• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 3
  • 1
  • Tagged with
  • 8
  • 8
  • 8
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Soil and water conservation programs in action the Vernon County Wisconsin experience /

Goto, Junko. January 1981 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 167-176).
2

Subsídios para a delimitação e planejamento territorial da zona de amortecimento do parque estadual turístico do Alto Ribeira (PETAR) / Subsidies for the delimitation and territorial planning of the buffer zone of Alto Ribeira Tourist State Park (PETAR)

Tatiana Francischinelli Rittl 27 April 2011 (has links)
As unidades de conservação (UC) são áreas com características naturais relevantes, com limites definidos e com o objetivo de proteção e preservação da natureza, sendo admitido apenas o uso indireto dos seus recursos naturais, o qual deve compatibilizar a conservação da natureza com o uso sustentável de parcela dos seus recursos naturais. As áreas em volta das UCs são estratégicas para a proteção da biodiversidade e para o desenvolvimento sustentável da população local. Entretanto, é necessário que hajam restrições e limites ao uso e ocupação do solo nos locais da circunvizinhança, para reduzir a influência dos impactos negativos na biodiversidade das áreas protegidas. O objetivo do presente estudo é fornecer embasamento técnico para a determinação de critérios que definam a extensão, o uso e a ocupação da zona de amortecimento (ZA) do Parque Estadual Turístico do Alto Ribeira (PETAR). Para isto foram elaborados critérios que definem: a) a extensão da zona de amortecimento e b) a utilização da zona de amortecimento. A definição da extensão da zona de amortecimento do PETAR baseou-se na delimitação das microbacias hidrográficas cujos cursos de água drenam para dentro do parque e na aproximação dos vetores antrópicos ao limite do parque. Os critérios que definiram o uso e ocupação da paisagem na zona de amortecimento foram baseados na vulnerabilidade à erosão do solo. Conclui-se que a zona de amortecimento de 10 quilômetros contempla os critérios aqui usados, abrangendo o limite das microbacias hidrográficas e os grandes fragmentos florestais. Entretanto a qualidade do parque está ameaçada pela expansão da agricultura, mineração, extração ilegal de palmito e silvicultura. A expansão dessas atividades ocorre de forma irregular em áreas de alta vulnerabilidades à erosão e coloca em risco a manutenção da qualidade do bioma protegido. / Conservation Units (UC) are areas with relevant natural features, with limits defined and with the goal of protecting and preserving nature, being admitted only the indirect use of its natural resources, which should reconcile nature conservation with the use sustainable portion of their natural resources. The areas around the UC are strategic to the protection of biodiversity and the local sustainable development of the population. However, it is necessary that there are restrictions and limits on the use and occupation of land in the surroundings, to reduce the influence of negative impacts on biodiversity in protected areas. The aim of this study is to provide a technical foundation for the determination of criteria that define the extent, use and occupancy of the buffer zone (BZ) of the Alto Ribeira Tourist State Park (PETAR). To this were developed criteria that define: a) the extent of the buffer zone and b) the use of the buffer zone. The definition of the extent of the buffer zone PETAR was based on the delineation of watersheds whose rivers drain into the park and approximation of the antropic vectors to the park boundary. The criteria that defined the use and occupancy of the landscape in the buffer zone were based on the vulnerability to soil erosion. It is concluded that the buffer zone of 10 km covers the criteria used here, covering the source of watersheds and large forest fragments. However the quality of the park is threatened by expanding agriculture, mining, illegal harvesting for palm-heart and forestry. The expansion of these activities occurs irregularly in areas of high vulnerability to erosion and can endanger the maintenance of the quality of the biome protected.
3

Subsídios para a delimitação e planejamento territorial da zona de amortecimento do parque estadual turístico do Alto Ribeira (PETAR) / Subsidies for the delimitation and territorial planning of the buffer zone of Alto Ribeira Tourist State Park (PETAR)

Rittl, Tatiana Francischinelli 27 April 2011 (has links)
As unidades de conservação (UC) são áreas com características naturais relevantes, com limites definidos e com o objetivo de proteção e preservação da natureza, sendo admitido apenas o uso indireto dos seus recursos naturais, o qual deve compatibilizar a conservação da natureza com o uso sustentável de parcela dos seus recursos naturais. As áreas em volta das UCs são estratégicas para a proteção da biodiversidade e para o desenvolvimento sustentável da população local. Entretanto, é necessário que hajam restrições e limites ao uso e ocupação do solo nos locais da circunvizinhança, para reduzir a influência dos impactos negativos na biodiversidade das áreas protegidas. O objetivo do presente estudo é fornecer embasamento técnico para a determinação de critérios que definam a extensão, o uso e a ocupação da zona de amortecimento (ZA) do Parque Estadual Turístico do Alto Ribeira (PETAR). Para isto foram elaborados critérios que definem: a) a extensão da zona de amortecimento e b) a utilização da zona de amortecimento. A definição da extensão da zona de amortecimento do PETAR baseou-se na delimitação das microbacias hidrográficas cujos cursos de água drenam para dentro do parque e na aproximação dos vetores antrópicos ao limite do parque. Os critérios que definiram o uso e ocupação da paisagem na zona de amortecimento foram baseados na vulnerabilidade à erosão do solo. Conclui-se que a zona de amortecimento de 10 quilômetros contempla os critérios aqui usados, abrangendo o limite das microbacias hidrográficas e os grandes fragmentos florestais. Entretanto a qualidade do parque está ameaçada pela expansão da agricultura, mineração, extração ilegal de palmito e silvicultura. A expansão dessas atividades ocorre de forma irregular em áreas de alta vulnerabilidades à erosão e coloca em risco a manutenção da qualidade do bioma protegido. / Conservation Units (UC) are areas with relevant natural features, with limits defined and with the goal of protecting and preserving nature, being admitted only the indirect use of its natural resources, which should reconcile nature conservation with the use sustainable portion of their natural resources. The areas around the UC are strategic to the protection of biodiversity and the local sustainable development of the population. However, it is necessary that there are restrictions and limits on the use and occupation of land in the surroundings, to reduce the influence of negative impacts on biodiversity in protected areas. The aim of this study is to provide a technical foundation for the determination of criteria that define the extent, use and occupancy of the buffer zone (BZ) of the Alto Ribeira Tourist State Park (PETAR). To this were developed criteria that define: a) the extent of the buffer zone and b) the use of the buffer zone. The definition of the extent of the buffer zone PETAR was based on the delineation of watersheds whose rivers drain into the park and approximation of the antropic vectors to the park boundary. The criteria that defined the use and occupancy of the landscape in the buffer zone were based on the vulnerability to soil erosion. It is concluded that the buffer zone of 10 km covers the criteria used here, covering the source of watersheds and large forest fragments. However the quality of the park is threatened by expanding agriculture, mining, illegal harvesting for palm-heart and forestry. The expansion of these activities occurs irregularly in areas of high vulnerability to erosion and can endanger the maintenance of the quality of the biome protected.
4

Demanda de água em sistemas de produção agrícola e seus impactos: ambientais e financeiros / Water supplying in production systems agricultural in impact: environmental in monetary.

Araújo, Antonio Flávio Batista de January 2009 (has links)
ARAÚJO, Antonio Flávio Batista de. Demanda de água em sistemas de produção agrícola e seus impactos: ambientais e financeiros. 2009. 84 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós em Engenharia Agrícola, Fortaleza-CE, 2009. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-14T14:22:29Z No. of bitstreams: 1 2009_dis_afbaraujo.pdf: 1570832 bytes, checksum: f92fc3f878d426c9e847801d10327717 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-14T14:23:00Z (GMT) No. of bitstreams: 1 2009_dis_afbaraujo.pdf: 1570832 bytes, checksum: f92fc3f878d426c9e847801d10327717 (MD5) / Made available in DSpace on 2016-06-14T14:23:00Z (GMT). No. of bitstreams: 1 2009_dis_afbaraujo.pdf: 1570832 bytes, checksum: f92fc3f878d426c9e847801d10327717 (MD5) Previous issue date: 2009 / This work aims to investigate the agricultural production systems used by small farmers in rainfed and irrigated areas and also to identify the water productivity. The explored irrigated agricultural field was the Curupati irrigated perimeter, located in Jaguaribara, Ceará, Brazil. The rainfed system (tillage) was implanted in the Chapada do Apodi region, sited in Tabuleiro do Norte, Ceará, Brazil. The quantification of the water required to supply the irrigated crops was quantified through the flow rate of drippers. Also, the moisture of the soil profile was evaluated until the depth of 120 cm. The total of applied water in the irrigated field was 2,663,296.20 m3. The studied crop was papaya, although the guava crop was also explored. In the rainfed crop using tillage, the field was a 137 ha with the sorghum culture. The supplying water was quantified by rain gate implemented and monitored throughout the rainy season of 2008. The total rainfall during the cycle of the culture was 940 mm. The productivity for the cultivation of papaya ranged from 80 ton ha -1 to 106 ton ha -1 during the it’s productivity period. It was identified that for every 1 kg of papaya produced, 1,042 m3 of water was consumed, expressing a 0.95 kg m3 yield. In the rainfed area, the productivity of sorghum ranged from 438 kg ha-1 to 2,143 kg ha-1. Due to the fact that the total rainfall depth in 2008 was 27.4% higher than the annual average of the region, it was not possible to evaluate the water productivity in the tillage system, since the total rainfall depth was 280% higher than the required by the culture. / O presente trabalho teve por finalidade investigar os sistemas de produção agrícola adotados pelos pequenos produtores em áreas de sequeiro e irrigada onde se identificasse a produtividade da água, bem como suas perdas. O campo agrícola explorado com o sistema de agricultura irrigada corresponde ao perímetro irrigado Curupati, localizada no Município de Jaguaribara enquanto que o sistema de sequeiro (plantio direto) foi implantado na região da Chapada do Apodi na porção inserida no Município de Tabuleiro do Norte. A quantificação da demanda de água na agricultura irrigada foi realizada computando-se os números de horas de funcionamento da unidade de bombeamento que abastece o lote, determinando-se a vazão dos gotejadores que compunham o sistema e avaliando-se o perfil de umidade do solo até a profundidade de 120 cm. O total de água aplicada no campo irrigado foi de 2.663.296,20 m3. A cultura irrigada considerada nessa pesquisa foi o mamão, embora os irrigantes também explorem a cultura da goiaba. Na área com plantio de sequeiro (plantio direto), o campo agrícola correspondia a 137 ha com a cultura do sorgo. A demanda de água foi quantificada através de pluviômetros implantados e monitorados por todo o período chuvoso do ano de 2008. O total precipitado durante o ciclo da cultura foi de 940 mm. A produtividade para a cultura do mamão variou de 80 ton ha-1 a 106 ton ha-1 durante o ciclo da cultura. Foi identificado que para cada 1 kg de mamão produzido foram consumidos 1,042 m3 de água expressando uma produtividade 0,95 kg m3 Na área de sequeiro a produtividade do sorgo variou de 438 kg ha-1 a 2.143 kg ha-1. Em decorrência do total precipitado para o ano de 2008 ter sido superior em 27,54%, da média anual da região, não se pode de fato avaliar a produtividade da água em sistema de plantio direto, uma vez que o total precipitado foi superior em 280% ao requerido pela cultura.
5

Caractérisation des ressources et usages de multiples hydro-sociosystèmes : les retenues collinaires du bassin du Merguellil (Tunisie centrale) / Upscaling water availability and water use assessments in hydro-social systems : the small reservoirs of the Merguellil catchment (Central Tunisia)

Ogilvie, Andrew 22 December 2015 (has links)
Les retenues collinaires connaissent un essor dans les zones semi-arides pour leur capacité à réduire l'érosion et l'envasement de barrages, et à mobiliser des ressources pour la petite agriculture. Face aux incertitudes sur la faible valorisation de ces ressources et au manque de données sur le potentiel hydrique de ces aménagements, les disponibilités en eau de multiples retenues collinaires sont quantifiées à l'aide d'observations hydrologiques, modélisation numérique et télédétection. Un indice MNDWI appliqué à 546 images Landsat et combiné avec un modèle GR4J+bilan hydrique à l'aide d'un filtre de Kalman d'ensemble est développé pour estimer les disponibilités en eau entre 1999 et 2014 de 50 retenues dans le bassin amont du Merguellil, Tunisie Centrale. Les erreurs sur la disponibilité moyenne journalière sont de l'ordre de 10 000 m3 sur des retenues aux capacités initiales variant de 20 000 m3 à plus de 1 000 000 m3 et permirent de quantifier et caractériser le potentiel hydrique de chaque retenue en saison sèche. En parallèle, la combinaison d'inventaires, d'enquêtes agricoles et entretiens ethnographiques permit de recenser l'hétérogénéité des pratiques, caractériser les bénéfices des retenues et éclairer les contraintes additionnelles freinant l'exploitation agricole. Au delà de prélèvements limités, cette approche multi-échelle permet d'apporter des éclairages sur la diversification des pratiques agricoles, sur les bénéfices indirects (citernes, élevage, recharge de puits), et sur l'intérêt porté par les riverains pour cette ressource, au sens large du terme. La confrontation entre les pratiques et le potentiel hydrologique confirme que la disponibilité en eau est un facteur limitant sur 80% des retenues mais rarement suffisant pour expliquer les disparités inter et intra retenues observées. La majorité des agriculteurs ont été inhibés par des problèmes d'accès à l'eau (d'ordre économique mais également politique) et ne sont pas équipés de stratégies permettant de composer avec la forte variabilité. Les quelques succès recensés sont le fruit d'entreprises individuelles, possédant un capital et une résilience économique, leur permettant notamment de surmonter les pénuries à l'aide d'autres ressources économiques (pour acheter des citernes) ou physiques (accès à d'autres points d'eau). Une approche intégrée et un appui sur le long terme de l'état auraient pu favoriser un développement plus large et équitable des ressources. Au vu des capacités limitées et des sécheresses durables, les retenues collinaires dans ce contexte climatique doivent cependant maintenir leur objectif initial d'irrigation de complément et non chercher à soutenir une intensification à plus grande échelle de l'agriculture. / Small reservoirs and other water and soil conservation techniques have become increasingly widespread across semi-arid regions, due to their ability to reduce transportation of eroded soil and harvest scarce and unreliable rainfall for local users. Revealing diverse but often limited levels of agricultural water use, the reasons behind these were explored based on assessments of water availability, practices and associated drivers upscaled across 50 small reservoirs in the Upper Merguellil catchment (Central Tunisia). MNDWI on 546 treated Landsat images over 1999-2014 were used in combination with extensive field data to develop and validate water availability assessments for all reservoirs. An Ensemble Kalman Filter approach was used to combine remotely sensed surface area with a GR4J-water balance model and notably reduce runoff uncertainties arising from highly variable and localised rainfall intensities. These notably reduced mean annual availability RMSE to the order of 10 000 m3 on lakes where initial capacities vary between 20 000 m3 and over 1 000 000 m3, and identified the potential of each lake to support agriculture during the dry season.In parallel, rapid surveys, quantitative questionnaires and semi directed interviews were used to identify water uses and socio economic and institutional drivers influencing the smallholder livelihoods around these reservoirs. Using multi-stage samples of farmers allowed to progressively narrow and refine the analysis which were then upscaled based on typologies of lakes. Results confirmed withdrawals remained limited and focussed essentially on the occasional watering of fruit trees. On a handful of lakes, water resources were a limiting factor but rarely a sufficient factor to explain the heterogeneous water uses observed around reservoirs. Most farmers were not equipped with the suitable capabilities to increase their withdrawals as a result of problems over pumps, water access and conflicts, compounded through limited and short term government assistance. Individual successes were observed as a result of farmers possessing adequate economic resilience and/or means to secure alternate water supplies during dry spells. Faced with limited available storage capacities and prolonged droughts, small reservoirs must in this climatic context retain their supplementary irrigation focus and not strive to support widespread intensification of practices.
6

Demanda de Ãgua em sistemas de produÃÃo agrÃcola e seus impactos: ambientais e financeiros / Water supplying in production systems agricultural in impact: environmental in monetary.

Antonio FlÃvio Batista de AraÃjo 29 July 1902 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O presente trabalho teve por finalidade investigar os sistemas de produÃÃo agrÃcola adotados pelos pequenos produtores em Ãreas de sequeiro e irrigada onde se identificasse a produtividade da Ãgua, bem como suas perdas. O campo agrÃcola explorado com o sistema de agricultura irrigada corresponde ao perÃmetro irrigado Curupati, localizada no MunicÃpio de Jaguaribara enquanto que o sistema de sequeiro (plantio direto) foi implantado na regiÃo da Chapada do Apodi na porÃÃo inserida no MunicÃpio de Tabuleiro do Norte. A quantificaÃÃo da demanda de Ãgua na agricultura irrigada foi realizada computando-se os nÃmeros de horas de funcionamento da unidade de bombeamento que abastece o lote, determinando-se a vazÃo dos gotejadores que compunham o sistema e avaliando-se o perfil de umidade do solo atà a profundidade de 120 cm. O total de Ãgua aplicada no campo irrigado foi de 2.663.296,20 m3. A cultura irrigada considerada nessa pesquisa foi o mamÃo, embora os irrigantes tambÃm explorem a cultura da goiaba. Na Ãrea com plantio de sequeiro (plantio direto), o campo agrÃcola correspondia a 137 ha com a cultura do sorgo. A demanda de Ãgua foi quantificada atravÃs de pluviÃmetros implantados e monitorados por todo o perÃodo chuvoso do ano de 2008. O total precipitado durante o ciclo da cultura foi de 940 mm. A produtividade para a cultura do mamÃo variou de 80 ton ha-1 a 106 ton ha-1 durante o ciclo da cultura. Foi identificado que para cada 1 kg de mamÃo produzido foram consumidos 1,042 m3 de Ãgua expressando uma produtividade 0,95 kg m3 Na Ãrea de sequeiro a produtividade do sorgo variou de 438 kg ha-1 a 2.143 kg ha-1. Em decorrÃncia do total precipitado para o ano de 2008 ter sido superior em 27,54%, da mÃdia anual da regiÃo, nÃo se pode de fato avaliar a produtividade da Ãgua em sistema de plantio direto, uma vez que o total precipitado foi superior em 280% ao requerido pela cultura. / This work aims to investigate the agricultural production systems used by small farmers in rainfed and irrigated areas and also to identify the water productivity. The explored irrigated agricultural field was the Curupati irrigated perimeter, located in Jaguaribara, CearÃ, Brazil. The rainfed system (tillage) was implanted in the Chapada do Apodi region, sited in Tabuleiro do Norte, CearÃ, Brazil. The quantification of the water required to supply the irrigated crops was quantified through the flow rate of drippers. Also, the moisture of the soil profile was evaluated until the depth of 120 cm. The total of applied water in the irrigated field was 2,663,296.20 m3. The studied crop was papaya, although the guava crop was also explored. In the rainfed crop using tillage, the field was a 137 ha with the sorghum culture. The supplying water was quantified by rain gate implemented and monitored throughout the rainy season of 2008. The total rainfall during the cycle of the culture was 940 mm. The productivity for the cultivation of papaya ranged from 80 ton ha -1 to 106 ton ha -1 during the itâs productivity period. It was identified that for every 1 kg of papaya produced, 1,042 m3 of water was consumed, expressing a 0.95 kg m3 yield. In the rainfed area, the productivity of sorghum ranged from 438 kg ha-1 to 2,143 kg ha-1. Due to the fact that the total rainfall depth in 2008 was 27.4% higher than the annual average of the region, it was not possible to evaluate the water productivity in the tillage system, since the total rainfall depth was 280% higher than the required by the culture.
7

物質資源・環境資源としての木曽谷の森林 (2) -木曽谷の森林の環境保全的効用 -

只木, 良也, TADAKI, Yoshiya, 鈴木, 道代, SUZUKI, Michiyo 12 1900 (has links) (PDF)
農林水産研究情報センターで作成したPDFファイルを使用している。
8

Impact of Land Use and Climate Change on Hydrological Ecosystem Services (Water Supply) in the Dryland Area of the Middle Reaches of the Yellow River

Zhang, Lulu 08 October 2015 (has links)
Driven by many factors, the water supply services (streamflow and groundwater) of many rivers in the dryland area of China have declined significantly. This aggravates the inherent severe water shortages and results in increased severity in the water use conflicts that are threatening sustainable development in the region. Innovative strategies towards more water-efficient land management are vital for enhancing water quantity to ensure water supply security. A key step in the successful development and implementation of such measures is to understand the response of hydrological processes and related services to changes in land management and climate. To this end, it was decided to investigate these processes and responses in the upper reaches of the Jing River (Jinghe), an important meso-scale watershed in the middle reaches of the Yellow River on the Loess Plateau (NW China). It has been shown that vegetation restoration efforts (planting trees and grass) are effective in controlling soil erosion on the Loess Plateau. Shifts in land cover/use lead to modifications of soil physical properties. Yet, it remains unclear if the hydraulic properties have also been improved by vegetation restoration. A better understanding of how vegetation restoration alters soil structure and related soil hydraulic properties, such as water conductivity and soil water storage capacity, is necessary. Three adjacent sites, with comparable soil texture, soil type, and topography but contrasting land cover (Black locust forest, grassland, and cropland), were investigated in a small catchment in the upstream Jinghe watershed (near Jingchuan, Gansu province). Seasonal variations of soil hydraulic properties in topsoil and subsoil were examined. Results revealed that the type of land use had a significant impact on field-saturated, near-saturated hydraulic conductivity, and soil water characteristics. Specifically, conversion from cropland to grass or forests promotes infiltration capacity as a result of increased saturated hydraulic conductivity, air capacity, and macroporosity. Moreover, conversion from cropland to forest tends to promote the formation of mesopores that increase soil water storage capacity. Tillage in cropland temporarily created well-structured topsoil, but also compacted subsoil, as indicated by low subsoil saturated hydraulic conductivity, air capacity, and plant available water capacity. An impact of land cover conversion on unsaturated hydraulic conductivities was not identified, indicating that changes in land cover do not affect functional meso- and microporosity. Changes in soil hydraulic properties and associated hydrological processes and services due to soil conservation efforts need to be considered, should soil conservation measures be implemented in water-limited regions for sustaining adequate water supply. To differentiate between the impacts of land management and climate change on streamflow, the variation of annual streamflow, precipitation, potential evapotranspiration, and climatic water balance in a small catchment of the upstream Jinghe watershed (near Pingliang, Gansu province) was examined during the period of 1955 – 2004. During this time the relative contributions of changes in land management and climate to the reduction of streamflow were estimated. A statistically significant decreasing trend of -1.14 mm y-1 in annual streamflow was detected. Furthermore, an abrupt streamflow reduction due to afforestation and construction of terraces and check-dams was identified around 1980. Remarkably, 74% of the total reduction in mean annual streamflow can be attributed to the soil conservation measures. Among various conservation measures, streamflow could be considerably reduced by afforestation and terracing (including damland creation), due to their low contribution to water yield. In contrast, slope farmland and grassland can maintain a certain level of water supply services due to higher runoff coefficients. According to a meta-analysis of the published studies on the Loess Plateau, the impact of changes in land management on annual streamflow appears to diminish with increasing catchment size while the impact of climate change appears uniform across space. This means that there is a dependency between the catchment size and the response of hydrological processes to environmental change. At least at the local scale, it appears that well-considered land management may help to ensure the water supply services. Due to limited surface water availability, groundwater is an essential water source for supporting ecosystem and socio-economic development in the dryland region. However, the groundwater process is susceptible and vulnerable to changes in climate and landscape (i.e., land cover and form) that in turn can result in profound adverse consequences on water supply services in water-limited regions. In addition, an improved understanding of the response of groundwater related processes to natural and artificial disturbances is likely to ensure more secure and more sustainable governance and management of such regions, as well as better options for adapting to climate change. Yet, this topic has seldom been researched, especially in areas that have already experienced large-scale alteration in landscape and are located in dryland regions, such as the Loess Plateau. Therefore, an investigation of the baseflow variation along the landscape change was conducted. The average annual baseflow has significantly decreased at catchment scale during the period of 1962 – 2002 without any obvious significant change in climate. At decadal scale, the reduction accounts for approximately 9% in the 1970s, 48% in the 1980s, and 92% in the 1990s, while the baseflow index declines averaging 5%, 16% and 67%, respectively. All of the monthly baseflow levels dropped at varying rates except in January, among which July was the most severe in terms of both magnitude (-4.17) and slope (-0.09 mm y-1). In perspective of landscape change, landform change (terrace and check-dam) tends to reduce baseflow by reallocation of surface fluxes and retention for crop growth causing limited deep drainage in other areas. Land cover change (i.e., afforestation) reduced the baseflow to a larger extent by enhanced evapotranspiration and thus hampered deep drainage as suggested by the soil moisture measurement underneath. The study indicates that knowledge about baseflow formation on catchment scale needs further improvement. Integrated soil conservation and water management for optimizing landscape structure and function in order to balance soil (erosion) and water (supply) related hydrological ecosystem services is vital. The governing processes to the changes of water-supply-services-related hydrological process (e.g., streamflow) are assumed to be different across space. To this end, the factors controlling streamflow were investigated on both a small and large scale. Streamflow in small catchments was found to be mainly controlled by precipitation and land cover type. On a larger scale, evaporative demand was found to be another additional major driving force. Hydrological modeling is a frequently used tool for the assessment of impacts of land use and climate change on water balance and water fluxes. However, application of the Soil and Water Assessment Tool (SWAT) model in the upstream Jinghe watershed was unsuccessful due to difficulties in calibration. The inability of the SWAT model to take the influence of terraces on steep slopes into consideration and the method how to calculate lateral flow were the main reasons for unsatisfactory calibration, at least for the current version of SWAT used in this study. Alternatively, Budyko’s frameworks were applied to predict the annual and long-term streamflow. However, the effect of changes in land management (e.g., afforestation) on streamflow could not be assessed due to a lack of vegetation factors. Therefore, an empirical analysis tool was derived based on an existing relationship for estimation. This method was found to be the most effective in reproducing the annual and long-term streamflow. The incorporation of temporal changes in land cover and form in the approach enables the estimation of the possible impact of soil conservation measures (e.g., afforestation or terracing). The importance of adaptive land management strategies for mitigating water shortage and securing the water supply services on the Loess Plateau was highlighted. A cross-sectoral view of the multiple services offered by managed ecosystems at different spatial scales under changing environments needs to be integrated to improve adaptive land management policy. In a water limited environment, such as the Loess Plateau, multiple ecosystem services including hydrological services need to be balanced with minimum trade-offs. This can only be achieved when management is based on a holistic understanding of the interdependencies among various ecosystem services and how they might change under alternative land management.

Page generated in 0.1631 seconds