Research Highlights

Linking Hydrology and Malaria

Hydrology is linked to Malaria mainly through the population dynamics of Anopheles mosquitoes. This short video explains the mechanisms of malaria transmission and how hydrology, climatology, and other factors could impact the malaria transmission potential. The video also introduces the field activities at Eltahir Research Group.

Role of the Indian Ocean in shaping the Natural Variability in the Flow of the Nile River

A significant fraction of the inter-annual variability in the Nile River flow is shaped by El Niño Southern Oscillation (ENSO). In this study, we investigate a similar role for the Indian Ocean sea surface temperature in shaping the inter-annual variability of the Nile river flow.

Evaluation of Climate Models Over Major African Basins

Climate models are the main tools for predicting future climate and for creating credible future climate change scenarios. However, prior to their use to simulate future climate conditions, we need evaluate their skill in simulating the current and past climates.

Interactions between Climate, Vegetation, and Mineral Aerosols

From agriculture losses to air travel disruption, dust storms affect millions of people every year. Moreover, research has shown that mineral aerosols (dust) have a profound effect on global and regional climate dynamics. However, little is known about interactions between the surrounding natural vegetation and dust emissions.

Early Warnings for Malaria Epidemics

We have developed a methodology to make early warnings of malaria transmission using HYDREMATS. Early warnings of malaria transmission are an important component of malaria control, as they allow local officials to prepare for or even prevent epidemics by reallcoating limited resources including staff and medication, conducting vector control activities, and urging people at risk to take precautions to avoid insect bites.

Assessing Changes in Agricultural Productivity with Climate Change

In January 1981, the The New York Times article “Down on the Farm, Higher Prices” explained the economic impacts of drought, predicting a 10%-15% increase in average US consumer food bills resulting from a lack of rainfall in 1980. Agricultural productivity is strongly correlated to soil moisture, as examined by studies such as: The Effect of Water Stress on Corn in its Various Stages [Claassen, 1995].

Efficacy of Neem for Sustainable Malaria Vector Control in an African village

Neem seeds were field tested as a locally-produced, sustainable larvicide. During the 2007 monsoon (June – September), we regularly applied crushed neem seeds to malaria mosquito breeding pools in Banizoumbou, Niger. We continued to monitor mosquito abundance and hydrological conditions in the same manner as in the 2005 and 2006 monsoons to assess the impact of this intervention. In addition, we monitored mosquito abundance in the nearby village Zindarou for the same three years, but for control purposes did not apply neem during the 2007 season.

Subcloud Layer Evaporation in Semiarid Climates

From radar studies and observations, it has been estimated that in dry environments between 20 and 50 percent of rainfall evaporates once falling from the cloudbase. When compared to observations, original simulations of RegCM3 over the Middle East contained large wet biases (on this order) in the Arabian Peninsula. Large annual overestimation of rainfall also led to substantially higher interannual variability than observations (CRU).

Hydrology, Entomology, and Malaria Transmission Simulator (HYDREMATS)

Prediction of impacts of interannual climate variability on malaria transmissibility in Banizoumbou. Using our mechanistic modeling approach, we have reproduced the seasonal and interannual variability in mosquito abundance between 2005 and 2006. This result is from HYDREMATS, our agent-based model coupled to a distributed hydrology model.

Asymmetry in the Response of Aquifer Water Level to Droughts and Floods in Illinois

In a recent study, Eltahir and Yeh (1999) presents a comprehensive data set on the hydrological cycle of Illinois. The following figure, taken from their paper, describes the propagation of hydrological floods and droughts from the atmosphere into the soil and down to the groundwater aquifers. If we focus on major events: the drought of 1988 and the flood of 1993, we can observe that the aquifer tends to amplify the drought and to dissipate the flood.

Mechanisms for the Persistence of Summer Floods and Droughts over North America

The Midwest region of North America experiences significant floods and droughts during the summer season. The 1988 drought and the 1993 floods are good examples for these extreme events.

Deforestation, Desertification, and the Drought in West Africa

The region of West Africa has experienced significant changes in land cover during this century, ranging from deforestation near the Atlantic coast to desertification near the border with the Sahara desert.

A New Methodology for Long-range Forecasting of the Nile Floods

Until recently, the lead time for forecasting the Nile floods was limited to less than the hydrologic response time scale: the time period between occurrence of rainfall over the Ethiopian Plateau and occurrence of stream-flow. For the Nile basin this response time is about one month. The following forecasting table, taken from Eltahir (1996), can be used for forecasting the Nile flood conditions, with a lead time of about six months. In March 1999, most models for forecasting ENSO predict a cold SST during the summer of 1999. Using this information we can almost rule out the possibility of a low flood in the Nile, six months ahead of the flood peak time in September.