Adoption decision and use intensity of soil and water conservation measures by smallholder subsistence farmers in Dedo District,Western Ethiopia

Soil degradation in the highlands of Ethiopia is a serious problem that threatens the sustainability of agriculture. Although efforts have been made to develop and promote several soil conservation technologies, their adoption has not been widespread. This study, based on responses from a sample of 101 households which operate on 204 plots in Western Ethiopia, interviewed in 2003 cropping year, employed a Tobit model to identify the main factors influencing farmers' decision to adopt and intensify the use of improved and indigenous soil and water conservation (SWC) measures. The results suggest that area of cultivated land, land/labour ratio, age and education level of household head and distance of the plot from home and slope of the plot provided statistically adequate predictive power on the use and intensity of SWC measures. These results are discussed and their implications for conservation programs are presented in the conclusion. Copyright © 2006 John Wiley & Sons, Ltd.     

Farmers' participation in soil and water conservation activities in the Chemoga Watershed,Blue Nile basin,Ethiopia

Soil erosion by water constitutes a threat to the maintenance of the subsistence living of the Ethiopian rural population. Past efforts at Soil and Water Conservation (SWC) did not bring about significant results, mainly because of the top‐down approach pursued. Uprooting this past oversight and instating a participatory approach has since then been strongly recommended as the correct strategy. This paper analyses the extent of farmers' participation in current SWC activities in the Chemoga watershed, East Gojjam Zone, Amhara Regional State. Formal household survey, informal and focus group discussions and field observation were used to generate the data. The results indicate that the majority of the farmers participated in the SWC against their will. The most important factor discouraging them from participating freely was the perceived ineffectiveness of the structures under construction. Awareness about soil erosion as a problem, labour shortage and land tenure insecurity were found to be less important in providing an explanation for the disinterest shown by most of the farmers towards the SWC activities. Therefore, the important factors that need immediate consideration for SWC efforts in the study area or the region at large are: (1) SWC structures have to be carefully designed and constructed taking into account ground realities, and (2) participation of the farmers has to be through their own conviction regarding the effectiveness and efficiency of the technologies. Alternative SWC technologies will have to be considered in this regard. Copyright © 2002 John Wiley & Sons, Ltd.     

水土保持功能评价及其在水土保持区划中的应用

随着国家对生态文明建设的日益重视,以及国家及地方主体功能区规划的实施,对于水土保持的功能研究也越来越多.结合全国水土保持规划工作的需要,提出水土保持功能的概念、类型确定原则和功能类型,阐述了水土保持基础功能和社会经济功能的评价方法,以及各基础功能的评价指标体系.以太行山东部山地丘陵区为例,举例说明水土保持功能评价的过程和结果.对全国水土保持区划三级区基础功能进行统计分析,明确各功能的区域比例,提出8个一级区水土保持工作主要方向,维护和提高区域水土保持功能将成为水土保持工作的重点和方向.     

水土保持农业技术措施分类初探

为进一步完善我国水土保持农业技术措施的分类体系,并服务于研究与生产,在论述水土保持农业技术措施的概念、分类现状基础上,依据措施实施的方式、作用和目标,并结合农艺环节,将水土保持农业技术划分为以改变微地形为主的蓄水保墒技术、以提高土壤抗蚀力为主的保护性耕作技术和以增加植物覆盖为主的栽培技术3大类,等高耕作、沟垄种植、坑田、半旱式耕作、深耕翻、保墒、覆盖、深松、少耕、培肥土壤、合理配置作物、播种保苗、栽培13个亚类和等高耕作等44个型,以供参考.     

Determinants of farmers' willingness to pay for soil conservation practices in the southeastern highlands of Ethiopia

This paper examines the determinants of farmers' willingness to pay for soil conservation practices in the highlands of Bale, southeast Ethiopia. The paper is based on analysis of data collected from 100 randomly selected household heads. The study applied Contingent Valuation Method for the purpose of eliciting farmers' valuation of soil conservation practices in terms of both cash payment and labour contribution. The results reveal that farmers in the study area are less willing to pay cash for soil conservation measures. In terms of labour contribution, however, it was found that they are willing to spend a substantial amount of time per week. Results from logistic regression analysis show that farmers' decisions to participate in soil conservation practices are influenced by a host of factors. The implication is that taking these factors into account while planning soil conservation measures enables policy makers to come up with projects that win acceptance by the local people. Copyright © 2004 John Wiley & Sons, Ltd.     

关于生物措施治理黄土高原水土流失的思考

 为加速黄土高原水土流失治理的健康发展,在深入分析黄土高原水土流失治理存在的主要问题,以及生物措施治理黄土高原水土流失作用的基础上,按照黄土高原河谷平原区、黄土丘陵沟壑区、黄土高原沟壑区、鄂尔多斯高原区和土石山区5个类型区,提出以植被建设和保护为核心的生态建设思路和治理对策,同时指出了采取生物措施治理水土流失时需注意的若干问题。     

上海市水力侵蚀现状与水土保持措施分析

为研究上海市水土流失及措施现状,以第一次全国水利普查水土保持情况普查结果为基础,结合上海市基本情况,分析上海市水力侵蚀现状和水土保持措施情况。结果表明,上海市水土流失面积超过了200km^2,水土流失以河道两岸和湖泊沿岸的坍塌淤浅为主要特征,建设项目施工造成的人为水土流失也是上海市水土流失的一个重要方面。上海市中心城区水土保持措施较完善,但郊区部分河道还没有采取有效护坡措施,基本处于自然状态,很容易发生水土流失;因此,河道边坡和湖泊岸线的护岸整治、海岸滩涂的保滩促淤治理是上海市水土保持工作的重点,同时还应加强建设项目的监管和水土保持监测,以防止人为水土流失。     

水土保持生态服务功能评价方法

 由于生态系统服务功能支撑与维持着地球生命系统的平衡与稳定,因此它已受到当今世界普遍关注。在我国水土流失严重的情况下,运用生态服务功能理论可以正确评价水土保持措施的作用,并为合理的生态建设规划提供依据。本文在总结Costanza等人理论的基础上,分析水土保持各项措施对保护和改良人类赖以生存的自然环境条件的综合效用。认为水土保持生态服务功能包括保护和涵养水源、保护和改良土壤、固碳释氧、净化空气和防风固沙等功能。另外,本文从水土保持工程措施、水土保持农业措施和水土保持林草措施3个方向为上述功能筛选了10个评价指标,且为各个指标分别建立了评价方法。这些指标及方法将有助于对水土保持措施的生态环境效应进行深入的分析与评价。     

关于水土保持措施适宜性的评价方法

在系统总结国内外水土保持措施适宜性研究成果的基础上,指出水土保持措施适宜性研究存在的明显不足之处,并提出水土保持措施适宜性的研究思路和方法,重点提出适宜性评价的“双套对偶评价指标体系”及“双套对偶评价指标差值最小法”的评价方法,为水土保持措施的适宜性评价提供新的思路和方法。     

北京石质山区不同水土保持措施对土壤物理性质及抗冲性的影响——以房山区蒲洼小流域为例

为评价北京山区多年来小流域综合治理的水土保持效果,也为以后小流域治理和植被重建提供理论支撑,以房山区蒲洼小流域为研究地,采用典型样地调查、野外抗冲性实验和室内样品处理的方法,对比分析不同水土保持措施的土壤物理性质、土壤质地和抗冲性.结果表明:随着土层加深,各类措施下土壤密度均呈现增大趋势,总孔隙度和毛管孔隙度呈现减小趋势,而非毛管孔隙度没有明显规律.不同水土保持措施下,土壤密度、总孔隙度和毛管孔隙度均有改善(侧柏林除外),改善程度由好到差依次为:辽东栎次生林＞油松落叶松混交林＞石坎梯田＞油松林＞落叶松林＞灌丛;各类措施下土壤颗粒均以细、中粉粒为最多,分形维数显示各类水保措施土壤通透性均较为良好;相比荒地,各类措施下土壤冲刷量显著减小,径流时间延长,冲刷量依次为油松落叶松混交林(0.82 kg/cm3)＜侧柏林(1.14 kg/cm3)＜落叶松林(1.30 kg/cm3)＜辽东栎次生林(3.91 kg/cm3)＜油松林(5.96 kg/cm3)＜荆条灌丛(10.88 kg/cm3),延缓径流冲刷时间由大到小依次为:辽东栎次生林(55.65 s/m)＞油松落叶松混交林(46.82 s/m)＞落叶松(28.19 s/m)＞荆条灌丛(22.39s/m)＞侧柏林(17.48 s/m)＞油松林(16.94 s/m).土壤抗冲性与细、中粉粒体积分数(正相关)、非毛管孔隙度呈显著(负相关)关系最为密切,由此推出大根径的根系穿插形成的非毛管孔隙对土壤抗冲性是负效应.综上,油松落叶松林混交林提升土壤蓄水持水性能、土壤抗冲性均显示出很大的优势;石坎梯田效果也较好,是小流域治理应首先考虑的2类措施.     

黄土丘陵沟壑区不同水保措施条件下土壤水分状况

黄土高原土壤水资源对植物的生长发育意义重大。水土保持措施会影响土壤水分的静态分布和动态过程。该文通过定位监测并引入土壤水分亏缺补偿度指标,旨在明确黄土丘陵沟壑区不同水土保持措施下土壤水分动态特征和雨季前后土壤水分的亏缺与补偿情况。结果表明：不同水土保持措施雨季前后土壤储水均处于亏缺状态,7月份土壤储水亏缺得到缓解;8月份表层土壤储水亏缺加剧;雨季后的10月份土壤储水均得到恢复。降雨对退耕坡地和梯田土壤水分均有正补偿作用。水平阶90 cm处和160 cm以下出现负补偿现象。鱼鳞坑在30 cm处出现负补偿。在0～200 cm土壤剖面上,土壤储水亏缺补偿度依次为退耕坡地＞梯田＞鱼鳞坑＞水平阶。由此可见,不同水土保持措施对土壤水分季节变化和垂直变化,以及降雨对土壤水分的补偿作用均产生不同影响。     

水源涵养基本功能区水力侵蚀现状分析简

针对全国水土保持区划中确定的22个具有水源涵养功能的基本功能区,利用第1次全国水利普查获取的水力侵蚀数据,分析这些区域的水力侵蚀现状.结果表明：1）水源涵养基本功能区水力侵蚀以轻中度侵蚀为主,超过80％,强烈、极强烈、剧烈面积分布较少,与全国基本状况相似;2）与第2次全国土壤侵蚀遥感调查成果相比,水源涵养基本功能区水力侵蚀整体上有所好转,水力侵蚀总面积减少3.75％,轻中度侵蚀面积大幅减少,减幅超过20％;3）水源涵养基本功能区局部地区水力侵蚀形势严峻,极强烈和剧烈侵蚀面积虽然不大,但是与第2次遥感调查成果相比,面积均有所增加,相对增幅较大,说明局部地区存在水力侵蚀恶化的现象.     

水土保持在综合调控流域水资源配置中的作用

 水是人类社会发展和经济活动的重要战略资源。从总体来看,我国水旱灾害呈现出发生频率逐渐增大、灾情愈渐加重的趋势。水土流失是导致水旱灾害日益严重的重要原因之一。水土保持是水资源调控和优化配置的重要措施,是解决水问题,实现水利事业可持续发展的重要途径。从调控和优化配置水资源的角度出发,如何科学合理地配置水土保持措施,还有必要系统地开展理论和技术研究。     

紫色土丘陵区典型水土保持措施的适宜性评价

为科学合理选择适宜的水土保持措施,利用特尔斐(Delphi)法和模糊数学原理,对紫色土丘陵区典型水土保持措施进行区域适宜性评价。以问卷调查为基础进行评价指标的筛选,从求-供和产-望2个角度建立2套评价指标体系。根据评价指标与水土保持措施适宜性之间的关系选择单项指标评价模型,采用特尔斐法确定各评价指标的权重,最后结合加权求和与几何平均方法对水土保持措施适宜性进行综合评价,并以四川省遂宁市群力村为例进行实证研究。结果表明:研究专家注重措施的水土保持效益和自然环境效益,当地农民则看重措施实施后的社会经济效益;在群力村较为普遍的4种水土保持措施中,退耕还草最为适宜,其次为退耕还林,等高耕作和梯田的适宜性相对较小,与实际推广情况一致;梯田和等高耕作的适宜性较低主要受到农村劳动力数量、农民投资能力和措施社会经济效益的限制。     

水泥工业项目水土保持准入条件

 通过对水泥工程的类型、组成、占地以及施工和生产工艺、土石方量及弃渣的分析,总结出水泥工程在建设与生产过程中的水土流失特点,水泥工程在建设期间的水土流失重点区域是厂区,而在生产运行期则是石灰石和黏土矿,此外在水泥生产厂区还会产生大量的粉尘。水泥工程除了应遵循"生产建设项目水土保持准入条件通用条款"中的条件外,对照涉及水泥产业的法律、法规、规范、政策、标准、发展纲要和行业发展规划,提出了水泥工程项目的否决、限批和缓批的13条水土保持准入条件。根据水土保持新国标和有关法规的规定,结合典型案例分析,提出须修正主体设计的5项准入条件和须修改水土保持方案的4项准入条件。     

水土保持措施对板栗林土壤呼吸的影响

为阐明板栗林土壤呼吸对水土保持措施的响应,采用IRGA法,对不同类型板栗林的土壤呼吸从2009年3月至2010年9月开展为期1年半的定位观测。结果表明:1)采取水土保持措施后,样地的土壤水分状况得到一定程度的改善,尤其随着采取水土保持措施年限的延长,其对土壤水分时空分布影响更为显著。2)4个板栗林样地的土壤呼吸速率均呈明显的单峰曲线变化,水土保持措施对土壤呼吸的季节动态无明显影响。3)样地Ⅰ和Ⅲ的参考呼吸R10分别为1.718和1.595μmol/(m2.s);而采取水土保持措施后,样地Ⅱ和Ⅳ的R10均表现为一定程度的降低,分别为1.092和1.324μmol/(m2.s)。样地Ⅰ和Ⅲ的土壤呼吸的温度敏感性指数Q10分别为1.927和1.899;采取水土保持措施后,样地Ⅱ和Ⅳ的Q10均表现为略微增加。采取水土保持措施后,土壤温度和土壤湿度对土壤呼吸速率的影响有一定程度的增强。研究结果可为把水土保持措施作为土壤严重侵蚀地区一种潜在的固碳减排模式提供基础数据。     

张家口地区水土保持措施空间配置效应评价

该文以张家口各个地貌类型区水土流失监测站实测数据为基础,研究了该区水土保持措施的空间配置的适宜性。结果表明：不论何种地貌类型区,总体的趋势是坡耕地组中水平梯田的水土保持效益最好,蓄水拦沙效益均达到90%以上,其次是经济林,再者是人工种草;荒坡地组中植被措施结合水平沟、鱼鳞坑整地形式的水土保持效益最好,基本在75%以上,自然封禁和人工种草的水土保持效益次之,且空间和年际之间差异较大,造成这种现象的主要原因可能是由于降雨条件的差异影响到植被生长的质量,其次是土壤本身的特征的差异。因此,采取封禁措施治理的初期不能简单依靠生态自身的修复,必须辅助以工程措施为植被的恢复创造条件。     

涉水交通工程水土保持准入条件

 港口码头、独立大桥与隧道、海堤防等涉水交通工程占地性质多为永久占地,土地的原有功能完全转变;由于涉河涉水兴建此类工程,其环境敏感性强,引发的水土流失危害及环境影响较为直接;土石方挖填量大,施工过程中发生的水土流失直接进入江河湖海。根据我国有关法规、政策、规划、标准等规定,结合涉水交通工程项目的特点,提出了此类项目准入、限批、缓批的主要条件,从项目水土保持准入方面提出了修正完善主体设计、修改完善水土保持方案后再报批的条件,以及水土保持方案准入排序意见。     

电力工程水土保持准入条件

 通过对电力工程的组成、占地以及施工和生产工艺、土石方量及弃渣等工程特点的分析,总结出电力工程建设过程与运行期间的水土流失特点。对照涉及电力项目产业发展规划、国家政策与产业布局,分别从电力项目水土保持的准入、限批和缓批方面提出共50项准入条件。根据有关技术规范和水土保持新国标的规定,结合典型案例分析,提出须修正主体设计的11项方案准入条件、须修改水土保持方案的7项方案准入条件。     

Social and economic factors affecting the adoption of soil and water conservation in West Usambara highlands,Tanzania

Accelerated soil erosion is one of the major constraints to agricultural production in many parts of the Tanzanian highlands. Although several soil and water conservation technologies have been developed and promoted, the adoption of many recommended measures is minimal and soil erosion continues to be a problem. This research was conducted in order to determine the social and economic factors that influence adoption of soil and water conservation (SWC) measures in the West Usambara highlands, Tanzania. For this research a household survey, group discussions and transect walks were undertaken. A total of 104 households were interviewed and several fields were visited during the transect walks. Data was analysed with the use of cross‐tabulation, cluster analysis, factor analysis and chi‐squared methods. The results obtained indicate that involvement in off‐farm activities, insecure land tenure, location of fields and a lack of short‐term benefits from SWC are among the major factors that negatively influence adoption of SWC measures. Membership in farmer groups, level of education, contacts with extension agents and SWC programmes were found to be positively influencing the adoption of SWC measures. Recommendations to facilitate adoption of different SWC measures include: integration of social and economic factors into SWC plans; the creation of more awareness among farmers of soil‐erosion effects and long‐term benefits of SWC; the development of flexible SWC measures to cater for different farm patterns and a participatory approach to SWC at catchment level rather than at individual farmers' fields. Copyright © 2004 John Wiley & Sons, Ltd.