Impact of crop diversification on livelihood improvement and sustainable land management in Chattogram Hill Tracts of Bangladesh

The study was conducted at Sorai union of Lama Upazilla under Bandarban district of Chattogram Hill Tracts. It was found that total 19 plant species including bamboos, timbers and fruit crops have been widely cultivated in the area. Among the species five bamboo (Mitinga, Baijja Muli, Borak and Kali), six timbers (Acacia, Eucalyptus, Garjon, Teak, Gamar and Rubber) and eight fruits (Mango, Olive, Papaya, Guava, Coconut, Hog pulm, Orange and Betel nut) were recorded. Bamboo based agro-forestry modules were developed and practiced which produced a very good cropping diversification to sustain the crop productivity, protection of land sliding, soil erosion, water shade and soil fertility in the hill areas. It has been observed that farmers’ have a very good positive attitude and perception in diversified cropping system to get better yields than mono cropping agricultural practice at their home- stead and farm- lands. It has a very good opportunity to make the crop diversification for sustainable production of hill farming and resource management. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(1): 1-8

Behaviour of Conventional Concrete Treated with Robo Sand and Iron Shavings

This paper deals with impact of M-sand utilization rather than ordinary fine total (N-Sand) and iron shavings as far as volume of cement to improve the elastic nature of the matrix material. Basically, concrete is a composite material invented in ancient period for construction purpose. Out of the total volume of concrete 30% of volume filled with fine aggregate which is brought from digging of rivers, lakes, and canals, which causes serious tread to environment by land sliding. Now this research is carried out to identify the suitability of alternative material instead of natural sand. In this context manufactured sand produced from crushing of basalt stone is being replaced in various percentages as 0%, 20%, 40%, 60%, 80% and 100% in the place of natural sand for M25 Grade concrete. Also Iron shavings was added at 0%, 2%, 4%, 6%, 8% and 10% for total volume of concrete.

Desain Dinding Penahan Tanah sebagai Perkuatan Pada Kelongsoran Villa di Hambalang

Landslide is one of major issue that occurred during rainy season. This problem is straightforward and able to be prevented with installing reinforcement into the designated landslide location prior to sliding failure. It is effective due to the reinforcement cutting through failure plane, hence strengthen the soil body. By and large, prior to land sliding, several indications are taken into place, such as soil cracking, structural cracking, vegetation movement, etc. By observing this event, one should be aware that further soil movement are very likely to follow afterwards. Consequently, safety precaution shall be taken. This paper presents one case study in Hambalang, Bogor, West Java, Indonesia. In this case, structural crackings are found in several places, especially at the poolside. These are appeared earlier this year, concurrently with very high intensity rainy season which is predicted to be the cause. Analysis is performed to check the current stability of the slope. The result is showing that the Safety Factor value is 1.181, below the allowable value of 1.5. Then, reinforcement is designed as a preventive measure. It is using retaining wall by employing bored pile coupled with sufficiently thick capping beam. From analysis, the safety factor is increased to 1.553 during critical condition. This value is above the criteria of 1.5 and concluded as a safe design. Structural capacity of bored pile is also designed. Accordingly, the retaining wall is constructed on site in final stage

Drainage Basin of Lake Kivu in the Western Rift of East Africa and Hazards Potential

A series of ArcGIS-generated maps were applied in analysing the potential for flooding and landslide hazards within the Lake Kivu drainage basin. This study was carried out using digital elevation data of the basin. The Kivu drainage basin encompasses an area of 7,382 km2. Sediment and water supply to Lake Kivu originate mostly from its eastern hinterland. The distribution of land sliding potentiality in the drainage basin shows that the northern and the southern portions of the basin are the ones with relatively low risk of land sliding, whereas the rift shoulders are most prone to land sliding. Mass wasting on slopes has the potential to grade downstream into debris and mudflows, promoting in turn further erosion and flooding. Keywords: drainage, Kivu, Africa, flooding, landslide, hazard

Performance of Photocatalytic Concrete Blended with Artificial Sand and Iron Shavings

Summary: This paper deals in the midst effect of M-sand usage instead of fine aggregate, TiO2 and iron shavings in terms of volume of concrete to improve the tensile nature of the concrete material. At present larger part of the structures built with solid material namely concrete. Concrete is a composite material arranged by including pounded rocks as course total, normal sand burrowing from conduits as fine total ,bond or lime as restricting material and adequate measure of water at specified extents to shape gel. Nowadays the quality of natural sand is degrading and digging at higher depth in water ways leads to land sliding etc. The atmosphere is being polluted due to the harmful gases and toxic byproducts that are released during the production of cement. The present research deals with finding the alternative material for minimizing the problems caused by fine aggregate and binding material. In this context, we are working by means of the stand-in of usual sand by means of manufacture sand producing from crushing of larger boulders into fine particles of required size in cubical shape in various percentages such as 20%, 40%. … (Volume batching) till occurring optimum percentages. At M-sand optimum percentage, we are partially replacing TiO2 instead of cement in various percentages such as 4%, 8%… in addition to that we are adding Iron shavings to concrete volume to improve tensile nature of the conventional concrete

Landslides and other damage to buildings and infrastructures following the April–May 2015 earthquake sequence, Solukhumbu District, Eastern Nepal

The study focuses on the eastern margin of the zone affected by the April–May 2015 earthquakes, i.e. the Dudh Koshi River section between the Khari Khola and Monjo (Solukhumbu District). Visits before and after the earthquake sequence allowed us to assess the geomorphic changes caused by the earthquakes and the subsequent monsoon. These changes are characterized by land sliding (rock falls, rockslides, landslides, gullies and debris flows), and cascading processes, which supplied coarse debris into rivers (bed load).The impact of the earthquakes on buildings, trails and existing infrastructures (canals, hydropower plants) was also investigated. While the age and construction quality of buildings are of some import, other parameters such as the nature and depth of colluvial deposits appear to be significant factors likely to amplify the effects of ground shaking, as observed on large block fields south-west of the Khari Khola catchment, which might be inherited from former undated seismic events.

Stock Price Natural Disaster: A Case of Pakistan Cement Sector

Current The aim of current study is to investigate the impact of natural disaster on stock market in case cement sector of Pakistan. The approach of current study is to explore the effect of natural disaster on change in stock price in a given index. The study has used event study methodology to explore the relationship. Stock markets react differently from certain natural disaster events. The natural events, flood, earthquake, extreme temperature, land sliding, has significant effect on stock prices and its effect on share price volatility. All evidence provide from Pakistan stock exchange.

Hydraulic Parameters for Sediment Transport and Prediction of Suspended Sediment for Kali Gandaki River Basin, Himalaya, Nepal

Sediment yield is a complex phenomenon of weathering, land sliding, and glacial and fluvial erosion. It is highly dependent on the catchment area, topography, slope of the catchment terrain, rainfall, temperature, and soil characteristics. This study was designed to evaluate the key hydraulic parameters of sediment transport for Kali Gandaki River at Setibeni, Syangja, located about 5 km upstream from a hydropower dam. Key parameters, including the bed shear stress (τb), specific stream power (ω), and flow velocity (v) associated with the maximum boulder size transport, were determined throughout the years, 2003 to 2011, by using a derived lower boundary equation. Clockwise hysteresis loops of the average hysteresis index of +1.59 were developed and an average of 40.904 ± 12.453 Megatons (Mt) suspended sediment have been transported annually from the higher Himalayas to the hydropower reservoir. Artificial neural networks (ANNs) were used to predict the daily suspended sediment rate and annual sediment load as 35.190 ± 7.018 Mt, which was satisfactory compared to the multiple linear regression, nonlinear multiple regression, general power model, and log transform models, including the sediment rating curve. Performance indicators were used to compare these models and satisfactory fittings were observed in ANNs. The root mean square error (RMSE) of 1982 kg s−1, percent bias (PBIAS) of +14.26, RMSE-observations standard deviation ratio (RSR) of 0.55, coefficient of determination (R2) of 0.71, and Nash–Sutcliffe efficiency (NSE) of +0.70 revealed that the ANNs’ model performed satisfactorily among all the proposed models.

Designing of buildings and structures at land sliding and slide hazardous segments of slopes

The main document of the regulatory framework for the design of buildings and structures on landslide and landslide-prone areas is DBN.1.1-46:2017 «Engineering protection of territories, buildings and structures from landslides and landslides. The main provisions» and the state standard DSTU-N B V.1.1-37:2016, «Manual on engineering protection of territories, buildings and structures from landslides and landslips». In development of the provisions of this set of regulatory framework, a number of regulations and standards have been developed to ensure the construction of buildings and structures on landslide and landslide-prone areas, considering the complex geological and hydro geological conditions of the construction site.

Experience of Weak Soil Reinforcement by Soil-Cement Elements Manufactured by Deep Soil Mixing Technology

Problematic issues of construction and operation in complex geotechnical conditions are systematized (subsiding and peaty soil, silt, filled, man-made soil, saturated, land sliding and seismically hazardous territories, densely developed areas) by the means of reinforcing soil massif by vertical soil-cement elements (SCE) using deep soil mixing (DSM) technology. The practical solution experience of highly efficient “man-made soil-cement base – foundation – structure” systems is shown by the example of complex geotechnical conditions under static and dynamic influences (including earthquakes and critical failure man-made loads), and excavation using SCE. A decreasing in a settlement of soil-cement bases of buildings by 2 – 4 times compared to natural soil massif and increasing in soil-cement mechanical features by 2.5 times has been established. The options of decreasing the seismic hazard (increasing the seismic stability of soil) for securing the emergency-free operation of oil storage vertical steel tank in case of the varying intensity earthquakes utilizing the man-made soil-cement base has been justified.