Opportunities and challenges for implementing managed aquifer recharge models in drought-prone Barind tract, Bangladesh

This study focuses on the Barind tract, a drought prone area situated in the north-west region of Bangladesh where inadequate rainfall and limited surface water have created high dependence on groundwater for irrigation and other purposes, leading to significant declines in groundwater level. Managed aquifer recharge (MAR) offers a potential solution to restore groundwater levels. This study sets out to identify the opportunities and challenges for implementing MAR in the Barind tract. To accomplish this aim, different data sets including bore log lithology, rainfall, groundwater levels, information about re-excavated ponds, dighis, kharies, beels, check dams, rubber dams, dug wells and other necessary information were collected from the Barind Multipurpose Development Authority (BMDA) and other sources and analyzed. Major opportunities for MAR are identified for about 2000 km of re-excavated kharies (canals) containing about 750 check dams, more than 3000 re-excavated ponds, a number of beels (comparatively large marshes) and other water bodies which are used to conserve runoff storm water for supplementary irrigation. The conserved water can be used for groundwater recharge and subsequently abstracted for irrigation. Furthermore, roof-top rain water from buildings can also be used for groundwater recharge purposes. In contrast, the major challenges include the high turbidity of storm water runoff leading to clogging of MAR structures, inadequacy of conventional direct surface methods of recharge due to the presence of a 15 m or more thick upper clay layer with limited percolation capacity, and lack of practical knowledge on MAR. Therefore, overcoming the challenges for MAR application is a prerequisite to maximize the opportunities from MAR that can support the sustainable use of groundwater resources.

Inclusion of Bivalve in Carp Polyculture Ponds Managed by Small Indigenous People Under Barind Tract

The present experiment was carried out in the household ponds (0.04 to 0.08 ha in area with 1.3 to 2.4 m in depth) of small indigenous people at Barind Tract region, northwest Bangladesh during September, 2017 to June, 2018 to know the growth performance of bivalve with carp. Two different treatments with 3 replicates were used, in treatment one (T1) only the carp polyculture was performed and in treatment two (T2) carp and bivalve polyculture was performed. Good quality of carp fingerlings (Labeo rohita, Gibelion catla, Cirrhinus cirrhousus, Hypophthalmichthys molitrix and Ctenopharyngodon idella) and freshwater bivalve (Lamellidens marginalis) seeds were stocked in the ponds. Stocking density and size of the seeds were similar for all of the study ponds. During the experiment there were no significant differences was observed in growth performance of the fishes between the two different treatments (p<0.05). The weight gain was recorded for L. rohita 420.31 g in T1 and 436.25 g in T2, for G. catla 237.01 g in T1 and 329.66 g in T2, for C. cirrhosus 263.53 g in T1 and 301.74 g in T2, for H. molitrix 559.6 g in T1 and 593.57 g in T2, for C. idella 510.11 g in T1 and 619.57g in T2. The weight gain of L. marginalis was 12.3 g in T2. During this experiment the production of carp was recorded 2524.5 kg/ha in T1 and 2618.2 kg/ha in T2 and the bivalve production was 1284.4 kg/ha in T2. This study is the first report on growth performance of bivalve with carp in the Barind Tract region of northwest Bangladesh. The result of this study will be helpful for the development of bivalve aquaculture in this climatically vulnerable region. J. Bio-Sci. 29(2): 99-110, 2021 (December)

Using market mechanism to stimulate sustainable use of the non-renewable environmental resource (groundwater) in Barind Tract of Bangladesh

Agriculture, the main economic driver of Barind Tract, is highly dependent on groundwater for surface water paucity in the area. Notwithstanding, farmers use water capriciously due to its low price that makes a substantial drop in the water table. In this context, the research attempts to determine a market-based water pricing mechanism to encourage an optimal use of the scarce non-renewable resource. Required data was collected by questionnaire survey, Focus Group Discussion (FGD), Contingent Valuation Method, expert-opinion survey and subsequent literature works. The results reveal that depletion level has arrived at 20, 11, 7.5 feet in high, mid and low tract respectively over the last 22 years, which results in a number of economic-environmental externalities in the area. The research monetarily evaluated the cost of externalities and incorporated it with the marginal cost of extraction to increase efficiency of an existing pricing system. Regarding human reaction to price elasticity, the new price can be a reliable attempt to reduce an overconsumption pattern of water. Quantity of consumed water can be reduced to 14190.4 m3, 17759.59 m3 and 38510.6 m3 in a year in high, mid and low tract area respectively with its implementation. The research will serve as an initiative to conserve the valuable groundwater resource for future generations by managing consumer practice.

Can Effective Drought Index (EDI) successfully characterise meteorological drought and seasonal agricultural losses?

&lt;p&gt;The nature and characteristics of drought are not like a flood, cyclone or storm surge since droughts cannot easily be tracked and are difficult to quantify as a distinct event. In this study, we examined the characteristics of meteorological drought occurrence and severity using the Effective Drought Index (EDI), including the drought events, drought chronology, onset and ending of drought, consecutive drought spells, drought frequency, intensity and severity, using North-Bengal of Bangladesh as a case study. The rainfall and temperature dataset of Bangladesh Meteorological Department (BMD) for the study region throughout 1979-2018 is utilised. The trends of drought are detected by using the Mann-Kendall test and Sen Slope estimation. We evaluated the performance of EDI using the Standardized Precipitation Index (SPI), historical drought records and rice production. The study finds that seasonal and annual droughts have become more frequent in all seasons except pre-monsoon. In addition, the largest decrease in seasonal EDI is found in the monsoon in both Teesta floodplain and Barind tract. In decades prior to the late 2000s, a drought spell typically started between March to May (&amp;#177; 15 days) and ended with the monsoonal rainfall in June/July. In the years since the last 2000s, monsoon and post-monsoon droughts spells have significantly increased. Overall, the peak intensities of droughts are higher in the Barind tract than in the Teesta floodplain, and the frequency and severity of moderate to severe drought are increasing significantly in the Barind tract. Though EDI is strongly correlated with the SPI index, EDI and rice production have a non-linear relationship and are not significantly correlated. Hence, this research suggests that there are other significant influences on yield rather than just climatological drought (e.g. irrigation, lack of technology and management etc.).&lt;/p&gt;

Postnatal development and egg morphometry of different breeds of pigeon available at northern Barind tract in Bangladesh

Pigeon farming, like chicken and duck farming, is getting popularity nowadays in Bangladesh. The present study was conducted on the postnatal development and morphometry of egg of different breeds of pigeon available at northern Barind tract of Bangladesh. The study was conducted at thirty selected pigeon farms of three districts (Rajshahi, Natore and Pabna) of northern Barind tract of Bangladesh. The postnatal development (weight gain of squabs) of five groups (D0, D7, D14, D21, D28; D=day), and morphometry of eggs (egg weight, egg width (short axis), and length (long axis)) of breeds of pigeon (n=20, each breed) available at northern Barind tract in Bangladesh were collected and analyses with Duncan's Multiple Range test (DMRT). Considerable differences in the postnatal weight gain and egg morphometry were found among breeds of pigeon. The mature body weight of Giribaz, Kormona, Nun and Owl breeds of pigeon were below 300 gm; Satinette, Mookee, Suachandan, Lakkha, Jacobin, Bokhara, Shirajee, Homer and Pouter were 300-500 gm, and King and Strasser were below 800 gm. The postnatal weight of an age group was significantly different (p<0.05) from other age groups of all studied breeds. The highest egg length was 4.37±0.02 cm in Strasser, and the lowest was 3.68±0.01 cm in Giribaz pigeon. The highest egg width was 3.24±0.19 cm in Mookee, and the lowest was 2.73±0.02 cm in Giribug pigeon. The highest egg weight was 21.20±0.49 gm in Strasser, and the lowest was 14.00±0.23 gm in Owl pigeon. Moreover, a relationship between the body weight and egg length, width and weight of pigeons was observed in pigeons of all studied breeds. Asian J. Med. Biol. Res. September 2020, 6(3): 594-598