A conceptual framework for including irrigation supply chains in the water footprint concept: gross and net blue and green water footprints in agriculture in Pakistan

The water footprint (WF) concept is a generally accepted tool introduced in 2002. Many studies applied water footprinting, indicating impacts of human consumption on freshwater, especially from agriculture. Although the WF includes supply chains, presently it excludes irrigation supply chains and non-beneficial evapotranspiration, and calculations for agriculture start from crop water requirements. We present a conceptual framework distinguishing between traditional (net) WFs and proposed gross WFs, defined as the sum of net WFs and irrigation supply chain related blue WFs and as the sum of green WFs and green WFs of weeds. Many water management studies focused on blue water supply efficiency, assessing water losses in supply chain links. The WF concept, however, excludes water flows to stocks where water remains available and recoverable, e.g. to usable groundwater, in contrast to many water management approaches. Also, many studies focused on irrigation technology improvement to save water. We argue that not only irrigation technology should be considered, but whole water supply chains, also distinguishing between surface and groundwater, to improve efficient blue water use in agriculture. This framework is applied to the Pakistani part of the Indus basin that includes the largest man-made irrigation network in the world. The gross blue WF is 1.6 times the net blue WF leading to a K value (ratio of gross and net blue WF) of 0.6. Surface water losses vary between 45 and 49 %, groundwater losses between 18 and 21 %. Presently, efficient irrigation receives much attention. However, it is important to take irrigation supply chains into account to improve irrigation efficiency. Earlier WF studies showing water scarcity in many regions underestimate agricultural water consumption if supply chains are neglected. More water efficient agriculture should take supply chain losses into account probably requiring water management adaptations, which is more a policy than an agriculture task.

Evaluation of Rain Water Harvesting Systems for coping water shortage in the Upper Blue Nile Basin, North West Ethiopia

Background The applicability of rainwater harvesting structure is very poor while the intended purpose is achievable in the Blue Nile basin. Therefore, this research was initiated to evaluate the performance of a rainwater harvesting structure and put possible strategies for dry season challenges. The study carried out for three years in the North West Ethiopia. Methods The data were analyzed using daily water balance model and other performance indicators (number of water day, relative irrigation supply, runoff storage efficiency and marginal rate of return). Results At the inception, it was established that the existing rain water harvesting system performs very low, runoff storage efficiency below 46%, no zero water day above 50%, relative irrigation supply below 27 % and marginal rate of return from 12 to 65%. However the greater the volume of the rain water harvesting structure the higher runoff storage efficiency, higher relative irrigation supply, and lower no water day under different irrigation technique was achieved. Conclusions For attaining household irrigation water demand in the dry season, the user should adopt storage capacity of 630m3 in Nitisol and 361m3 in Vertisol for double cropping and 273 m3 in Rigosol for supplemental irrigation. Hence, applying rainwater harvesting technologies with efficient water management technique enhance the net benefit of the system.

Simulating the Shallow Groundwater Level Response to Artificial Recharge and Storage in the Plain Area of the Daqing River Basin, China

Water shortage and overexploitation of groundwater (GW) have become the key factors restricting the development of the Xiongan New Area (XNA), the environmental management of Baiyangdian Lake, and the social and economic development of surrounding areas. This study used a numerical GW flow model to quantitatively analyze the changes to the shallow GW level and GW reserves of the plain area of the Daqing River Basin over the next 15 years (2021–2035) under different artificial recharge schemes with the south to north water diversion project (SNWDP) acting as the GW recharge source. The results showed increasing GW storage and GW levels and that the regional GW resources are in a positive equilibrium state. The rates of change of the well irrigation supply scheme and the joint river-well irrigation supply scheme in the XNA will increase by 14.56% and 11.04% by 2035 as compared with the current situation. The well irrigation recharge scheme for the XNA was determined to be the most effective when comparing with the effects of the different artificial recharge schemes on the GW levels and recharge. This study provides a reference for the management and protection of aquifers in other areas suffering serious GW overexploitation.

THE ROLE OF IRRIGATION SUPPLY OF GROUND WATER IN CHANGING THE ENVIRONMENTAL CONDITIONS OF IRRIGATED AREAS

В статье рассматривается взгляд автора и материалы исследований формирования ирригационного питания грунтовых на орошаемых землях и анализ его влияния на изменение экологических условий. Если влияние орошения мелиорируемых почв осуществляется на площади непосредственной реализации мелиоративных мероприятий, то его влияние за счет увеличения инфильтрационного питания грунтовых вод перераспределяется на значительные территории на иерархических уровнях от локального до бассейнового. The article discusses the author's view and research materials on the formation of irrigation nutrition of ground on irrigated lands and the analysis of its impact on changes in environmental conditions. If the influence of irrigation of reclaimed soils is carried out on the area of direct implementation of reclamation measures, then its influence by increasing the infiltration supply of groundwater is redistributed to significant territories at hierarchical levels from local to basin.

Modeling Future Streamflow for Adaptive Water Allocation under Climate Change for the Tanjung Karang Rice Irrigation Scheme Malaysia

Spatial and temporal climatic variability influence on the productivity of agricultural watershed and irrigation systems. In a large irrigation system, the quantification and regulation of the flow at different locations of the channel is quite difficult manually, leading to a poor delivery of supply and demand. Water shortage is a crucial issue due to mismatch between available water and demand at intake point of Tanjung-Karang Irrigation Scheme. This study assessed the potential impacts of climate change on basin outflow for 2010–2039, 2040–2069, and 2070–2099 to the baseline period (1976–2005) and used it as input hydrograph to simulate river discharge. A Hydrologic Engineering Corps Hydrologic Modeling System (HEC-HMS) model driven by projections from ten global climate models (GCMs) with three scenarios (Representative Concentration Pathways (RCPs) 4.5, 6.0, and 8.5) used to simulate the outflow and the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model applied for hydraulic modeling. The projected seasonal streamflow showed a decreasing trend for future periods. The average available irrigation supply for historical period is 15.97 m3/s, which would decrease by 12%, 18%, and 21% under RCPs 4.5, 6.0, and 8.5, respectively. Projected irrigation supply showed oversupply and undersupply to the required supply during the growing season. Simulated discharge could therefore be incorporated into cropping practices to boost the sustainable distribution of water under the new realities of climate change in the future.

Analysis of Farmers' Perceptions on Privatisation of Irrigation Supply in the Nandom District of Upper West Region, Ghana

Water is an important and non-substitutable input in agricultural production. Its adequacy and quality supply is a necessity for sustainable production. However, it is increasingly getting scarce due to poor rainfall and inefficiency in use of available water. To improve the reliability of agricultural water supply, there are arguments to the effect that water needs to be privatised and treated as an economic good with an efficient price scheme. But what farmers, in reality, think about this idea of privatising irrigation is vital as they are the ultimate beneficiaries. This study therefore assessed the perception of farmers towards privatising irrigation supply using cross-sectional data collected from 240 randomly sampled famers from different households in four communities in the Nandom District. With descriptive statistics involving simple frequencies and measure of association, perceptions of farmers were analysed. The study revealed that farmers generally perceived privatisation will ensure wider provision of irrigation schemes in remote locations, make operators respond better to farmers’ needs as well as ensure service sustainability. Farmers, however, were concerned about affordability of irrigated water to the resource poor farmers when it is privatised. They were of the view that, priority might be put on profit maximisation at the expense of social welfare in a market oriented irrigation system. The study therefore recommends that the Government of Ghana, under the ‘One-village One-dam’ flagship initiative should encourage and regulate private investment in the supply of irrigation to ensure affordable and sustainable supply of the services to interested farmers.