Seasonally in ENSO‐related precipitation, river discharges, soil moisture, and vegetation index in Colombia

Poveda, Germán; Jaramillo, Álvaro; Gil, Marta María; Quiceno, Natalia; Mantilla, Ricardo

doi:10.1029/2000wr900395

Cited by 231 publications

(219 citation statements)

References 22 publications

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“…On the other hand, the process variables (PRC and EVP) are the most complex in the region HPREC= 0.76 and HEVP= 0.71. This result confirms the diversity of factors that make part of the hydro-climatic variance at interannual timescale, thus reflecting the implicit complexity of the linkages between these two processes over TropSA [44,46,59,[70][71][72]. The high entropy of EVP can be also explained in terms of the multivariate influence of water and energy fluxes in TropSA [22,47,73].…”

Section: Svd Noise Reduction and Entropysupporting

confidence: 65%

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Bedoya-Soto

Poveda

2017

Proceedings of First International Electronic Conference on the Hydrological Cycle

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Abstract:Using monthly data for the period 1979-2010, we study the dynamics and strength of land surface-atmosphere feedbacks (LAFs) among variables involved in the heat and moisture fluxes, at interannual timescales in Tropical South America (TropSA). The variables include precipitation, surface air temperature, specific humidity at 925 hPa, evaporation, and estimates of volumetric soil water content. We use a Maximum Covariance Analysis (MCA) to reduce the dimensionality and to rank the relative contributions to LAFs and group the time series into Maximum Covariance States (MCS) with common mechanisms among variables. We estimate linear (Pearson correlations) and non-linear association (information transfer or causality) metrics among pairs of variables to configure the structure of linkages. The main MCS associated with LAFs over TropSA are strongly influenced by ENSO, and the meridional and equatorial SSTs modes over the Atlantic and Indian Oceans. ENSO favors a unimodal behavior, with center of action in the Amazon River basin, while the SSTs mode over the Tropical North Atlantic (TNA) results in a dipole between northern and southern TropSA. Our results show that soil moisture plays a leading role in regulating heat and water anomalies, and provides the memory of the LAFs and their subsequent influence. Thus, volumetric soil water becomes a fundamental variable leading up to 9 month-lags. ENSO enhances the interannual connectivity and memory inside LAF mechanisms with respect to other modes. Within the identified multivariate structure, evaporation and soil moisture enhance the interannual connectivity of the whole set of variables since both variables exhibit more frequent two-way feedbacks with the remaining variables.

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Section: Svd Noise Reduction and Entropysupporting

confidence: 65%

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Bedoya-Soto

Poveda

2017

Proceedings of First International Electronic Conference on the Hydrological Cycle

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“…However, during intense El Niño-Southern Oscillation (ENSO) events, the ITCZ can extend anomalously far south bringing drought conditions in the MRB. In contrast, during La Niña events the MRB experiences heavier than normal rains and colder conditions that often extend-sometimes even bridging ITCZ events, leading to rainy periods that can last a year 10 or longer (Poveda, Jaramillo, Gil, Quiceno, & Mantilla, 2001;Poveda & Mesa, 1997). The strong relation between anomalously high or low stream flow conditions at four stations in the MRB and the Oceanic Niño Index, a measure of ENSO, is illustrated in Figure 2.…”

Section: System Descriptionmentioning

confidence: 99%

Large-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia

Angarita¹,

Wickel²,

Sieber³

et al. 2017

Preprint

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A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America. Annual large-scale inundation of floodplains and associated wetlands regulates water-, nutrient-, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food 15 supplies. In this study, we present a comparative analysis of the potential effects of hydropower expansion to meet projected electricity requirements by 2050, in terms of 1) basin-level implications of cumulative changes in streamflow regime, sediment trapping, and loss of river connectivity, and 2) the impact of upstream regulation on the hydrologic dynamics of the Mompós Depression wetlands at a monthly to decadal scale. To this end, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the Mompós Depression floodplains water balance at a 20 medium scale (~1000 to 10 000 km 2 ) and evaluation of the potential impacts of upstream water management practices. Our results indicate that potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80%, respectively, from pre-dam conditions. In some 25 development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry periods and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.

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“…Seasonal forecasts of soil moisture could give a useful indication of flood risk in dry regions of Africa (Fig. 4), and these forecasts are also likely to have seasonal predictability in areas where they can be well initialized, notably due to the persistence of soil moisture (Kanamitsu et al, 2002;Koster et al, 2010;Poveda et al, 2001). This also takes evaporation into account.…”

Section: Discussionmentioning

confidence: 99%

Should seasonal rainfall forecasts be used for flood preparedness?

Pérez

Stephens

Bischiniotis

et al. 2017

Hydrol. Earth Syst. Sci.

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Abstract. In light of strong encouragement for disaster managers to use climate services for flood preparation, we question whether seasonal rainfall forecasts should indeed be used as indicators of the likelihood of flooding. Here, we investigate the primary indicators of flooding at the seasonal timescale across sub-Saharan Africa. Given the sparsity of hydrological observations, we input bias-corrected reanalysis rainfall into the Global Flood Awareness System to identify seasonal indicators of floodiness. Results demonstrate that in some regions of western, central, and eastern Africa with typically wet climates, even a perfect tercile forecast of seasonal total rainfall would provide little to no indication of the seasonal likelihood of flooding. The number of extreme events within a season shows the highest correlations with floodiness consistently across regions. Otherwise, results vary across climate regimes: floodiness in arid regions in southern and eastern Africa shows the strongest correlations with seasonal average soil moisture and seasonal total rainfall. Floodiness in wetter climates of western and central Africa and Madagascar shows the strongest relationship with measures of the intensity of seasonal rainfall. Measures of rainfall patterns, such as the length of dry spells, are least related to seasonal floodiness across the continent. Ultimately, identifying the drivers of seasonal flooding can be used to improve forecast information for flood preparedness and to avoid misleading decision-makers.

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Seasonally in ENSO‐related precipitation, river discharges, soil moisture, and vegetation index in Colombia

Cited by 231 publications

References 22 publications

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Large-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia

Should seasonal rainfall forecasts be used for flood preparedness?

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