Model-Based Evaluation of Land Use and Management Strategies in a Nitrate-Polluted Drinking Water Catchment in North Germany

Author(s):  
Kurt Christian Kersebaum
Quaternary ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 32 ◽  
Author(s):  
Alejandra Domic ◽  
José Capriles ◽  
Katerine Escobar-Torrez ◽  
Calogero Santoro ◽  
Antonio Maldonado

The European conquest of the New World produced major socio-environmental reorganization in the Americas, but for many specific regions and ecosystems, we still do not understand how these changes occurred within a broader temporal framework. In this paper, we reconstruct the long-term environmental and vegetation changes experienced by high-altitude wetlands of the southcentral Andes over the last two millennia. Pollen and charcoal analyses of a 5.5-m-long core recovered from the semi-arid puna of northern Chile indicate that while climatic drivers influenced vegetation turnaround, human land use and management strategies significantly affected long-term changes. Our results indicate that the puna vegetation mostly dominated by grasslands and some peatland taxa stabilized during the late Holocene, xerophytic shrubs expanded during extremely dry events, and peatland vegetation persisted in relation to landscape-scale management strategies by Andean pastoralist societies. Environmental changes produced during the post-conquest period included the introduction of exotic taxa, such as clovers, associated with the translocation of exotic herding animals (sheep, cattle, and donkeys) and a deterioration in the management of highland wetlands.


2021 ◽  
pp. 205301962110075
Author(s):  
Ilan Stavi ◽  
Joana Roque de Pinho ◽  
Anastasia K Paschalidou ◽  
Susana B Adamo ◽  
Kathleen Galvin ◽  
...  

During the last decades, pastoralist, and agropastoralist populations of the world’s drylands have become exceedingly vulnerable to regional and global changes. Specifically, exacerbated stressors imposed on these populations have adversely affected their food security status, causing humanitarian emergencies and catastrophes. Of these stressors, climate variability and change, land-use and management practices, and dynamics of human demography are of a special importance. These factors affect all four pillars of food security, namely, food availability, access to food, food utilization, and food stability. The objective of this study was to critically review relevant literature to assess the complex web of interrelations and feedbacks that affect these factors. The increasing pressures on the world’s drylands necessitate a comprehensive analysis to advise policy makers regarding the complexity and linkages among factors, and to improve global action. The acquired insights may be the basis for alleviating food insecurity of vulnerable dryland populations.


Author(s):  
Temesgen Mulualem ◽  
Enyew Adgo ◽  
Derege Tsegaye Meshesha ◽  
Atsushi Tsunekawa ◽  
Nigussie Haregeweyn ◽  
...  

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.


Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 627
Author(s):  
Duong H. Nong ◽  
An T. Ngo ◽  
Hoa P. T. Nguyen ◽  
Thuy T. Nguyen ◽  
Lan T. Nguyen ◽  
...  

We analyzed the agricultural land-use changes in the coastal areas of Tien Hai district, Thai Binh province, in 2005, 2010, 2015, and 2020, using Landsat 5 and Landsat 8 data. We used the object-oriented classification method with the maximum likelihood algorithm to classify six types of land uses. The series of land-use maps we produced had an overall accuracy of more than 80%. We then conducted a spatial analysis of the 5-year land-use change using ArcGIS software. In addition, we surveyed 150 farm households using a structured questionnaire regarding the impacts of climate change on agricultural productivity and land uses, as well as farmers’ adaptation and responses. The results showed that from 2005 to 2020, cropland decreased, while aquaculture land and forest land increased. We observed that the most remarkable decreases were in the area of rice (485.58 ha), the area of perennial crops (109.7 ha), and the area of non-agricultural land (747.35 ha). The area of land used for aquaculture and forest increased by 566.88 ha and 772.60 ha, respectively. We found that the manifestations of climate change, such as extreme weather events, saltwater intrusion, drought, and floods, have had a profound impact on agricultural production and land uses in the district, especially for annual crops and aquaculture. The results provide useful information for state authorities to design land-management strategies and solutions that are economic and effective in adapting to climate change.


Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 330
Author(s):  
Jean-Christophe Castella ◽  
Sonnasack Phaipasith

Road expansion has played a prominent role in the agrarian transition that marked the integration of swidden-based farming systems into the market economy in Southeast Asia. Rural roads deeply altered the landscape and livelihood structures by allowing the penetration of boom crops such as hybrid maize in remote territories. In this article, we investigate the impact of rural road developments on livelihoods in northern Laos through a longitudinal study conducted over a period of 15 years in a forest frontier. We studied adaptive management strategies of local stakeholders through the combination of individual surveys, focus group discussions, participatory mapping and remote-sensing approaches. The study revealed the short-term benefits of the maize feeder roads on poverty alleviation and rural development, but also the negative long-term effects on agroecosystem health and agricultural productivity related to unsustainable land use. Lessons learnt about the mechanisms of agricultural intensification helped understanding the constraints faced by external interventions promoting sustainable land management practices. When negotiated by local communities for their own interest, roads may provide livelihood-enhancing opportunities through access to external resources, rather than undermining them.


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