scholarly journals Storage-Discharge Relationships under Forest Cover Change in Ethiopian Highlands

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2310
Author(s):  
Solomon Gebreyohannis Gebrehiwot ◽  
Lutz Breuer ◽  
Steve W. Lyon

Detecting the impacts of forest cover changes on hydrology is challenging given uncertainties in how changes will manifest in observed streamflow. Considering changes in the rate of change of observed streamflow (e.g., recession characteristics) may offer insights to hydrological shifts driven by forest cover change that are not seen when considering absolute changes of streamflow itself. This study assesses the impacts of forest cover changes on the storage–discharge relationships in three meso-scale watersheds in the highlands of Ethiopia based on a 30-year hydro-climatic and land cover change dataset. We analyze streamflow recessions and fitted parameters of a linear reservoir model to depict fundamental shifts in the storage–discharge relation for these watersheds. Our analysis shows that recession slopes and the total storages increase as natural forest covers decrease in the 273 km2 Woshi-Dimbira and 1980 km2 Upper-Didesa watersheds. The linear reservoir model storage coefficient parameter shows an increasing trend with time for the 41 km2 Sokoru watershed which is afforested, indicating faster drainage and reduction in storage. Our work highlights that considering storage–discharge relationships may be useful for assessing the impacts of forest cover change on water resources in regions where land use change is active and rapid.

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 173
Author(s):  
Changjun Gu ◽  
Yili Zhang ◽  
Linshan Liu ◽  
Lanhui Li ◽  
Shicheng Li ◽  
...  

Land use and land cover (LULC) changes are regarded as one of the key drivers of ecosystem services degradation, especially in mountain regions where they may provide various ecosystem services to local livelihoods and surrounding areas. Additionally, ecosystems and habitats extend across political boundaries, causing more difficulties for ecosystem conservation. LULC in the Kailash Sacred Landscape (KSL) has undergone obvious changes over the past four decades; however, the spatiotemporal changes of the LULC across the whole of the KSL are still unclear, as well as the effects of LULC changes on ecosystem service values (ESVs). Thus, in this study we analyzed LULC changes across the whole of the KSL between 2000 and 2015 using Google Earth Engine (GEE) and quantified their impacts on ESVs. The greatest loss in LULC was found in forest cover, which decreased from 5443.20 km2 in 2000 to 5003.37 km2 in 2015 and which mainly occurred in KSL-Nepal. Meanwhile, the largest growth was observed in grassland (increased by 548.46 km2), followed by cropland (increased by 346.90 km2), both of which mainly occurred in KSL-Nepal. Further analysis showed that the expansions of cropland were the major drivers of the forest cover change in the KSL. Furthermore, the conversion of cropland to shrub land indicated that farmland abandonment existed in the KSL during the study period. The observed forest degradation directly influenced the ESV changes in the KSL. The total ESVs in the KSL decreased from 36.53 × 108 USD y−1 in 2000 to 35.35 × 108 USD y−1 in 2015. Meanwhile, the ESVs of the forestry areas decreased by 1.34 × 108 USD y−1. This shows that the decrease of ESVs in forestry was the primary cause to the loss of total ESVs and also of the high elasticity. Our findings show that even small changes to the LULC, especially in forestry areas, are noteworthy as they could induce a strong ESV response.


2019 ◽  
Vol 10 (3) ◽  
pp. 212-235
Author(s):  
Fabiana da Silva Pereira ◽  
Ima Célia Guimarães Vieira

The objective of this paper was to evaluate the degree of anthropic transformation of a river basin in the Amazon region. We used the digital data of the TerraClass Project to calculate the Anthropic Transformation Index - ATI. In order to verify spatial and temporal changes along a decade in the Gurupi river basin, we used the database of the years 2004 and 2014. The results showed an increase of anthropic changes in the basin over a decade, as a result of forest cover conversion into agricultural and pastures areas. Although the Gurupi river basin remains at a regular level of degradation after a decade, the intensification of land use and land cover change is a threat to the few rainforest remnants of the river basin, which can lead the region to the next level of degradation, if effective forest protection, conservation and restoration actions are not implemented in the region.  


2014 ◽  
Vol 33 (3) ◽  
pp. 55-63 ◽  
Author(s):  
Dominik Kaim ◽  
Jacek Kozak ◽  
Krzysztof Ostafin ◽  
Monika Dobosz ◽  
Katarzyna Ostapowicz ◽  
...  

Abstract The paper presents the outcomes of the uncertainty investigation of a long-term forest cover change analysis in the Polish Carpathians (nearly 20,000 km2) and Swiss Alps (nearly 10,000 km2) based on topographic maps. Following Leyk et al. (2005) all possible uncertainties are grouped into three domains - production-oriented, transformation- oriented and application-oriented. We show typical examples for each uncertainty domain, encountered during the forest cover change analysis and discuss consequences for change detection. Finally, a proposal for reliability assessment is presented.


Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 867 ◽  
Author(s):  
Justyna Jaworek-Jakubska ◽  
Maciej Filipiak ◽  
Anna Napierała-Filipiak

Though on a global scale, for ecological reasons, increased forest cover is universally regarded as positive, on a local scale, the reforestation of arable land may pose threats to cultural landscapes by removing characteristic landscape features. Particularly vulnerable are marginal rural areas, e.g., mountain regions, where most traditional land use systems have survived and which are subject to the most spectacular land use change. The purpose of this article is to draw attention to the issue of the management of forest cover in historical cultural landscapes in mountain territories in Poland within the context of widespread land use change in Eastern Europe. Land cover data were obtained from historical and contemporary aerial photographs, as well as topographic maps from five time points between 1824 and 2016. The study was conducted by means of spatio-temporal forest cover trajectory analysis (LCTA), transition and time–depth analysis, and land cover change calculations that were made by means of ArcGIS. Our research indicates that the rate of change has risen considerably in the last two decades, and the current share of forest cover is much bigger than that reflected in the official data. Eight principal forest cover trajectory types were identified. The biggest area is occupied by woodland of long-term stability. Another large group is constituted by forests created on the basis of arable land and grassland as a result of simple conversion at one point in time, mainly in the years 1824–1886 and 1939–1994. At the same time, a sizeable group is made up by areas that have been subject to unplanned cyclical or dynamic changes during various periods. A very important group is comprised new forests that were created in 1994–2016, predominantly as a result of natural succession, that are often not included in official land classifications. The constant expansion of woodlands has led to a shrinking of historical former coppice woodlands. This indicates that the current landscape management mechanisms in Poland are inadequate for protecting the cultural landscape. The barriers include the lack of intersectoral cooperation and the overlooking of the historical context of landscapes. The present situation calls not only for verification of the existing forest policy but also for increasing the role and engagement of local communities, as well as making comprehensive local development plans, all of which may be helped by the findings of our study and of similar research.


2015 ◽  
Vol 22 (4) ◽  
Author(s):  
Daiva Juknelienė ◽  
Gintautas Mozgeris

The trends of forest cover change in Lithuanian municipalities are introduced in the current paper. Two sources of information on the forest cover in 1950s and today (2013) were used in this study: (i) a geographic forest cover database developed using historical orthophotomaps based on aerial photography, which was carried out in the period just after the World War II, and (ii) the information originating from the State Forest Cadaster and referring to the year 2013. These two layers were compared using GIS overlay techniques. The data was made available for the analyses aggregated up to the municipality level. The Global Moran’s I statistic and Anselin Local Moran’s I were used to identify global and local patterns in the distribution of forest cover characteristics in Lithuanian municipalities, respectively. The  main finding of this study was that the  proportion of the  forest cover in 1950 was 26.5%, i. e. notably differing from the official statistics – 19.7%. The proportion of the forest cover increased in all municipalities during the period 1950–2013. The largest increase in forest cover proportion was in the areas less suitable for agriculture. The relatively largest areas of new forests were identified in the south-eastern part of Lithuania, the deforestation was relatively slowest around less forested municipalities, while the afforestation was relatively slowest around the agricultural Pakruojis municipality. Deforestation was most commonly associated with the forest transformation into agricultural land, less often into scrublands or waters.


Author(s):  
Le Quang Toan ◽  
Pham Van Cu ◽  
Bui Quang Thanh

Abstract: The expansion of perennial crops area plays an important role for supporting the human livelihood in the Central Highlands, so have negative impacts on deforestation and sustainable development. Remote sensing and GIS were used to analyze the trajectories of perennial crops cover change in relationship with deforestation. The Logistic regression models were used to analyze proximate reasons and spatial changing determinants of main land cover changes for the period 2004-2016 of Bảo Lâm district. The result show that the perennial crops changes are indicator for deforestation in Bảo Lâm district with high deforestation rate 0,8% per year caused by the expansion of annual crops, blind area and the expansion of perennial crops. The facile accessed forest and suitable forest area for perennial crops have more destroyed. The trajectories of perennial crops and forest cover changes are important scientific towards sustainable development.  


2018 ◽  
Vol 96 ◽  
pp. 153-165 ◽  
Author(s):  
Derek Bruggeman ◽  
Patrick Meyfroidt ◽  
Eric F. Lambin

2020 ◽  
Vol 12 (15) ◽  
pp. 6123
Author(s):  
Changjun Gu ◽  
Pei Zhao ◽  
Qiong Chen ◽  
Shicheng Li ◽  
Lanhui Li ◽  
...  

Himalaya, a global biodiversity hotspot, has undergone considerable forest cover fluctuation in recent decades, and numerous protected areas (PAs) have been established to prohibit forest degradation there. However, the spatiotemporal characteristics of this forest cover change across the whole region are still unknown, as are the effectiveness of its PAs. Therefore, here, we first mapped the forest cover of Himalaya in 1998, 2008, and 2018 with high accuracy (>90%) using a random forest (RF) algorithm based on Google Earth Engine (GEE) platform. The propensity score matching (PSM) method was applied with eight control variables to balance the heterogeneity of land characteristics inside and outside PAs. The effectiveness of PAs in Himalaya was quantified based on matched samples. The results showed that the forest cover in Himalaya increased by 4983.65 km2 from 1998 to 2008, but decreased by 4732.71 km2 from 2008 to 2018. Further analysis revealed that deforestation and reforestation mainly occurred at the edge of forest tracts, with over 55% of forest fluctuation occurring below a 2000 m elevation. Forest cover changes in PAs of Himalaya were analyzed; these results indicated that about 56% of PAs had a decreasing trend from 1998 to 2018, including the Torsa (Ia PA), an area representative of the most natural conditions, which is strictly protected. Even so, as a whole, PAs in Himalaya played a positive role in halting deforestation.


2020 ◽  
Vol 12 (20) ◽  
pp. 3351
Author(s):  
Sawaid Abbas ◽  
Man Sing Wong ◽  
Jin Wu ◽  
Naeem Shahzad ◽  
Syed Muhammad Irteza

Tropical forests are acknowledged for providing important ecosystem services and are renowned as “the lungs of the planet Earth” due to their role in the exchange of gasses—particularly inhaling CO2 and breathing out O2—within the atmosphere. Overall, the forests provide 50% of the total plant biomass of the Earth, which accounts for 450–650 PgC globally. Understanding and accurate estimates of tropical forest biomass stocks are imperative in ascertaining the contribution of the tropical forests in global carbon dynamics. This article provides a review of remote-sensing-based approaches for the assessment of above-ground biomass (AGB) across the tropical forests (global to national scales), summarizes the current estimate of pan-tropical AGB, and discusses major advancements in remote-sensing-based approaches for AGB mapping. The review is based on the journal papers, books and internet resources during the 1980s to 2020. Over the past 10 years, a myriad of research has been carried out to develop methods of estimating AGB by integrating different remote sensing datasets at varying spatial scales. Relationships of biomass with canopy height and other structural attributes have developed a new paradigm of pan-tropical or global AGB estimation from space-borne satellite remote sensing. Uncertainties in mapping tropical forest cover and/or forest cover change are related to spatial resolution; definition adapted for ‘forest’ classification; the frequency of available images; cloud covers; time steps used to map forest cover change and post-deforestation land cover land use (LCLU)-type mapping. The integration of products derived from recent Synthetic Aperture Radar (SAR) and Light Detection and Ranging (LiDAR) satellite missions with conventional optical satellite images has strong potential to overcome most of these uncertainties for recent or future biomass estimates. However, it will remain a challenging task to map reference biomass stock in the 1980s and 1990s and consequently to accurately quantify the loss or gain in forest cover over the periods. Aside from these limitations, the estimation of biomass and carbon balance can be enhanced by taking account of post-deforestation forest recovery and LCLU type; land-use history; diversity of forest being recovered; variations in physical attributes of plants (e.g., tree height; diameter; and canopy spread); environmental constraints; abundance and mortalities of trees; and the age of secondary forests. New methods should consider peak carbon sink time while developing carbon sequestration models for intact or old-growth tropical forests as well as the carbon sequestration capacity of recovering forest with varying levels of floristic diversity.


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