Your search found 7 records
(Location: IWMI HQ Call no: P 7866 Record No: H039981)
(Location: IWMI HQ Call no: 633.18 G708 SCH Record No: H040112)
(Location: IWMI HQ Call no: 633.18 G784 PAN Record No: H040113)
4 Valentin, Christian; Agus, F.; Alamban, R.; Boosaner, A.; Bricquet, J. P.; Chaplot, V.; de Guzman, T.; de Rouw, A.; Janeau, J. L.; Orange, Didier; Phachomphonh, K.; Phai, Do Duy; Podwojewski, P.; Ribolzi, O.; Silvera, N.; Subagyono, K.; Thiebaux, Jean-Pierre; Toan, Tran Duc; Vadari, T. 2008. Runoff and sediment losses from 27 upland catchments in Southeast Asia: impact of rapid land use changes and conservation practices. Agriculture, Ecosystems and Environment, 128:225-238.
(Location: IWMI HQ Call no: IWMI 631.45 G800 VAL Record No: H041507)
(Location: IWMI HQ Call no: e-copy only Record No: H041849)
(0.58 MB)
In the hills of south-east Asia shifting cultivation is developing towards more permanent cropping systems. In association with short fallow periods, fields suffer from weed pressure and this, in turn, leads to more frequent and deeper manual tillage. Due to steep slopes these operations induce tillage erosion. Measurements of such soil losses under on-farm conditions are still scarce. In this study tillage erosion was assessed and a predictive model of tillage erosion was established based on slope angle and contact cover, i.e. basal crop area and weed cover. The experiments were conducted in the Houay Pano, Northern Laos. The farmers cultivate annual crops in rotation with 1–3 year fallow periods without external inputs and using only hand tools. Tillage erosion was assessed using the tracer method across nine slope classes (0.30–1.10 m m1) for two crops, upland rice and Job’s tears (Coix lacryma-jobi L.). Soil movement due to land preparation and weeding were assessed separately because different tools are used, a medium size hoe and a small curved hoe. A multivariate regression showed a highly significant relation (R2 = 0.83) between soil losses due to land preparation, slope gradient and contact cover. Predicting models of soil losses due to weeding were also highly significant (R2 = 0.79 for upland rice, R2 = 0.88 for Job’s tears), confirming the importance of tillage erosion on steep slopes (4, 6 and 11 t ha1 year1 on slopes with gradients of 0.30, 0.60 and 0.90 m m1, respectively). Tillage erosion has increased exponentially over the last 40 years because of weed invasion associated with short fallow periods; the initially no-till system has changed into a system heavily dependent on tillage to control weeds and this greatly contributes to soil degradation.
(Location: IWMI HQ Call no: e-copy only Record No: H047838)
Hydropower development with concomitant changes in water and land regimes often results in livelihood transformation of affected people, entailing changes in intra-household decision-making upon which livelihood strategies are based. Economic factors underlying gender dimensions of household decision-making have been studied rigorously since the 1970s. However, empirical data on gender and decision-making within households, needed for evidence-based action, remain scarce. This is more so in hydropower contexts. This article explores gender and livelihood-related decision-making within rural households in the context of hydropower development in Lao PDR. Based on a social well-being conceptual approach with data from a household survey and qualitative interviews, it focuses on household decisions in an ethnic minority resettlement site soon after displacement, from an interpretive perspective. The article, first, aims to assess the extent to which household decision-making is gendered and secondly, to understand the complex reasoning behind household decisions, especially the relevance of material, relational, and subjective factors. It argues that while most household decisions are ostensibly considered as ‘joint’ in the study site, the nuanced nature of gendered values, norms, practices, relations, attitudes, and feelings underlying these decisions are important to assessing why households might or might not adopt livelihood interventions proposed by hydropower developers.
(Location: IWMI HQ Call no: e-copy only Record No: H049705)
(2.71 MB)
Rice yield responses forecast (YIELDCAST) is a very useful decision support tool in climate adaptation in Sahel, where crops are purely rainfed climate-stressors sensitive. This study aims to construct upland rice yield responses forecasting algebraic formulation code referred as YIELDCAST by using gene-expression programming (GEP) based on observed rainfall and temperatures data (1979–2011), and forcing with global climate model (GCM) downscaled outputs under CO2 emission scenarios SR-A1B, A2 and B1 (2012–2100) over Bobo-Dioulasso, a Sahelian region. Statistically, GEP is a capable tool to downscale climate variables in the region (R = 0.746-0.949), and construct reliable rice YIELDCAST tool (R = 0.930; MSE = 0.037 ton/ha; MAE = 0.155 ton/ha, RSE = 0.137 ton/ha). Yields forecasted (2012–2100) showed a noticeable statistically significant difference between scenarios; however, fluctuating with no substantial increase (average below 1.60 ton/ha); suggesting that the increase observed in temperatures and decrease in rains will either reduced or hindered yield to largely increase in Sahel. With no such YIELDCAST tool to support adaptation decision, Sahel will still be under the trap of the broad array of adaptation strategy, which is a trial and error, less specific and costly. The model can help anticipate adaptation decision support on-farm water management, shift to suitable planting periods, and use of improved drought resistant and short duration varieties adapted to a local weather pattern.
Powered by DB/Text
WebPublisher, from