Report from Households and Water Management Organizations Quantitative Surveys

The Ganges project on ‘Water Governance and Community-Based Management’ conducted a series of household and water management organization surveys in its coastal Bangladesh study sites. This report presents the methodology and describes the results from the survey. The report can be read as a quantitative situation analysis of the area. Most of the results are desegregated by location for a comparison purpose: comparison between two types of institutions (polders/sub-projects) and comparison between three main geo-hydrologic zones (high, medium and low level of salinity). In addition, when this is relevant, the figures are desegregated by gender, by age or by poverty level. The first part of the report focuses on the methodology used for the survey, describing the sampling methodology, the instruments as well as the data collection and data entry processes. Based on the analysis from descriptive statistics, the second part of the report draws the picture of the surveyed areas in terms of poverty levels, domestic and productive water uses, agriculture and aquaculture cropping systems, livelihoods, participation and water management practices. Finally the third part presents the results from the survey conducted with Water Management Organizations, the institutional features, financial features and the activities and perceptions about these groups are analysed

Making renewable energy investments sustainable through grid-connected solar pumps in Bangladesh

The Bangladesh government plans to generate 10% of its electricity from renewable sources by 2030. The Infrastructure Development Company Limited (IDCOL), a nodal agency for renewable energy in Bangladesh, has so far installed 1,523 off-grid solar irrigation pumps (SIPs) with 42.1 megawatts (MW) capacity through an innovative fee-for-service model. These pumps have a high panel-to-pump capacity ratio to meet irrigation demands during the peak irrigation season of summer boro paddy. However, beyond the boro season, irrigation demand is limited. Over reliance on one crop for revenue generation and low usage during the off-season affect the financial viability of SIP investments. Grid integration can offer a one-stop solution for increasing the capacity utilization of solar panels and helping the government meet its renewable energy targets by utilizing the existing solar infrastructure

Institutional modalities for decarbonizing irrigation in Bangladesh

Diesel-based groundwater irrigation has been crucial in expanding dry season boro paddy cultivation in Bangladesh. Boro paddy was, in turn, instrumental in ensuring the country’s food security. But high dependence on imported diesel is a financial burden for the government. Transitioning to clean and renewable energy sources, like solar, can alleviate the government’s fiscal burden and help decarbonize the agricultural sector. Bangladesh has promoted multiple models for the diffusion of solar irrigation pumps (SIPs), ranging from the conventional subsidy-driven models of SIP ownership to the fee-for-service model that leverages private sector investments for expanding the outreach of irrigation services. The fee-for-service model promoted in Bangladesh by the Infrastructure Development Company Limited (IDCOL) is unique in the South-Asian context for bringing public-private partnership in SIP expansion. This model also offers useful lessons for the provision of affordable irrigation to smallholder farmers in the region

FR1.1: Do Water, Energy and Food Policies in Support of Solar Irrigation Enable Gender Transformative Changes in South Asia? Evidence from Policy Analysis in Bangladesh and Nepal

Solar-powered irrigation pumps (SIPs) is emerging as a popular technology to address water, energy and climate change challenges in South Asia, while enhancing livelihoods and food security. SIPs are deemed to be woman friendly renewable energy technology (RETs) because of its design, operation systems, and safety. While gender dimensions of natural resources are well documented, to what extent do water, energy and food (WEF) policies, including policies to promote SIP technologies in the countries of South Asia conceptualize and operationalize gender equality and social inclusion (GESI) are not well understood. We draw on a gender transformative analysis approach and rank WEF policies on a continuum ranging from scale of 0-3 (denoting gender blind, gender aware, gender responsive and gender transformative). We deploy this method to review 37 WEF sectoral policies of Bangladesh and Nepal. We find that while national governments are committed to gender equality and women's advancement and enshrine these principles in their Constitution, these higher-level aspirational principles are not always translated to the WEF sector policies. We find that WEF policies are aware of the need to include GESI and social equity in sectoral programming, yet operational rules for implementation of these policies often fail to the challenge structural barriers that prevent women and marginalized groups from participating in and benefiting from WEF policies, including from deployment of SIP technologies. This calls for transformation not only in the project implementation, but also in the policymaking processes of the WEF sectors in the South Asia region

Mitigation and beyond: Multiple co-benefits of solar irrigation in Bangladesh

Irrigation in Bangladesh depends primarily on imported diesel. The Government of Bangladesh (GoB) has started investing in solar irrigation pumps (SIPs) to replace diesel pumps in off-grid areas. The objective is to achieve energy security and reduce agriculture's greenhouse gas (GHG) emissions. Results from a representative survey of farmers in the command areas of the SIPs installed by the Infrastructure Development Company Limited (IDCOL) show that beyond effectively achieving the primary objective of reducing the use of diesel (mitigation), these pumps also provide other significant benefits to the farmers. The study found that these SIPs reduce farmers' cost of irrigation by 20% to 30% compared to diesel irrigation pumps, offer them access to less labor-intensive, time-saving irrigation services, and support their needs for supplementary irrigation in case of delayed monsoons

Improving equity outcomes in the solar irrigation subsidy delivery mechanism in Nepal

As of 2021, Nepal has installed over 2000 solar pumps. The Alternative Energy Promotion Centre (AEPC) provides a 60% subsidy to install these pumps. Data from AEPC shows that in the five years between 2016 and 2021, a total of 9100 farmers had applied for solar pumps, and 21% of those farmers, mainly from Nepal’s Tarai, got these pumps. The number of pumps given was limited by budget allocation but increased over time as outlays increased. The applicant pool tended to be relatively large holder male farmers from upper castes. While choosing beneficiaries for these subsidized solar pumps, officials of the AEPC managed to allocate a larger share of pumps to those with comparatively smaller landholdings, and 22% of the beneficiaries were women. However, with no formal criteria for selecting beneficiaries, the actual allocation process is subject to the discretion of the officials. Currently, the subsidy delivery policy is being revised. Transparent and inclusive criteria for beneficiary selection, greater involvement of local government institutions in the subsidy delivery process, better after-sales services, and periodic revisions of solar pump prices are recommended. These steps will likely help create demand from more diverse groups of farmers and ensure equity outcomes in the distribution of solar irrigation subsidies

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

A gravitational-wave standard siren measurement of the Hubble constant

On 17 August 2017, the Advanced LIGO 1 and Virgo 2 detectors observed the gravitational-wave event GW170817-a strong signal from the merger of a binary neutron-star system 3 . Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source 4-6 . This sky region was subsequently observed by optical astronomy facilities 7 , resulting in the identification 8-13 of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first 'multi-messenger' astronomical observation. Such observations enable GW170817 to be used as a 'standard siren' 14-18 (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic 'distance ladder' 19 : the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements 20,21 , while being completely independent of them. Additional standard siren measurements from future gravitationalwave sources will enable the Hubble constant to be constrained to high precision

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta