Severe wind gusts associated with mid-latitude convective storms contribute to an increasing amount of natural hazard related losses in Europe. Modifications of the atmosphere associated with anthropogenic climate change are projected to increase the frequency of favorable conditions for convective storms, and it is absolutely critical to understand the implications of these changes to prepare for a resilient future. To this end, the fate of convective gusts in Europe in a future warmer climate is addressed through the output of two high resolution regional climate models (RCMs). One RCM includes convection permitting (CP) physics, and the other assumes hydrostatic conditions in which deep convection is parameterized. It is found that the magnitude and characteristics of extreme straight line gusts from mesoscale convective systems are well resolved in the CP-RCM but not in the hydrostatic RCM.
The RCMs are forced with a high carbon emission scenario for the end of the 21st century, and the CP-RCM shows an increase in the frequency and magnitude of extreme convective gusts over mainland Europe. These changes are likely related to an increase in conditions where strong wind shear (≥15 m/s) simultaneously occurs with unstable environments (lifted index ≤-2). However, the inherent low frequency of extreme convective storms requires continued investigation to draw more robust conclusions. In addition, the environmental conditions in which the severe gusts take place indicate the importance of addressing gusts separately from the more commonly studied effects of climate change on extreme convective precipitation. This thesis provides an important bridge to understand the fate of extreme gusts from convective storms in a future warmer climate and the high potential of CP-RCMs in such studies. ... Read more

This report represents the baseline study of the Project "Cotton Water", a collaboration between Solidaridad Asia, TU Delft and other participating instututions to improve the livelihood of cotton farmers in the Vidarbha and Marathwada regions of Maharashtra, India. This baseline study was divided in three main steps: a desktop study, where high resolution maps of precipitation, potential evaporation, soil type and landuse were used in conjunction with a smallholder socio-hydrological model to identify 'hotspots' where farmers' capital falls below poverty lines; a field survey, in which farmers were extensively questioned on their financial situation and farming practices as well as their perception of water scarcity and irrigation schemes; and a final synthesis where interventions are analysed with the smallholder socio-hydrological model and a psycho-social analysis of farmer behaviour is delivered alongside a mapping of current water productivity of cotton in the study area. The main results found are that the proposed water harvesting and recharge interventions increase and stabilize yields, and the overall effect on capital are moderate. Other factors that do not impact water availability including fertilizer and labour were found to have notable impacts and should be well understood to accurately improve farmers' situations. Financial aspects including cotton sale prices and loan interest rates had strong impacts on farmers' capital development as well, particularly with high interest rates punishing some farmers. An analysis of good- and poor-performing farmers demonstrated that irrigation in general and micro-irrigation did improve probability of good farmer performance as did increased yields. Older men also showed higher rates of profit, demonstrating that the impact of experience may increase profit margins, even if it necessarily doesn't increase likelihood to adopt interventions. What was found to increase probability of adopting irrigation and irrigation technology was low promotion exposure. It is hypothesized that increased promotion may influence many farmers negatively, fostering an attitude of despair rather than informing them of opportunity. The psycho-social evaluation also found that solutions that are reasonably expensive but not too costly have higher chances of being adopted.
Four main recommendations were made to help improve farmer welfare with respect to the scope specified. It was recommended to: limit promotion and to be more selective and positive with the message; focus on localized water storage interventions to increase farmers' access to water; regulate cotton prices through government intervention or contracts with clothing companies to decrease vulnerability to price changes; and improve access to loans from the government and reduce the role of money lenders who often are the ones charging the greatest interest rates. ... Read more