川东北方山丘陵地貌区水资源保护措施

以方山为地貌特色的川东北低山丘陵区水资源严重缺乏。从地质构造、地形地貌、气候、土地设施建设利用方式和水利设施建设等方面对四川达州千口岭方山水资源缺乏原因进行剖析,探讨水资源保护措施,对保水措施的综合效益进行评价。结果表明:千口岭以厚层或巨厚层砂岩为主的地层条件、构造裂隙和风化裂隙较发育的构造背景及方山 “顶平、坡陡、麓缓”的地貌特性,使得水资源极易流失;亚热带季风气候以及副高控制,易形成伏旱和春旱;土地利用方式、耕作制度和水利设施历史遗留原因使得水资源利用效益低下;适宜于方山区“Ω”形槽谷、垭口和平缓地形区的3种小型水利工程措施,是解决方山区缺水问题的主要途径。研究结果可为解决同类地区缺水问题提供借鉴。

Measures of Water Resources Protection in Mesa andHilly Region of Northeast Sichuan Province

Water resources are seriously lacking in the low mountainous area of Northeast Sichuan where mesa(table mountain) is a topographic character. With the mesa in Qiankouling, Dazhou, Sichuan Province as the research object, we expounded the causes of water shortage from aspects of geology,geomorphology,climate,land use,and water conservancy, and further discussed the measures of water conservation and evaluated the comprehensive benefits of the measures. Results show that mesas in the study area are prone to suffer from water shortage due to the strata of Qiankouling mainly composed of thick or mega-thick sandstone, the tectonic fissures and weathering fissures, as well as the geomorphic characteristics of “flat top, steep slope, and gentle foothills”. Controlled by the subtropical monsoon and the subtropical high, the spatial and temporal distribution of precipitation is uneven, easily leading to summer drought and spring drought. Moreover, the land use, farming system and historical reasons of water conservancy facilities make the crops insufficiently irrigated. Three small-scale water conservancy engineering measures suitable for the Ω-shaped trough valley, the saddle (narrow pass between two trough valleys), and the gentle terrain in mesa region are put forward to provide reference for solving the problem of water shortage in similar areas.