The Xinanjiang model has been successfully and widely applied in humid and semi-humid regions of China for rainfall–runoff simulation and flood forecasting. However, its forecasting precision is seriously affected by antecedent precipitation (Pa). Commonly applied methods relying on the experience of individual modelers are not standardized and difficult to transfer. In particular, the Xinanjiang daily model may result in obvious errors in the determination of Pa. Thus, a practical method for estimating Pa is proposed in this paper, which is based on a genetic algorithm (GA) and is estimated during a rising flood period. In the optimization process of a GA, Pa values form a chromosome, the root-mean-squared error between the observed and simulated streamflow is chosen as the fitness function. Simultaneously, the best individual reserved strategy is adopted between correction periods to avoid complete independence between each optimization process as well as to ensure the stability of the algorithm. Twenty-seven historical floods observed at the gauge station of the Shuangpai reservoir in Hunan Province of China are used to test the presented algorithm for estimation of Pa, and the results demonstrate that the proposed method significantly improves the quality of flood forecasting in the Xinanjiang model.
Case study - Buoy-based temperature profiling in the Bavarian Lakes
In summertime a temperature stratification occurs in deep lakes – the surface water is warm, but deep down the water is cold. This has considerable influence on the nutrient balance and the biological habitat in these lakes. Due to generally higher air temperatures induced by the climate change, both change and have effects on the life conditions of the ecosystems in the lakes.Researchers use OTT buoys and the OTT net DL datalogger to study the long term effects of climate change on the Bavaraian lakes. Back...
Case study - Precipitation measurement in East Tyrolia high mountains
The Defereggen Valley`s remote location is in the middle of the East Tyrolean high mountain valleys in the Alps. Due to the remote location, extreme weather conditions, and lack of infrastructure, it had not been possible to install an official precipitation measurement station in the Defereggen Valley, yet. It was a "white spot" on the map, from a meteorological point of view.Today, precipitation data, air temperature, humidity and snow height are monitored and radio transmitted to the Tyrolean regional government...
Safe Landings Whatever the Weather: Lufft Sensors on Airports
Pilots, air traffic controllers and airport operators do their best to make air travel safer and more efficient. Sometimes, however, flight security depends on external factors we can hardly influence. This especially refers to risky weather conditions: Strong winds, icy cold or strong precipitation can have serious consequences. On average, 23% of all aircraft accidents and 68% of canceled flights in 2015 are attributable to adverse weather conditions (source: FAA). How dangerous weather conditions are, is...
´More Stations. More Data. Better Forecasts.´ – the NYS Mesonet
“More Stations. More Data. Better Forecasts.” – that’s the slogan of New York State Mesonet. The weather observation network consists of a total of 125 weather stations all over the state of New York and Lufft was selected as one of the vendors to support them in capturing the data. All 125 of the weathers stations have the standard instrumentation suite. Of those 125, 17 sites are equipped with additional vertical sensing systems, 17 with additional surface energy budget sensors and 20...
The challenges and benefits of local air quality monitoring
A new generation of air quality monitors is now being offered to provide localised, real-time air quality readings – but the potential benefit is only just starting to be realised. It is generally accepted that whilst measurements from air quality reference stations are highly accurate, they are not sufficiently location-specific. Key pollutants – such as NO2 and PM2.5 – vary dramatically over short distances and time intervals, but the large size, maintenance requirements and relatively high...