Your search found 87 records
1 Sik, Y. K.; Young, C. J.; Kyu, C. J.; Gwon, S. J.; Woong, K. J. 2000. Effects of rainfall amount on nitrogen and phosphorous concentrations in runoff from a paddy field. In ICID, Asian Regional Workshop on Sustainable Development of Irrigation and Drainage for Rice Paddy Fields - Proceedings, July 24th to 28th, 2000, Tokyo Japan. Tokyo, Japan: ICID. Japanese National Committee. pp.249-253.
Paddy fields ; Rice ; Rainfall ; Nitrogen ; Runoff ; Water quality ; Monitoring ; Fertilizers ; Experiments ; Measuring instruments ; Precipitation / Korea Republic
(Location: IWMI-HQ Call no: 631.7.2 G570 ICI Record No: H027891)
2 Giakoumakis, S.; Tsakiris, G. 2001. Experimental validation of a linearized kinematic wave equation for micro-catchment water harvesting design. Water Resources Management, 15(4):235-246.
Catchment areas ; Water harvesting ; Catchment areas ; Water harvesting ; Design ; Soil properties ; Runoff ; Flumes ; Rainfall ; Simulation ; Soil water ; Measurement
(Location: IWMI-HQ Call no: PER Record No: H029559)
3 McCarthy, N.; Vanderlinden, J. P. 2004. Resource management under climatic risk: A case study from Niger. The Journal of Development Studies, 40(5):120-142.
Resource management ; Common property ; Pastoralism ; Livestock ; Rainfall ; Climate ; Risks ; Land management / Niger
(Location: IWMI-HQ Call no: PER Record No: H035309)
4 Walker, S.; Tsubo, M.; Hensley, M. 2005. Quantifying risk for water harvesting under semi-arid conditions: Part II - Crop yield simulation. Agricultural Water Management, 76(2):94-107.
(Location: IWMI-HQ Call no: PER Record No: H037136)
5 McGill, B. M.; Altchenko, Yvan; Hamilton, S. K.; Kenabatho, P. K.; Sylvester, S. R.; Villholth, Karen G. 2019. Complex interactions between climate change, sanitation, and groundwater quality: a case study from Ramotswa, Botswana. Hydrogeology Journal, 27(3):997-1015. [doi: https://doi.org/10.1007/s10040-018-1901-4]
Climate change ; Sanitation ; Groundwater management ; Water quality ; Water supply ; Water security ; Drinking water ; Monitoring ; Wastewater treatment ; Water pollution ; Ecological factors ; Environmental factors ; Environmental protection ; Nitrates ; Denitrification ; Contamination ; Aquifers ; Rainfall ; Drought ; Pit latrines ; Faecal coliforms ; Caffeine ; Human wastes ; Case studies / Africa South of Sahara / Botswana / Ramotswa
(Location: IWMI HQ Call no: e-copy only Record No: H049051)
https://link.springer.com/content/pdf/10.1007%2Fs10040-018-1901-4.pdf
https://vlibrary.iwmi.org/pdf/H049051.pdf
https://vlibrary.iwmi.org/pdf/H049051.pdf
(1.98 MB)
Groundwater quantity and quality may be affected by climate change through intricate direct and indirect mechanisms. At the same time, population growth and rapid urbanization have made groundwater an increasingly important source of water for multiple uses around the world, including southern Africa. The present study investigates the coupled human and natural system (CHANS) linking climate, sanitation, and groundwater quality in Ramotswa, a rapidly growing peri-urban area in the semi-arid southeastern Botswana, which relies on the transboundary Ramotswa aquifer for water supply. Analysis of long-term rainfall records indicated that droughts like the one in 2013–2016 are increasing in likelihood in the area due to climate change. Key informant interviews showed that due to the drought, people increasingly used pit latrines rather than flush toilets. Nitrate, fecal coliforms, and caffeine analyses of Ramotswa groundwater revealed that human waste leaching from pit latrines is the likely source of nitrate pollution. The results in conjunction indicate critical indirect linkages between climate change, sanitation, groundwater quality, and water security in the area. Improved sanitation, groundwater protection and remediation, and local water treatment would enhance reliable access to water, de-couple the community from reliance on surface water and associated water shortage risks, and help prevent transboundary tension over the shared aquifer.
6 Worqlul, A. W.; Dile, Y. T.; Jeong, J.; Adimassu, Zenebe; Lefore, Nicole; Gerik, T.; Srinivasan, R.; Clarke, N. 2019. Effect of climate change on land suitability for surface irrigation and irrigation potential of the shallow groundwater in Ghana. Computers and Electronics in Agriculture, 157: 110-125. [doi: https://doi.org/10.1016/j.compag.2018.12.040]
Climate change ; Land suitability ; Land use ; Irrigation methods ; Surface irrigation ; Groundwater management ; Water resources ; Surface water ; GIS ; Slope ; Soils ; Socioeconomic environment ; Population density ; Rainfall ; Temperature ; Evapotranspiration / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H049052)
https://reader.elsevier.com/reader/sd/pii/S0168169918311426?token=D47C9342836EF05EF9C7A103181929ACB8DDE1F80AD6AF06C2A5B98E687E907761A212B911EFC4AC23D7985048ACB910
https://vlibrary.iwmi.org/pdf/H049052.pdf
https://vlibrary.iwmi.org/pdf/H049052.pdf
(6.84 MB)
Estimating the potential land resources suitable for irrigation and evaluating the possible impact of climate change on land suitability is essential for planning a sustainable agricultural system. This study applied a GIS-based Multi-Criteria Evaluation (MCE) technique to evaluate the suitability of land for irrigation in Ghana for a baseline period (1990 to 2010) and future time horizons 2050s (2041 to 2060) and 2070s (2061 to 2080). Key factors considered to evaluate the suitability of the land for irrigation include biophysical features (such as climate, land use, soil, and slope) and socioeconomic factors (such as proximity to roads and population density). These factors were weighted using a pairwise comparison matrix then reclassified and overlaid on a 30 m grid to estimate the irrigation potential of the country. Groundwater data from the British Geological Survey (BGS) were superimposed onto the land suitability map layer to evaluate the irrigation potential and the accessibility of shallow groundwater with simple water lifting technologies. Downscaled and bias-corrected future climate data from HadGEM2-ES under Representative Concentration Pathways (RCP) 4.5 emission scenario were used to represent the future climate horizon. Due to climate change, on average, rainfall will increase by 15 mm and 20 mm from the baseline period in the 2050s and 2070s, respectively. The average temperature shows a consistent increase in the majority of Ghana and a higher rate of increase is expected in the 2070s. Consequently, the rising temperature will increase the potential evapotranspiration by 6.0% and 7.6% in the 2050s and 2070s, respectively. The suitability analysis indicates that approximately 9% of the country is suitable for surface irrigation under the baseline period. A large portion of the potential land is located in the southwestern part of the country. The potential suitable land has an average groundwater access of 12 m from the surface with an average borehole potential yield of 2.5 L/second, which makes it favorable for utilization of simple water lifting technologies. Due to climate change, 9.5% of the suitable land will become unfavorable for irrigation in 2050s, and it is expected to reach 17% in 2070s.
7 Nhamo, Luxon; Matchaya, Greenwell; Mabhaudhi, T.; Nhlengethwa, Sibusiso; Nhemachena, Charles; Mpandeli, S. 2019. Cereal production trends under climate change: impacts and adaptation strategies in Southern Africa. Agriculture, 9(2): 1-17. [doi: https://doi.org/10.3390/agriculture9020030]
Agricultural production ; Agricultural policy ; Agricultural sector ; Cereal products ; Maize ; Climate change adaptation ; Drought ; Flooding ; Temperature ; Rainfall ; Water scarcity ; Food security ; Economic aspects / Southern Africa
(Location: IWMI HQ Call no: e-copy only Record No: H049086)
(3.94 MB)
The increasing frequency and intensity of droughts and floods, coupled with increasing temperatures and declining rainfall totals, are exacerbating existing vulnerabilities in southern Africa. Agriculture is the most affected sector as 95% of cultivated area is rainfed. This review addressed trends in moisture stress and the impacts on crop production, highlighting adaptation possible strategies to ensure food security in southern Africa. Notable changes in rainfall patterns and deficiencies in soil moisture are estimated and discussed, as well as the impact of rainfall variability on crop production and proposed adaptation strategies in agriculture. Climate moisture index (CMI) was used to assess aridity levels. Southern Africa is described as a climate hotspot due to increasing aridity, low adaptive capacity, underdevelopment and marginalisation. Although crop yields have been increasing due to increases in irrigated area and use of improved seed varieties, they have not been able to meet the food requirements of a growing population, compromising regional food security targets. Most countries in the region depend on international aid to supplement yield deficits. The recurrence of droughts caused by the El Niño Southern Oscillation (ENSO) continue devastating the region, affecting livelihoods, economies and the environment. An example is the 2015/2016 ENSO drought that caused the region to call for international aid to feed about 40 million people. In spite of the water scarcity challenges, cereal production continues to increase steadily due to increased investment in irrigated agriculture and improved crop varieties. Given the current and future vulnerability of the agriculture sector in southern Africa, proactive adaptation interventions are important to help farming communities develop resilient systems to adapt to the changes and variability in climate and other stressors.
8 Nhamo, Luxon; Mabhaudhi, T.; Modi, A. T. 2019. Preparedness or repeated short-term relief aid?: building drought resilience through early warning in southern Africa. Water SA, 45(1): 75-85. [doi: https://doi.org/10.4314/wsa.v45i1.09]
Early warning systems ; Drought resistance ; Water scarcity ; Water resources ; Disaster risk reduction ; Environmental degradation ; Natural disasters ; Rainfall ; Monitoring ; Environmental impact assessment ; Weather forecasting / Southern Africa
(Location: IWMI HQ Call no: e-copy only Record No: H049087)
https://www.ajol.info/index.php/wsa/article/view/182966/172340
https://vlibrary.iwmi.org/pdf/H049087.pdf
https://vlibrary.iwmi.org/pdf/H049087.pdf
(985 KB)
Southern Africa is highly vulnerable to drought because of its dependence on climate-sensitive sectors of agriculture, hydroenergy and fisheries. Recurring droughts continue to impact rural livelihoods and degrade the environment. Drought severity in southern Africa is exacerbated by poor levels of preparedness and low adaptive capacity. Whilst weather extremes and hazards are inevitable, the preparedness to manage such hazards determines their impact and whether they become disasters. Southern Africa is often caught unprepared by drought as existing early warning systems lack the drought forecasting component, which often results in reactionary interventions as opposed to well-planned and proactive response mechanisms. This study assesses the spatio-temporal changes of rainfall and aridity in southern Africa through an analysis of long-term precipitation and evaporation trends from 1960 to 2007. Stakeholder consultation was conducted in Madagascar, Malawi, Zambia and Zimbabwe during the peak of the 2015/16 drought, focusing on overall drought impacts, current water resource availability, existing early warning systems, adaptation mechanisms and institutional capacity to mitigate and manage droughts as part of overall disaster risk reduction strategies. Average rainfall has decreased by 26% in the region between 1960 and 2007, and aridity has increased by 11% between 1980 and 2007. The absence of drought forecasting and lack of institutional capacity to mitigate drought impede regional drought risk reduction initiatives. Existing multi-hazard early warning systems in the region focus on flooding and drought monitoring and assessment. Drought forecasting is often not given due consideration, yet it is a key component of early warning and resilience building. We propose a regional drought early warning framework, emphasising the importance of both monitoring and forecasting as being integral to a drought early warning system and building resilience to drought.
9 Bharati, Luna; Bhattarai, Utsav; Khadka, Ambika; Gurung, Pabitra; Neumann, L. E.; Penton, D. J.; Dhaubanjar, Sanita; Nepal, S. 2019. From the mountains to the plains: impact of climate change on water resources in the Koshi River Basin. Colombo, Sri Lanka: International Water Management Institute (IWMI) 49p. (IWMI Working Paper 187) [doi: https://doi.org/10.5337/2019.205]
Climate change ; Climatic data ; Water resources ; Water balance ; Water yield ; Water availability ; Mountains ; Plains ; River basin management ; Soil analysis ; Soil water balance ; Calibration ; Spatial distribution ; Hydropower ; Precipitation ; Evapotranspiration ; Temperature ; Rainfall ; Monsoon climate ; Catchment areas ; Hydrological data ; Impact assessment ; Models ; Flow discharge ; Runoff ; Land use ; Seasonal variation / China / Nepal / India / Koshi River Basin
(Location: IWMI HQ Call no: IWMI Record No: H049130)
(8 MB)
The Koshi Basin, spread across China, Nepal and India, is perceived as having high potential for hydropower and irrigation development, both seen as ways to promote economic development in the region. This paper quantifies and assesses the past and projected future spatial and temporal water balances in the Koshi Basin. Results show that precipitation and net water yield are lowest in the transmountain region and the Tibetan plateau. The values are highest in the mountain region, followed by the hills and Indo-Gangetic Plains. Approximately 65% of average annual precipitation is converted to flows, indicating high water availability. Actual evapotranspiration is highest in the Indo-Gangetic Plains region due to the presence of irrigated agriculture and a few forested mountain watersheds. As most of the water from the mountain and hill regions eventually flows down to the plains, the mountain and hill regions in Nepal are important for maintaining agriculture in the plains in both Nepal and India. Results from the flow analyses indicate the high temporal variability of flows in the basin. The frequent occurrences of both high- and low-flow events demonstrate the existing vulnerability of the region to both floods and droughts, leading to a very risk-prone livelihood system. Climate change projections show an increasing trend in precipitation and net water yield for most of the basin, except the transmountain region. Therefore, it is important to consider the climate change impacts on water resources in future planning.
10 Kolusu, S. R.; Shamsudduha, M.; Todd, M. C.; Taylor, R. G.; Seddon, D.; Kashaigili, J. J.; Ebrahim, Girma Y.; Cuthbert, M. O.; Sorensen, J. P. R.; Villholth, Karen G.; MacDonald, A. M.; MacLeod, D. A. 2019. The El Nino event of 2015-2016: climate anomalies and their impact on groundwater resources in East and Southern Africa. Hydrology and Earth System Sciences, 23: 1751-1762. [doi: https://doi.org/10.5194/hess-23-1751-2019]
El Nino ; Groundwater management ; Water resources ; Water storage ; Climate change ; Rainfall ; Drought ; Water balance ; Water levels ; Surface water ; Precipitation ; Evapotranspiration ; Satellite imagery ; Satellite observation / East Africa / SouthernAfrica / Limpopo Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049164)
https://www.hydrol-earth-syst-sci.net/23/1751/2019/hess-23-1751-2019.pdf
https://vlibrary.iwmi.org/pdf/H049164.pdf
https://vlibrary.iwmi.org/pdf/H049164.pdf
(2.80 MB)
The impact of climate variability on groundwater storage has received limited attention despite widespread dependence on groundwater as a resource for drinking water, agriculture and industry. Here, we assess the climate anomalies that occurred over Southern Africa (SA) and East Africa, south of the Equator (EASE), during the major El Niño event of 2015–2016, and their associated impacts on groundwater storage, across scales, through analysis of in situ groundwater piezometry and Gravity Recovery and Climate Experiment (GRACE) satellite data. At the continental scale, the El Niño of 2015–2016 was associated with a pronounced dipole of opposing rainfall anomalies over EASE and Southern Africa, north–south of ~12° S, a characteristic pattern of the El Niño–Southern Oscillation (ENSO). Over Southern Africa the most intense drought event in the historical record occurred, based on an analysis of the cross-scale areal intensity of surface water balance anomalies (as represented by the standardised precipitation evapotranspiration index – SPEI), with an estimated return period of at least 200 years and a best estimate of 260 years. Climate risks are changing, and we estimate that anthropogenic warming only (ignoring changes to other climate variables, e.g. precipitation) has approximately doubled the risk of such an extreme SPEI drought event. These surface water balance deficits suppressed groundwater recharge, leading to a substantial groundwater storage decline indicated by both GRACE satellite and piezometric data in the Limpopo basin. Conversely, over EASE during the 2015–2016 El Niño event, anomalously wet conditions were observed with an estimated return period of ~10 years, likely moderated by the absence of a strongly positive Indian Ocean zonal mode phase. The strong but not extreme rainy season increased groundwater storage, as shown by satellite GRACE data and rising groundwater levels observed at a site in central Tanzania. We note substantial uncertainties in separating groundwater from total water storage in GRACE data and show that consistency between GRACE and piezometric estimates of groundwater storage is apparent when spatial averaging scales are comparable. These results have implications for sustainable and climate-resilient groundwater resource management, including the potential for adaptive strategies, such as managed aquifer recharge during episodic recharge events.
11 Ma, X.; Lacombe, Guillaume; Harrison, R.; Xu, J.; van Noordwijk, M. 2019. Expanding rubber plantations in southern China: evidence for hydrological impacts. Water, 11(4): 1-15. [doi: https://doi.org/10.3390/w11040651]
Rubber industry ; Hydrological factors ; Agroforestry ; Catchment areas ; Humid tropics ; Impact assessment ; Land cover change ; Water balance ; Watershed management ; Rainfall ; Farmland ; Grasslands ; Slope / Southeast Asia / Southern China
(Location: IWMI HQ Call no: e-copy only Record No: H049180)
(2.26 MB) (2.26 MB)
While there is increasing evidence concerning the detrimental effects of expanding rubber plantations on biodiversity and local water balances, their implications on regional hydrology remain uncertain. We studied a mesoscale watershed (100 km2) in the Xishuangbanna prefecture, Yunnan Province, China. The influence of land-cover change on streamflow recorded since 1992 was isolated from that of rainfall variability using cross-simulation matrices produced with the monthly lumped conceptual water balance model GR2M. Our results indicate a statistically significant reduction in wet and dry season streamflow from 1992 to 2002, followed by an insignificant increase until 2006. Analysis of satellite images from 1992, 2002, 2007, and 2010 shows a gradual increase in the areal percentage of rubber tree plantations at the watershed scale. However, there were marked heterogeneities in land conversions (between forest, farmland, grassland, and rubber tree plantations), and in their distribution across elevations and slopes, among the studied periods. Possible effects of this heterogeneity on hydrological processes, controlled mainly by infiltration and evapotranspiration, are discussed in light of the hydrological changes observed over the study period. We suggest pathways to improve the eco-hydrological functionalities of rubber tree plantations, particularly those enhancing dry-season base flow, and recommend how to monitor them.
12 Suhardiman, Diana; de Silva, Sanjiv; Arulingam, Indika; Rodrigo, Sashan; Nicol, Alan. 2019. Review of water and climate adaptation financing and institutional frameworks in South Asia. Background Paper 3. Colombo, Sri Lanka: International Water Management Institute (IWMI). 110p. (Climate Risks and Solutions: Adaptation Frameworks for Water Resources Planning, Development and Management in South Asia) [doi: https://doi.org/10.5337/2019.204]
Water resources development ; Water demand ; Water availability ; Water quality ; Water management ; Water supply ; Water institutions ; Water scarcity ; Water governance ; International waters ; Climate change adaptation ; Flooding ; Drought ; Rainfall ; Economic situation ; Financing ; Funding ; Costs ; Landscape ; Decision making ; Planning ; Energy resources ; Food security ; Food production ; Hydropower ; Surface water ; Groundwater depletion ; Integrated management ; Population growth ; Poverty ; Climate-smart agriculture ; Domestic water ; Cooperation ; Nongovernmental organizations ; Government agencies ; Risk management ; Irrigation systems ; Coastal area ; Stakeholders / South Asia / Sri Lanka / Nepal / Bangladesh / India / Pakistan / Afghanistan / Bhutan
(Location: IWMI HQ Call no: e-copy only Record No: H049186)
(1.55 MB)
13 Birhanu, B. Z.; Sanogo, K.; Traore, S. S.; Minh, Thai; Kizito, F. 2023. Solar-based irrigation systems as a game changer to improve agricultural practices in Sub-Sahara Africa: a case study from Mali. Frontiers in Sustainable Food Systems, 7:1085335. [doi: https://doi.org/10.3389/fsufs.2023.1085335]
Solar powered irrigation systems ; Agricultural practices ; Climate-smart agriculture ; Technology ; Smallholders ; Farmers ; Land suitability ; Land use ; Land cover ; Slope ; Soil types ; Sustainable intensification ; Water management ; Water use ; Groundwater ; Solar energy ; Rainfall ; Rural areas ; Households ; Socioeconomic aspects ; Case studies / Africa South of Sahara / Mali / Sikasso / Bougouni / Koutiala
(Location: IWMI HQ Call no: e-copy only Record No: H051767)
https://www.frontiersin.org/articles/10.3389/fsufs.2023.1085335/pdf
https://vlibrary.iwmi.org/pdf/H051767.pdf
https://vlibrary.iwmi.org/pdf/H051767.pdf
(6.20 MB) (6.20 MB)
Introduction: In rainfed agricultural systems, sustainable and efficient water management practices are key to improved agricultural productivity and natural resource management. The agricultural system in sub-Saharan Africa (SSA) relies heavily on the availability of rainfall. With the erratic and unreliable rainfall pattern associated with poor and fragile soils, agricultural productivity has remained very low over the years. Much of the SSA agricultural land has been degraded with low fertility as a result of ongoing cultivation and wind and water erosion. This has resulted in an increased food shortage due to the ever-increasing population and land degradation. Better agricultural and nutritional security are further hampered by the lack of reliable access to the available water resources in the subsurface hydrological system.
Methods: This study used socio-economic data from 112 farm households and Boolean and Fuzzy methods to understand farmers' perceptions and identify suitable areas to implement Solar Based Irrigation Systems (SBISs) in the agro-ecologies of Bougouni and Koutiala districts of southern Mali.
Results and discussion: Results revealed that the usage of SBISs has been recent (4.5 years), majorly (77%) constructed by donor-funded projects mainly for domestic water use and livestock (88%). With regards to irrigation, vegetable production was the dominant water use (60%) enabling rural farm households to gain over 40% of extra household income during the dry season. Results further showed that 4,274 km2 (22%) of the total land area for the Bougouni district, and 1,722 km2 (18%) of the Koutiala district are suitable for solar-based irrigation. The affordability of solar panels in many places makes SBISs to be an emerging climate-smart technology for most rural Malian populations.
Methods: This study used socio-economic data from 112 farm households and Boolean and Fuzzy methods to understand farmers' perceptions and identify suitable areas to implement Solar Based Irrigation Systems (SBISs) in the agro-ecologies of Bougouni and Koutiala districts of southern Mali.
Results and discussion: Results revealed that the usage of SBISs has been recent (4.5 years), majorly (77%) constructed by donor-funded projects mainly for domestic water use and livestock (88%). With regards to irrigation, vegetable production was the dominant water use (60%) enabling rural farm households to gain over 40% of extra household income during the dry season. Results further showed that 4,274 km2 (22%) of the total land area for the Bougouni district, and 1,722 km2 (18%) of the Koutiala district are suitable for solar-based irrigation. The affordability of solar panels in many places makes SBISs to be an emerging climate-smart technology for most rural Malian populations.
14 Wubaye, G. B.; Gashaw, T.; Worqlul, A. W.; Dile, Y. T.; Taye, Meron Teferi; Haileslassie, Amare; Zaitchik, B.; Birhan, D. A.; Adgo, E.; Mohammed, J. A.; Lebeza, T. M.; Bantider, A.; Seid, Abdulkarim; Srinivasan, R. 2023. Trends in rainfall and temperature extremes in Ethiopia: station and agro-ecological zone levels of analysis. Atmosphere, 14(3):483. (Special issue: Water Management and Crop Production in the Face of Climate Change) [doi: https://doi.org/10.3390/atmos14030483]
Extreme weather events ; Rainfall ; Temperature ; Trends ; Meteorological stations ; Agroecological zones ; Climate change adaptation ; Precipitation ; Spatial distribution ; Time series analysis / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H051768)
https://www.mdpi.com/2073-4433/14/3/483/pdf?version=1678174504
https://vlibrary.iwmi.org/pdf/H051768.pdf
https://vlibrary.iwmi.org/pdf/H051768.pdf
(9.01 MB) (9.01 MB)
Climate extreme events have been observed more frequently since the 1970s throughout Ethiopia, which adversely affects the socio-economic development of the country, as its economy depends on agriculture, which, in turn, relies heavily on annual and seasonal rainfall. Climate extremes studies conducted in Ethiopia are mainly limited to a specific location or watershed, making it difficult to have insights at the national level. The present study thus aims to examine the observed climate extreme events in Ethiopia at both station and agro-ecological zone (AEZ) levels. Daily rainfall and temperature data for 47 and 37 stations, respectively (1986 up to 2020), were obtained from the National Meteorology Agency (NMA). The Modified Mann–Kendall (MMK) trend test and the Theil–Sen slope estimator were employed to estimate the trends in rainfall and temperature extremes. This study examines trends of 13 temperature and 10 rainfall extreme indices using RClimDex in R software. The results revealed that most of the extreme rainfall indices showed a positive trend in the majority of the climate stations. For example, an increase in consecutive dry days (CDD), very heavy rainfall days (R20), number of heavy rainfall days (R10) and consecutive wet days (CWD) were exhibited in most climate stations. In relation to AEZs, the greater number of extreme rainfall indices illustrated an upward trend in cool and sub-humid, cool and humid, and cool and moist AEZs, a declining trend in hot arid AEZ, and equal proportions of increasing and decreasing trends in warm semi-arid AEZs. Concerning extreme temperature indices, the result indicated an increasing trend of warm temperature extreme indices and a downward trend of cold temperature extreme indices in most of the climate stations, indicating the overall warming and dryness trends in the country. With reference to AEZs, an overall warming was exhibited in all AEZs, except in the hot arid AEZ. The observed trends in the rainfall and temperature extremes will have tremendous direct and indirect impacts on agriculture, water resources, health, and other sectors in the country. Therefore, the findings suggest the need for identifying and developing climate change adaptation strategies to minimize the ill effects of these extreme climate events on the social, economic, and developmental sectors.
15 Chunga, B. A.; Marx, W.; Cai, Xueliang; de Clercq, W.; Watson, A.; Malota, M. 2023. Water allocation using system dynamic modelling in the aquaculture integrated with small-scale irrigation systems in Malawi. Physics and Chemistry of the Earth, 129:103355. [doi: https://doi.org/10.1016/j.pce.2022.103355]
Water allocation ; Modelling ; Aquaculture ; Small-scale irrigation ; Decision support systems ; Fish ponds ; Maize ; Crop production ; Soil water balance ; Water depth ; Water-use efficiency ; Biomass production ; Crop yield ; Water resources ; Rainfall ; Rural areas ; Farmers ; Climate change / Malawi / Zomba / Chingale
(Location: IWMI HQ Call no: e-copy only Record No: H051813)
(5.07 MB)
The agricultural sector is faced with numerous challenges including climate change and water scarcity in many developing countries. In order to address scarcity and improve water use efficiency for rural farmers, fish farming is being integrated with small-scale irrigation. However, there are challenges in how to allocate water between the two farming enterprises. This study explored the capabilities of system dynamics to allocate water between a fish pond and a crop field in Chingale, Malawi using a system dynamic software, Vensim™ PLE. For soil water and pond water, a simple water balance structure was built and connected to the crop growth structure. Simulations run for 125 days corresponding to the maize growth period. Model results are similar to the actual yield (about 3.5 ton/ha for hybrid) and biomass production (about 7 ton/ha) in the area. Results also show it was possible to maintain pond water depth at recommended depths for raising fish: fish stocking (1 m), operation of the pond (1.5–2.0 m) and harvesting of the fish (less than 1.2 m) throughout the maize growing period. While the study did not comprehensively build and simulate fish growth, the use of such simple tools would benefit rural farmers with few resources. Based on the promising capabilities and the results of the tool it is recommended that further comprehensive analysis to fully incorporate all key sub-components affecting crop and fish growth be carried out.
16 Akinseye, F. M.; Birhanu, B. Z.; Ajeigbe, H. A.; Diancoumba, M.; Sanogo, K.; Tabo, R. 2023. Impacts of fertilization management strategies on improved sorghums varieties in smallholder farming systems in Mali: productivity and profitability differences. Heliyon, 9(3):E14497. [doi: https://doi.org/10.1016/j.heliyon.2023.e14497]
Fertilization ; Strategies ; Organic fertilizers ; Inorganic fertilizers ; Smallholders ; Farming systems ; Small-scale farming ; Sorghum ; Agricultural productivity ; Profitability ; Benefit-cost ratio ; Crop yield ; Rainfall ; Soil fertility ; Farmers / Mali / Bamako / Bougouni / Koutiala
(Location: IWMI HQ Call no: e-copy only Record No: H051835)
https://www.cell.com/action/showPdf?pii=S2405-8440%2823%2901704-8
https://vlibrary.iwmi.org/pdf/H051835.pdf
https://vlibrary.iwmi.org/pdf/H051835.pdf
(2.68 MB) (2.68 MB)
Sorghum is an important cereal crop cultivated by smallholder farmers of Mali, contributing significantly to their food demand and security. The study evaluated different fertilization strategies that combined organic and inorganic fertilizer applications with three sorghum varieties. The experiments were conducted over three cropping seasons (2017–2019) in three sites (Bamako, Bougouni, and Koutiala respectively) within the Sudanian region of Mali. Our results showed a significant effect of season, variety, and fertilization strategies on grain and stalk yields. Grain yield increased by 8–40% in Koutiala, 11–53% in Bougouni, and 44–110% in Bamako while the average stalk yield was above 5000 kg ha- 1 with fertilized treatment compared to unfertilized treatment in the three sites. Fadda performed the best variety, mean grain yield was 23% and 42% higher than that of Soumba and Tieble, respectively. Similarly, there was a progressive increase in grain yield with an increasing level of poultry manure (PM) from 0 to 150 g/hill and cattle manure (CM) from 0 to 100 g/hill. However, the application of 100 g/hill of CM and PM plus 3 g/ hill of Di-ammonium Phosphate (DAP) increased yield by 8% and 12% respectively compared to only CM or PM treatments. The results further revealed higher yield gain by 51% (Bamako), 57% (Koutiala), and 42% (Bougouni) for T10-[PM (100 g/hill) + Micro-D_DAP (3 g/hill)] equivalent to 73 kgNha- 1 than others (T2-T9), but not proportionate to the highest value-cost ratio (VCR). Radar charts used to visualize sustainable intensification (SI) performance in the three domains (productivity, profitability, and environment) showed that the environmental variable has a direct influence on productivity, meanwhile profitability across the strategies ranged from low to moderate value across sites and different fertilizer strategies. Our study, therefore, recommends the use of multiple-choice fertilizer strategies includingT2-CM (50 g/hill)+PM(50 g/hill), T5-DAPMicro-D (3 g/hill), T6-DAP41:46:00 and T9-PM(50 g/hill) alongside with improved sorghum varieties tested, for higher productivity and profitability across the region.
17 Sishu, F. K.; Tilahun, Seifu A.; Schmitter, Petra; Steenhuis, T. S. 2023. Investigating nitrate with other constituents in groundwater in two contrasting tropical highland watersheds. Hydrology, 10(4):82. (Special issue: Editorial Board Members’ Collection Series: Integrated Surface Water and Groundwater Resources Management) [doi: https://doi.org/10.3390/hydrology10040082]
Groundwater table ; Nitrates ; Watersheds ; Highlands ; Volcanic areas ; Aquifers ; Wells ; Precipitation ; Rainfall ; Chlorides ; Ammonia ; Fertilizers ; Runoff / Africa South of Sahara / Ethiopia / Lake Tana Basin / Dangishta Watershed / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H051839)
https://www.mdpi.com/2306-5338/10/4/82/pdf?version=1680523739
https://vlibrary.iwmi.org/pdf/H051839.pdf
https://vlibrary.iwmi.org/pdf/H051839.pdf
(8.28 MB) (8.28 MB)
Nitrate is globally the most widespread and widely studied groundwater contaminant. However, few studies have been conducted in sub-Saharan Africa, where the leaching potential is enhanced during the rainy monsoon phase. The few monitoring studies found concentrations over drinking water standards of 10 mg N-NO3 - L -1 in the groundwater, the primary water supply in rural communities. Studies on nitrate movement are limited to the volcanic Ethiopian highlands. Therefore, this study aimed to evaluate the transport and fate of nitrate in groundwater and identify processes that control the concentrations. Water table height, nitrate, chloride, ammonium, reduced iron, and three other groundwater constituents were determined monthly in the groundwater in over 30 wells in two contrasting volcanic watersheds over two years in the Ethiopian highlands. The first watershed was Dangishta, with lava intrusion dikes that blocked the subsurface flow in the valley bottom. The water table remained within 3 m of the surface. The second watershed without volcanic barriers was Robit Bata. The water table dropped rapidly within three months of the end of the rain phase and disappeared except near faults. The average nitrate concentration in both watersheds was between 4 and 5 mg N-NO3 - L -1 . Hydrogeology influenced the transport and fate of nitrogen. In Dangishta, water was blocked by volcanic lava intrusion dikes, and residence time in the aquifer was larger than in Robit Bata. Consequently, nitrate remained high (in several wells, 10 mg N-NO3 - L -1 ) and decreased slowly due to denitrification. In Robit Bata, the water residence time was lower, and peak concentrations were only observed in the month after fertilizer application; otherwise, it was near an average of 4 mg N-NO3 - L -1 . Nitrate concentrations were predicted using a multiple linear regression model. Hydrology explained the nitrate concentrations in Robit Bata. In Dangishta, biogeochemistry was also significant.
18 Adamseged, Muluken Elias; Kebede, S. W. 2023. Are farmers’ climate change adaptation strategies understated? Evidence from two communities in northern Ethiopian highlands. Climate Services, 30:100369. [doi: https://doi.org/10.1016/j.cliser.2023.100369]
Climate change adaptation ; Farmers ; Strategies ; Livelihoods ; Households ; Rural communities ; Soil conservation ; Irrigation ; Rainfall ; Socioeconomic aspects ; Migration / Ethiopia / Shumsheha / Harresaw
(Location: IWMI HQ Call no: e-copy only Record No: H051884)
https://www.sciencedirect.com/science/article/pii/S2405880723000304/pdfft?md5=7f40a3008858c2286cb07e392e3a502c&pid=1-s2.0-S2405880723000304-main.pdf
https://vlibrary.iwmi.org/pdf/H051884.pdf
https://vlibrary.iwmi.org/pdf/H051884.pdf
(1.57 MB) (1.57 MB)
Research and policy analyses of climate change adaptation in Africa are often centre to examine adjustments in agricultural operations. This mainly bases on a misconception that rural households merely depend on agriculture for their livelihoods. This research aimed at positioning livelihood (farm and non-farm activities) as the centre of climate adaptation strategies to better understand rural households’ adaptation strategic options and capacities, using two rural communities in the Northern highlands of Ethiopia. The result showed that rural households have broader options both in farm and non-farm strategies for combating adverse climate condition than previously reported. A strong and positive association are found between wealth indicators such as farm size (0.08) and productive assets (0.0917) with farm-level adaptation strategies such as short maturing crop and irrigation. Non-farm adaptation strategies (such as business activities and wage employment) are, mainly, influenced by household demographic characteristics such as age of the household head (0.01) and adult household size (0.09). This indicates that there is no specific adaptation strategy panacea for rural households. Rather, rural households use a mix of strategies to meet the particular agro-ecological settings (for farm-level adaptation strategies), and infrastructure and the location of the community, which enable to access market and other services (for non-farm adaptation strategies). Thus, national level climate policies and strategies need to be tailored to address the specific agro-ecology, and infrastructure of the local area and the socio-economic context of the households in the two communities. In this regard, the different levels of government and nongovernmental organizations should provide more adaptation measures on agricultural extension services, access to loans, roads, transport, market, knowledge and creation of wage employment and business opportunities in the vicinity of rural communities and its surrounding towns.
19 Ahmed, N.; Zhu, L.; Wang, G.; Adeyeri, O. E.; Shah, S.; Ali, S.; Marhaento, H.; Munir, Sarfraz. 2023. Occurrence and distribution of long-term variability in precipitation classes in the source region of the Yangtze River. Sustainability, 15(7):5834. (Special issue: Hydro-Meteorology and its Application in Hydrological Modeling) [doi: https://doi.org/10.3390/su15075834]
Climate change ; Precipitation ; Trends ; Rivers ; Rainfall ; Drought ; Time series analysis ; Hydrological factors ; Dry spells ; Vegetation / China / Yangtze River
(Location: IWMI HQ Call no: e-copy only Record No: H051888)
https://www.mdpi.com/2071-1050/15/7/5834/pdf?version=1679974417
https://vlibrary.iwmi.org/pdf/H051888.pdf
https://vlibrary.iwmi.org/pdf/H051888.pdf
(6.22 MB) (6.22 MB)
Various precipitation-related studies have been conducted on the Yangtze River. However, the topography and atmospheric circulation regime of the Source Region of the Yangtze River (SRYZ) differ from other basin parts. Along with natural uniqueness, precipitation constitutes over 60% of the direct discharge in the SRYZ, which depicts the decisive role of precipitation and a necessary study on the verge of climate change. The study evaluates the event distribution of long-term variability in precipitation classes in the SRYZ. The precipitation was classified into three precipitation classes: light precipitation (0–5 mm, 5–10 mm), moderate precipitation (10–15 mm, 15–20 mm, 20–25 mm), and heavy precipitation (>25 mm). The year 1998 was detected as a changing year using the Pettitt test in the precipitation time series; therefore, the time series was divided into three scenarios: Scenario-R (1961–2016), the pre-change point (Scenario-I; 1961–1998), and the post-change point (Scenario-II; 1999–2016). Observed annual precipitation amounts in the SRYZ during Scenario-R and Scenario-I significantly increased by 13.63 mm/decade and 48.8 mm/decade, respectively. The same increasing trend was evident in seasonal periods. On a daily scale, light precipitation (0–5 mm) covered most of the days during the entire period, with rainy days accounting for 83.50%, 84.5%, and 81.30%. These rainy days received up to 40%, 41%, and 38% of the annual precipitation during Scenario-R, Scenario-I, and Scenario-II, respectively. Consequently, these key findings of the study will be helpful in basin-scale water resources management.
20 Pranjal, P.; Chatterjee, R. S.; Kumar, D.; Dwivedi, S.; Jally, S. K.; Kumar, B. 2023. Satellite gravity observation and hydrological modelling-based integrated groundwater storage change in northwestern India. Journal of Hydroinformatics, 25(2):226-242. [doi: https://doi.org/10.2166/hydro.2023.072]
Groundwater recharge ; Hydrological modelling ; Satellite observation ; Hydrometeorology ; Water storage ; Soil moisture ; Groundwater table ; Water balance ; Groundwater depletion ; Infiltration ; Aquifers ; River basins ; Land use ; Land cover ; Infiltration water ; Remote sensing ; Rainfall ; Runoff ; Evapotranspiration ; Soil moisture / India / Delhi / Haryana / Punjab / Rajasthan / Gujarat / Uttar Pradesh / Uttarakhand / Himachal Pradesh / Madhya Pradesh / Maharashtra / Upper Ganga Basin / Yamuna Basin / Chambal Basin / Luni-Ghaggar Basin / Narmada Basin
(Location: IWMI HQ Call no: e-copy only Record No: H051924)
https://iwaponline.com/jh/article-pdf/25/2/226/1201970/jh0250226.pdf
https://vlibrary.iwmi.org/pdf/H051924.pdf
https://vlibrary.iwmi.org/pdf/H051924.pdf
(1.46 MB) (1.46 MB)
This paper presents a novel approach for an improved estimate of regional groundwater storage (GWS) change in Northwestern India by integrating satellite-based Gravity Recovery and Climate Exchange (GRACE) gravity observation and hydrological modelling of satellite/in situ hydrometeorological data. Initially, GRACE observation-based terrestrial water storage (TWS) change and hydrological model-based TWS change products were integrated using weight coefficients derived from multi-linear regression analysis of TWS change vs governing hydrological components. Later, the monthly average soil moisture change was subtracted from the monthly average individual and integrated TWS change products to obtain GWS change products. By spatial correlation analysis, three GWS change products were then compared with groundwater level (GWL) fluctuation-based in situ GWS change. Hydrological model, spaceborne GRACE observation, and integrated GWS change products show a positive correlation in ~59, ~69, and ~73% of the area with in situ GWS change. While a hydrological model-based estimate considers geology, terrain, and hydrometeorological conditions, GRACE gravity observation includes groundwater withdrawal from aquifers. All the factors are included in the integrated product. The approach overcomes the limitations of GRACE observation (spatial resolution, geology, terrain, and hydrometeorological factors), hydrological modelling (groundwater withdrawal conditions), and conventional GWL fluctuation-based method (inadequate spatial continuity and cumbersome, labour-intensive exercise).
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