Impact Of Water Resource Development Research Articles

Gazelle–livestock interactions and impact of water resource development in the Ouadi Rimé–Ouadi Achim Reserve, Chad

AbstractThe Ouadi Rimé–Ouadi Achim Reserve (Réserve de l'Ouadi Rimé–Ouadi Achim) in central Chad supports large numbers of livestock and rare antelopes, and is the site of ongoing reintroductions of the scimitar-horned oryxOryx dammahand addaxAddax nasomaculatus. We present results of surveys conducted during 2011–2019 to examine patterns of relative abundance and distribution of dorcas gazellesGazella dorcas, dama gazellesNanger damaand livestock in relation to each other and to water sources in a 3,500 km2area in the centre of the Reserve. Dorcas gazelles numbered 7,700–18,000, moving extensively across the area. Livestock varied between c. 2,000 and 68,000 tropical livestock units across surveys, with density doubling in the wet season. Dorcas gazelle distribution was negatively associated with livestock, and livestock density was positively associated with artificial water sources. Dorcas gazelle densities were positively associated with locations where there had been wild fires in the 6 months prior to a survey. Dama gazelles were encountered only 13 times, insufficient to estimate their population size reliably. Opportunistic observations suggest dama gazelles avoid livestock and burnt ground. Our findings highlight the importance of the Reserve. We recommend the designation of a large, well-managed conservation priority zone in the Reserve's core area in which no further development of water resources is permitted. Management of livestock numbers within this zone at or below current levels is essential to integrate national goals for both biodiversity conservation and pastoralism development.

Impact of water resource development on connectivity and primary productivity across a tropical river floodplain

Abstract Floodplain wetlands provide an important subsidy for riverine food webs as sites of high algal production. However, this subsidy depends on the degree of landscape connectivity during flood pulses, which provides the opportunity for movement of higher order consumers between rivers and floodplains to access these productive habitats. Changes in floodplain inundation extent and duration, due to variable wet season flows or water resource development (WRD), can impact landscape connectivity and ultimately the magnitude of the food web subsidy. We explored landscape connectivity using graph theory and derived four new metrics to measure how different flow scenarios can affect connectivity and algal production. We considered a historic scenario with the present level of water resource development in our study area, the Mitchell River, and a WRD scenario with the inclusion of three new dams in the catchment. We generated 240 unique daily spatial graphs, using surface water inundation maps across 40‐day flood events to compare a dry year (2006), an average flow year (2001) and a wet year (2009) with and without a WRD scenario. Drier years and WRD scenario resulted in floodplain fragmentation, potentially constraining the movement of higher order consumers. Changes in connectivity due to WRD resulted in predicted reductions of up to 26% of algal production on the floodplain that was otherwise connected to the main river channels. Synthesis and applications. The approach developed in this study provides new metrics to identify how changes in floodplain surface water extent due to water resource development and climatic variation may impact ecosystem function such as connectivity that facilitates access of higher order consumers to primary production in floodplain wetlands. With a direct link to river flow alteration, these metrics can inform catchment planning and management to ensure that the conservation of floodplain ecosystem functions is adequately considered in water resource management decisions.

Impact of water resource development plan on water abstraction and water balance of Lake Ziway, Ethiopia

Lake Ziway is providing water for a wide variety of sectors in the central rift valley of Ethiopia. However, there is a lack of systematic study that informs the effect of water abstraction on the lake water balance. In the present study, we conducted a Water Abstraction Survey (WAS) to estimate actual water withdrawal from the lake and developed a water balance model of the lake to evaluate the associated impact on the lake water storage and outflow for three development plans. The mean error and root mean square error of the simulated lake water level as compared with observed counterparts were estimated as 0.1 and 0.2 m, respectively, which is smaller than the range of the observed fluctuation of the lake water level under natural condition. Our findings indicate that the actual storage and outflow of Lake Ziway are significantly impacted by the existing water withdrawal. When the future development plans are fully implemented, the annual amount of irrigation and domestic water withdrawal from the lake will reach 95 Mm3. This will cause the lake water level to drop by 0.94 m, which translates to 38 km2 reductions in the lake surface area. Consequently, the lake will lose 26.5% of its actual storage volume when the future development plan (2029–2038) is implemented as compared to the observed storage between 1986 and 2000. Hence, the current impact of water resources development around the lake is substantially large and will exacerbate in the future. This indicates the need for urgent actions to monitor and manage water abstraction from the lake.

Genetic diversity and gene flow patterns in two riverine plant species with contrasting life-history traits and distributions across a large inland floodplain

Gene flow is a key evolutionary driver of spatial genetic structure, reflecting demographic processes and dispersal mechanisms. Understanding how genetic structure is maintained across a landscape can assist in setting conservation objectives. In Australia, floodplains naturally experience highly variable flooding regimes that structure the vegetation communities. Flooding plays an important role, connecting communities on floodplains and enabling dispersal via hydrochory. Water resource development has changed the lateral-connectivity of floodplain-river systems. One possible consequence of these changes is reduced physical and subsequent genetic connections. This study aimed to identify and compare the population structure and dispersal patterns of tangled lignum (Duma florulenta) and river cooba (Acacia stenophylla) across a large inland floodplain using a landscape genetics approach. Both species are widespread throughout flood prone areas of arid and semiarid Australia. Tangled lignum occurs on floodplains while river cooba occurs along rivers. Leaves were collected from 144 tangled lignum plants across 10 sites and 84 river cooba plants across 6 sites, on the floodplain of the lower and mid Lachlan River, and the Murrumbidgee River, NSW. DNA was extracted and genotyped using DArTseq platforms (double digest RADseq). Genetic diversity was compared with floodplain-river connection frequency, and genetic distance (FST) was compared with river distance, geographic distance and floodplain-river connection frequency between sites. Genetic similarity increased with increasing floodplain-river connection frequency in tangled lignum but not in river cooba. In tangled lignum, sites that experience more frequent flooding had greater genetic diversity and were more genetically homogenous. There was also an isolation by distance effect where increasing geographic distance correlated with increasing genetic differentiation in tangled lignum, but not in river cooba. The distribution of river cooba along rivers facilitates regular dispersal of seeds via hydrochory regardless of river level, while the dispersal of seeds of tangled lignum between patches is dependent on flooding events. The genetic impact of water resource development may be greater for species which occur on floodplains compared with species along river channels.

A Framework for Assessing Instream Supporting Ecosystem Services Based on Hydroecological Modelling

River systems provide diverse ecosystem services (ES), such as flood regulation (regulating), fresh water (provisioning), nutrient cycling (supporting), and recreation (cultural), among others. The construction of infrastructure (e.g., for hydropower, irrigation) enhances the delivery of tangible ES for example food or energy (generally provisioning) to meet human needs. However, the resulting change to river flows threatens both the ecological health of a river and its ability to provide intangible but vital ES, for example those which support the delivery of other services. Understanding these supporting ES processes in river systems is essential to fully recognise the impact of water resources development on ES delivery. Whilst approaches for assessing instream supporting ES are under development, to date few provide quantitative methods for assessing delivery. Thus, this paper sets out a framework for the assessment of instream supporting ES using hydroecological modelling. It links supporting ES delivery to fluvial hydrological indicators through the use of ecologically relevant hydrological indices and macroinvertebrate flow preferences. The proposed framework is demonstrated on the Beas River basin (Western Himalayas, India), and is flexible enough to be transferred to a basin-wide model, thereby allowing ES relationships to be accounted for in basin-wide water resources planning.

Impact of Water Resources Development on Water Availability for Hydropower Production and Irrigated Agriculture of the Eastern Nile Basin

The Eastern Nile riparian countries are currently developing several reservoir projects to contribute to the needs for energy and food production in the region. In the absence of formal mechanisms for collaboration, the transboundary nature of the Eastern Nile basin makes water resources development challenging. The large seasonal and interannual variability of the river flow increases those challenges. This paper assesses the implications of water resources development in the Eastern Nile basin on water availability for hydropower generation and irrigation demands at country and regional levels, using simulation and scenario analysis methods. Twelve scenarios are used to test developments of several dams and irrigation demands, Grand Ethiopian Renaissance Dam (GERD) operation options, and unilateral (status quo) versus integrated transboundary management of dams. A RIBASIM model that included 20 dams and 21 irrigation schemes was built, using a complete data set of 103 years at a monthly time step. Four indicators have been used for evaluating the performance of the system: hydroenergy generation (MWh=year), reliability of irrigation supply (%), reservoir net evaporation (106 m3/year), and flow regimes of rivers (m3/s). The results show that in case of managing the system in an integrated transboundary manner and without new irrigation development projects, GERD would increase the hydroenergy generation in Ethiopia by + 1,500% and in Sudan by + 17%, with a slight reduction in Egypt of -1%. Supply reliability of existing and planned irrigation schemes in Sudan would not be practically influenced by the GERD, but the reliability will be reduced by about 8% when upstream development and new irrigation expansion materialize. Full development of the Eastern Nile basin would reduce the irrigation supply reliability in Egypt to 92% compared to the base scenario (100%). Compared to integrated management, unilateral management would increase the hydroenergy generation in Ethiopia (+16%), increase the rate of evaporation losses in the basin (+15%), and reduce the irrigation supply reliability in Sudan after full development of dams and irrigation projects (-10%). Water resources development would have considerable but varying effects on the countries.

Future hydrological alterations in the Mekong Delta under the impact of water resources development, land subsidence and sea level rise

Study regionThe Mekong floodplains and delta are among the most agriculturally productive and biologically diverse waterscapes of the world, but sea level rise, land subsidence, and the proposed upstream development of over 126 hydropower dams and extensive delta-based water infrastructure have raised concern due to potential impacts on the hydrology of the region. Study focusThis study aims to quantify the effects of water infrastructure development, land subsidence and sea level rise on hydrological regimes of the Mekong floodplains and delta through the development and application of a hydrodynamic model. New hydrological insights for the regionDepending on hydrological characteristics of each region (river-dominated, transitional or tidal), the influence of each potential driver may vary. The operation of proposed hydropower dams would change river-dominated upper floodplain’s water levels by 26 to 70% and −0.8 to −5.9% in the dry and wet season respectively, but the impact diminishes throughout the floodplains. In the wet season, the upper Vietnamese Delta changes from a transitional stage to a river-dominated stage, and localized water infrastructure development in the upper delta has the greatest effect on water levels in the region. Land subsidence combined with sea level rise could have the greatest future influence on flooding in the delta if current rates are extrapolated. Sustainable water management strategies are thus necessary to mitigate changes in the floodplains and delta and increase resilience to sea level rise and land subsidence.

Continental impacts of water development on waterbirds, contrasting two Australian river basins: Global implications for sustainable water use.

The world's freshwater biotas are declining in diversity, range and abundance, more than in other realms, with human appropriation of water. Despite considerable data on the distribution of dams and their hydrological effects on river systems, there are few expansive and long analyses of impacts on freshwater biota. We investigated trends in waterbird communities over 32years, (1983-2014), at three spatial scales in two similarly sized large river basins, with contrasting levels of water resource development, representing almost a third (29%) of Australia: the Murray-Darling Basin and the Lake Eyre Basin. The Murray-Darling Basin is Australia's most developed river basin (240 dams storing 29,893GL) while the Lake Eyre Basin is one of the less developed basins (1 dam storing 14GL). We compared the long-term responses of waterbird communities in the two river basins at river basin, catchment and major wetland scales. Waterbird abundances were strongly related to river flows and rainfall. For the developed Murray-Darling Basin, we identified significant long-term declines in total abundances, functional response groups (e.g., piscivores) and individual species of waterbird (n=50), associated with reductions in cumulative annual flow. These trends indicated ecosystem level changes. Contrastingly, we found no evidence of waterbird declines in the undeveloped Lake Eyre Basin. We also modelled the effects of the Australian Government buying up water rights and returning these to the riverine environment, at a substantial cost (>3.1AUD billion) which were projected to partly (18% improvement) restore waterbird abundances, but projected climate change effects could reduce these benefits considerably to only a 1% or 4% improvement, with respective annual recovery of environmental flows of 2,800GL or 3,200GL. Our unique large temporal and spatial scale analyses demonstrated severe long-term ecological impact of water resource development on prominent freshwater animals, with implications for global management of water resources.

Impact of Water Resources Development and Technology Introductions on Livelihood of Farmers in Eastern India: A Case Study

Agricultural technology introductions were carried out and their impact was studied in two clusters of villages in the Dhenkanal Sadar and Odapada blocks of Dhenkanal District in Odisha in the eastern Indian plateau region. Ten water-harvesting structures (WHSs) were constructed in two clusters of villages in the farmers' fields on a participatory basis. Harvested water in WHSs was used for multiple purposes, viz. agriculture, fish culture, on-dyke horticulture, vegetable cultivation, poultry, dairy and mushroom cultivation; integrated farming system (IFS) models were developed. Adequate training was also given to the farmers. The net income from the integrated farming systems varied widely between Rs. 16 100 and 251 000 ha−1. Poultry farming in the uplands and intensive cultivation around the embankments of the ponds were found to be effective in increasing the net return from the IFS models. Impact analysis of the water resources development and technology introductions at the study sites was carried out by analysing the comparative position of physical, social, financial, human and natural assets of the farmers before and after adoption of the introductions. The overall standard of living of the study farmers increased from 13.5 to 17.1 on a scale of 5 to 25, respectively. Copyright © 2016 John Wiley & Sons, Ltd.

WEAP modeling of surface water resources allocation in Didessa Sub-Basin, West Ethiopia

The extensive water resources development plan that Ethiopia has recently embarked on encompasses all major river basins, including the Abbay Basin where Didessa Sub-basin is situated. The main objective of the study was to assess the impact of water resources development on instream and downstream water availability, and identify intra-sub-basin locations vulnerable to shortage of surface water, in Didessa Sub-basin. The Water Evaluation And Planning (WEAP) Tool was used to model the surface water resources allocation of the sub-basin, based on the water demand data extracted mainly from the Abbay Basin integrated development master plan. Existing demand sites were collected from irrigation and water supply sectors of the government. To estimate the crop water requirement and instream flows requirement (IFR), respectively CROPWAT 8.0 and Indicators of Hydrologic Alteration (IHA) programs were used. The shortage of recorded data of streamflow was supplemented by the outputs of SWAT hydrological model. Three development scenarios, viz., current development (2014), medium-term future development (2015–2030) and long-term future development (2031–2050), were built. It was demonstrated that the model sufficiently represented surface water flow of the sub-basin. The results indicated that at the last year of scenarios (2050), there will be a 1.101 billion cubic meters (BCM), i.e., 10.3 %, reduction in the total annual flow of Didessa River. Besides, it was found out that some of the schemes in Anger, Dabena and Upper Didessa watersheds will have unmet demands at the last year of scenarios. Nonetheless, it was shown that IFR of 5.46 BCM will be fully delivered at the outlet of Didessa River; hence, no sub-basin wide absolute scarcity of water would develop.

An ecosystem approach for determining environmental water allocations in Australian dryland river systems: the role of geomorphology

The allocation of water for environmental purposes is a key management issue in many dryland regions. Many different methods have been developed for determining environmental water requirements but these are not directly applicable to dryland rivers because of inherent flow and habitat variability. An ecosystem approach for determining environmental water allocations in dryland regions is presented in this paper. This four-step process involves (1) a hierarchical characterisation of the river system, to assess what mesohabitats are present and where they are located; (2) the determination of flows that would inundate these habitats and perform other key ecological processes; (3) hydrological analyses in which the key hydrological signatures of the river are identified and the impact of water resource development on these is determined; and (4) the derivation of a water management decision tree that enables managers to allocate water to consumptive users during individual flood pulses (events). It is recommended that the flood pulse should be the focus for environmental flow management in dryland regions. If rivers are indeed nested hierarchies, then a change in hydrological behaviour at the scale of a flood pulse will, with time, extend throughout the hydrological hierarchy. Current environmental flow management strategies in dryland river systems are essentially focused at the flow regime and history scale; this is inappropriate given the inherent flow variability of these systems. The ecosystem approach is outlined for the Condamine-Balonne River, a large dryland system in Australia.

Feeding Ecology of Sandhill Cranes during Spring Migration in Nebraska

We studied the food habits of midcontinent sandhill cranes (Grus canadensis) during spring 1978 and 1979 at their primary staging area along the Platte River and compared population food and foraging habitat requirements with availability. Crane diets varied among the 3 principal foraging habitats, but not between sexes, ages, or years. Cranes feeding in cornfields ate >99% corn (total dry wt); those feeding in native grasslands and alfalfa fields consumed 79-99% invertebrates. The composite diet of cranes was 97% corn and 3% invertebrates, including 2% earthworms, 0.5% snails, and 0.5% insects. Presumably, corn provided energy, whereas invertebrates from grasslands and alfalfa fields provided supplemental nutrients to compensate for protein and calcium deficiencies in corn. The mean density of waste corn decreased (P 50%. Management by burning, haying, and grazing is compatible with crane use of grasslands, and reduced-till farming could benefit cranes by increasing invertebrate populations. J. WILDL. MANAGE. 50(1):71-79 A growing awareness of the impact of water resource development on spring staging habitat of sandhill cranes in the Platte River Valley of Nebraska has stimulated private, state, and federal conservation efforts (Krapu et al. 1982). Depletion of flows in the river has increased development of native wet meadows for crop production and reduced the width of river channels. This has concentrated cranes in restricted reaches of the river and caused concern that food resources needed to meet energy and nutrient requirements of the population may become inadequate. In particular, the role of grasslands in the feeding ecology of cranes needs more study (Wheeler and Lewis 1972, Reinecke and Krapu 1979). Our research was part of a larger investigation of sandhill crane staging ecology (U.S. Fish and Wildl. Serv. 1981) that provided necessary background information to assess the management implications of population food and energy requirements. The objectives of our study were to: (1) relate qualitative aspects of food use t foraging habitat, (2) calculate daily and seasonal population food requirements, and (3) estimate food availability for comparison with projected requirements. We thank C. R. Frith and R. J. Wicht for assistance in contacting landowners and the landowners of the Platte River Valley for access to their properties. D. Janke and D. Jenson contributed to our corn sampling project. B. A. Hanson assisted with insect taxonomy and, along with D. G. Jorde, R. E. Atkins, and G. R. Lingle, collected crane specimens. Molluscs and earthworms were identified by F. M. Uhler and W. N. Beyer, respectively. D. H. Johnson and A. M. Frank supervised the statistical analyses, and T. J. Dwyer and C. E. Korschgen reviewed the manuscript.

Water resources development and schistosomiasis ecology in the Awash Valley, Ethiopia

This paper examines the impact of water resources development, particularly river regulation and irrigated agriculture, on the occurence of schistosomiasis and its intermediate host snails in the Awash Valley. An ecologic—geographic approach based on: a combination of comparative schistosomiasis prevalence and human ecological studies of indigenous seminomadic pastoralists and migrant laborers from the Ethiopian highland; analysis of snail intermediate host ecology—geography; and longitudinal studies of water resources development, is used to evaluate the endemicity status and changing spatial distribution of schistosomiasis mansoni and schistosomiasis haematobium. This study confirms the suitability of epidemiologic—ecologic methods for analyzing relationships between causal processes and the spatiality of schistosomiasis. In this context local schistosomiasis control programs are reviewed and recommendations made for their improvements.

Impact of water resource development on salinization of semi-arid lands

Historical development of the water resources of California's San Joaquin Valley is described. Impacts of increased consumptive use of water and reallocation of available resources within the valley include reduction of flows in the lower reaches of the river system, and progressive deterioration of water quality. Salt accretions associated with the development of saline lands can be reduced by installation of drainage facilities. Preliminary assessments of the efficacy of tile drains using two-dimensional finite element models are presented.

Impact of Water Resource Development on the Hydrology and Sedimentology of the Brazos River, Texas with Implications on Shoreline Erosion

Major dam and reservoir development within the Brazos River Basin is correlative with a significant decrease in the suspended sediment load of the river and with increased coastal erosion rates near the Brazos delta. A hydrologic analysis of the river discharge, by use of cumulative frequency curves, shows that discharge control by dam regulation has reduced the frequency of high discharges, thus smoothing out the river hydrograph and reducing the amount of sediment the river is able to carry and deliver to the coastal zone. In addition, the reservoirs are presently trapping about 76% of all sand produced within the basin. The amount of sand denied access to the coastal zone through changing geologic processes is estimated to be 30 mcf/yr and, through the loss of the river9s transporting ability and reservoir entrapment, has been determined to be an additional 60 mcf/yr. The increase in the coastal erosion rates in the study area, at least since 1941, can be related to the construction of water resource structures. Sand losses brought about by the construction of reservoirs on the Brazos River, or one of its major tributaries, can be predicted from a relationship between the ratio of sand load (tons) to discharge (acre-ft) to the effective drainage basin (area of the basin below the water resource structures).