scholarly journals A Modelling Framework for Addressing the Synergies Between Global Conventions Through Land Use Changes: Carbon Sequestration, Biodiversity Conservation, Prevention of Land Degradation and Food Security in Agricultural and Forested Lands in Developing Countries

Author(s):  
Raul Ponce-Hernandez
Author(s):  
Luoman Pu ◽  
Jiuchun Yang ◽  
Lingxue Yu ◽  
Changsheng Xiong ◽  
Fengqin Yan ◽  
...  

Crop potential yields in cropland are the essential reflection of the utilization of cropland resources. The changes of the quantity, quality, and spatial distribution of cropland will directly affect the crop potential yields, so it is very crucial to simulate future cropland distribution and predict crop potential yields to ensure the future food security. In the present study, the Cellular Automata (CA)-Markov model was employed to simulate land-use changes in Northeast China during 2015–2050. Then, the Global Agro-ecological Zones (GAEZ) model was used to predict maize potential yields in Northeast China in 2050, and the spatio-temporal changes of maize potential yields during 2015–2050 were explored. The results were the following. (1) The woodland and grassland decreased by 5.13 million ha and 1.74 million ha respectively in Northeast China from 2015 to 2050, which were mainly converted into unused land. Most of the dryland was converted to paddy field and built-up land. (2) In 2050, the total maize potential production and average potential yield in Northeast China were 218.09 million tonnes and 6880.59 kg/ha. Thirteen prefecture-level cities had maize potential production of more than 7 million tonnes, and 11 cities had maize potential yields of more than 8000 kg/ha. (3) During 2015–2050, the total maize potential production and average yield decreased by around 23 million tonnes and 700 kg/ha in Northeast China, respectively. (4) The maize potential production increased in 15 cities located in the plain areas over the 35 years. The potential yields increased in only nine cities, which were mainly located in the Sanjiang Plain and the southeastern regions. The results highlight the importance of coping with the future land-use changes actively, maintaining the balance of farmland occupation and compensation, improving the cropland quality, and ensuring food security in Northeast China.


2021 ◽  
Author(s):  
Qing He ◽  
Kwok Pan Chun ◽  
Omer Yetemen ◽  
Bastien Dieppois ◽  
Liang Chen ◽  
...  

<p>Disentangling the effects of climate and land use changes on regional hydrological conditions is critical for local water and food security. The water variability over climate transition regions at the midlatitudes is sensitive to changes in regional climate and land use. Gansu, located in northwest China, is a midlatitude climate transition region with sharp climate and vegetation gradients. In this study, the effects of climate and land‑use changes on water balances are investigated over Gansu between 1981 and 2015 using a Budyko framework. Results show that there is reduced runoff generation potential over Gansu during 1981 and 2015, especially in the southern part of the region. Based on statistical scaling relationships, local runoff generation potential over Gansu are related to the El Nino-Southern Oscillation (ENSO). Intensified El Nino conditions weaken the Asian monsoons, leading to precipitation deficits over Gansu. Moreover, the regional evapotranspiration (ET) is increasing due to the warming temperature. The decreasing precipitation and increasing ET cause the decline of runoff generation potential over Gansu. Using the dynamical downscaling model outputs, the Budyko analysis indicates that increasing coverage of forests and croplands may lead to higher ET and may reduce runoff generation potential over Gansu. Moreover, the contributions of climate variability and land‑use changes vary spatially. In the southwest part of Gansu, the impacts of climate variability on water variations are larger (around 80%) than that of land‑use changes (around 20%), while land use changes are the dominant drivers of water variability in the southeast part of the region. The decline of runoff generation potential reveals a potential risk for local water and food security over Gansu. The water‑resource assessment approach developed in this study is applicable for collaborative planning at other climate transition regions at the midlatitudes with complex climate and land types for the Belt and Road Initiative.</p>


Author(s):  
Farida Afriani Astuti ◽  
Herwin Lukito

Kabupaten Sleman memiliki banyak daya tarik yang memicu terjadinya urbanisasi yang dapat terlihat dari fenomeno perubahan penggunaan lahan . Perubahan penggunaan lahan di Kabupaten Sleman terjadi pada kawasan keamanan dan ketahanan pangan yang terdiri dari Kecamatan Moyudan, Minggir, Sayegan, Godean, Mlati, dan Tempel.  Fenomena perubahan penggunaan lahan penting untuk dikontrol dan dikendalikan karena kawasan tersebut memiliki peran penting bagi ketahanan pangan di Kabupaten Sleman. Metode penelitian yang digunakan adalah metode deskriptif. Di dalam metode deskriptif terdapat metode survey yang digunakaan untuk mengetahui kondisi eksisting penggunaan lahan di daerah penelitian. Sedangkan untuk perubahan penggunaan lahan pada kawasan keamanan dan ketahanan pangan di Kabupaten Sleman dari Tahun 2012 sampai Tahun 2018 diperoleh dengan metode overlay peta penggunaan lahan yang diperoleh dari Citra Quickbird pada tahun tersebut. Perubahan penggunaan lahan pada kawasan keamanan dan ketahanan pangan Kabupaten Sleman mencapai 57,33 km2 atau 33,93% dari luas total daerah penelitian. Perubahan penggunaan lahan didominasi oleh perubahan lahan sawah menjadi hutan produksi seluas 15,05 km2. Faktor pendorong adanya perubahan penggunaan lahan tersebut adalah produktivitas pertanian sawah yang semakin menurun tiap tahunnya.Sleman Regency has many attractions that trigger urbanization which can be seen from the phenomenon of land-use change. This phenomenon occurs in Sleman Regency particularly in the area of food security and sustainability which is spreading in various districts such as Moyudan, Minggir, Sayegan, Godean, Mlati, and Tempel. The phenomenon of land change must be managed and controlled because the areas have an important role for food security in Sleman Regency. The method used for the research is descriptive method. Survey is a part of descriptive method which used to determine the existing conditions of land use in the research object areas. Whereas for land-use changes in the area of food security and sustainability in Sleman Regency from 2012 to 2018 was obtained with the method of land-use map overlay obtained from Quickbird imagery in those years.Land-use change in the area of food security and sustainability of  Sleman Regency reaches 57.33 km2 or 33.93% from the total of research study area. Land-use change is dominated by the diversions of rice fields to forests that reach 15.05 km2. The driving factor for this phenomenon is the decreasing annual productivity of rice field. 


2015 ◽  
Vol 7 (1) ◽  
pp. 115-145 ◽  
Author(s):  
Y. Mohawesh ◽  
A. Taimeh ◽  
F. Ziadat

Abstract. Land degradation resulting from improper land use and management is a major cause of declined productivity in the arid environment. The objectives of this study were to examine the effects of a sequence of land use changes, soil conservation measures, and the time since their implementation on the degradation of selected soil properties. The climate for the selected 105 km2 watershed varies from semi-arid sub-tropical to Mediterranean sub-humid. Land use changes were detected using aerial photographs acquired in 1953, 1978, and 2008. A total of 218 samples were collected from 40 sites in three different rainfall zones to represent different land use changes and different lengths of time since the construction of stone walls. Analyses of variance were used to test the differences between the sequences of land use changes (interchangeable sequences of forest, orchards, field crops, and range), the time since the implementation of soil conservation measures, and rainfall on the thickness of the A-horizon, soil organic carbon content, and texture. Soil organic carbon reacts actively with different combinations and sequences of land use changes. The time since stone walls were constructed showed significant impacts on soil organic carbon and the thickness of the surface horizon. The effects of changing the land use and whether the changes were associated with the construction of stone walls, varied according to the annual rainfall. The results help in understanding the effects of land use changes on land degradation processes and carbon sequestration potential and in formulating sound soil conservation plans.


1994 ◽  
Vol 23 (4) ◽  
pp. 249-255 ◽  
Author(s):  
W.G. Sombroek ◽  
J. Antoine

Nations, village communities and individual land users need to make choices about land use in order to support development without risk of land degradation. Computerized land information systems (LIS) based on geographic information systems (GIS) have emerged as powerful tools for generating maps and reports to inform such decisions. Recently, FAO has been developing GIS/LIS systems in linkage with its agroecological zoning (AEZ) and other models, and using them to tackle issues of land, food and people at global, national and subnational levels. They have been successfully developed for land resource management at different scales, but practical difficulties have been encountered in making them accessible to the casual user in most developing countries, due to scarcity of data and poor training support.


2020 ◽  
Author(s):  
Jose Rodriguez ◽  
Eliana Jorquera ◽  
Patricia Saco ◽  
Angelo Breda

<p>Coastal wetlands are at the interface between land and sea, receiving water, sediment and nutrients from upstream catchments and also being subject to tides, wave and changing sea levels. Analysis of their future evolution requires the analysis of the entire catchment to coast system, including the effects of climate variability and change and land use changes. We have developed a modelling framework that is able to include both catchment and coastal processes into the evolution of coastal wetlands by coupling an ecogeomorphological wetland evolution model with a hydrosedimentological catchment model to include both tidal and catchment runoff inputs. We drive the model with storm events and sea-level variations and analyse scenarios of future climate and land use for a catchment in Vanua Levu, Fiji that includes a mangrove wetland at the catchment outlet. We inform our model with field, remote sensing and historical data on land use, tides, sediment and nutrient transport and cyclone activity.</p>


Solid Earth ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 857-868 ◽  
Author(s):  
Y. Mohawesh ◽  
A. Taimeh ◽  
F. Ziadat

Abstract. Land degradation resulting from improper land use and management is a major cause of declined productivity in the arid environment. The objectives of this study were to examine the effects of a sequence of land use changes, soil conservation measures, and the time since their implementation on the degradation of selected soil properties. The climate for the selected 105 km2 watershed varies from semi-arid sub-tropical to Mediterranean sub-humid. Land use changes were detected using aerial photographs acquired in 1953, 1978, and 2008. A total of 218 samples were collected from 40 sites in three different rainfall zones to represent different land use changes and variable lengths of time since the construction of stone walls. Analyses of variance were used to test the differences between the sequences of land use changes (interchangeable sequences of forest, orchards, field crops, and range), the time since the implementation of soil conservation measures, rainfall on the thickness of the A-horizon, soil organic carbon content, and texture. Soil organic carbon reacts actively with different combinations and sequences of land use changes. The time since stone walls were constructed showed significant impacts on soil organic carbon and the thickness of the surface horizon. The effects of changing the land use and whether the changes were associated with the construction of stone walls varied according to the annual rainfall. The changes in soil properties could be used as indicators of land degradation and to assess the impact of soil conservation programs. The results help in understanding the effects of land use changes on land degradation processes and carbon sequestration potential and in formulating sound soil conservation plans.


Author(s):  
Omar El Aroussi

In Morocco, the spectacular expansion of erosive processes shows increasingly alarming aspects. Due to the considerable costs of detailed ground surveys for studying this phenomenon, remote sensing is an appropriate alternative for analyzing and evaluating the risks of the expansion of soil degradation. According to an FAO study (2001), Erosion threatens 13 million ha of cropland and rangeland in northern Morocco and induces an estimated average water storage capacity loss of 50 million m3 each year through dam silting. The lost water volume could potentially be used to irrigate 5000 to 6000 ha / year. This study analyses soil erosion on the Oued El Malleh catchment, a 34 km2 catchment located in the north of Fez (Morocco). This contribution aims at mapping the spatio-temporal evolution of land use and modelling the erosion and sedimentation processes using the well known RUSLE model. Land use changes were assessed using Landsat-5 TM and Landsat-7 ETM+ images, from the 1987-2011 periods which were validated by field studies. The images were first georeferenced and projected into the Moroccan coordinate system (Merchich North) then processed to evaluate soil loss through a GIS package (Idrisi Andes Software). These static assessments of soil loss were then used in a deposition/sedimentation algorithm to model soil loss propagation to the downstream. The soil loss averages determined by the model vary between 1.09 t/ha/yr as a minimum value for the reforested lands and 169.4 t/ha/yr as a maximum value for the uncultivated lands (badlands). The latter generally correspond to Regosols or low protected soils located on steep slopes. In comparison with RUSLE, the sedimentation model yields lower values of soil losses; only 97.3 t/h/year for the uncultivated lands, and -0.34 t/ha/year in the reforested land, indicating an on-going sedimentation process. By taking into account the temporal variability of erosion and deposition jointly lower values of soil erosion are calculated by the RUSLE model. However, despite this decline, land degradation problems are still important due to the combination of land use and local lithology. The results of this study were used to indentify areas where interventions are needed to limit land degradation processes.


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