Hydrological Response Assessment of Land Cover Change in a Peruvian Amazonian Basin Impacted by Deforestation Using the SWAT Model

The watershed hydrologic conditions in the Madre de Dios (MDD) Basin in the Peruvian Amazon have been irreversibly impacted by deforestation and changes in land cover. These changes have also had detrimental effects on the geomorphology, water quality, and aquatic habitat within the basin. However, there is a scarcity of hydrological modeling studies in this area, primarily due to the limited availability of hydrometeorological data. The primary objective of this study was to examine how deforestation impacts the hydrological conditions in the MDD Basin. By implementing the Soil and Water Assessment Tool (SWAT) model, this study determined that replacing 12% of the evergreen broadleaf forest area with bare land resulted in a significant increase in surface runoff, by 38% monthly, a 1% annual reduction of evapotranspiration, and an average monthly streamflow increase of 12%. Changes in spatial patterns reveal that the primary impacted watershed is the Inambari River subbasin, a significant tributary of the Madre de Dios River. This area experiences an annual average surge of 187% in surface runoff generation while witnessing an annual average reduction of 8% in evapotranspiration. These findings have important implications, as they can contribute to instances of flooding and extreme inundation events, which have already occurred in the MDD region

Assessment of bottom-up satellite precipitation products on river streamflow estimations in the Peruvian Pacific drainage

In regions with limited precipitation information, like Peru, many studies rely on precipitation data derived from satellite products (SPP) and model reanalysis. These products provide near-real-time information and offer global spatial coverage, making them attractive for various applications. However, it is essential to consider their uncertainties when conducting hydrological simulations, especially in a key region like the Pacific drainage (Pd), where 56% of the Peruvian population resides (including the capital, Lima). This study, for the first time, assessed the performance of two bottom-up Satellite-based Precipitation Products (SPP), GPM + SM2RAIN and SM2RAIN-ASCAT, and one top-down approach SPP, ERA5-Land, for runoff simulation in the Pacific drainage of Peru. Hydrological modeling was conducted on 30 basins distributed across the Pd, which were grouped into 5 regions (I–V, ordered from south to north). The results showed that SM2RAIN-ASCAT performed well in regions I-III-IV, ERA5-Land in region II, and GPM + SM2RAIN in region V. The hydrological model GR4J was tested, and better efficiency criteria were obtained with SM2RAIN-ASCAT and GPM + SM2RAIN when comparing the simulated versus observed streamflows. The hydrological modeling using SM2RAIN-ASCAT and GPM + SM2RAIN demonstrated satisfactory efficiency metrics (KGE > 0.75; NSE > 0.65). Additionally, ten hydrological signatures were quantified to assess the variability of the simulated streamflows in each basin, with metrics such as Mean Flow (Q mean), 5th Quantile Flow (Q5), and 95th Quantile Flow (Q95) showing an overall better performance. Finally, the results of this study demonstrate the reliability of using bottom-up satellite products in Pd basins

Rainfall Erosivity in Peru: A New Gridded Dataset Based on GPMIMERG and Comprehensive Assessment (2000–2020)

In soil erosion estimation models, the variable with the greatest impact is rainfall erosivity (RE), which is the measurement of precipitation energy and its potential capacity to cause erosion, and erosivity density (ED), which relates RE to precipitation. The RE requires high temporal resolution records for its estimation. However, due to the limited observed information and the increasing availability of rainfall estimates based on remote sensing, recent research has shown the usefulness of using observed-corrected satellite data for RE estimation. This study evaluates the performance of a new gridded dataset of RE and ED in Peru (PISCO_reed) by merging data from the IMERG v06 product, through a new calibration approach with hourly records of automatic weather stations, during the period of 2000-2020. By using this method, a correlation of 0.7 was found between the PISCO_reed and RE obtained by the observed data. An average annual RE for Peru of 4831 M Jmmha−1h −1 was estimated with a general increase towards the lowland Amazon regions and high values are found on the north-coast Pacific area of Peru. The spatial identification of the most risk areas of erosion, was carried out through a relationship between the ED and rainfall. Both erosivity data sets will allow us to expand our fundamental understanding and quantify soil erosion with greater precision

The dynamics of floods in the Bolivian Amazon Basin

In 1997, a study was initiated by IRD, Bolivia to analyse the dynamics of floods in the Bolivian Amazon, which commonly affect an area of 100 000 to 150 000 km(2) for about 4 months of the year. This region is characterized by vast isolated areas with difficult access and is continuously covered by clouds in the wet season. For these reasons, this hydrological study depends heavily on the use of remote sensing, and particularly radar data, for flood monitoring and the identification of areas at risk of inundation. This article presents preliminary results obtained in the Trinidad area, around the Mamore River, using LANDSAT, ERS and RADARSAT radar data from dry, wet and flood seasons (collected between 1996 and 1998), and water level and., hydrometeorological data obtained from the upper and lower parts of the Mamore basin. After characterizing the annual flood cycle within the Study area, a TM colour composite (to map the vegetation) and a radar colour composite (multi-temporal), are used to evaluate the potential contribution of microwave data (RADARSAT and ERS) for mapping the extent of flooding at both the regional (all the flood plain) and the local scale (around the city of Trinidad)

Congreso boliviano de limnologia y recursos acuaticos

La Amazonia boliviana se caracteriza por una gran llanura central regularmente inundada mas de 4 meses al ano. La superficie afectada puede abarcar 100000 a 150000 km2 segun la variabilidad meteorologica interanual. Las inundaciones provocan generalmente perdidas de muchas cabezas de ganado y afectan numerosas poblaciones. Sin embargo, la intensidad y la duracion de la inundacion condiciona directamente la diversidad biologica y la produccion piscicola. En 1997, el IRD ha iniciado, con sus socios bolivianos del SENAMHI, ABTEMA y SEMANA un programa de investigaciones (BIOCAB: Biodiversidad acuatica en la Cuenca Amazonica Boliviana) que incluye un estudio de la dinamica de las inundaciones en la llanura central del rio Mamore. El conocimiento hidrologico aportado permitira entender el funcionamiento ecologico de esta zona y aprovechar, con un manejo sostenible, el producto de la inundacion. (Résumé d'auteur

Spatio-temporal dynamics of the floods in the Guayas watersheds (Ecuatorian Pacific coast) using Envisat Asar images

International audienceRemotely sensed images allow a frequent monitoring of land cover variations at regional and global scale. Recently launched Sentinel-1 satellite offers a global cover of land areas at an unprecedented spatial (20 m) and temporal (6 days at the Equator). We propose here to compare the performances of commonly used supervised classification techniques (i.e. k-nearest neighbors, linear and Gaussian support vector machines, naive Bayes, linear and quadratic discriminant analyzes, adaptative boosting, loggit regression, ridge regression with one-vs-one voting, random forest, extremely randomized trees) for land cover applications in the Guayas Basin, the largest river basin of the Pacific coast of Ecuator (area ∼32,000 km 2). The reason of this choice is the importance of this region in Ecuatorian economy as its watershed represents 13% of the total area of Ecuador where 40% of the Ecuadorian population lives. It also corresponds to the most productive region of Ecuador for agriculture and aquaculture. Fifty percents of the country shrimp farming production comes from this watershed, and represents with agriculture the largest source of revenue of the country. Similar comparisons are also performed using ENVISAT ASAR images acquired in global mode (1 km of spatial resolution). Accuracy of the results will be achieved using land cover map derived from multi-spectral images

The Use of Remote Sensing in Hydrology

Remotely sensed data are nowadays commonly used for regional/global monitoring of hydrological variables including soil moisture, rainfall, water levels, flood extent, evapotranspiration or land water storage, as well as the forcing, calibration and assimilation into hydrodynamic, hydrological and hydrometeorological models. In the years to come, recent and future satellite sensors, some of them specifically designed for hydrological purposes, will provide systematic observations of hydrological parameters (e.g., surface and sub-surface storage and flux) at high spatial and temporal resolutions. This will offer new applications for the hydrological community. This book presents reviews and recent advances of general interest regarding the use of remote sensing for hydrology. The chapters are related to any hydrological reservoir (e.g., surface storage, soil moisture, groundwater, etc.) or flux (e.g., rainfall, evapotranspiration, discharge, etc.), the integration of satellite data into hydrological models, and the improvements to hydrology that can be expected from future satellite missions

Manaus'99 : hydrological and geochemical processes in large scale river

La Amazonia boliviana se caracteriza por una gran llanura central regularmente inundada mas de 4 meses al ano. En epoca de lluvias, esta region presenta una persistente cobertura nubosa y zonas vastas de dificil acceso: por esta razon, este estudio hidrologico se basa primero sobre la utilizacion de la percepcion remota radar que permite de prender la distribucion espacio-temporal de las inundaciones. Este articulo presenta los primeros resultados obtenidos, en la llanura de inundaicon, con la fertilizacion de imagenes LANDSAT, ERS y RADARSAT correspondientes a las epocas seca e inundada (de 1996 a 1998), y tambien de datos hidrometeorologicos y niveles diarios de agua (en losrios y en la llanura) obtenidos en estaciones ubicadas en la parte alta y en la parte baja de la cuenca del rio Mamore. Despues de la caracterizacion del ciclo hidrometeorologico anual de las inundaciones estudiadas, son presentadas una compuesta coloreada de una imagen LANDSAT TM (mapeo de vegetacion) y luego algunas compuestas coloreadas radar (multitemporal) son utilizadas para valuar las respectivas contribuiones de los datos radar en el mapeo de la extension de las inundaciones al nivel regional (de toda la llanura de inundacion) y local (alrededor de la ciudad de Trinidad). (Résumé d'auteur

Congreso boliviano de limnologia y recursos acuaticos

La Amazonia boliviana se caracteriza por una gran llanura central regularmente inundada mas de 4 meses al ano. La superficie afectada puede abarcar 100000 a 150000 km2 segun la variabilidad meteorologica interanual. Las inundaciones provocan generalmente perdidas de muchas cabezas de ganado y afectan numerosas poblaciones. Sin embargo, la intensidad y la duracion de la inundacion condiciona directamente la diversidad biologica y la produccion piscicola. En 1997, el IRD ha iniciado, con sus socios bolivianos del SENAMHI, ABTEMA y SEMANA un programa de investigaciones (BIOCAB: Biodiversidad acuatica en la Cuenca Amazonica Boliviana) que incluye un estudio de la dinamica de las inundaciones en la llanura central del rio Mamore. El conocimiento hidrologico aportado permitira entender el funcionamiento ecologico de esta zona y aprovechar, con un manejo sostenible, el producto de la inundacion. (Résumé d'auteur