Your search found 106 records
1 Liebe, J.; Andreini, Marc; van de Giesen, N.; Steenhuis, T. 2007. The small reservoirs project: research to improve water availability and economic development in rural semi-arid areas. In Kitissou, M.; Ndulo, M.; Nagel, M.; Grieco, M. (Eds.). The hydropolitics of Africa: a contemporary challenge. Newcastle, UK: Cambridge Scholars. pp.325-332.
(Location: IWMI HQ Call no: IWMI, 333.91 G000 KIT Record No: H044806)
(0.51 MB)
2 Shiferaw, B.; Kebede, T. A.; Reddy, V. R. 2012. Community watershed management in semiarid India: the state of collective action and its effects on natural resources and rural livelihoods. In Mwangi, E.; Markelova, H.; Meinzen-Dick, R. (Eds.). Collective action and property rights for poverty reduction. Philadelphia, PA, USA: University of Pennsylvania Press. pp.153-188.
(Location: IWMI HQ Call no: 333.7 G000 MWA Record No: H045634)
(Location: IWMI HQ Call no: e-copy only Record No: H046369)
(3.53 MB)
The ‘silent revolution’ is a phenomenon describing the individualistic behaviour of farmers in the adoption of intensive groundwater abstraction technologies, which in some cases has led to groundwater over-abstraction and environmental degradation in semiarid areas such as La Mancha, Spain. However, a lacuna exists as to the extent to which state politics have affected the development of groundwater abstraction technologies in Spain. With new quantitative and qualitative data from the irrigation community of Manzanares and public irrigation and colonisation plans, this report studies the adoption of groundwater abstraction technology and investigates the historical role of the state in the development of modern groundwater-fed irrigation socio-ecologies in the semiarid area of La Mancha in Spain.
4 Wagener, T.; Franks, S.; Gupta, H. V.; Bogh, E.; Bastidas, L.; Nobre, C.; de Oliverira Galvao, C. (Eds.) 2005. Regional hydrological impacts of climatic change: impact assessment and decision making. Proceedings of the International Symposium on Regional Hydrological Impacts of Climate Variability and Change with an Emphasis on Less Developed Countries (S6) held during the 7th Scientific Assembly of the International Association of Hydrological Sciences (IAHS), Foz do Iguaco, Brazil, 3-9 April 2005. Part 1. Wallingford, UK: International Association of Hydrological Sciences (IAHS). 356p. (IAHS Publication 295)
(Location: IWMI HQ Call no: 577.22 G000 WAG Record No: H046622)
(0.44 MB)
5 Oosthuizen, L. K.; Meiring, J. A.; Botes, J. H. F.; Bosch, D. J.; Breytenbach, P. 1996. Development of a decision support system for increasing the economic efficiency of water and energy use for irrigation at whole farm level in central RSA, taking risk into account. Vol. 1. Report to the Water Research Commission. Pretoria, South Africa: Water Research Commission (WRC). 58p. (WRC Report 347/1/96)
(Location: IWMI HQ Call no: 631.587 G178 OOS Record No: H046666)
(0.38 MB)
(Location: IWMI HQ Call no: IWMI Record No: H046909)
(2 MB)
7 Erkossa, Teklu; Langan, Simon J.; Hagos, Fitsum. 2014. Constraints to the development, operation and maintenance of spate irrigation schemes in Ethiopia. In Erkossa, Teklu; Hagos, Fitsum; Lefore, Nicole. (Eds.). 2014. Proceedings of the Workshop on Flood-based Farming for Food Security and Adaption to Climate Change in Ethiopia: Potential and Challenges, Adama, Ethiopia, 30-31 October 2013. Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.5-22.
(Location: IWMI HQ Call no: IWMI Record No: H046925)
Flood-based farming is among the potential options in ensuring access to water for crop and livestock production for small-scale farmers in the arid and semiarid lowlands of sub-Saharan Africa, and Ethiopia in particular. Flood-based irrigation while inexpensive is rooted in tradition in many rural communities which is in contrast to many other irrigation types which are unavailable (in terms of water source, technology or capacity) or are costly to develop. Spate irrigation has been practiced in different parts of Ethiopia for many decades, but it was only recently that it gained the government’s attention. This study was conducted through a review and informal discussion with the objectives of documenting the current status, trends and prospects of spate irrigation in the country and the associated challenges, taking cases of selected schemes in different regional states. The study revealed that spate irrigation is expanding either through improvement of traditional schemes or by developing new ones. Neither the traditional nor modern schemes are free of challenges. The traditional schemes suffer from floods that damage their diversion structures, while poor design and construction of diversion structures have led to the failure of new ones. A range of socio-technical improvements in the planning, implementation and operation of schemes is proposed, including the design of headworks and canals consistent with the size and nature of expected flows, structures to minimize sedimentation, building capacity of farmers and district officers, and monitoring and improving the management that currently adversely impacts the performance of the schemes. Consulting farmers at every stage of the development, and building the capacity of engineers to deal with the unique nature of spate flows are the most likely interventions to ensure successful agricultural production using spate irrigation.
8 Dankelman, I. (Ed.) 2010. Gender and climate change: an introduction. London, UK: Earthscan. 284p.
(Location: IWMI HQ Call no: 304.25 G000 DAN Record No: H047037)
(0.36 MB)
9 Dankelman, I. (Ed.) 2010. Gender and climate change: an introduction. London, UK: Earthscan. 284p.
(Location: IWMI HQ Call no: 304.25 G000 DAN c2 Record No: H047149)
(0.36 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H047499)
(1.01 MB)
The use of treated wastewater (WW) for irrigation is a common practice, especially in arid and semiarid agroecosystems. We aimed to evaluate the influence of long-term (up to 45 years) irrigation with WW on the soil microbial community structure, microbial activity and physicochemical properties, in comparison with soil irrigated with fresh water (FW), in a semiarid orange-tree orchard. Phospholipid fatty acid (PLFA) analysis was used to assess the shifts in the soil microbial community in response to the application of WW. Total organic carbon and available P increased significantly, by about 49% and 37%, respectively, due to WW irrigation. The urease, -glucosidase, alkaline phosphatase and dehydrogenase activities and aggregate stability were higher in the soil irrigated with WW than in that irrigated with FW. The PLFA analysis showed a significant increase in bacterial abundance, particularly in G+ bacteria. The relative abundances of fungi, G- bacteria and actinobacteria were similar in the two soils. Principal components analysis of the PLFAs showed discrimination between the FW-irrigated soil and the WW-irrigated soil, which was enriched in actinobacterial PLFA 10Me18:0. The prolonged use of treated WW for irrigation in a semiarid agroecosystem promoted the establishment of a specific and persistent microbial community that was functionally more active.
(Location: IWMI HQ Call no: e-copy only Record No: H047462)
(3.43 MB)
Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physica or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.
(Location: IWMI HQ Call no: e-copy only Record No: H047605)
(3.70 MB)
Water harvesting techniques (WHTs) improve the availability of water, which is essential for growing crops, especially in arid and semi-arid areas. A decision support approach can help in the selection of WHTs suitable under site-specific bio-physical and socio-economic conditions. This paper describes a participatory approach for the selection of suitable WHTs in watersheds in (semi) arid regions. It builds on a database of suitability indicators for WHTs, which was developed by integrating worldwide knowledge on their suitability. Once developed, the approach was applied on a case study for WHTs in the upper Geba watershed in northern Ethiopia. First, based on evaluation criteria and participants’ scientific and local knowledge, a pre-selection of most promising WHTs took place in a multi-stakeholder workshop. Next, the suitability indicators and a GIS-based multi-criteria analysis (MCA) were used to identify suitable areas for these WHTs. The results of the MCA were presented to stakeholders during a second stakeholder workshop. At this workshop, a final selection of WHTs to test was made based on a participatory ranking of WHTs using economic, ecological and socio-cultural criteria. The MCA approach was validated by comparing the predicted suitable areas with the already existing WHTs in the watershed. This led to the result that 90% of the existing check dams and 93% of the percolation ponds were correctly identified by the approach. We conclude therefore that this approach can be successfully applied for the participatory selection of WHTs and the identification of suitable areas for their implementation. Given that this approach is based on the newly developed database of WHTs, it can be easily applied in other (semi) arid regions.
(Location: IWMI HQ Call no: 338.927 G000 IND Record No: H047643)
(0.30 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H047682)
(1.29 MB)
Tigray is one of the semi-arid and drought-prone regions of Ethiopia. The rainfed agriculture is characterized by low productivity and the region faces an average annual cereal food deficit of 180 000 t. Realizing these problems, the regional government has been engaged in earthen dam irrigation development activities since 1995. So far 44 earthen dams with related irrigation facilities have been constructed. The Gumsalasa earthen dam was constructed in 1995 with a reservoir capacity of 1.9 million m3 , which irrigates about 67 ha. In Tigray the main irrigation season starts in January, which is four months after the end of the main rainy season. The reservoir is therefore exposed to evaporation during these four months. This demands formulation and implementation of an operational plan that can reduce losses and increase the benefits. In this regard, a change in reservoir operation from the present (January– June) to the proposed (September–January) has shown the possibility of increasing the irrigated area and the number of farmers. This indicates the potential of the proposed change to contribute towards regional food security if it is practised at existing and future earthen dam irrigation schemes in Tigray.
(Location: IWMI HQ Call no: e-copy only Record No: H047698)
(1.17 MB)
In Pakistan, like many of the developing countries, crop yields under dryland agriculture are very low. This field research aimed at investigating improving land and water productivities and farmers’ incomes through improved water management, crop intensification and diversification under rainfed and supplemental irrigation (SI) conditions. With improved packages (e.g. high yielding varieties, appropriate seed rates, time of sowing, and use of fertilizers) an average of 31% higher yields of rainfed wheat (Triticum aestivum) were obtained by farmers compared to their traditional practices. The net income under the improved package was about Rs. 70,000/ha (1 US$ = Rs. 72), almost double that under farmers’ current practices. The highest wheat yield of 5102 kg/ha obtained in small plots was 28% higher than for farmers’ current practices; followed by the raised bed yield of 4776 kg/ha. With only 20% extra cost for water used as SI for small plot sowing with improved practices, there was 47% higher wheat yield and over 60% higher net income obtained compared to farmers’ practices. Similarly, with about 10% additional cost for SI, groundnut (Arachis hypogea) yield and net income increased up to four times compared to farmers’ practices. It may be concluded that, in this environment, much of the yield gap between farmers and research may be closed by adopting simple and low cost integrated packages.
(Location: IWMI HQ Call no: e-copy only Record No: H047777)
(1.58 MB)
The present study focuses on drought analysis with an aim to understand the drought vulnerability, estimate and map the drought duration and severity in drought prone North Interior Karnataka region, India. A detailed analysis were carried out using rainfall data of more than 178 (with greater than 30 years data) stations to understand the drought characteristics. Rainfall descriptive variability, percentage occurrence of drought incidences and spatial distribution of rainfall were derived. In order to evaluate the drought severity and its extent and to map, method proposed by Ponce et al. (2000) and the Geographic Information System has been used. The method by Ponce et al. (2000) characterize drought based on intensity, duration and recurrence interval using mean annual precipitation of a location. The results obtained for the study area indicate that, the region is mostly semi-arid with drought occur for more than 50 % of the time. The majority of the drought events are of moderate intensity with few extreme intensity events. Further, it is noticed that, in many station, the rainfall show a decreasing trend. Since, rainfall in this region are mostly declining due to climatic change, the area would experience increasing drought severity in the forthcoming years. The outcome of the study would be useful in understanding the drought pattern, severity and extent in the study area which can be used by scientists and water management professionals to plan drought mitigation measures.
17 Kiptala, J. K. 2016. Managing basin interdependencies in a heterogeneous, highly utilized and data scarce river basin in semi-arid Africa: the case of the Pangani River Basin, eastern Africa. PhD thesis. Leiden, Netherlands: CRC Press - Balkema. 174p.
(Location: IWMI HQ Call no: 333.91 G132 KIP Record No: H047471)
(10 MB)
18 Rejani, R.; Rao, K. V.; Rao, C. H. S.; Osman, M.; Reddy, K. S.; George, B.; Kranthi, G. S. P.; Chary, G. R.; Swamy, M. V.; Rao, P. J. 2017. Identification of potential rainwater-harvesting sites for the sustainable management of a semi-arid watershed. Irrigation and Drainage, 66(2):227-237. [doi: https://doi.org/10.1002/ird.2101]
(Location: IWMI HQ Call no: e-copy only Record No: H048128)
(0.98 MB)
In the present study, the potential locations for constructing different water-harvesting structures in a semi-arid watershed located at Goparajpalli, in southern India, were derived using GIS in three stages. The locations were first identified based on land use land cover, land slope, rainfall characteristics, soil texture and soil depth. Then a number of structures and suitable semi-arid rainfed regions have limitations in their runoff potential availability; these locations were further optimized based on the runoff available after in situ water conservation and storage in existing water-harvesting structures. The surplus runoff volume available in a normal year after storage was estimated to be 870 000 m3 . Suitable locations for 25 rock fill dams (RFD), 74 farm ponds and 5 check dams were identified. These derived sites were validated by exporting to Google Earth and investigated for their suitability with ground truth information. At present, the number of structures existing is more than the optimum number of structures derived, but they have less storage capacity. Hence those structures such as farm ponds located at potential sites are recommended for desiltation and renovation by increasing their size along with lining so that they can be utilized for rainwater harvesting and supplementary irrigation. This methodology for identification of potential locations for water-harvesting structures is less time-consuming, more precise and can be utilized for the planning of large catchments to improve the water availability and productivity.
(Location: IWMI HQ Call no: e-copy only Record No: H048145)
(0.90 MB)
The study was conducted in the semi-arid areas of northern Ethiopia with the objective of evaluating the effect of surge flow and alternate irrigation on irrigation performance indicators, water use efficiency and crop yield. The experiment consists of two factors, irrigation systems (alternate furrow (Af) and conventional furrow (CF)) and irrigation flow methods (continuous (C), Surge 1 (S1), Surge 2 (S2), and Surge 3 (S3)). Eight treatment combinations replicated three times were arranged in a factorial randomized complete block design. Onion crop was used as indicator crop for the experiment because of its dominant and cash crop in the region. The result of this experiment indicated that the interaction effect of the irrigation system and irrigation flow methods did not show statistically significant difference on the performance indicators, crop yield and water use efficiency. The irrigation system (Af and CF) as a factor has not significant effect on yield of onion. However, the irrigation flow methods (C, S1, S2 and S3) were significantly affected the irrigation performance indicators (application efficiency, distribution uniformity, deep percolation and tail water runoff losses) and likewise, irrigation water use efficiency and yield of onion were significantly different. Higher crop yield (13208 kg/ha), water use efficiency (1.96–2.55 kg/m3), application efficiency (52.9–58.7%) and distribution uniformity (81.4–86.2%) were obtained from both surge flow and alternate irrigation as compared to continuous flow and conventional furrow irrigation (every furrow water application) which was recorded less 10142 kg/ha, 1.36–1.65 kg/m3, 44–54.7%, 67.1–79.6%, respectively. The result of this study explicitly showed that demonstration of these irrigation methods can enhance the poor water management practices in the semi-arid areas of Ethiopia and elsewhere in the world with limited water resources and similar soil characteristics. The authors of this paper recommend the farmers, irrigation experts, water resources managers and decision makers in the region to apply those techniques for improving water use efficiency.
(Location: IWMI HQ Call no: e-copy only Record No: H048187)
(0.92 MB)
Performance evaluation of irrigation has been an important area of research for better management of water resources. The present study was conducted to evaluate the effect of drip lateral lengths and system operating pressures on water and fertilizer application uniformity at the Indian Agricultural Research Institute (IARI), New Delhi, India. The following parameters of nutrients and water were studied to design and evaluate the performance of drip irrigation systems: (i) uniformity coefficient; (ii) discharge variation; (iii) distribution uniformity; (iv) statistical uniformity. Drip-line lengths and system operating pressures (P < 0.05 and P < 0.01) significantly affect the different parameters of fertilizer and water application. The highest values of uniformity coefficient (99.2%), statistical uniformity (99.2%) and distribution uniformity (97.4%) for irrigation water were observed at a pressure of 1.5 kg cm 2 with a 25 m long drip-line. Lower values of discharge variation (2.65%) and coefficient of variation (0.04) were observed at the same operating pressure (1.5 kg cm 2 ) and drip-line length. However, the lowest value of the uniformity coefficient (88.1%), statistical uniformity (93.7%) and distribution uniformity (93.2%) for irrigation water were recorded at 0.5 kg cm 2 pressure with a 100 m long drip-line length. The highest values of urea, potassium and phosphorus distribution uniformity were found to be 97.8, 97.1 and 98.2%, respectively, at 1.5 kg cm 2 pressure with 25 m long drip-line, and lower values of urea, potassium and phosphorus distribution uniformity (93.1, 92.6 and 93.2%, respectively) were recorded at 0.5 kg cm 2 pressure with a 100 m long drip-line. Water and fertilizer distribution uniformity decreased with increase in drip-line length, and increased with increase in system operating pressure.
Powered by DB/Text
WebPublisher, from