Essam Heggy

National Aeronautics and Space Administration · Jet Propulsion Laboratory

Soil erosion in North Africa modulates agricultural and urban developments as well as the impacts of flash floods. Existing investigations and associated datasets are mainly performed in localized urban areas, often representing a limited part of a watershed. The above compromises the implementation of mitigation measures for this vast area under a...

Existing climate studies mainly assessed the effect of greenhouse gases and aerosols, among other forcings on Earth’s temperature. None of them has not evaluated the effect of the planetary orbital changes on Earth’s temperature. Here, we deconvolved the effects of greenhouse gases and planetary orbital changes on Earth’s temperature and to forecas...

Evapotranspiration is an essential component of the hydrological cycle. Forecasting the reference crop evapotranspiration ( ET0) using a reliable and generalized framework is crucial for agricultural operations, especially irrigation. This study was aimed at evaluating the performance of a hybrid system including the K-Best selection (KBest), multi...

Intensifying hydroclimatic changes in North Africa are causing unprecedented floods, droughts, and land degradation patterns that are increasingly associated with human casualties, socioeconomic instabilities, and outflow migrations. These patterns’ and their future forecasts remain largely unquantified, aggravating the impacts on several populous...

The eastern Mediterranean basin is witnessing increased storm activity impacting populous urban coastal areas that historically were not prone to catastrophic flooding. In the fall of 2023, Storm Daniel struck the eastern coast of Libya, causing unprecedented flash floods with a tragic death toll and large-scale infrastructure damages. We use Senti...

Climate change and human activity are leading to water scarcity in southwestern Europe. Groundwater use is thought to be unsustainable in the region, yet regional assessments using measured data are missing. Here, we evaluate long-term trends and drivers of groundwater levels and found a more complex situation. Historical data (1960–2020) from 12,3...

Sandy beaches in Southern California are experiencing rising coastal erosion due to changes in precipitation patterns and urban growth. As a result, beach nourishment is necessary for mitigation. In our study, we forecast the rates of shoreline retreat and the required volumes of sand nourishment to mitigate it for the coming decades. We employ pho...

Several North African coasts, including low-lying sandy and deltaic areas, are at high risk of coastal hazards due to increased climatic fluctuations. Alexandria, a historic and densely populated Mediterranean port city that is representative of several coastal cities in North Africa, has experienced over 280 building collapses near its shorelines...

The low-lying, arid coastal regions of the Southern Mediterranean basin, extending over 4600 km, face daunting sea level rise and hydroclimatic changes due to shifting weather patterns. The impacts of the above on coastal urban buildings and infrastructure still need to be more qualified and understood. Alexandria, a historic and densely populated...

Due to pronounced hydroclimatic fluctuations and rapid urban growth, coastal lagoonal systems in the Southern Mediterranean semi-arid areas undergo pronounced shoreline retreats and increased coastal floodings. The socioeconomic impacts of these alarming coastal changes remain poorly uncharacterized. To address this deficiency, we calculate the Soc...

Urban flooding is recognized as a nature-driven disaster shaped by inherent factors such as climate, morphology, and hydrology, affecting vulnerability and flood exposure. While these factors play a paramount role, significant psychosocial intricate drivers are acknowledged, though they are challenging for prediction and assessment. This study delv...

Optimizing hydropower generation from mega-dams during prolonged droughts while minimizing downstream water deficits is decisive to resolving the ongoing major conflict on transboundary river management in the highly populous Eastern Nile basin. Our study provides comprehensive assessments of the efficiency of multiple drought-mitigation operation...

The SESMAR dataset offers readily available maps and raster images tailored for scientists and decision-makers. It is derived from a wealth of remote sensing data covering the period from 2001 to 2023. Operating at a spatial resolution of 500m, this dataset evaluates soil loss susceptibility in the North African region. The application of the Revis...

Coastal aquifer vulnerability assessment (CAVA) studies are essential for mitigating the effects of seawater intrusion (SWI) worldwide. In this research, the vulnerability of the coastal aquifer in the Lahijan region of northwest Iran was investigated. A vulnerability map (VM) was created applying hydrogeological parameters derived from the origina...

Lakes with a small footprint in non-glaciated lands, are immense sources of our planet's biodiversity, which deliver undeniable benefits to human life and aquatic-terrestrial ecosystems. However, water quality in global lakes is threatened by unsustainable development and changing climate, with profound consequences for food-web dynamics and bio-ge...

Shallow aquifers are the largest freshwater bodies in the North African Sahara and the Arabian Peninsula. Their groundwater dynamics and response to climatic variability and anthropogenic discharge remain largely unquantified due to the absence of large-scale monitoring methods. Currently, the assessment of groundwater dynamics in these aquifer sys...

The wetland loss rate in Iran is faster than the global average. Comprehending the shrinkage rate in Iranian wetlands and identifying the underlying drivers of these changes is essential for safeguarding their ecosystems' health and services. This study proposes a novel gray‐box modeling framework to quantify the effects of climate change and anthr...

Shallow aquifers are the primary water source to mitigate rising hydroclimatic fluctuations in arid areas, notably in North Africa and the Arabian Peninsula. The occurrence and dynamics of these expansive water-bodies remain poorly characterized due to the reliance on sporadic monitoring wells. To address this deficiency, several studies are explor...

Increasing water and energy demands, hydroclimatic fluctuations, damming, and usage rights disputes present major challenges in managing transboundary rivers worldwide. Of particular interest is the Eastern Nile River Basin (ENRB), which is subject to broad debate over which modeling approach should be applied to resolve the disparities in transbou...

Groundwater recharge feeds aquifers supplying fresh-water to a population over 80 million in Iran—a global hotspot for groundwater depletion. Using an extended database comprising abstractions from over one million groundwater wells, springs, and qanats, from 2002 to 2017, here we show a significant decline of around −3.8 mm/yr in the nationwide gr...

Landslides are among the most frequent secondary disasters caused by earthquakes in areas prone to seismic activity. Given the necessity of assessing the current seismic conditions for ensuring the safety of life and infrastructure, there is a rising demand worldwide to recognize the extent of landslides and map their susceptibility. This study inv...

Most bridge failures result from scouring around bridge piers, resulting in economic losses and risks to public safety. The conventional equations for predicting the depth of scour at bridge piers have several limitations: (1) They mainly use regression-based techniques that cannot robustly capture the nonlinear relationship between the scour depth...

Land degradation and soil erosion are becoming increasingly problematic in Africa's rapidly developing urban areas, particularly in Major Port Cities. Uncontrolled expansion and human pressures are hindering planning, adaptation, and conservation efforts. To understand the extent of these issues, this study combined morphometric analysis, soil loss...

A survey based on the City Development Strategy for Sustainable Development criterion, assessing the inhabitants' perceptions of the degeneration and transformation of Alexandria's most iconic and historic urban waterway, Mahmoudieh Canal.

Land degradation and soil erosion are becoming increasingly problematic in Africa's rapidly developing urban areas, particularly in Major Port Cities. Uncontrolled expansion and human pressures are hindering planning, adaptation, and conservation efforts. To understand the extent of these issues, this study combined morphometric analysis, soil loss...

Sandy barriers are coastal features formed and reworked by terrestrial and marine-induced processes along decadal to millenary scale periods. In the semi-arid areas along the extended North African coast, these coastal landscapes are undergoing accelerated morphodynamical changes induced by intensifying anthropogenic and climate drivers in the last...

Soil moisture (SM) and land surface temperature (LST) are entangled, and the retrieval of one of them requires a priori specification of the other one. Due to insufficient observational information, retrieval of LST and SM from passive microwave remote sensing data is often ill-posed, and the retrieval accuracy needs to be improved. In this study,...

Egypt observes one of the highest water budget deficits in Africa that is mainly compensated by intensive reuse of untreated agricultural drainage water in the Nile Delta. The implications of untreated water reuse on increasing soil pollution levels remain poorly characterized; however, a large-scale pollution can compromise crop production and wat...

Groundwater recharge feeds aquifers supplying fresh water to a population over 80 million in Iran – a global hotspot for groundwater depletion. Using a rich database comprising abstractions from about one million groundwater wells, springs and qanats, from 2002 to 2017, here we show a significant decline of around -3.8 mm/yr in the nationwide groun...

More than 20% of global liquefied natural gas (LNG) exports and almost all of Qatar’s drinking water production originate from three industrial sites on Qatar’s eastern coast. They are all vulnerable to oil spills, and this vulnerability remains largely unquantified. Here we model oil-spill dispersal in the shallow maritime waters surrounding Qatar...

The IPCC-AR6 report suggests that the sea-level in the Persian Gulf is expected to rise by 2.1-4.9mm/year by 2100, which is lower than the global projections of 4-14mm/year. However, a central nationwide ground subsidence in Bahrain's low-lying island can aggravate these figures. The island is only 14-kilometers-wide, yet we observe a 7×12-kilomete...

Large-scale characterization of water table depth in shallow aquifers in hyper-arid areas provides crucial insights into groundwater dynamics under increasing anthropogenic discharge and climatic fluctuations. Due to their penetration capabilities into arid soils, airborne VHF sounding radars can achieve this objective under specific system design,...

Waterways’ regeneration is proposed as one of the main mitigation strategies for addressing the alarming water budget deficit in the populous, hyper-arid Egypt, relying primarily on the Nile as its most important water source. The latter is increasingly under pressure from a rise in internal consumption, droughts, and upstream damming. We perform h...

We thank Wheeler et al for positively confirming our results’ reproducibility; however, we show herein that their critique misrepresents the aim, approach, and interpretations reported in Heggy et al (2021 Environ. Res. Lett. 16 074022), which remain valid. The reply herein demonstrates that Wheeler et al incorrectly interpreted Heggy et al ’s (202...

The water crisis is still a major issue in Qatar. Seawater desalination has been strongly implemented in the Persian Gulf region. However, it is costly and there is corrosion in piping materials and other equipment. Hence, there is a vital need to detect groundwater resources in Qatar. Various factors affect the variability of groundwater in Qatar...

The reply herein shows the factual incorrectness of the comment by Eladawy, Asefa and El Nour, which is primarily supported by miscitations and misinterpretations of published research, as well as by claims from social media and unreliable TV interviews. The comment mistakenly omit the different components of the calculated total water budget defic...

Land subsidence (LS), which mainly results from poor watershed management, is a complex and non-linear phenomenon. In the present study, LS at a country-wide assessment of Iran was mapped by using several geo-environmental conditioning factors (namely, altitude, slope degree and aspect, plan and profile curvature, distance from a river, road, or fa...

The intensifying impacts of aridity and water stress on the dynamics and ecological degradation of wetlands in North Africa are often underestimated and largely remain unquantified. To address this deficiency, we assessed decadal changes in the sedimentary, sea surface salinity (SSS), and microfaunistic patterns of the Bizerte Lagoon, a climaticall...

Near-surface air temperature (Ta) is an important physical parameter that reflects climate change. Many methods are used to obtain the daily maximum (Tmax⁡), minimum (Tmin⁡), and average (Tavg) temperature, but are affected by multiple factors. To obtain daily Ta data (Tmax⁡, Tmin⁡, and Tavg) with high spatio-temporal resolution in China, we fully...

Opportunistic bistatic radar (BSR) observations of planetary surfaces can probe the textural and electrical properties of several solar system bodies without needing a dedicated instrument or additional mission requirements, providing unique insights into volatile enrichment and supporting future landing, anchoring, and in situ sampling. Given thei...

The absence of large archaeological settlements in the Eastern Arabian Peninsula suggests that most of the recent wet periods occurring during climate oscillations in these areas were short-lived. However, a ~ 2-by-3-km buried rectangular feature was discovered opportunistically in the southeast of the Qatar Peninsula while performing radar subsurf...

The alarming vulnerability of low-lying sandy beaches to the acceleration of global sea level rise has been confirmed in the recent IPCC AR6 report. The situation is worsened by increasing coastal erosion, resulting in additional shoreline retreat of sandy beaches along several semi-arid urban coastal areas around the globe. The additional shorelin...

Ta (Near-surface air temperature) is an important physical parameter that reflects climate change. Although there are currently many methods to obtain the daily maximum (Tmax), minimum (Tmin), and average (Tavg) temperature (meteorological stations, remote sensing, and reanalysis data), these methods are affected by many factors. In order to obtain...

Asteroid Ceres, the only dwarf planet located in the inner solar system, shows unique surface mineralogy and geomorphology as observed by the Dawn mission. Of particular interest is understanding the role that upper regolith porosity plays in retaining volatiles and shaping Ceres’ surface. Unfortunately, Ceres’ near-surface porosity remains largely...

Shallow aquifer mapping and large-scale characterization of groundwater dynamics in the Saharan-Arabian desert is largely impeded by the limited hydrological datasets from sparse and unevenly distributed well logs. Today, as these aquifers are depleting at alarming rates in response to climatic and anthropogenic stresses, accurate knowledge of thei...

Utilizing new approaches to accurately predict groundwater level (GWL) in arid regions is of vital importance. In this study, support vector regression (SVR), Gaussian process regression (GPR), and their combination with wavelet transformation (named wavelet-support vector regression (W-SVR) and wavelet-Gaussian process regression (W-GPR)) are used...

The Nile River is a unique environmental system and essential water resource for its basin riparian nations. Population growth, changes in precipitation patterns, damming and usage rights disputes present extreme challenges in utilizing and managing the basin’s primary water resource. These stress factors are of particular concern for highly popula...

The impact of land cover/land use (LCLU) changes on surface runoff and groundwater contamination have been widely investigated, yet their impact on groundwater mixing is still poorly understood. The stress on resources in the Nile Delta triggered a vast migration of urban, agricultural, and industrial activities to its desert fringes exposing the Q...

The arid coasts of North Africa, extending over 4633 km from the Gulf of Tunis to the Nile Delta, are undergoing pronounced shoreline retreats and coastal floodings that are reported as a consequence of the ongoing sea level rise resulting from global warming. Of particular interest are the abnormal shoreline dynamics for deltaic and sandy beaches,...