HS6.8

To assess the capability of globally available satellite or remote sensed data products (GASRSDP) for distributed hydrological modelling and expedite their widespread uptake require a comprehensive knowledge-base related to their efficiency, temporal and spatial specifications and extents. Moreover, it is important to assess their performance in setting up hydrological models, their use as forcing data of models or for calibration, validation or evaluation of the model itself, along with an assessment of their limitation.

Hydrological models are the key tools for sustainable water management decision-making process. In order to capture the spatio-temporal variation in hydrological fluxes, the input data and representation of physical parameters in hydrological models plays an important role in their credibility. Models require rich amounts of data, which is mostly not readily available in data scare regions. The remotely sensed or satellite derived globally available data products are a vast and rich source of data with continuous addition to daily inventory. This data is widely in use for setting up hydrological models, their calibration, validation, evaluation and improvement.

Each day new data products are being released by different agencies. The scientific community is continuously mentioning the use of these data products in scientific articles. Present article does a systematic literature review of the articles over the last 5 years (2016 to 2021) in order to analyse the use of remote sensed / satellite globally available data products for detailed distributed hydrological modelling so that the progress in this context can be ascertain and future directions can be established. The review process was started by sourcing 179 articles from Scopus and 206 articles from Web of Science. After excluding the common and out of scope articles, the full analysis has been performed on about 100 articles. We conclude that the use of GASRSDP for the hydrological modelling of macro-scaled catchments has extensively explored and their performance is being evaluated by many authors while their worth for setting up physically based distributed hydrological model for catchment at meso-scale still need exploration, evaluation and assessments.

How to cite: Ali, M. H., Popescu, I., Jonoski, A., and Solomatine, D.: Review of scientific literature on the use of globally available remote sensed data products for distributed hydrological modelling., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10200, https://doi.org/10.5194/egusphere-egu22-10200, 2022.

As the built-up areas extend and become denser with time, high-resolution land use and especially imperviousness data is of increasing importance, e.g., for detailed studies on settlement and landscape water retention to provide for extremes such as (flash) floods, heatwaves, and droughts.

The open-source COPERNICUS imperviousness density dataset covers 2006 until 2018 with a three-year timestep with incremental raster resolution (2018: ten meters). On the other hand, there is an accurate object-oriented cadastre dataset of German authorities called ATKIS. It describes the geometries of buildings and all types of traffic routes from airports to dirt roads with an increasing amount of attributes like shape, area, width, or material. While both datasets are very detailed, they have specific (dis-)advantages due to their very different data and surveying type.

We used the information stored in the ATKIS database of 2020 to create an alternative object-based imperviousness map of the German state Bavaria with roughly 70,000 km² to contrast and compare it with the COPERNICUS imperviousness density dataset of 2018 in several different (urban and rural) areas. We found that COPERNICUS indicates much higher imperviousness for densely settled areas as city centres and commercial and industrial zones and can describe even complex types of significant extent (such as golf courses, transhipment stations, and allot settlements) better. Vice versa, ATKIS could resolve even linear traffic elements in rural areas and detached house settlements to an outstanding level of detail, which COPERNICUS cannot afford due to its limited resolution. Both products cannot distinguish clearly between sealed concrete and loose stony material (e.g., from construction or mining sites), nor give indications on sub-surface water retention or sewage infrastructure.

Overall, we can name both methods' (dis-)advantages, relate them to surprisingly distinct land use classes, and give guidance, where additional object-oriented information can significantly improve COPERNICUS imperviousness data. Finally, the resulting maps highlight the hotspots of extreme building-independent imperviousness. They can serve as a tool to prioritize areal and building-centred measures to prevent large amounts of fast runoff.

How to cite: Mitterer, J. and Disse, M.: Remote sensing versus surveyed object-based cadastre data: Comparing the advantages of COPERNICUS imperviousness density and ATKIS data in Bavaria/Germany using GIS analysis, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7477, https://doi.org/10.5194/egusphere-egu22-7477, 2022.

One of the important issues faced by human in 21^st century is to meet the need of food particularly in the background of increasing population. Steep-slope agricultural landscapes are making a relevant contribution for food protection. To protect and mitigate the impact of more frequent rainfall events as well as improve the food production in, more researches about how to increase water resource efficiency and management is necessary. In addition, understanding the interactions between water management infrastructure and runoff process is a great concern on the sustainable development of steep-slope agricultural landscapes. Several researches focused on water and soil conservation measures aims at soil erosion control, while less studies were conducted to study on runoff trapping under different rainfall intensities and water managements measures through the remote sensing data. In this study, we simulated surface water flow under different rainfall events before and after the application of designed water storages network to search the best solution for water runoff mitigation and water conservation in steep-slope agricultural areas. In detail, our works focus on (1) to design the sustainable and cost-effective water management infrastructures to the study area; (2) to quantify the amount of water resource maintained by appropriate management measures; (3) to simulated the overflow in steep slope agricultural areas under different rainfall conditions using hydrologic model based on high-resolution topography derived by remote sense data, with the aims to test the impacts of designed water storages in saving water and mitigating runoff. The research results not only have theoretical significance, but also provide a more accurate example of the how to design the reliable water resource managements in steep slope agricultural areas under the background of climate change.

How to cite: Wang, W., Straffelini, E., and Tarolli, P.: Influence of water resource management on runoff trapping under different rainfall events based on remote sense technology in steep-slope agricultural landscapes, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5092, https://doi.org/10.5194/egusphere-egu22-5092, 2022.

The worldwide spread of invasive aquatic plants in freshwater environments often leads to serious environmental (including ecological and socio-economic) problems, which requires a deeper knowledge of the extent of infestations (in time and space), and the abundance and propagation rates of aquatic weeds in invaded water systems. In particular, water hyacinth (Eichhornia crassipes) has become a threat to many aquatic environments: by presenting a rapid reproductive capacity; water hyacinth outcompetes other aquatic plant species, forming dense free-floating mats, which in many instances completely cover fresh-water surfaces. The infestation leads to several impacts that are hazardous to aquatic systems, disables human uses of surface waters, and affects hydraulic infrastructures (e.g., waterways, pumping stations). In general, the water hyacinth’s fast growth rate is explained, to a large extent, by eutrophication in water bodies.

This study explores the use of remote sensing tools to characterize the presence of water hyacinth in a river environment, aiming at new insights into the detection, observation, and mapping of this invasive plant using multispectral based vegetation indices and water indices, such as NDVI and NDWI. The study focuses on a small watercourse located in the downstream part of the Mondego River Valley, in Portugal. Multi-temporal data were acquired by multispectral satellite Sentinel-2; the data spatial resolution is 10 m. Results from this study show that the new generation sensors’ data have the potential to better detect the spatial distribution of invasive plant species and temporal dynamic changes in their incursion level, compared to data collected during (traditional) time costly ground-based surveys. The remote sensing approach provides a baseline to inform planners and decision-makers and a framework for developing water hyacinth management and important eradication strategies.

How to cite: P. de Lima, I. and Gerardo, R.: Analysis of water hyacinth (Eichhornia crassipes) infestation in a river branch using Sentinel-2 satellite data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6664, https://doi.org/10.5194/egusphere-egu22-6664, 2022.

Irrigation is the largest consumer of freshwater and irrigated lands contribute a significant proportion of total food production. These statements are often accompanied by figures illustrating inefficient water use in agriculture. Policy decisions concerning water in agriculture tend to reference efficiency as the principal metric assessing performance. We see this reflected in documents such as the United Nations Social Development Goal 6 target 4 which aims to “substantially increase water-use efficiency across all sectors”. Optimising the output from a limited resource is necessary, however, the true measure of irrigation efficiency has been widely debated, creating different approaches and interpretations. The typical avenue is techno-centric and can lead to an offhand dismissal of so-called ‘old’ lower-technology irrigation systems as wasteful and inefficient. Irrigation efficiency has become a powerful tool both in political discourse as well as marketing campaigns for irrigation equipment.

A majority of farms are family-run enterprises and do not have at their disposal the capital and expertise of large agro-industrial companies. Challenges they face at field level may not be overcome by upgrading traditional irrigation methods with higher technology systems. The complexity of large irrigation schemes as hydrosocial systems cannot be overstated and compound the challenges individual farmers may be experiencing, such as problems related to their position in a scheme or along the supply network. The head-end/tail-end effect is one situation where farmers further from the head-end of water supply find a disadvantage compared to their head-end neighbours.

This work aims to follow recent research in irrigation efficiency which encourages employing a wider ranging and more comprehensive framework of indicators of irrigation performance, looking beyond the purely technical irrigation efficiency perspective and across scales. Working toward this, field level crop performance knowledge gaps were addressed. Using a set of phenology, crop stress and biomass productivity indicators derived from high-resolution optical and thermal satellite imagery, we were able to reveal important spatial patterns among farmers’ fields which may be linked to the performance of the irrigation scheme.

The study looks at the arid Northern Peruvian coast where the 110,000 ha Chancay-Lambayeque Irrigation System is supplied by water from the Andes. A substantial reservoir buffers discharge in the Chancay river on which an offtake supplies a 65 km main canal with an initial construction over 1000 years ago. The scheme is owned and operated by several Water Users’ Associations and small farmers share the supply with agro-industrial enterprises upstream. In this climate of almost negligible precipitation, crop stress and seasonal biomass production may be good performance indicators for irrigation. The resolutions are 30 m for crop stress using Landsat-8 surface temperature data and 20 m for biomass productivity using Sentinel-2 derived fAPAR. A spatial pattern analysis alongside the irrigation canal network was based on these indicators aiming to elucidate how a farmer may be affected by their location relative to the supply network, the crop type grown on their own or a (upstream/downstream) neighbour’s field and the condition of supply (abundance/scarcity).  

How to cite: Carthy, B., Degerickx, J., Somers, B., Wyseure, G., and Rufasto, E.: Field level crop performance, farmer pressures and challenges in a large irrigation scheme, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10297, https://doi.org/10.5194/egusphere-egu22-10297, 2022.

Earth Observations (EO) have become popular in hydrology because they provide valuable information in locations where direct measurements are either unavailable or prohibitively expensive to make. Recent scientific advances have enabled the assimilation of EO’s into hydrological models to improve the estimation of initial states and fluxes which further leads to improved forecasting of different hydrometeorological variables. When assimilated, the data exert additional controls on the quality of the forecasts; it is hence important to apportion the effects according to model forcing and the assimilated data. Here, we investigate the impact of assimilating different EO and in itu data-sets individually and as combinations on the discharge and reservoir inflow estimations in the snow dominated Umeälven catchment in northern Sweden. We further assess the impact of the assimilations on seasonal predictions over the catchment. Six datasets are assimilated comprising of four EO products (fractional snow cover, snow water equivalent, and the actual and potential evapotranspiration) and two in situ datasets (discharge and reservoir inflow). For the latter investigation,  we drive the E-HYPE hydrological model with two meteorological forcings: (i) a down-scaled GCM product based on the bias-adjusted ECMWF SEAS5 seasonal forecasts, and (ii) historical meteorological data based on the Ensemble Streamflow Prediction (ESP) method. We finally assess the impacts of the meteorological forcing and the assimilated data on the streamflow and reservoir inflow seasonal forecasting skill for the period 2001-2015. We assessed the value of assimilating different data-sets and identified the datasets that can be meaningfully combined. We further show that all assimilations generally improve the forecasting skill but the improvement varies depending on the season and assimilated variable. The lead times until when the data assimilations influence the forecast quality are also different for different datasets and seasons; as an example, the impact from assimilating snow water equivalent persists for more than 20 weeks during the winter. We finally show that the assimilated datasets exert more control on the forecasting skill than the meteorological forcing, highlighting the importance of initial hydrological conditions for this snow-dominated river system.

How to cite: Musuuza, J. L., Crochemore, L., and Pechlivanidis, I. G.: The impact of assimilating Earth Observation and in situ data on seasonal hydrological predictions in a snow-dominated river system, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1010, https://doi.org/10.5194/egusphere-egu22-1010, 2022.

Crystalline basement formations are originally without any hydrogeological potential  due to the poor primary porosity of rocks that they content. Therefore, finding productive zones of groundwater in those area becomes possible by a better knowledge of fracturing. The mapping of linear features on remotely sensed data is one of the keys to understand groundwater occurrence, in those area. For that purpose, The extraction of lineaments is a preliminary step in the selection of favorable sites for exploration of basement aquifers. The purpose of this work is to study the hydraulic role of the major lineaments of the Mayo-Banyo department (Adamawa Region, Cameroon) in the productivity of the boreholes through the analysis of the correlation between the productivity parameters of the high flow boreholes and the proximity to the major lineaments associated with other productivity index parameters such as topography, drilling depth, proximity to the nearest fracture node, lineament density and alteration thickness, and to suggest favorable areas for future hydraulic surveys. The application of the Canny filter and the shaded relief respectively on the Landsat 8 and SRTM image of the study area shows after statistical analysis a good correlation between the two methods in view of the obtained directional rosettes for lineaments. The main directions of the extracted lineaments are N-S, NNE-SSW and NNW-SSE. The NNE-SSW direction as indicated by several structural studies carried out in the region corresponds to the orientation of the D1 phase of tangential tectonics that the region underwent. The correlation analysis between the productivity of high flow boreholes (Q> 5 m3/h) and the proximity to major lineaments (L> 5km) of the NNE-SSW directional class shows a positive and relatively significant correlation (0.41). This result shows that the productivity of the boreholes in the department is influenced by the proximity to the main fracture directions. In addition, the analyses also show a combined effect of lineament density, topography (slope), borehole depth and alteration thickness on the productivity of high flow boreholes. The northeast and west of the study area have a greater density of lineaments. These areas would have been affected by greater structural deformation and therefore may have a higher potential for groundwater infiltration due to a greater density of lineaments that serve as weaving. Therefore, more local analysis with geophysical data in those areas should help to better locate future wells. 
Keywords: lineaments, basement aquifers, Mayo-Banyo.

How to cite: Brice, T. D., Hermans, T., Daniel Hervé, G., Theophile, N. M., and Adoua, N. K.: Estimating the productivity of boreholes in fractured crystalline basement using lineaments extracted from remote sensing data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12908, https://doi.org/10.5194/egusphere-egu22-12908, 2022.