Human modified landscape structure and its implication on ecosystem services at Guder watershed in Ethiopia

Unveiling the threshold in forest patch shapes to soil retention ecosystem services

Soil erosion is a critical process that leads to landscape degradation, compromising soil fertility and ecosystem functions. Forest ecosystems, with their intricate characteristics, play a pivotal role in mitigating soil erosion and providing soil retention ecosystem services (SRES). This study explores the impact of forest patch thresholds and critical points on soil erosion rates, focusing on 401 catchments in Poland using generalised additive models to identify thresholds and critical points in forest patches. Landscape metrics were applied to measure landscape structure, including shape, fractal dimension, contiguity, related circumscribing circles, and perimeter-area ratio indexes. These metrics, along with slope, rainfall, organic carbon content, water content, and clay ratio variables, were considered dependent variables in the models. The developed models have demonstrated reliable performance in estimating soil erosion rates, with a significant deviation explained from 80.5 to 81.1 for coniferous forest patches, 79.1 to 80.1 for broad-leave forest patches, and 80.9 to 81.4 for mixed forest patches at p < 0.05. In broad-leaved forests, three thresholds are identified in the shape index, which influence soil erosion rates in a complex manner. For coniferous forests, thresholds in the perimeter area ratio, related circumscribing circles, and contiguity indexes exhibit nonlinear relationships with soil erosion rates. Mixed forests show two thresholds in the related circumscribing circle and one in the fractal dimension index, affecting soil erosion rates differently. This research contributes significantly to understanding the interplay between forest patch shapes and soil erosion rates, providing decision support for land use planning. The identified thresholds and critical points offer valuable tools to enhance sustainable landscape functionality, emphasizing the importance of considering forest landscape structure in preserving soil retention ecosystem services.

Urban Trees and Hydrological Ecosystem Service: A Novel Approach to Analyzing the Relationship Between Landscape Structure and Runoff Reduction

Urban stormwater runoff has posed significant challenges in the face of urbanization and climate change, emphasizing the importance of trees in providing runoff reduction ecosystem services (RRES). However, the sustainability of RRES can be disturbed by urban landscape modification. Understanding the impact of landscape structure on RRES is crucial to manage urban landscapes effectively to sustain supply of RRES. So, this study developed a new approach that analyzes the relationship between the landscape structural pattern and the RRES in Tabriz, Iran. The provision of RRES was estimated using the i-Tree Eco model. Landscape structure-related metrics of land use and cover (LULC) were derived using FRAGSTATS to quantify the landscape structure. Stepwise regression analysis was used to assess the relationship between landscape structure metrics and the provision of RRES. The results indicated that throughout the city, the trees prevented 196854.15 m3 of runoff annually. Regression models (p ≤ 0.05) suggested that the provision of RRES could be predicted using the measures of the related circumscribing circle metric (0.889 ≤ r2 ≤ 0.954) and the shape index (r2 = 0.983) of LULC patches. The findings also revealed that the regularity or regularity of the given LULC patches' shape could impact the patches' functions, which, in turn, affects the provision of RRES. The landscape metrics can serve as proxies to predict the capacity of trees for potential RRES using the obtained regression models. This helps to allocate suitable LULC through optimizing landscape metrics and management guidance to sustain RRES.

Modelling vegetation land fragmentation in urban areas of Western Province, Sri Lanka using an Artificial Intelligence-based simulation technique

Vegetation land fragmentation has had numerous negative repercussions on sustainable development around the world. Urban planners are currently avidly investigating vegetation land fragmentation due to its effects on sustainable development. The literature has identified a research gap in the development of Artificial Intelligence [AI]-based models to simulate vegetation land fragmentation in urban contexts with multiple affecting elements. As a result, the primary aim of this research is to create an AI-based simulation framework to simulate vegetation land fragmentation in metropolitan settings. The main objective is to use non-linear analysis to identify the factors that contribute to vegetation land fragmentation. The proposed methodology is applied for Western Province, Sri Lanka. Accessibility growth, initial vegetation large patch size, initial vegetation land fragmentation, initial built-up land fragmentation, initial vegetation shape irregularity, initial vegetation circularity, initial building density, and initial vegetation patch association are the main variables used to frame the model among the 20 variables related to patches, corridors, matrix and other. This study created a feed-forward Artificial Neural Network [ANN] using R statistical software to analyze non-linear interactions and their magnitudes. The study likewise utilized WEKA software to create a Decision Tree [DT] modeling framework to explain the effect of variables. According to the ANN olden algorithm, accessibility growth has the maximum importance level [44] between -50 and 50, while DT reveals accessibility growth as the root of the Level of Vegetation Land Fragmentation [LVLF]. Small, irregular, and dispersed vegetation patches are especially vulnerable to fragmentation. As a result, study contributes detech and managing vegetation land fragmentation patterns in urban environments, while opening up vegetation land fragmentation research topics to AI applications.

Soil erosion risk assessment and treatment priority classification: A case study on guder watersheds, Abay river basin, Oromia, Ethiopia

Soil erosion is the most persistent environmental problem in the Upper Blue Nile River (UBNR) basin of Ethiopia. Guder River is one of thetributaries of UBNR basin which critically required soil conservation practices. The main objective of this particular research article was to appraise soil erosion hazard priority classification with an easy and uncomplicated erosion modelling tool, the universal soil loss equation (USLE) using GIS software and RS data. Remote Sensing data such as annual mean precipitation, land-use land-cover, and soil map, digital elevation model map were used to determine the USLE factor values. The average annual rainfall data was derived from the widely used climate dataset CRU TS (Climatic Research Unit gridded Time Series) and converted to rainfall erosivity factor. Soil Erodibility Factor Soil (K) was calculated from FAO soil data "Digital Soil Map of the World - ESRI shapefile format". Topographic Factor (LS) was delineated from a 30m digital elevation model. Cover Factor (C) and Support Practice Factor (P) were estimated from a 20m Ethiopia Sentinel2 Land-use Land-cover year, 2016. The study classified the Guder watersheds into different kinds of severity classes for prioritization of soil and water management options and conservation strategy. The mean annual soil eroded for the whole sub-basin was estimated at 25.23 tha^-1y^-1. The study output outcomes demonstrated that about 0.1% (426ha) 6.9% (46764 ha), 8.9% (60055 ha), and 19.8 % (134320ha) have been under Catastrophic, very severe, severe, high erosion severity class respectively. About half of the Guder sub-basin has been underneath a very slight erosion. Nevertheless, the area covered by very severe erosion was 6.9%, and the annual percent of sum-total soil erosion accounted for was 46.86%. The second and third in magnitude soil lost annually from the sub-basin with regards to per cent of total soil loss were severe (26.53%), and high (21.53%) respectively. In only 7% of the area under investigation, soil erosion estimated was to go beyond 100 t/ha/yr. erosion rate. District wise erosion affected and hotspot areas were identified: Middle of Steep slopes Mountainous parts of Ginde Beret, Jeldu, Ifata, Ambo, parts Ababo and Horo Guduru located in the study area borderline, Toke Kutaye, along the boundary of Midakegn and Cheliya were found in severe to very severe erosion. Finally, the study proposed that the government, policymakers, and soil and water management agents plan and implement the conservation measures and give awareness to stakeholders for optimum use of limited precious resources.

Functional Zoning and Path Selection of Land Comprehensive Consolidation Based on Grey Constellation Clustering: A Case Study of Dongying City, China

The functional zoning of land comprehensive consolidation and the selection of consolidation paths are the key content of the current land and space planning, and it is also an important measure to achieve regional sustainable development. At present, the research system on land comprehensive consolidation is not yet mature. The previous research area is relatively small and not representative, and an effective method system has not been formed. Research on the selection of functional zoning and a consolidation path is also relatively scarce. There is an urgent need to construct the theory and method system of land comprehensive consolidation functional zoning and consolidation path selection. Taking Dongying City in China as an example, this paper constructs a zoning index system from four aspects including natural conditions, location advantages, social economy and land use. The entropy method is used to determine the weights, and GIS spatial data visualization is used to analyze the spatial distribution characteristics of the index system. Based on the analysis, the grey constellation clustering method is used to divide the study area into four types of land comprehensive consolidation functional areas, and the results of functional zoning are adjusted according to the ranking of comprehensive index values, the principle of maximum similarity, and the continuity of natural space. The research results show that: ① There are 10 functional zonings for urban development and ecological protection land consolidation, and the main consolidation path should be the ecological country park consolidation model, which can effectively serve the urban ecological construction. ② There are nine functional zonings for rural development and cultivated land conservation consolidation, and their consolidation path should be based on a comprehensive rural improvement model that enhances the quality of the village and the development, utilization and protection of cultivated land resources. ③ There are 18 functional zonings for cultivated land improvement and ecological protection land consolidation, and the main consolidation path should focus on the cultivated land ecological improvement mode that emphasizes the quality of cultivated land and the improvement of regional ecological functions. ④ There are four functional zonings for ecological conservation and fallow recuperative land consolidation, and their main consolidation path should be the land ecological restoration and improvement model of construction land reclamation, cultivated land ecological conservation, and conversion of farmland to forest and grassland. The research results can provide references for Dongying City to formulate land and space planning, and can be extended to the design of comprehensive land remediation projects in other regions. It is of great significance to promote regional sustainable and scientific development.

Impact of landscape pattern changes on hydrological ecosystem services in the Beressa watershed of the Blue Nile Basin in Ethiopia

Landscape pattern changes are mostly due to human activities, and such changes often affect ecosystem functions and services. This study was conducted to evaluate the response of hydrological ecosystem services (HESs) to structural landscape changes. Spatiotemporal changes in two specific HES indicators, water yield (WY) and sediment export (SE), were quantified by analyzing historic (1972-2017) and projected land use/land cover changes (2017-2047). The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Model was used for this purpose. Results indicated that WY and SE changed significantly (p ˂ 0.01) during the study period. The total WY and SE increased by 30.29% and 98.69%, respectively, between 1972 and 2017. Analysis of the projections for the next three decades (2017-2047) suggested an increase in WY and SE by 4.8% and 93.11%, respectively. Furthermore, results revealed that WY and SE are strongly influenced by landscape composition, and metrics such as percentage of landscape (PLAND), mean patch size (MPS), and large patch index (LPI) of farmland and plantations were found to be key factors affecting HESs degradation in the Beressa watershed. PLAND (VIP = 1.34; w = 0.55; and VIP = 1.32; w = 0.56) and MPS (VIP = 1.32; w = 0.50 and VIP = 1.31; w = 0.56)) of farmland cover contributed most to the changes in WY and SE, respectively. Similarly, PLAND (VIP = 1.33; w = 0.54 and VIP = 1.28; w = 0.52), LPI (VIP = 1.27; w = 0.52 and VIP = 1.30; w = 0.54) and MPS (VIP = 1.29; w = 0.52) of plantation cover also contributed more to the change in WY and SE. Besides that, of anthropogenic factors, compositions of natural vegetation and grassland cover were found to heavily influence HESs in the watershed studied. The findings of the study suggest that soil and water conservation interventions are vital to minimize and control water-related problems and enhance ESs.

Assessment of the linkages between ecosystem service provision and land use/land cover change in Fincha watershed, North-Western Ethiopia

Fincha watershed is characterized by the presence of large scale government development projects, such as hydroelectric dam and sugarcane plantation. Within this watershed, land use/land cover (LULC) changes and its linkages with ecosystem services were analyzed for a period of more than three decades (1987-2019). The study first assessed LULC dynamics using ArcGIS software with a standard method. After data on LULC change was obtained, the study used a globally developed values coefficients to estimate the Ecosystem Service Values (ESVs) of the study watershed. The findings revealed that; cultivated land, water body, settlement and sugar cane plantation increased at a rate of 579.8 ha/yr, 199.7 ha/yr, 141.2 ha/yr and 137.1 ha/yr, respectively, whereas wetland, forest land and bare land reduced by 600 ha/y, 328.7 ha/yr and 60.3 ha/yr, respectively, for the study period (1987-2019) considered in the watershed. The increase in water body and sugar cane plantation is mainly attributed to large scale government development projects, while the increase in settlement and cultivated land is the result of small scale farming in the area. Both subsistence farming practices and large scale government projects compete on forest land and wetland. This has resulted in the decrease of the total NCV (Natural Capital Value) by 13.2%. The total ecosystem service values were dominated by cultivated land, which contributed 42.9% of the values in 2019. Elasticity of ESV change in relation to LULC showed the dominance of cultivated land in the overall values of the natural capital. To optimize the values of natural capital at the watershed, making synergies and tradeoffs between land uses is vital by all concerned stakeholders involved in modification of the land uses.

Changes in landscape composition and configuration in the Beressa watershed, Blue Nile basin of Ethiopian Highlands: historical and future exploration

Analyzing long-term dynamics of landscape patterns can provide important insights into the changes in landscape functions, that are necessary for optimizing resource management strategies. This study primarily aimed at quantifying landscape structural change. The Land use/land cover (LULC) layers of 1972, 1987, 2002, and 2017 were mapped from Landsat images, and projected to 2032 and 2047. Factor analysis was then employed to select independent core metrics of landscape composition and configuration to characterize the landscape. A post-classification comparison indicated that, between 1972 and 2017, natural vegetation, grassland, barren land and waterbody covers declined by 89.9%, 67.9%, 67.8 and 15.9%, respectively. On the other hand, plantation increased by 692.1% followed by human settlement (138%) and farmland (21.8%). A similar trend is likely to continue in 2032 and 2047 with a slight decline in the plantation category in 2047. Analysis of landscape metrics revealed that between 1972 and 2017, the number of patches increased. Specifically, plantation, barren land, settlement and grassland increased by 171.4%, 69.7%, 65.8% and 28.6%, respectively. In contrast, natural vegetation, farmland and waterbody declined by 53.1%, 46.3% and 33.9%, respectively. Future predictions showed a declining trend of the number of patches for all LULC types. An increasing trend in the largest patch index and patch size for farmland, plantation, and settlement categories was observed across all years, suggesting intensified human activities in the landscape. Consequently, natural habitat category has declined and become fragmented. Landscape pattern has changed considerably and become more fragmented over the last 45 years. Nevertheless, the future projections suggest a decline in fragmentation and potentially increased assemblage of patches forming simple patterns with fewer number of large size class patches. The results of this study could perhaps be applied in designing strategies for landscape management planning and resource conservation decision-making.

The impact of land use and land cover (LULC) dynamics on soil erosion and sediment yield in Ethiopia

The central highlands of Ethiopia are characterized as a region of high rates of land degradation and soil erosion. This study aimed to estimate total amount of soil loss and sediment yield using RUSLE model within GIS environment. LULC maps of 1973–2015 were used to evaluate the impact of land use change on soil loss and sediment yield. Each model parameter and sediment deliver ration was computed by using Williams and Berndt empirical equation. The net soil erosion and sediment yield at the Guder river mouth and soil risk map was estimated for the watershed. LULC dynamic for the study period and watershed have shown that there existed a rapid conversion of vegetated land uses to human modified land uses. The study revealed that the mean soil loss from the watershed ranges between 25 and 30 t/ha−1 yr−1 which accounted 25.8, 28.7 and 30.3 t/ha/yr for 1973, 1995 and 2015 periods respectively. The estimated total soil loss in 1973, 1995 and 2015 periods were 198Mt yr-1, 221Mt yr-1 and 239Mt yr-1 respectively. The mean sediment yield estimated was 6.79, 8.65 and 9.44t ha-1 yr-1 for 1973, 1995 and 2015 periods respectively. The sediment deliver ratio (SDR) of the watershed ranged between 0 and 0.26. The spatial distribution of SDR showed that the highest value was recorded on central and eastern part of the watershed. Prioritizing erosion host spot areas is recommended to rehabilitate degraded lands using suitable soil and water conservation structures.