Climate change impacts need to be considered in water resource planning. This work aims to study of the impacts climate change on Lavrinha headwater watershed, located in the Mantiqueira Range, southeastern Brazil. The impacts from climate change (RCP 8.5 scenario) in the Lavrinha watershed runoff were analyzed based on the "Distributed Hydrology Soil Vegetation Model" (DHSVM), forced with the climate simulated for this future climate change scenario. These simulations, in turn, were generated by the Eta regional climate model coupled to Global Climate Model (GCM) HadGEM2-ES for the 2011-2040, 2041-2070 and 2071-2099 periods. The results of this study showed that the runoff is very sensitive to rising temperatures and reduced precipitation, both projected for the RCP 8.5 scenario. The hydrological simulation projected a reduction in the monthly streamflow between 20 and 77% over the twenty-first century (2011-2099), corresponding to drastic reductions in the runoff behavior and consequently in the water production capacity of the region.

Pumping systems are the largest energy consumers in center pivot irrigation systems. One action to reduce energy consumption is to adjust the pumping pressure to that which is strictly needed by using variable speed drives (VSDs). The objective of this study was to determine the feasibility of including VSDs in pumping systems that feed center pivot systems operating in an area with variable topography. The VSPM (Variable Speed Pivot Model) was developed to perform hydraulic and energy analyses of center pivot systems using the EPANET hydraulics engine. This tool is able to determine the elevation of each tower for each position of the center pivot using any type of digital elevation model. It is also capable of simulating, in an accurate manner, the performance of the center pivot controlled with a VSD. The tool was applied to a real case study, located in Albacete, Spain. The results show a reduction in energy consumption of 12.2%, with specific energy consumptions of 0.214 and 0.244 kWh m⁻³ of distributed water obtained for the variable speed and fixed speed of the pumping station, respectively. The results also show that for an irrigation season, to meet the water requirements of the maize crop in the region of the study (627 mm), an average annual savings of 14,107.35 kWh was obtained, which resulted in an economic savings of 2821.47€.

In recent years, concerns regarding the impacts of deforestation of riparian vegetation on water resources have created social and political tensions in Brazil. This research analyzed simulated hydrologic components of a 6.76 km² headwater watershed with different widths of riparian vegetation. Lavrinha Watershed (LW) hydrological responses were simulated using the Distributed Hydrology Soil Vegetation Model (DHSVM), which was forced using meteorological data from one station (2005-2010). Land cover scenarios where the percent land cover of Atlantic Forest was increased from the control resulted in changes in hydrologic components in the watershed due to increased evapotranspiration and rainfall interception and reduced runoff and overland flow. The base flow/runoff relationship has increased, suggesting that riparian vegetation plays an important role in groundwater recharge. Modeling of hydrologic components linked to riparian buffer scenarios, such as the process used in this study, can be a useful tool for decision-making strategies regarding watershed management.