Land Use Optimization Model Research Articles

REGIONAL MANIFESTATIONS OF THE DETERIORATION OF THE NATURAL CONDITIONS OF HEAT AND MOISTURE SUPPLY OF THE TERRITORY IN THE CONDITIONS OF MAINTAINING THE SUSTAINABLE FUNCTIONING OF ECONOMY SYSTEMS IN THE TERRITORY OF TERNOPIL REGION

The publication examines the influence of regional manifestations of the deterioration of natural conditions (moisture supply and unfavorable thermal parameters) on agricultural management. Global climate changes are superimposed by regional manifestations of adverse processes, such as the emission of greenhouse gases generated by an unbalanced land structure, in which we observe an excessive share of arable land. Excessive plowing of the territory leads to increased production of greenhouse gases by arable land, which complicates the manifestation of the greenhouse effect at the local level. Data on the structure of land plots of Ternopil region and Borsukiv territorial community are given. Attention is drawn to the map scheme of changes in the moisture supply of the territory of Ukraine, according to which a very wet climatic annual balance will be preserved only in the mountainous part of the Carpathians, Ternopil region will go from wet to insufficiently wet in its southeastern part, and over time, according to the forecast of 2100, to an insufficiently wet balance in the greater its territory At the same time, about 55% of the southeastern regions are threatened by dry and very dry climatic annual balance. According to the authors, the search for ways to solve the problem can be found in the optimization of land use. The algorithm of the optimization model is prescribed in the methodology of Professor Mykhailo Grodzynskii and consists in determining and ranking the development priorities of the research area and achieving a scientifically justified ratio between natural and anthropogenic land areas. Based on the materials of the Borsukiv territorial community, an optimization model of land use was created, according to which it is proposed to reduce the share of arable land from 65% to 45% due to the removal of heavily eroded and poorly productive lands from the arable wedge and their transfer to liming and afforestation, the share of which in the land use structure of the territorial community increased respectively 21% and 23%. Such optimization measures will ensure the transition from the emission of greenhouse gases by land to their assimilation by forest and meadow vegetation. Increasing the share of forests by 14% will contribute to a 5% increase in precipitation of local origin, which is especially important for stabilizing the water balance of the territory. An increase in the share of natural vegetation will contribute to the maintenance of ecological balance, restoration of biotic and landscape diversity, improved water balance, and natural living conditions of the population.Increasing or stabilizing the degree of humidification of territories under the conditions of global and regional climate changes is becoming an important scientific and applied problem, the solution of which requires the development and implementation of strategic tasks of sustainable development at the levels of regional, administrative and district territorial entities, the level of territorial communities, Starosty districts. Taking into account the priority criteria for the development of territorial entities is the first stage of optimizing the use of nature in these administrative-territorial entities. The second stage of the landscape and ecological optimization of territories is the substantiation of the ratio of natural and anthropogenic lands. Land optimization will contribute to tireless use of nature and the balancing of basic natural processes with anthropogenic ones. In the future, we envisage the creation of optimization models of land use for all territorial communities of the region, which will optimize the development of natural and economic systems. Keywords: regional manifestations of climatic conditions, land use structure, optimization, territorial community.

Using Zipf’s Law to Optimize Urban Spatial Layouts in an Urban Agglomeration Area

The study of the land use optimization of urban agglomerations is of great significance to the rational utilization of land resources and the sustainable development of urban agglomerations. Previous studies have simply regarded the urban agglomeration as a whole area or each city as an isolated individual, without considering the regional coordinated development of urban agglomerations in land use optimization objectives. This study proposed the first attempt to couple Zipf’s law and a multiobjective optimization model of land use in an urban agglomeration. Zipf’s law was applied to quantify the coordinated development of urban agglomeration and use it as one of the objectives of land use optimization. The genetic algorithm was adopted to establish the optimization model, and different future development scenarios were designed for comparison. The Beijing–Tianjin–Hebei (BTH) urban agglomeration was selected as the study area, and the proposed model obtained effective results within an acceptable time. The Zipf’s law–based optimization objective provided a more coordinated scale structure for urban growth and led the urban structure to develop toward the optimized state. There was a conflict, however, between the coordination and the other two objectives (compactness and suitability). Different stakeholders need to consider the trade-offs among these optimization objectives in urban planning. Finally, based on the optimization patterns of local areas, we suggest the following: Some large-scale cities (e.g., Beijing and Tianjin) should strictly control their new urban expansion or transfer part of their resources and population; Langfang and Xingtai should accelerate their development or take over part of the noncapital function of Beijing; and Zhangjiakou and Chengde should optimize their urban morphology and suitability.

Intensive land management through policy intervention and spatiotemporal optimization can achieve carbon neutrality in advance

Ineffective control over industrialization and urbanization has exposed the shortcomings of land resource management. The overexploitation of limited high-quality land resources is exacerbating the global ecological and food crisis. There is an urgent need to change from “expansion” to “intensification” in land resource utilization. Taking the northwest oasis region of China as a case study, a spatio-temporal optimization model of land use and land cover (LULC) based on dynamic competitiveness evaluation was constructed, and four simulation scenarios, including natural growth without policy intervention (SN), economic priority (SE), food security (SF) and ecological protection (SP), were set up to evaluate and predict the contribution of land intensification to regional carbon neutrality. The results show that the total carbon emissions in the study region will rise sharply by 157.56% in 2030 compared with 2020 without policy intervention (SN). In contrast, all three land intensification scenarios have great emission reduction potential: total regional carbon emissions can be reduced by 21.15% (SE), 22.78% (SF), and 51.72% (SP), respectively, compared with SN. Notably, the implementation of the ecological protection policy (SP) in the region will result in an average carbon emission per unit of GDP of 0.57 t/104 yuan in 2030, which is 25.44% lower than in 2020, implying a downward trend in carbon emissions per GDP between 2020 and 2030, and SP scenario will see the region achieve carbon peaking before 2030. The results can provide novelty methods and policy opinions for optimal land management from the perspective of a low-carbon city.

Comparative characteristics of the land use structure for different types of territorial communities

Purpose. The assess and compare the structure of land use of urban, township and rural territorial communities, to develop an optimization model to land use in case of decentralization Methods. Assessment, comparative-geographical, geoinformation, statistical, mathematical, geoecological analysis and optimization modeling. During the study, special methods were used to determine the anthropogenic pressure, coefficients of ecological stability and anthropogenic transformation of different types territorial communities. Results. According to the results of comparative assessment of the land use structure of urban, township and rural territorial communities, it was found that all three types of communities are characterized by a high degree of plowing (˃60%) and low forest share (5-10%). The share of natural lands within the studied territorial communities is 23-30%. The calculated coefficients of anthropogenic transformation, ecological stability, anthropogenic load, showed that Vyshnivets township and Borsukivska rural territorial communities belong to the category of ecologically unstable territories, Lanovets urban territorial community - to medium ecologically stable territories. In all three types of territorial communities, landscapes are moderately transformed. Urban, township and rural territorial communities experience a sufficiently high (above average) anthropogenic pressure. The obtained results of calculations create objective preconditions for optimizing the structure of land use of the studied territorial communities. Conclusions. To correct and improve the situation, to bring the territories of the studied territorial communities of different types to ecological stability, it is necessary to implement a number of optimization measures. The developed optimization model of land use of Lanovets city, Vyshnivets township and Borsukivka rural territorial communities envisages reduction of arable lands by 20-26%, increase of forest cover by 13-18% and bringing the share of natural lands to the optimal 50%. The implementation of such an approach requires a change in the purpose of individual land plots and the organization of their landscape-adapted use.

LAND USE OPTIMIZATION IN UKRAINE AT THE STAGE OF LAND MARKET FORMATION

In the context of the reform of the sale of agricultural land, the priority is to optimize land use, which is to find a balance of land that would meet their environmental, economic and social compliance with the functions of the agricultural sector. Two main approaches to the optimization process are considered. The first is by intensifying agriculture with significant energy costs, land depletion and the inevitable increase in environmental pressures. And the second is the gradual formation of a balanced agrosphere with alternative agriculture and environmentally friendly livestock.
 The structure of land plots in terms of regions of Ukraine, which in the conditions of the land market does not promote balanced land use, is analyzed. Acquired arable land will not be transferred to other categories of land at auctions, even if it is significantly degraded.
 When forming the pricing policy in the land sector, it is important to compare the value of arable land in Ukraine and European countries. This comparative analysis shows the underestimated value of arable land in Ukraine (the lowest figure in Europe is less than 1 thousand euros / ha) at the initial stage of sale. It is estimated that the six-year lease of arable land at this stage of land reform is more appropriate than their sale.
 The fact of plowing part of pastures under these conditions and increasing the share of arable land in river valleys, drained lands, etc. is alarming. According to the results of the calculations, Table 1 shows the value of arable land, pastures, hayfields by administrative regions. The comparative characteristic of agricultural lands on the available highly productive lands is carried out. The highest share of such lands in Ternopil, Poltava and Cherkasy oblasts was found out, which provides for their highest valuation.
 The created map diagram of the general cost assessment of agricultural lands demonstrates their land resource potential and reflects the spatial differentiation of this indicator by typological groups of regions. The authors analyzed the optimization model of land use in Ukraine, developed by a group of leading domestic scientists under the project "Sustainable Development Programs", and proposed to consider the category of productive lands as basic arable lands, the share of which in Ukraine is 44.8% of arable land.
 The directions of reforming land relations in Ukraine taking into account historical traditions and granting the highest status of the basic land user - the rural community are offered.
 At the same time to make calculations, based on the results of which to identify production types (specialization) of farms, which will be the most objective, as it takes into account local natural and economic conditions;
 - on the basis of specialization of peasant farms, study of types of land use in enterprises of various forms of ownership and data on natural land fertility to perform agricultural zoning of the territory;
 - in each allocated agricultural area, the whole array of land in use, divided into at least 3 groups:
 1) lands of peasant farms, which over time should be granted the right of life ownership with the possibility of inheritance and on which the state should support non-profit, subsistence farming;
 2) lands withdrawn from agricultural circulation due to the destruction of their natural fertility and those to be transferred to the nature reserve fund, and, over time, included in the national ecological network;
 3) lands that have not yet lost their natural fertility and those that are in the use of agricultural enterprises of various forms of ownership.
 Key words: land optimization, monetary valuation of agricultural lands, land resource potential, spatial differentiation of lands, land relations.

Model Development for Optimized Land Usage in Urban Agglomeration Zone Using Bee Colony Algorithms

This research work was developed to increase the output of urban zone regions and also to bring out the best use of the space of the urban zone regions. The problems associated with the current research work is basically poor accuracy, slow convergence speed and low rationality of evaluation index. We have proposed to use Bee Colony Algorithm which optimizes the usage areas of land in urban zone regions. The work that we developed a model using the bee colony algorithm for best optimization. The various evaluation units are divided by grid method. By this algorithm principle the weighted summation method of indexes is used to calculate the evaluation units. The the evaluation model is developed by using the above calculated evaluation value of land usage spatial adaptability in the required regions. By the evaluation function of urban land suitability, the cost function and spatial coordination function of urban land usage and the spatial optimization model of land use in urban agglomeration development zone is constructed. The model is developed by the bee colony algorithm and best fitting solution of land usage in urban agglomeration development zone is obtained. The research results prove that the evaluation index of the proposed method is reasonable, the accuracy of the evaluation results is high, and the convergence speed is fast.

Land use optimization modelling with ecological priority perspective for large-scale spatial planning

Land-use optimization model provides an effective means of finding solutions to mitigate ecological impacts resulting from land use and land cover changes (LUCCs). However, current land-use optimization models usually underestimate the control/ effectiveness of ecological indicators in the model's operation process. How to incorporate ecological indicators into the land-use simulation to optimize multiple land-use patterns is scarce and worth discussing. In our study, we proposed a Future Land use Optimization model for Ecological protection (FLOE) by integrating a cellular automata (CA) model, ant colony optimization (ACO) algorithm, and ecological protection for optimizing land-use patterns from an ecological priority perspective. Firstly, we discuss the coupling pattern in incorporating ecological indicators into models to support the use of models for design and verification in large-scale land-use optimization. Secondly, the proposed FLOE model improves the effectiveness of ecological indicators in the land-use optimization process and better meets the predetermined optimization objectives in a dynamic feedback mechanism. The LUCCs of the Yangtze River Economic Belt (YREB) during 2010–2015 were selected to validate the applicability of the proposed FLOE model. The validation results show that compared to actual LUCCs, the proposed model can significantly reduce ecosystem function loss. Moreover, the proposed model was also applied to the land use optimization from 2010 to 2030 in YREB. The optimization results show a 31.23 % reduction in the total ecosystem function loss than land-use simulation without ecological optimization. The study is expected to provide a reference for land use optimization modelling with ecological conservation in methodology and offers important implications for the formulation and management of large-scale spatial planning.

Basin systems of small rivers of Western Podillya: state, change tendencies, perspectives of nature management and nature protection optimization

The level of anthropogenization of the natural processes and the geocomponents of the basin geosystems of small rivers in Western Podillya has been estimated and rated as ecologically dangerous from the viewpoint of sustainable and conflict free functioning. The scales of the transformation of the components of natural environment by economic activities since 1774 were revealed using the method of comparative-geographic analysis of cartographic sources. The scales of deforestation were determined, as well as the scales of the influences of drainage meliorations on wetlands, river floodplains and riverbed complexes. It has been established that such transformations of the state of the components of landscape systems have caused the manifestation of a set of unfavorable processes and phenomena (lowering of ground water level, promoting desiccation, soil erosion and deflation, soil dehumification, decreasing landscape and biological diversity, etc.). Calculated indices of the anthropogenic modification of natural components testify that the strongest adversary impacts on river systems and basin landscapes are caused by agriculture, deforestation, and drainage meliorations. Our analysis of the current state of reclaimed lands in the basins of the rivers Dzhuryn and Nichlava confirmed the conclusions of B. I Kozlovsky on the effects of drainage reclamation on groundwater in drained lands and of the formation within them and around drainage systems of negative hydrogeological zones of different widths. In the absence of precipitation for 30-45 consecutive days in summer there is a sharp decrease in groundwater levels, and overdrying of soils, which causes the manifestation and intensification of deflation, shallowing and even drying of the upper reaches of rivers and streams. At the final stage of the study, a system of measures aimed at ensuring the sustainability of river basin geosystems was substantiated. The introduction of an optimization model of land use in the basin geosystem is one of the priority tasks in the context of negative changes in the water regime of watercourses and the water balance of river basin systems. Optimization measures provide for the transformation of the part of degraded and unproductive lands towards the grasslands and the planting of gardens (slopes up to 7°) and afforestation (surface steepness over 7°) to improve the quality of environment and to form the environmentally secure land use system. Regional indices of anthropogenic transformation for the existing and proposed land structure as a normative regional indices of nature utilization optimality are calculated. Substantiation of schemes of basin nature protection networks was based on taking into account the role of protected areas in maintaining certain functional features at the sources, in the middle and lower parts of river basins. Based on the results of field surveys, it is proposed to create nine protected areas within the Dzhuryn Basin and eight protected areas within the Nichlava river basin, which will increase the share of protected areas of the Dzhuryn basin to 8% (compared to present 4.8%) and Nichlava to 19%. At the same time, it is proposed to change the structure of the nature reserve fund of the Nichlava river basin, taking into account the existing high share (77%) of general zoological reserves, inefficient from the standpoint of conservation of natural complexes, instead creating six landscape reserves on an area of about 800 hectares. The paper considers the possibility of further development of the tourist and recreational sphere in the near-Dnister sections of the river basins of Dzhuryn and Nichlava, and proposes the creation of Borshchiv Regional landscape park in the picturesque valley of the Nichlava River.

Geoecological Assessment of the Land Use Structure of Ternopil City United Territorial Community

Purpose. To assess of the land use structure of Ternopil city united territorial community and justify the priority areas for its optimization. Methods. Descriptive, comparative-geographical, geoinformation, statistical, mathematical, geoecological analysis and optimization modeling. During the study, special methods were used to determine the anthropogenic load, coefficients of ecological stability and anthropogenic transformation of the Ternopil city united territorial community. Results. Analyzing of the land use structure of Ternopil city united territorial community, it was found that the share of natural lands within it is only 32.5%. The main geoecological problems of the land use of Ternopil city united territorial community are the imbalance of land structure, the lack of master plans of rural settlements and territorial boundaries, the lack of inventory and regulatory monetary valuation of land. The coefficient of anthropogenic transformation of the territory of Ternopil city united territorial community is 6.7, which corresponds to the category of highly transformed landscapes. The coefficient of ecological stability of the Ternopil city united territorial community is 0.28, the territory is ecological unstable with a score of anthropogenic load of 3.22. The geoecological assessment of the land use structure of Ternopil city united territorial community, testified the need to optimize the structure of land and to introduce effective scientifically sound measures. Conclusions. To correct and improve the situation, bringing the territory of the Ternopil city united territorial community to ecological stability, it is necessary to implement optimization measures. In the study we have developed an optimization model of land use in the Ternopil city united territorial community, which provides for the reduction of arable land by 18%, increase in forest cover by 12% and bringing the share of natural lands to the optimal 50%. The implementation of such an approach requires a change in the purpose of individual land plots and the organization of their landscape-adapted use.

Optimization Model of Land Use Planning to Reduce Land Erosion Level: Case Study in the Upper Ciujung River Basin

Abstract Uncontrolled changes in land use located in the upstream river can result in land erosion, which will eventually increase river sedimentation as well as floods, reduce the estimated planned life of the downstream reservoir, and reduce soil productivity due to the loss of nutrients. This study is aimed to find the best land use pattern through optimization, in order to reduce the level of land erosion. The optimization model used is the Linear Programming (LP) method which is combined with the USLE method and Geographic Information System software based on raster grids. The potential sedimentation prediction that is collected from the measurement data in the river is used to calibrate the simulation of the real conditions of land erosion. The optimization results of this study in the Upper Ciujung river basin, Banten, can be obtained by expanding as much as possible the area of corn-fields/moors to become plantations (which are denser and bigger tree fields) or even forests. The results can reduce the level of land erosion by 38.0%, or from 99.03 tons/ha/year to 61.32 tons/ha/year. However, the results above cannot be generally applied in all locations. What can be generally accepted is that the optimization model of this study can be used to reduce the level of land erosion by regulating the size of the area and location of each type of land use, and by considering the factors of soil erodibility, slope, and rain erosivity at the site. Abstrak Perubahan tata guna lahan yang tidak terkendali di daerah hulu aliran sungai dapat mengakibatkan erosi lahan, yang pada akhirnya akan meningkatkan sedimentasi di sungai dan banjir, mengurangi umur rencana waduk di hilirnya, serta menurunkan produktivitas tanah karena lapisan hara yang hilang. Penelitian ini ditujukan untuk mencari pola tata guna lahan yang terbaik dengan cara optimasi guna mengurangi tingkat erosi lahan. Model optimasi yang digunakan adalah metode program linier (LP) yang digabung dengan metode USLE dan software SIG (system informasi geografis) berbasis raster grid. Prediksi potensi sedimentasi dari data pengukuran sedimen di sungai digunakan untuk kalibrasi simulasi kondisi nyata erosi lahan. Hasil optimasi pada penelitian di Sub DAS Ciujung Hulu, Provinsi Banten, bisa didapat dengan merubah seluas mungkin areal ladang/tegalan yang sudah ada untuk menjadi kebun campuran atau hutan. Hasilnya dapat memperkecil tingkat erosi lahan sebesar 38,0%, atau turun dari semula sebesar 99.03 ton/ha/thn menjadi 61,32 ton/ha/thn. Namun hasil tersebut diatas tidak bisa berlaku secara umum di semua lokasi. Yang bisa berlaku umum adalah bahwa model optimasi dari studi ini dapat dipakai untuk mengurangi tingkat erosi lahan dengan mengatur luas areal dan penempatan lokasi jenis-jenis penggunaan lahan, dengan mempertimbangkan faktor erodibilitas tanah, kemiringan lereng, dan erosivitas hujan di lokasi.

PSOLA: A Heuristic Land-Use Allocation Model Using Patch-Level Operations and Knowledge-Informed Rules

Optimizing land-use allocation is important to regional sustainable development, as it promotes the social equality of public services, increases the economic benefits of land-use activities, and reduces the ecological risk of land-use planning. Most land-use optimization models allocate land-use using cell-level operations that fragment land-use patches. These models do not cooperate well with land-use planning knowledge, leading to irrational land-use patterns. This study focuses on building a heuristic land-use allocation model (PSOLA) using particle swarm optimization. The model allocates land-use with patch-level operations to avoid fragmentation. The patch-level operations include a patch-edge operator, a patch-size operator, and a patch-compactness operator that constrain the size and shape of land-use patches. The model is also integrated with knowledge-informed rules to provide auxiliary knowledge of land-use planning during optimization. The knowledge-informed rules consist of suitability, accessibility, land use policy, and stakeholders’ preference. To validate the PSOLA model, a case study was performed in Gaoqiao Town in Zhejiang Province, China. The results demonstrate that the PSOLA model outperforms a basic PSO (Particle Swarm Optimization) in the terms of the social, economic, ecological, and overall benefits by 3.60%, 7.10%, 1.53% and 4.06%, respectively, which confirms the effectiveness of our improvements. Furthermore, the model has an open architecture, enabling its extension as a generic tool to support decision making in land-use planning.

Land-use and carbon cycle responses to moderate climate change: implications for land-based mitigation?

Climate change has impacts on agricultural yields, which could alter cropland requirements and hence deforestation rates. Thus, land-use responses to climate change might influence terrestrial carbon stocks. Moreover, climate change could alter the carbon storage capacity of the terrestrial biosphere and hence the land-based mitigation potential. We use a global spatially explicit economic land-use optimization model to (a) estimate the mitigation potential of a climate policy that provides economic incentives for carbon stock conservation and enhancement, (b) simulate land-use and carbon cycle responses to moderate climate change (RCP2.6), and (c) investigate the combined effects throughout the 21st century. The climate policy immediately stops deforestation and strongly increases afforestation, resulting in a global mitigation potential of 191 GtC in 2100. Climate change increases terrestrial carbon stocks not only directly through enhanced carbon sequestration (62 GtC by 2100) but also indirectly through less deforestation due to higher crop yields (16 GtC by 2100). However, such beneficial climate impacts increase the potential of the climate policy only marginally, as the potential is already large under static climatic conditions. In the broader picture, this study highlights the importance of land-use dynamics for modeling carbon cycle responses to climate change in integrated assessment modeling.

A land-use allocation optimization model to mitigate potential seismic damages

Seismic hazard mitigation is becoming an important consideration in planning for disaster-resilient cities. Seismic hazard and urban vulnerability are the two major factors in the assessment of seismic risk. Peak ground acceleration (PGA) and peak ground displacement (PGD) are the two major measures of seismic hazards, and land-use and building patterns characterize urban vulnerability. A set of pseudodata is generated by an earthquake-engineering simulation model for the city of Taichung, Taiwan, using twenty-two significant historical seismic events. A seismic damage model is first statistically estimated, relating monetary building damages to seismic impacts (PGA and PGD) and building inventories (residential, commercial, industrial, government). This damage function is then incorporated into a seismic land-use optimization model to allocate future land uses to the available land while minimizing aggregate seismic damages. Solving the model under the twenty-two seismic events and under different regional growth scenarios generates robust site rankings, pointing to priority locations for future activities away from the most severe historical earthquakes. These rankings can help decision makers allocate future activities under the uncertainty of both regional development and seismic hazard.

The global economic long-term potential of modern biomass in a climate-constrained world

Low-stabilization scenarios consistent with the 2 °C target project large-scale deployment of purpose-grown lignocellulosic biomass. In case a GHG price regime integrates emissions from energy conversion and from land-use/land-use change, the strong demand for bioenergy and the pricing of terrestrial emissions are likely to coincide. We explore the global potential of purpose-grown lignocellulosic biomass and ask the question how the supply prices of biomass depend on prices for greenhouse gas (GHG) emissions from the land-use sector. Using the spatially explicit global land-use optimization model MAgPIE, we construct bioenergy supply curves for ten world regions and a global aggregate in two scenarios, with and without a GHG tax. We find that the implementation of GHG taxes is crucial for the slope of the supply function and the GHG emissions from the land-use sector. Global supply prices start at $5 GJ−1 and increase almost linearly, doubling at 150 EJ (in 2055 and 2095). The GHG tax increases bioenergy prices by $5 GJ−1 in 2055 and by $10 GJ−1 in 2095, since it effectively stops deforestation and thus excludes large amounts of high-productivity land. Prices additionally increase due to costs for N2O emissions from fertilizer use. The GHG tax decreases global land-use change emissions by one-third. However, the carbon emissions due to bioenergy production increase by more than 50% from conversion of land that is not under emission control. Average yields required to produce 240 EJ in 2095 are roughly 600 GJ ha−1 yr−1 with and without tax.

N<sub>2</sub>O emissions from the global agricultural nitrogen cycle – current state and future scenarios

Abstract. Reactive nitrogen (Nr) is not only an important nutrient for plant growth, thereby safeguarding human alimentation, but it also heavily disturbs natural systems. To mitigate air, land, aquatic, and atmospheric pollution caused by the excessive availability of Nr, it is crucial to understand the long-term development of the global agricultural Nr cycle. For our analysis, we combine a material flow model with a land-use optimization model. In a first step we estimate the state of the Nr cycle in 1995. In a second step we create four scenarios for the 21st century in line with the SRES storylines. Our results indicate that in 1995 only half of the Nr applied to croplands was incorporated into plant biomass. Moreover, less than 10 per cent of all Nr in cropland plant biomass and grazed pasture was consumed by humans. In our scenarios a strong surge of the Nr cycle occurs in the first half of the 21st century, even in the environmentally oriented scenarios. Nitrous oxide (N2O) emissions rise from 3 Tg N2O-N in 1995 to 7–9 in 2045 and 5–12 Tg in 2095. Reinforced Nr pollution mitigation efforts are therefore required.

Regional energy autarky: Potentials, costs and consequences for an Austrian region

Local actors at community level often thrive for energy autarky to decrease the dependence on imported energy resources. We assess the potentials and trade-offs between benefits and costs of increasing levels of energy autarky for a small rural region of around 21,000 inhabitants in Austria. We use a novel modeling approach which couples a regional energy system model with a regional land use optimization model. We have collected and processed data on the spatial distribution of energy demand and potentials of biomass, photovoltaics and solar thermal resources. The impacts of increasing biomass production on the agricultural sector are assessed with a land-use optimization model that allows deriving regional biomass supply curves. An energy system model is subsequently applied to find the least cost solution for supplying the region with energy resources. Model results indicate that fossil fuel use for heating can be replaced at low costs by increasing forestry and agricultural biomass production. However, autarky in the electricity and the heating sector would significantly increase biomass production and require a full use of the potentials of photovoltaics on roof tops. Attaining energy autarky implies high costs to consumers and a decline in the local production of food and feed.

Optimizing the Management of Soil Erosion

Abstract To reduce the environmental and economical impact of soil erosion resulting from improper management of land-use activities, a study was initiated by the Iranian Ministry of Construction on Syahrood, one of the sub-basins of the Damavand watershed in Iran. Land-use optimization is one of the appropriate strategies for soil conservation. It can empower the decision maker or watershed manager to choose from different land-use scenarios to reach the best decision with the different combinations of variables. The output results of the sediment yield model, including the integration of the Modified Universal Soil Loss Equation (MUSLE) with Spatial Analysis System-Geographic Information System (SPANS-GIS), along with the net income of each land use were used as input in the land-use optimization model for minimizing the sediment yield and maximizing farm production of each land use. The multi-objective linear programming simplex method of Steuer (1995) was used to solve the problem. The optimization process allocated dryland farming areas to rangelands if no changes were made to the current supporting practice system. The expected annual sediment yield from the entire sub-basin was reduced by 2420 tonnes/year (or by 5%) and the annual net farm income was increased by 3.99 billion Iranian Rial/year (or by 134%).