Surface Water Availability Research Articles

Hydrological response of hydrographic sub-basins in the Piracicaba River Basin - Southeast Region of Brazil

Use of water for several human needs, associated with climate change, indicates the need understand the response of watersheds, in order to provide adequate water resources planning and management. This study was carried out in two pairs of hydrographic watersheds, in the Piracicaba River Basin, southeast of Brazil, analyzing water response, integrating in-situ collected precipitation and flow data, natural environment attributes, and anthropic environmental data. To support the analysis, Surface Runoff Potential Charts (SRPC). The evaluation of the physical characteristics of the sub watersheds (SW(A) and SW(B)) shows that these areas present very low to low potential, indicating greater infiltration capacity. The use and coverage of the soil partially justifies the flow changes in pair 1, since SW(A) has a larger extent of agricultural areas that can use irrigation. SW(B), even with a greater variety of crops, has a smaller cultivated area and tends to demand less water. At pair 2, the low runoff potential is mainly due to the predominance of flat relief in the sub-basins. The soils that compose them present a higher fraction of silt and clay, with thicknesses > 5m in SW(C) and varying from 0.5m, reaching depths above 5m in SW(D), however, the physical properties of these soils do not provide a low flow rate, but associated with the low slope of the land, the geological characteristics and low drainage density are configured in regions where the flow flows more slowly, contributing to the evaporation and infiltration process. The use and coverage of the soil also partially justifies the flow oscillations, due to anthropic activities in SW(C) and SW(D), such as irrigation and spraying of citrus, fertirrigation of sugarcane, irrigation of seedling nurseries, directly interfering with the availability of surface water.

APPLICATION OF GEOGRAPHIC INFORMATION SYSTEM AND REMOTE SENSING IN MAPPING SURFACE WATER IN EKITI CENTRAL SENATORIAL DISTRICT, NIGERIA

The demands on surface water for agricultural, industrial and domestic activities has been on the increase while the quality and quantity of freshwater supply is decreasing geometrically as a result of rapid population growth in Ekiti Central Senatorial District, Nigeria. The supply of surface water to every nock and crannies of the studied area must be met. To achieve this, the application of Geographic Information System (GIS) and remote sensing was used to map out surface water for effective and efficient water distribution at the required quantity and quality to the studied area. Surface water mapping provides accessible, accurate, readable and reliable information about the location, quantity, availability and distribution of surface water in Ekiti Central Senatorial District. The LANDSAT ETM+ was used to acquire the satellite imageries of surface water in the studied area. The surfer 8 and Arc GIS 10 softwares were used to generate the digital elevation model, flow direction, flow length, flow accumulation, land use and drainage maps of the studied area, respectively. The results revealed that the studied area has a steady flow of water which can be evenly distributed throughout the senatorial district. Water flows from the areas of high elevation to the areas of low elevation, while accumulates at the downstream of the water flow. Geographic Information Systems (GIS) and remote sensing technologies provides easily read and rapidly accessible maps that can be used to monitor the surface water to enhance water distribution for domestic, industrial and agricultural purposes and the system can also be used to manage water resources correctly and effectively.

Modelling the impact of lining and covering irrigation canals on underlying groundwater stores in the Nile Delta, Egypt

AbstractCanal seepage losses can contribute significantly to groundwater aquifers in arid and semi‐arid regions worldwide. In addition, surface water evaporation and evapotranspiration from adjacent riparian vegetation directly affect surface water availability across these regions. This study aims to evaluate interactions between irrigation canals and the Nile Delta groundwater aquifer in Egypt under four operational scenarios: (i) decreased stream flows in the four main diversion canals associated with upper Nile diversions and climate change, (ii) concrete lining of irrigation canals, (iii) combined lining and use of Photo‐Voltaic (PV) Solar Panel covers on canals and (iv) enclosure of the canals in closed conduits. We investigated the effects of these scenarios on regional groundwater supplies and levels using MODFLOW and water budget analyses. Decreased streamflow (scenario 1) resulted in decreased aquifer recharge (from 732 910 to 483 800 m3 day−1) and lower groundwater levels as compared to the base case (present) conditions. Moreover, groundwater flows from the aquifer to the four main canals noticeably increased from 23 176 to 79 364 m3 day−1. Water budget analyses associated with canal lining scenarios (2, 3, & 4) indicated that canal leakage to the aquifer accounted for 146 582, 146 582, and 73 291 m3 day−1 respectively. The changes in canal efficiencies reached 29.3%, 67.1%, 75.3%, and 91.8% while the changes in aquifer recharge efficiencies were 66%, 20%, 20%, and 10% for the four scenarios, respectively. Overall, we found that canals lining is likely the most suitable solution for managing water resources in the Nile Delta. Further aspects to be considered in future studies include the loss of biodiversity along streams embankments due to channel lining.

Modeling Surface Water Availability for Irrigation Development in Mbarali River Sub-Catchment Mbeya, Tanzania

Although Tanzania has a large land suitable for irrigation development, only 4.2% of the arable land which is potential for irrigation has been developed. Mbarali District is characterized by commercial and small-scale irrigation activities for paddy production. Currently, surface water availability for irrigation in Mbarali District is dwindling due to high water demands. Inadequate studies that estimate water availability for irrigation is one of the underlying factors to the lack of irrigation development in many parts of Tanzania including in Mbarali District. This study, therefore, aimed to model surface water availability for irrigation development in Mbarali River sub-catchment Mbeya, Tanzania. The Soil and Water Analysis Tool (SWAT) model and field observations were used to accomplish the study. The model estimates that Mbarali River sub-catchment receives about 631 mm of total mean precipitation annually. About 53% of received precipitation is lost through evapotranspiration, 12% recharged to deep aquifer and the remaining 35% discharged to the stream flow through surface runoff, lateral flow and return flow from unconfined aquifer. Discharge to the steam flow contributes to the total annual means of river discharge ranging from 0 - 10 cubic meters per second at upper catchment to 120 - 140 cubic meters per second at lower catchment. The study recommends that the lower reach of the Mbarali River sub-catchment is potential for irrigation than the upper reach as it has potential river flow that can support irrigation activities. The study also notes the urgent need for water reallocation plan to meet competing water needs in the lower reach of Mbarali River sub-catchment. Moreover, the study addresses the potentiality of irrigation in upper catchment under sustainable water management practices including excavation of small ponds to capture and store surface runoff for dry season use or to supplement irrigation as the rainfall declines.

Coupling Remote Sensing and Hydrological Model for Evaluating the Impacts of Climate Change on Streamflow in Data-Scarce Environment

The Kabul River Basin (KRB) in Afghanistan is densely inhabited and heterogenic. The basin’s water resources are limited, and climate change is anticipated to worsen this problem. Unfortunately, there is a scarcity of data to measure the impacts of climate change on the KRB’s current water resources. The objective of the current study is to introduce a methodology that couples remote sensing and the Soil and Water Assessment Tool (SWAT) for simulating the impact of climate change on the existing water resources of the KRB. Most of the biophysical parameters required for the SWAT model were derived from remote sensing-based algorithms. The SUFI-2 technique was used for calibrating and validating the SWAT model with streamflow data. The stream-gauge stations for monitoring the streamflow are not only sparse, but the streamflow data are also scarce and limited. Therefore, we selected only the stations that are properly being monitored. During the calibration period, the coefficient of determination (R2) and Nash–Sutcliffe Efficiency (NSE) were 0.75–0.86 and 0.62–0.81, respectively. During the validation period (2011–2013), the NSE and R2 values were 0.52–0.73 and 0.65–0.86, respectively. The validated SWAT model was then used to evaluate the potential impacts of climate change on streamflow. Regional Climate Model (RegCM4-4) was used to extract the data for the climate change scenarios (RCP 4.5 and 8.5) from the CORDEX domain. The results show that streamflow in most tributaries of the KRB would decrease by a maximum of 5% and 8.5% under the RCP 4.5 and 8.5 scenarios, respectively. However, streamflow for the Nawabad tributary would increase by 2.4% and 3.3% under the RCP 4.5 and 8.5 scenarios, respectively. To mitigate the impact of climate change on reduced/increased surface water availability, the SWAT model, when combined with remote sensing data, can be an effective tool to support the sustainable management and strategic planning of water resources. Furthermore, the methodological approach used in this study can be applied in any of the data-scarce regions around the world.

Run-Of-River Small Hydropower Plants as Hydro-Resilience Assets against Climate Change

Renewable energy sources, due to their direct (e.g., wind turbines) or indirect (e.g., hydropower, with precipitation being the generator of runoff) dependence on climatic variables, are foreseen to be affected by climate change. In this research, two run-of-river small hydropower plants (SHPPs) located at different water districts in Greece are being calibrated and validated, in order to be simulated in terms of future power production under climate change conditions. In doing so, future river discharges derived by the forcing of a hydrology model, by three Regional Climate Models under two Representative Concentration Pathways, are used as inputs for the simulation of the SHPPs. The research concludes, by comparing the outputs of short-term (2031–2060) and long-term (2071–2100) future periods to a reference period (1971–2000), that in the case of a significant projected decrease in river discharges (~25–30%), a relevant important decrease in the simulated future power generation is foreseen (~20–25%). On the other hand, in the decline projections of smaller discharges (up to ~15%) the generated energy depends on the intermonthly variations of the river runoff, establishing that runoff decreases in the wet months of the year have much lower impact on the produced energy than those occurring in the dry months. The latter is attributed to the non-existence of reservoirs that control the operation of run-of-river SHPPs; nevertheless, these types of hydropower plants can partially remediate the energy losses, since they are taking advantage of low flows for hydropower production. Hence, run-of-river SHPPs are designated as important hydro-resilience assets against the projected surface water availability decrease due to climate change.

Evaluation of surface water for agricultural irrigation in Lobalain District, Rote Ndao Regency, East Nusa Tenggara Province, Indonesia

The average rice productivity of the Rote Ndao Regency is still below the national rice productivity. The cropping pattern’s lack of management and limited water sources can only be planted once a year. This study aims to determine the availability and quality of surface water used for irrigation with the existing rice-corn-fallow cropping pattern. The research was carried out by measuring discharge in the field, surveying the types and cropping patterns, irrigation area research, surface water quality analysis, and hydrological analysis. The results showed that the need for irrigation water for agriculture in the study area with the current cropping pattern was 0.84 lt/second/ha. Therefore, the existing irrigation area of ±3,762.00 Ha requires a water discharge of ±3.159 m3/second. The availability of surface water in the Lobalain District is low, with a discharge of ±1.598 m3/second. Surface water quality shows the percentage of sodium (Na%) dominated by excellent to permissible class, and the sodium adsorption ratio (SAR) excellent. The existing resource of surface water could not support agricultural irrigation. Therefore, it is necessary to find an alternative water source such as groundwater.

Determinants of per capita water supply in Indian cities with low surface water availability

Rapid urbanization is putting stress on urban water resources. Cities with inadequate surface water resources import water to meet the needs of a rapidly growing population. Water supply in urban areas is frequently held accountable by local administrative bodies across the world. In India, several Urban Local Bodies (ULBs) import water from long distances. Ministry of Urban Development, Government of India, has devised nine Service Level Benchmarks (SLB) indicators to evaluate the performance of ULBs in water supply management. The present study considered 30 million-plus Indian cities with low surface water availability. The data pertaining to the population, surface water availability, and SLB performance were collected for the selected cities. The data were then used to find the effect of eight SLB performance indicators on the per capita water supply (PCS) indicator using correlation matrices and multiple regression, where PCS is considered as the only dependent variable. The findings indicate that coverage of water supply connections (COV), extent of metering of connections (MTR), extent of non-revenue water (NRW), and continuity of water supply (CNT) have considerable effects on the PCS. The study is helpful for the ULBs and Policymakers to understand the association between PCS and other indicators and make the intervention for an effective urban water supply management.

Analysis of water availability of the Singkoyo River for the irrigation needs in the Banggai Regency, Indonesian

Indonesia relies on its food security by expanding the area and productivity of agricultural land. This condition requires water to irrigate existing rice fields, such as in the Singkoyo area. This study aims to determine the study area’s surface water availability (Q80), irrigation needs, and water balance. Some methods are applied, such as Penman-Monteith for the evapotranspiration calculation, and the FJ Mock method for the dependable flow and water need based on the annual cropping plan. The result shows that the Singkoyo River, with a catchment area of 408.55 km2, has an average flow rate for Q80 is 6.24 m3sec-1, whereas the most significant discharge occurs in July 15.48 m3sec-1 and the smallest occurs in November at 2.86 m3sec-1. On the other hand, applying the worst scenario with three times of planting per year with rice, the need for three irrigation areas vary according to the NFR during the plantation phase from 7.20 m3sec-1 at the 3rd planting season in October, and the lowest is 2.0 m3sec-1 at the 2nd planting season in February. The water balance is mostly surplus from December to August, but then deficit during September to November by -1.34 m3 sec-1 on average.

Rainfall-Runoff Simulation for Water Availability Estimation in Small Island Using Distributed Hydrological Model wflow

Hydrological data in Indonesia, especially in the small islands, is minimal, including spatial distribution and temporal completeness. It will affect the accuracy of water availability estimation for water resources management interest. One of the solutions that can be undertaken is applying rainfall-runoff modeling to obtain the discharge value at a specific location. This study aims to determine surface water availability in each sub-catchment of the small island by implementing the hydrological model. The wflow model is applying to perform the model. This model uses input data including Digital Elevation Model (DEM), landuse, soil, Leaf Area Index (LAI), rainfall, evapotranspiration, and observation of river discharge for the calibration process. As a result, this island consists of 30 catchments with some potential catchments, namely Cao, Sakita, and Tatamo, that have a 90% dependable flow of 4213.3 L/s, 3803.6 L/s 8117 L/s, respectively. The result of water availability in Morotai Island is highly expected to be the reference for water resources management, especially for tourism and urban development.

Changes in Dry-Season Water Availability and Attributions in the Yellow River Basin, China

Global warming will significantly change patterns of precipitation (P) and evapotranspiration (E) and thus the surface water availability (P minus E, P–E). Changes in P–E will challenge freshwater supply, food security, and sustainability of the ecosystems. Therefore, understanding the spatiotemporal change in P–E and its drivers is key for water resources management. Here, we quantified the changes in water availability during the driest month of the year and identified its drivers in the Yellow River Basin (YRB), China, during 1982–2016. Our results showed that 89.6% of the YRB showed declining dry-season water availability in 2000–2016 compared with 1982–1999, although the total dry-season water resources (defined as the proportion of the sum of monthly P–E to the P) remained nearly unchanged due to the increased P. Changes in seasonal P and E contributed to 87.0 and 99.0% declines in dry-season water availability, respectively, demonstrating the key role of E in net seasonal water fluxes. Increased air temperature (41.8%), vegetation greening (30.8%), and vapor pressure deficit (19.2%) were the main factors driving changes in E in the YRB during the study period. Our study highlighted a drier dry season in the YRB during 1982–2016 and illustrated that climate and vegetation changes played important roles in driving changes in dry-season water availability. Seasonal water fluxes must be considered in future water resources management in the YRB, especially in the context of climate warming and revegetation programs.

Large-scale sensitivities of groundwater and surface water to groundwater withdrawal

Abstract. Increasing population, economic growth and changes in diet have dramatically increased the demand for food and water over the last decades. To meet increasing demands, irrigated agriculture has expanded into semi-arid areas with limited precipitation and surface water availability. This has greatly intensified the dependence of irrigated crops on groundwater withdrawal and caused a steady increase in groundwater withdrawal and groundwater depletion. One of the effects of groundwater pumping is the reduction in streamflow through capture of groundwater recharge, with detrimental effects on aquatic ecosystems. The degree to which groundwater withdrawal affects streamflow or groundwater storage depends on the nature of the groundwater–surface water interaction (GWSI). So far, analytical solutions that have been derived to calculate the impact of groundwater on streamflow depletion involve single wells and streams and do not allow the GWSI to shift from connected to disconnected, i.e. from a situation with two-way interaction to one with a one-way interaction between groundwater and surface water. Including this shift and also analysing the effects of many wells requires numerical groundwater models that are expensive to set up. Here, we introduce an analytical framework based on a simple lumped conceptual model that allows us to estimate to what extent groundwater withdrawal affects groundwater heads and streamflow at regional scales. It accounts for a shift in GWSI, calculates at which critical withdrawal rate such a shift is expected, and when it is likely to occur after withdrawal commences. It also provides estimates of streamflow depletion and which part of the groundwater withdrawal comes out of groundwater storage and which parts from a reduction in streamflow. After a local sensitivity analysis, the framework is combined with parameters and inputs from a global hydrological model and subsequently used to provide global maps of critical withdrawal rates and timing, the areas where current withdrawal exceeds critical limits and maps of groundwater and streamflow depletion rates that result from groundwater withdrawal. The resulting global depletion rates are compared with estimates from in situ observations and regional and global groundwater models and satellites. Pairing of the analytical framework with more complex global hydrological models presents a screening tool for fast first-order assessments of regional-scale groundwater sustainability and for supporting hydro-economic models that require simple relationships between groundwater withdrawal rates and the evolution of pumping costs and environmental externalities.

Application of Sentinel 2 Satellite Imagery for Sustainable Groundwater Management in Agricultural Areas—Chtouka Aquifer, Morocco

In semi-arid regions that are characterized by large agricultural activities, a high volume of water is needed to cover the water requirements for agricultural production. Due to low precipitation and the associated limited availability of surface water, aquifers often represent the main source of irrigation water in these regions. Especially in coastal aquifers, high groundwater abstraction rates may change the flow dynamics of the aquifer and may lead to saltwater intrusion. In this study, within the framework of German–Moroccan international cooperation, the agricultural areas for the summer period 2019 of the Chtouka coastal aquifer in southern Morocco are classified using optical and multi-spectral Sentinel 2 data. Based on the developed land use maps, the groundwater abstraction for irrigation is then quantified by referring to local farmers’ irrigation practices. Following this approach, the total amount of groundwater abstraction is estimated at 157 million m3 for the summer period 2019 in the Chtouka aquifer.

Societal Implications of Forest and Water Body Area Evolution in Czechia and Selected Regions

Land cover evolution is an environmental factor that can be used to characterize forest ecosystem services (FES). This study aims to analyze the change in forest cover and water bodies between 1990 and 2018 in the whole Czech Republic, and in the Central Bohemian and South Moravian regions, and its effects on freshwater provision. Additionally, we attempt to understand the societal implications of water quality, public perception, and environmental investment on natural ecosystems. Forest cover and water body data were obtained from the Corine land cover database, while water quality and investment were compiled from the Czech Statistical Office. Public perceptions on the Czech FES were collected from a national survey. Between 1990 and 2018, forest cover has increased by 3.94% and water bodies by 7.65%; however, from 2014 to 2018, severe droughts were reported that compromised the availability of surface water, presumably on artificial structures, causing an increase in the occupied area. Regarding public perception, respondents with less education, and the older population, obtained an assessment of the low performance of the FES, while the water quality and investment indicate that environmental funding has contributed to improving the quality of outflow water from the wastewater treatment plants, fulfilling all the allowed limits of the urban wastewater treatment directive. Hence, a multidisciplinary approach can help decision makers promote policies that integrate environmental management measures, investment protection, and contribute to sustainable development.

Sustainable water management using rainfall-runoff modeling: A geospatial approach

The rainfall-runoff modeling was carried out using Lacey's and rational formulas to identify the possible locations for surplus precipitation to the groundwater regime with Rain Water Harvesting (RWH) systems, evaluate total recharge potential, and impact on the groundwater regime. Our results found that the total recharge potential created by these artificial recharge systems with injection well is to the tune of 72.07 × 104 m3/annum. These recharge measures will help to improve the groundwater levels as well as control the declining water levels, helps in maintain/improve the existing quality of groundwater, and the quantity of groundwater also increase. While recharging rainfall-runoff water through these RWH systems to the groundwater regime, the overall impact on the groundwater regime will be a positive effect. Groundwater reserves will improve as per the water level fluctuation method; these effects will change the area's replenishable reserves. This phenomenon of continuous recharge of runoff water to groundwater regime, those blocks are in critical/semi-critical/overexploited maybe help to renovate them into the safe category. It may add an excellent source to the groundwater for excess water consumption for irrigation/domestic/industries/mining users. Moreover, considering the cost of installation and maintenance expenses, these systems are effective and economical. This research provides a scientific approach to arrest the extreme possibility of precipitation runoff during different rainfall events, water conservation with groundwater recharge the studied area and helps to ensure the availability of surface and subsurface water in sustainable in long-term uses even in drought period/deficit rainfall events and help mitigate the flood risk hazards.

Modeling Impact of Climate Change on Surface Water Availability Using SWAT Model in a Semi-Arid Basin: Case of El Kalb River, Lebanon

Assessing the impact of climate change on streamflow is crucial for depicting the vulnerability of water resources and for identifying proper adaptation measures. This study used the Soil and Water Assessment Tool (SWAT) to simulate the impact of climate change on the streamflow of El Kalb river, a major perennial river in Lebanon. The model performance was tested for monthly flow at two stations under a nine-year calibration period (2003–2011) and a four-year validation period (2012–2015). The model results indicated satisfactory precision in fitting observed and simulated flow using various acceptable statistical indices. Future projections of climate change were obtained for three Representative Concentration Pathways (RCPs) (2.6, 4.5, and 8.5). The model indicated that the average annual discharge of El Kalb River in the near future (2021–2040) will decrease by around 28–29% under the three RCP scenarios. End-of-century projections (2081–2100) indicated that the flow will decrease by 23%, 28%, and 45% under RCP 2.6, RCP 4.5, and RCP 8.5, respectively.

Additional surface-water deficit to meet global universal water accessibility by 2030

Universal access to safe drinking water for all is a key target of the United Nations Sustainable Development Goal 6. However, how water accessibility improvement impacts domestic water demand and surface-water deficit (the quantity of water demand that exceeds surface-water availability) are poorly known due to uncertainty and variability in domestic water use intensities (WUIdom). Here, we developed a data-driven model to create global gridded maps of historical and future WUIdom, constrained by 1758 survey-based records spanning 220 administrative units. The results show that water accessibility improvement dominated the growth in WUIdom over the period 1990–2015, particularly in developing and least-developed economies. Achieving universal water accessibility by 2030 may lead to an additional growth in global mean WUIdom by 21.7 L capita−1 day−1. Additional 88.3 million people, from 14 developing countries and 9 least-developed countries, may move into domestic surface-water deficit. Another 16% of global irrigated areas would be at risk of irrigation surface-water deficit mainly in South Asia, Central Asia, and North Africa. These findings imply the need of spatially flexible set of actions to achieve global universal water accessibility by 2030 without worsening surface-water deficit.

Quantitative evaluation of drainage attributes to infer hydrologic and morphological characteristics of upper Beas Basin, Himachal Pradesh: A GIS-based approach

ABSTRACT Drainage morphometric analysis is a quantitative indexing of linear, areal, and relief attributes of a watershed, which is an essential prerequisite to understand the ongoing geomorphological, geological, and tectonic processes in a watershed that modifies its landscape. The present study is an investigation of the morphometric parameters of upper Beas basin. ALOS PALSAR digital elevation model available at 12.5 m resolution from Alaska Satellite Facility has been used for the study in Arc GIS 10.2 environment. The findings of the study categorize upper Beas as a sixth order drainage basin with a total area of 4958.98 km2. High bifurcation values infer an accelerated state of erosion and underline the mountainous origin and late youthful stage of river Beas and its tributaries. Geometrically, the basin has an elongated shape indicating lower peak flow but for a longer duration making flood management ambiguous. Upper Beas basin has a coarse drainage density and texture, suggesting high infiltration and less surface water availability. Tectonically, studyarea has some prominent faults and thrusts (MBT, MCT, and STD), making the region susceptible to water infiltration. These observations unquestionably indicate a strong tectonic and lithological control over the evolution of drainage patterns in the study area.

Changes in surface water drive the movements of Shoebills

Animal movement is mainly determined by spatial and temporal changes in resource availability. For wetland specialists, the seasonal availability of surface water may be a major determinant of their movement patterns. This study is the first to examine the movements of Shoebills (Balaeniceps rex), an iconic and vulnerable bird species. Using GPS transmitters deployed on six immature and one adult Shoebills over a 5-year period, during which four immatures matured into adults, we analyse their home ranges and distances moved in the Bangweulu Wetlands, Zambia. We relate their movements at the start of the rainy season (October to December) to changes in Normalized Difference Water Index (NDWI), a proxy for surface water. We show that Shoebills stay in the Bangweulu Wetlands all year round, moving less than 3 km per day on 81% of days. However, average annual home ranges were large, with high individual variability, but were similar between age classes. Immature and adult Shoebills responded differently to changes in surface water; sites that adults abandoned became drier, while sites abandoned by immatures became wetter. However, there were no differences in NDWI of areas used by Shoebills before abandonment and newly selected sites, suggesting that Shoebills select areas with similar surface water. We hypothesise that the different responses to changes in surface water by immature and adult Shoebills are related to age-specific optimal foraging conditions and fishing techniques. Our study highlights the need to understand the movements of Shoebills throughout their life cycle to design successful conservation actions for this emblematic, yet poorly known, species.

Effect of land use/land cover changes on surface water availability in the Omo-Gibe basin, Ethiopia

ABSTRACT Land use/land cover (LULC) changes due to natural and anthropogenic interference have altered the hydrological processes of the Omo-Gibe basin, Ethiopia. In this study, hydrological modelling and remote sensing techniques were used to assess LULC changes in water availability in the basin. The LULCs were classified from satellite imagery from 1987 to 2017 using normalized difference indices, and the changes were observed to be significant for the basin. The calibration and validation performance of the Soil and Water Assessment Tool (SWAT) model using the observed streamflow and sediment yield for the basin was satisfactory. Afterwards, the SWAT was used to simulate the runoffs and sediment yields for different management practices such as introducing filter strips, parallel terracing, and reforestation. The sediment yields in critical sub-basins of Omo-Gibe reduced significantly on reforestation as the best practice. The study outputs are helpful for the various stakeholders and policymakers in managing water resources properly.