middle Pleistocene and long sub-arial exposure of the shell. The Recent Mediterranean pectinid shell displays slight enrichment in δ¹⁸O and δ¹³C values referring to deeper inhabitation of this species with a low temperature and high salinity environment. The scalerochronological variations in both δ¹⁸O and δ¹³C values, along these shells is referred to seasonal variations or kinetic effects.     

Farm income,inequality, and poverty among farm families of a flood-prone area in Bangladesh: climate change vulnerability assessment

GeoJournal - This paper examines the farm income differences, income inequality of farm households, parameters of income variability that ascertain vulnerability levels, and cost-income variability...     

Feasibility and acceptability study of rainwater use to the acute water shortage areas in Dhaka City,Bangladesh

This study explored the feasibility and acceptability of harvested rainwater in rural communities of Bangladesh as well as densely populated City like Dhaka, using simple and low-cost technology. As a part of this study, a field survey was conducted in the water-scarce Dhaka City. Four slums were selected for conducting questionnaire survey. A questionnaire was furnished to know some information such as the socio-economic condition for those slum dwellers and family information, housing condition, sanitation condition, health condition, economic condition, existing water supply condition, knowledge about rainwater, willingness to accept rainwater, etc. Two hundred people from different representative groups were selected randomly. Yield after spillage and yield before spillage models were developed to know the actual rainwater availability and storage conditions, which were used to justify the effective tank size. Cost-benefit analysis and feasibility analysis were performed using the survey results and the research findings. A sensitivity analysis was performed to check the important parameters toward the implementation of the system as well. The results showed that cost was the most sensitive parameter (48.1%), the second highest sensitive parameter was roof area (25.9%) and the lowest sensitive parameter was demand (2.2%). The study showed that the low-cost rainwater harvesting technique was feasible and acceptable to the slum dwellers as the only potential alternative source of safe drinking water.     

A study of trace elements in lithotypes of some selected Indian coals

Ashes of the lithotypes from some Indian coals were analyzed by emission spectroscopy for some selected elements. Based on the combined concentration and differential fixation, the elements Pb and Co appear to be supplied by the woody portion of the proto-coal material whereas Ga, Nb, Ni, Cr and In can be attributed to the non-woody portions of the proto-coal. On the other hand, Cu, Mo and part of the available Cr appear to come from both organic and inorganic sources, whereas V, Mn, Sr, La and Ba have been attributed to an extraneous inorganic source. The differential fixation of the trace elements appears to be mainly dependent on the physicochemical environment of the basin.     

Modernization of the migrant women in Dhaka,Bangladesh: analysis of some demographic variables

The author analyzes the demographic variables as signes of urban adaptation and modernization by poor females as a result of the influence of rural-urban migration. The migrant females show their ability and change or modify their rural values in terms of various demographic issues by living in the urban areas. They are able to modernize themselves by adopting new knowledge and can develop individual thinking against the traditional values as well as maintaining some traditions in the city. They develop practical ideas and self-consciousness with respect to life and family.     

Tillage and farm manure affect root growth and nutrient uptake of wheat and rice under semi-arid conditions

Tillage systems affect soil properties, crop growth and nutrient uptake under various agro-ecological conditions. The uptake of water and nutrients are largely dependent on the root systems of wheat (Triticum aestivum L.) and rice (Oryza sativa L.). The application of manure has direct influence on the nutrient uptake by the crop plants. A 2 year field experiment was conducted to evaluate the impact of tillage and farm manure on root growth by measuring the root length density on a sandy clay loam (Typic calciargid soil). Three tillage systems were used; (i) minimum tillage (MT), (ii) deep tillage (DT) and (iii) conventional tillage (CT). Three farm manure levels were used; (i) FM₀ (only chemical fertilizers), (ii) FM₁₅ (farm manure at 15 Mg ha^?1) and (iii) FM₃₀ (farm manure at 30 Mg ha^?1). The incorporation of farm manure into soil markedly improved the root length density (RLD) of both wheat and rice crops. For wheat, the application of FM₃₀ increased RLD by 16% and 9% in cases of deep tillage and minimum tillage, respectively. For rice, the increase in RLD at the same farm manure rate (FM₃₀) was 13% and 17%, during first and second year, respectively. Averaged across tillage, the trend of RLD for both wheat and rice was DT > CT > MT. The incorporation of FM has increased the uptake of N, P and K significantly (P < 0.05), thereby increasing the agronomic parameters. The manure may be used to ameliorate the deleterious effects of tillage for sustainable crop yield.