scholarly journals Simulation of groundwater flow and analysis of the effects of water-management options in the North Platte Natural Resources District, Nebraska

Author(s):  
Steven M. Peterson ◽  
Amanda T. Flynn ◽  
Joseph Vrabel ◽  
Derek W. Ryter
2021 ◽  
Author(s):  
Sebastian Heller ◽  
Peter Gatersleben ◽  
Sebastian Oehmke ◽  
Ullrich Dettmann ◽  
Melanie Bräuer ◽  
...  

<p>The vast majority of peatlands in the North German Plain are cultivated as grassland. Intensive drainage measures are a prerequisite for conventional agricultural use of peatlands, but this practice causes high emissions of greenhouse gases (GHG), mainly carbon dioxide (CO<sub>2</sub>). Thus, raising the water levels is necessary to reduce or stop CO<sub>2</sub> emissions. Water management options such as submerged drains (SD) and ditch blocking (DB) are discussed as a potential compromise between maintaining the trafficability for intensive grassland use and reducing the GHG emissions. Furthermore, grassland renewal is regularly practiced to improve the fodder quality for dairy farming; however, this might cause additional release of GHGs, especially nitrous oxide (N<sub>2</sub>O). Here, we present results of a four-year study on the GHG emissions from an intensively used grassland on fen peat equipped with SD and DB. Additionally, the effect of grassland renewal by shallow ploughing and direct sowing was evaluated.</p><p>The target groundwater levels were set to -0.30 m below ground. In the first year, the water management system was optimized. In the following years, mean annual water levels at the parcels with SD were -0.23 m and at the parcels with DB -0.37 m. The groundwater level at the SD parcels was around 0.18 m higher than at the conventionally drained control parcels. Thus, water management by SD enabled us to even surpass the target water levels. However, year two and three of the study were dryer than usual, the differences between the SD parcels and the control parcels are expected to be lower in wet years. DB, in contrast, raised the water levels only marginally.</p><p>During the first three years, control parcels with ditch drainage emitted 27-49 t CO<sub>2</sub>-eq. ha<sup>-1</sup> a<sup>-1</sup>. This is within the typical range of emissions from grasslands on fen peat in Germany. On average, the parcels with SD showed slightly lower emissions than the drained control parcels, but these were highly variable (16-60 t CO<sub>2</sub>-eq. ha<sup>-1</sup> a<sup>-1</sup>). Due to similar groundwater levels the emissions from the parcel with DB (23-43 t CO<sub>2</sub>-eq. ha<sup>-1</sup> a<sup>-1</sup>) were comparable to the drained control parcels. Reasons for the high CO<sub>2</sub> emissions despite increased groundwater levels by SD remain so far unclear. Both types of grassland renewal lead to higher N<sub>2</sub>O emissions during the first year after renewal. Afterwards, effects became ambiguous.  </p><p>Results from the fourth measurement year (2020) will be presented as well. So far, the data seems to support the results of the previous years.</p>


2016 ◽  
Vol 39 ◽  
pp. 85-88
Author(s):  
Giovanni Formentin ◽  
Mauro Consonni ◽  
Simone Sala ◽  
Vincenzo Francani

1998 ◽  
Vol 38 (11) ◽  
pp. 87-95
Author(s):  
R. Fenz ◽  
M. Zessner ◽  
N. Kreuzinger ◽  
H. Kroiss

In Austria approximately 70% of the population is connected to sewerage and to biological waste water treatment plants. Whereas the urban areas are already provided with these facilities to a very high extent, effort is still needed in rural areas to meet the requirements of the Austrian legislation. The way, this task should be solved has provoked much controversy. It is mainly the question, whether centralised or decentralised sewage disposal systems are preferable from the ecological and economical point of view, that became a political issue during the last 5 years. The Institute for Water Quality and Waste Management was asked to elaborate a waste water management concept for the Lainsitz River Basin, a mainly rural area in the north of Austria discharging to the Elbe river. Both ecological and economical aspects should be considered. This paper presents the methodology that was applied and the criteria which were decisive for the selection of the final solution.


2020 ◽  
Author(s):  
Antonio Cardona ◽  
◽  
Cristian Abraham Rivera-Armendariz ◽  
Socrates Alonso Torres ◽  
Isidro Montes-Avila

2012 ◽  
Vol 16 (7) ◽  
pp. 1845-1862 ◽  
Author(s):  
F. Jørgensen ◽  
W. Scheer ◽  
S. Thomsen ◽  
T. O. Sonnenborg ◽  
K. Hinsby ◽  
...  

Abstract. Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system), a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.


2021 ◽  
Vol 13 (14) ◽  
pp. 7956
Author(s):  
Xiangmin Zhang ◽  
Bin Yu ◽  
Hailong Yu ◽  
Zhuofan Li ◽  
Shen Luo ◽  
...  

The demand structure of resources for new economy is different from the traditional one in that its development may significantly change China’s economic location map and spatial pattern. Based on 343 administrative units of prefecture-level cities in China, this research constructs the measurement index system of terrestrial surface natural resources under the orientation of the new economic demands; this research mainly analyses the spatial distribution characteristics and geographical mechanism of natural resources by means of the spatial autocorrelation and spatial similarity calculation methods. The results show that: (1) The structure and endowment of natural resources under the orientation of the new economic demands need to be reexamined. The significance of a good environment and ecological resources has been highlighted. The coupling of resource elements better reveals the availability of natural resources. (2) The natural resources decrease from southeast to northwest, showing a pattern of “abundant in the south and east and scarce in the north and west”. Natural resources have a significant positive correlation in spatial distribution with two types of agglomeration: high-high agglomeration and low-low agglomeration, showing the local agglomeration feature of “high in the south and low in the north”. (3) Natural factors such as temperature, precipitation and altitude affect the spatial distribution of natural resources, with the temperature being the most significant. This indicates that the original natural environment and its role are the geographical mechanism for the formation and distribution of natural resources. The results could provide a reference for the development and the optimization of China’s new economy.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 425
Author(s):  
Rodrigue Vivien Cao Diogo ◽  
Luc Hippolyte Dossa ◽  
Sèyi Fridaïus Ulrich Vanvanhossou ◽  
Badirou Dine Abdoulaye ◽  
Kossi Hélliot Dosseh ◽  
...  

The sustainable use of rangelands in pastoral areas requires the inclusion of all stakeholders to develop sound management strategies. However, the role of these actors in the sustainable management of natural resources is still poorly understood. The present study aims to (i) assess the perception of farmers and herders of the risks and opportunities of transhumance on rangeland resource use and management, and to (ii) generate useful knowledge for the design and implementation of policies that favor the coexistence of these actors and reduce competition over rangeland resources use in Benin. To this end, interviews were conducted with 240 crop farmers and herders using a semi-structured questionnaire in two contrasting agroecological zones in the northern (Kandi) and the southern (Kétou) part of the country. Among the respondents, 64% of farmers in the North were agro-pastoralists (owning 10.6 ha of land and 10.7 cattle) and 36% were herders (keeping 45.8 cattle and cultivating about 3.7 ha of land). They perceived that communal rangelands were entirely degraded. In the South, 36% of respondents were agro-pastoralists (with 0.3 cattle and farming 4 ha of land) and 64% cattle herders (raising 45.3 cattle and farming 0.9 ha of land only). Of the herders, 50% kept cattle for more than 20 years, while agro-pastoralists had no previous experience in cattle herding. Cultivation practices among crop farmers, such as high use of mineral fertilization (23.8%) and bush fires for land clearing (22.5%), were reported in Kandi (North) and Kétou (South) as factors that might contribute to land degradation. However, these farmers perceived transhumance as a threat to the sustainable use of natural resources. In contrast, herders perceived transhumance as an opportunity to valorize unused land and increase the availability of manure to cropland. The prevalent negative attitude of crop farmers regarding transhumant herders increases the vulnerability of cattle herding in both regions. There is an urgent need of raising awareness concerning the mutual benefits provided by the coexistence of crop farmers with herders to promote participative rangeland management strategies. This may contribute towards coping with the current challenges of food insecurity and increasing climate variability as well as to reducing recurrent conflicts in the region.


Water ◽  
2016 ◽  
Vol 8 (8) ◽  
pp. 336 ◽  
Author(s):  
Federica Monaco ◽  
Guido Sali ◽  
Manel Ben Hassen ◽  
Arianna Facchi ◽  
Marco Romani ◽  
...  

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Robert F. Brand ◽  
Pieter J. Du Preez ◽  
Leslie R. Brown

Within the Platberg area and the wider Drakensberg region, the shrinking natural resources and the threat posed to biodiversity are of concern to conservation management and require an understanding of long-term ecological processes. The vegetation of Platberg was investigated as part of an ecological survey to establish Afromontane floristic links to the Drakensberg as well as for the management of natural resources. From a TWINSPAN classification, refined by the Braun-Blanquet method, four main plant communities were identified, which were subdivided into fynbos, wetland, a woody/shrub community and grassland. A classification and description of the fynbos are presented in this article.The analysis showed the fynbos divided into two communities comprising four sub-communities and seven variants. The fynbos community had an average of 28.34 species per relevé, ranging from 14 to 54 species per sample plot. Twenty-four endemic or near-endemic Drakensberg Alpine Centre (DAC) species and 22 exotic (alien-invasive) species were recorded. Numerous floristic links with the DAC, Cape flora fynbos and grassland bioregions to the north and west were also found. The description of the fynbos plant communities can serve as a basis for the formulation of management plans for the area.


Sign in / Sign up

Export Citation Format

Share Document